Blood, Vol. 94 No. 2 (July 15), 1999:
pp. 694-700
Unravelling an HLA-DR Association in Childhood Acute Lymphoblastic
Leukemia
By
M. Tevfik Dorak,
Tom Lawson,
Helmut K.G. Machulla,
Chris Darke,
Ken I. Mills, and
Alan K. Burnett
From the Department of Haematology, University of Wales College of
Medicine, Cardiff, Wales, UK.
 |
ABSTRACT |
Genetic and environmental factors play an interactive role in the
development of childhood acute lymphoblastic leukemia (ALL). Since the
demonstration of a major histocompatibility complex (MHC) influence on
mouse leukemia in 1964, an HLA association has been considered as a
possible genetic risk factor. Despite extensive efforts, however, no
strong evidence comparable to the H-2k influence on mouse
leukemia has been shown. The number of negative serological studies
resulted in a loss of interest and consequently, no molecular HLA-DR
association study has been published to date. We reconsidered the
HLA-DR association in childhood ALL in 114 patients from a single
center and 325 local newborn controls by polymerase chain reaction
(PCR) analysis of the HLA-DRB1/3/4/5 loci. With conventional analysis,
there was a moderate allelic association with the most common allele in
the HLA-DR53 group, HLA-DRB1*04, in the whole group that was stronger
in males (P = .0005, odds ratio = 2.9). When the other
expressed HLA-DRB loci were examined, homozygosity for HLA-DRB4*01,
encoding the HLA-DR53 specificity, was increased in patients (21.1%
v 8.3%; odds ratio = 2.9, P = .0005).
Consideration of gender showed that all of these associations were
reflections of a male-specific increase in homozygosity for HLA-DRB4*01
(32.8% v 4.0%; odds ratio = 11.7, 95% confidence interval
[CI] = 4.9 to 28.0; P = 3 × 10
8). This highly significant result provided the
long-suspected evidence for the HLA-DR influence on the development of
childhood ALL while confirming the recessive nature of the MHC
influence on human leukemogenesis as in experimental models. The
cross-reactivity between HLA-DR53 and H-2Ek, extensive
mimicry of the immunodominant epitope of HLA-DR53 by several
carcinogenic viruses, and the extra amount of DNA in the vicinity of
the HLA-DRB4 gene argue for the case that HLA-DRB4*01 may be one of the
genetic risk factors for childhood ALL.
© 1999 by The American Society of Hematology.
| |
INTRODUCTION |
ACUTE LYMPHOBLASTIC leukemia (ALL) is the
most common cancer in children.1 Large epidemiological
studies have suggested some of the factors involved in
susceptibility,2-4 with most consistent ones being an
association with a history of maternal fetal loss5-7 and a
putative infection in the etiology.8-10 It is now generally
agreed that both genetic and environmental factors play an interactive
role in the development of childhood ALL, particularly in the common
ALL (cALL) subtype.4
The involvement of the HLA system has also been examined in childhood
ALL following the demonstration of a major histocompatibility complex
(MHC) influence on the development of mouse leukemia.11 In
1964, Lilly et al11 reported an increased risk of
spontaneous and virus-induced leukemia in congenic mice homozygous for
the H-2k haplotype. Although, human studies in
leukemia have not shown a consistent association, they strongly
suggested a recessive influence as in the experimental
models.12 The serological studies in childhood ALL point to
an association with HLA-A2.13 Despite the excessive number
of serological studies on the HLA-DR locus, no polymerase chain
reaction (PCR)-based investigation of this locus in childhood ALL has
been published. The only HLA-DR/DQ association was inferred as a
male-specific homozygosity for the HLA class II supertype DR53 from
HLA-DQA restriction fragment length polymorphism (RFLP)
analysis of 63 patients and an adult control group.14 It is
important to examine the HLA-associated susceptibility to childhood
ALL, as this may provide clues to leukemogenesis in general and to the
role of other risk factors. For example, it has been repeatedly
suggested that an HLA class II association with childhood leukemia
would provide support for a viral link in the etiology.4,15
On the other hand, we pointed out that an HLA association may be the
common immunogenetic basis for leukemia susceptibility and increased
reproductive failure rate in leukemic families.12 Indeed,
both childhood leukemia16 and spontaneous recurrent
miscarriages17,18 are associated with increased parental
HLA-DR compatibility.
The supertypic specificity HLA-DR53 is encoded by the HLA-DRB4 locus in
the HLA class II region. HLA-DRB4 is one of the expressed HLA loci,
which exists only on haplotypes possessing HLA-DRB1*04, DRB1*07, and
DRB1*09. The expression level of HLA-DRB4 is variable,19 and it is not expressed only by the HLA-B57,DR7,Dw11
haplotype.20 The HLA-DRB4 gene or its protein product
HLA-DR53 have been associated with increased risk for all major types
of leukemia.14,21-24 Most HLA-DR53 haplotypes carry HLA-A2,
which is the other risk factor.13
In the present study, we have investigated all expressed HLA-DRB loci
in a large group of patients using local newborns as controls by
directly typing the HLA-DRB1/3/4/5 loci by PCR analysis. The data,
therefore, can be used to estimate the relative risk of developing
childhood ALL for a newborn baby. The results showed a highly
significant association of a homozygous HLA-DR genotype in childhood
ALL with a strong gender effect. This association was not correlated
with the age groups or disease subtypes.
| |
MATERIALS AND METHODS |
Controls.
Random, anonymous umbilical cord blood samples were obtained from
babies born in the University Hospital of Wales and Llandough Hospital
in Cardiff over a period of 12 months. It was not practically possible
to obtain samples from each and every newborn over this period, but no
newborn baby was excluded on the basis of any selection criteria. The
samples were collected until the number in each sex group exceeded 150. In the final group of 325 newborns, there were 150 boys and 175 girls.
Patients.
The patient group consisted of 114 patients (61 boys and 53 girls; 
14 years) with childhood ALL consecutively diagnosed in Cardiff since
1988. Cross-checking with the Wales Leukemia Registry showed that five
samples were missing in the study group. Non-Caucasoid patients were
not excluded (n = 4). The number of patients with cALL was 77 (40 boys
and 37 girls). The study was performed in accordance with the
guidelines set up by the local ethics committee.
DNA extraction.
DNA from patients diagnosed before 1996 was extracted by the
salting-out method.25 DNA from more recent leukemia samples and all newborn samples were prepared from peripheral blood using the
QIAamp Midi-Blood kit (Qiagen, West Sussex, UK).
HLA-DRB typing.
All patients and newborn controls were typed using the Biotest
DRB-ELPHA (enzyme-linked probe hybridization assay) kit (Biotest, West
Midlands, UK) according to the manufacturer's instructions. This kit
allows low-resolution DNA-typing of all expressed HLA-DRB loci
(DRB1/3/4/5). No further subtyping of any allele was attempted.
Determination of homozygosity for HLA-DR supertypes.
HLA class II supertypes are not allelic with each other and some
haplotypes even lack a supertype. Because of this, to determine homozygosity for HLA class II supertypes (homozygosity for HLA-DRB3, -DRB4, or -DRB5), HLA-DRB1 typing was necessary. A sample was assigned
as homozygous for HLA-DRB4*01 (HLA-DR53) when no other supertype was
detected and the HLA-DRB1 type consisted of any combination of
HLA-DRB1*04, *07 or *09. Because no further allelic subtypic was
performed, this meant having a double dose of the HLA-DRB4 gene. A
sample was assigned as HLA-DR52 homozygous if the HLA-DRB1 type
consisted of only HLA-DRB1*03, *11, *12, *13, *14. Those typed as
having only HLA-DRB1*15 and/or *16 were HLA-DR51 homozygous.
HLA-Bw4/6 typing.
The supertypes of the HLA-B locus in the class I region were typed by
PCR analysis using allele-specific primers.26 PCR products
were visualized by ethidium bromide on 2% agarose gels.
HSP70-2 typing.
Patients and controls were typed by PCR analysis for a biallelic (183 bp and 188 bp) polymorphism arising from a pentanucleotide duplication
linked to 3' untranslated region (UTR) of the
HSP70-2 gene.27 The presence of the duplication (188 bp)
associates most commonly with the presence of the PstI site in
HSP70-2 (ie, the 8.5-kb PstI/RFLP allele).27 The
primers and the reaction conditions were as described by Dressel and
Gunther.27 PCR products were analyzed on a 2.5% agarose
gel, stained with ethidium bromide, and visualized under ultraviolet
(UV) illumination.
Determination of sex.
Documented gender was checked on the HLA-DRB4*01 homozygous samples
using a Y-chromosome-specific PCR assay.28 The primer sequences were:
|
Y1.1 5'-tccactttattccaggcctgtcc
|
|
Y1.2 5'-ttgaatggaatgggaacgaatgg.
|
Amplification reactions were set up in 50 µL volume containing 1.5 mmol/L magnesium chloride. For amplification, samples were first heated
at 95°C for 7 minutes and then a two-step cycle consisting of 1.5 minutes at 92°C and 1.5 minutes at 63°C was used for 25 cycles.
Five microliters of the reaction mixture was used for direct
visualization by ethidium bromide on agarose gel.
Statistical analysis.
Comparisons between two observed frequencies were made using the
2 test (with Yates' correction when a cell frequency
was less than 20) unless any expected frequency was less than 5, in
which case, Fisher's exact test was used. All P values are
two-tailed for one degree of freedom. The odds ratio (OR) was
calculated as OR=ad/bc where a,b,c,d are the entries to the 2 × 2 table. The 95% confidence interval (CI) of the OR was calculated as
OR(1±1.96/X) (X is the square-root of the
X2), the 95% CI of a single proportion was calculated as
p±1.96
p(1-p)/n.29 The deviation of an observed homozygosity rate from the Hardy-Weinberg expectation
(p2) was tested by the two-tailed Z-test for a
single proportion.
Although the statistical analysis included multiple and subgroup
comparisons, the conventional statistical safeguards were not applied
because of the magnitude of the P value for the main association and because the same association has been noted before.
| |
RESULTS |
Conventional analysis.
This included the comparison of frequencies for HLA-DRB1 alleles in
patients and controls. The allele frequencies (proportion of subjects
possessing the relevant allele) instead of gene frequencies were
examined as recommended for HLA-disease association
studies.30 When this was done for the 13 classical HLA-DRB1
alleles and three supertypes (Tables 1 and
2), a weak association was found for HLA-DRB1*04 (-DR4) between the patients and controls (P = .02; OR = 1.7; 95% CI = 1.1 to 2.6). The increase in the allele frequency was restricted to males (P = .0005; OR = 2.9; 95% CI = 1.6 to 5.4). Homozygosity for HLA-DRB1*04 was more markedly increased in male
patients compared with the male newborns (P = .003; OR = 9.6;
95% CI = 2.1 to 43.5). As shown below, these were not independent associations.
Analysis of supertypes.
Despite no significant change in supertypic allele frequencies between
patients and controls (P = .42), there was an
increase in homozygosity for HLA-DRB4*01 (-DR53) in patients (Table 2). The increase in the whole group yielded an OR of 2.9 (P = .0003; 95% CI = 1.7 to 5.2). The difference was again mainly due to a high homozygosity rate in male patients (OR = 11.7, 95% CI = 4.9 to
28.0, P = 3 × 108). No significant
change was observed for girls with the same genotype (7.5% v
12.0%; P = .51). None of the four non-Caucasoid patients was
homozygous for HLA-DRB4*01 (they were not excluded from the analysis).
Because HLA-DRB1*04 is the most common member of the DR53 supertypic
group, its association was thought to be secondary to the association
of HLA-DRB4*01.
There was no correlation between the age and the homozygosity rate. In
particular, it was not significantly different in the childhood ALL
peak age (24 to 60 months; n = 61) compared with the rest of the group
(16.4% v 26.4%; P = .28). The same comparison only
for boys (30% v 35.5%; P = .85) did not show any
difference either.
To see whether a sampling error in the control group has caused this
association, the homozygosity rate in boys with ALL was compared with
that of the RFLP-defined healthy adult males (n = 449) of our previous
study. The result was again statistically significant (32.8% v
14.5%, P = .0006). The comparison was also made to the
female-specific newborn homozygosity rate (32.8% v 12.0%,
P = .0002). Thus, it was clear that the association was due to
an increased homozygosity rate in male patients, but not the low
homozygosity rate in newborn boys.
The previous RFLP-based study comprised the first 63 patients of the
current group. In the additional 51 patients diagnosed since then,
there were 25 boys. The homozygosity rate for HLA-DRB4*01 in this group
was 40.0%. This was significantly higher from the newborn controls as
a separate group (P = 3 × 106).
Therefore, if the new patients were treated as an independent group,
the results of the two separate groups were in agreement.
Another significant deviation between patients and controls was found
in the analysis of supertypes. The allele frequency of HLA-DR52 (the
frequency of possessing the HLA-DRB3 gene regardless of its alleles)
was decreased in the whole group of patients (P = .003), but
mainly in males (P = .0009, OR = 0.4, 95% CI = 0.2 to 0.7) and
not in females. These deviations were not due to changes in
homozygosity rates for HLA-DR52, as the decrease in homozygosity was
not statistically significant. These findings suggested that a dominant
protection was conferred by HLA-DR52 in line with our previous finding
in chronic lymphocytic leukemia (CLL).24
Although significant, this negative association at the allelic level
should be interpreted with caution, as it may be the mirror image of the positive association with a homozygous genotype.
Homozygosity rate for HLA-DRB4*01 and gender.
As shown in Table 2, the distribution of homozygosity for HLA-DRB4*01
between genders was different for patients and newborns. In the
patients' group, 20 of 24 homozygotes were male (sex-ratio = 0.83),
whereas the proportion of males in newborns was 6 of 27 giving a
sex-ratio of 0.22 (P = .00002). This skewed sex-ratio for
homozygotes resulted in significant differences in gender-specific homozygosity rates for the leukemia susceptibility genotype in patients
(P = .001) and in controls (P = .016). The decreased homozygosity rate for HLA-DRB4*01 in newborn boys was tested against the expected frequency calculated from the gene frequency in newborns (30.9%). The male-specific homozygosity rate in newborns (4.0%) was
significantly lower than the expected rate (9.6%, 95% CI = 6.4 to
12.8; P = .02).
Homozygosity for HLA-DRB4*01 in the cALL group.
Because of the possible immunologic and genetic differences in the
etiology of cALL, this group was analyzed separately for the main HLA
association. In the whole group, the homozygosity rate for HLA-DRB4*01
was 23.4% (8.3% in controls, P = .0004, OR = 3.4; 95% CI = 1.7 to 6.6). Again, this was due to an increased homozygosity rate in
boys with cALL (37.5% v 4.0% in newborn boys, P = 2 × 106 [Fisher], OR = 14.4, 95% CI = 5.8 to
35.9). Homozygosity in female patients with cALL was not significantly
different from female newborns (8.1% v 12.0%, P = .58).
Homozygosity for HLA-DRB4*01 in the non-cALL group.
In the group of 37 patients who had non-cALL, the homozygosity rate was
16.2% (P = .12 for comparison with newborns); and the
male-specific homozygosity rate for patients with non-cALL (n = 21) was
23.8% (P = .005; OR = 7.5 for comparison with newborn boys;
95% CI = 2.0 to 28.1). Thus, the association seemed to be stronger for
cALL, but the number of patients with non-cALL is too small to reach a
firm conclusion.
Allele and genotype frequencies for HLA-B supertypes and HSP70-2
alleles.
The only slight differences concerned the HSP70 alleles
(Table 3). These changes were interpreted
as secondary to the linkage disequilibrium between HSP188 and HLA-DR52
and HSP-183 and HLA-DR53 (data not shown). More importantly,
comparisons between the observed homozygosity rates in newborns and
expected homozygosity rates did not show any violation of the
Hardy-Weinberg equilibrium in these loci (unlike the HLA-DRB4 locus).
| |
DISCUSSION |
This is the first PCR-based HLA-DR association study in childhood ALL,
which analyzed more than 100 patients and controls from a single center
using the same technique. It showed that the odds ratio to develop
childhood ALL is 11.7 for a newborn boy having a double dose of the
HLA-DRB4*01 gene with a negligible probability of error. We unravelled
this highly significant association by taking into account the
supertypes, homozygosity, and gender. While one third of boys with ALL
had this genotype, in newborns, the same genotype had a decreased
frequency in boys.
The lack of strong allelic associations in the DRB1 locus partly
explains why previous studies did not find the same association. Since
the demonstration of the MHC influence on the development of mouse
leukemia in 1964,11 a number of studies have investigated HLA associations in childhood and adult leukemias, some of which included the analysis of HLA-DR/DQ antigens or
genes.14-16,21-24,31-41 With a few exceptions, these
studies did not report an HLA-DR association as strong as the present
study has found. This may have been due to the technical difficulties
to detect supertypes and their subsequent exclusion from the analysis.
Among the above-mentioned studies, when HLA-DR53 was investigated, an
association or a hint of it was usually found. The earliest HLA-DR
studies in childhood ALL showed an increase for
HLA-DR7.31-33 In one study, adult ALL showed a weak
association with HLA-DR437 and in another, CLL was
associated with HLA-DR53.22 The most convincing result on
the relevance of HLA-DRB4*01/DR53 as a risk factor for leukemia was
presented by Seremetis et al.21 They used a monoclonal
antibody specific for the hypervariable region 3 (HVR3) epitope of
HLA-DR53 and found a relative risk of 7.9 (P < .000005) for
acute myeloblastic leukemia (AML). Also, in our other molecular studies
in ALL, CML, and CLL, the homozygous genotype for HLA-DR53 had an
increased frequency in patients either by RFLP14,23 or PCR
analysis.24
Although no other molecular study has investigated the same locus in
childhood leukemia, a parallel between our results and mouse models can
be postulated. The first study on the influence of the MHC on the
development of virus-induced and spontaneous leukemia in congenic mice
found a strong influence of a homozygous MHC genotype.11
Since then, the influence of homozygosity for the H-2k
haplotype has been confirmed in many other studies,42-44
and one of the susceptibility loci has been mapped to the class II
region of this haplotype.44,45 Similar to the lack of any
increase in the allele frequency of HLA-DRB4*01 in childhood leukemia, heterozygosity for the H-2k haplotype has no effect on
mouse leukemogenesis. Similarities extend further by the observation
that a monoclonal antibody specific for the class II supertype of the
H-2k haplotype is cross-reactive with the human HLA-DR53
specificity.46
In a study of a polymorphic system, chance deviations in the genotype
frequencies may result in spurious associations. This possibility was
considered in the analysis of the data. The high homozygosity rate for
HLA-DRB4*01 in boys with ALL is in accord with our earlier finding
inferred from HLA-DQA1 RFLP analysis in a smaller group. Although the
sample size of 61 for boys with ALL is still relatively small, this
includes all patients diagnosed in the last 10 years and could not be
increased in a single-center study. Suffice it to say that if there
were to be no more homozygotes in the next 61 male patients with ALL,
the association would still be significant (hypothetical P
value = .001). Another finding suggesting the male-specificity of the
association with HLA-DRB4*01 is that the genotypes of the other two
loci in the class I and class III regions did not show any change in
patients or any sex-specific difference in allele or genotype
frequencies. It was not possible to have an age- and sex-matched
control group, which would have been ideal. Although, the association
seemed to be primarily due to an excess of homozygotes for HLA-DRB4*01
in male patients, a possible age-related change in the frequency of
this genotype in healthy children may have contributed to the magnitude
of this association and should be considered in the interpretation of the results.
The gender effect we observed has not been reported in HLA association
studies in leukemia before. There is, however, a similar observation in
rheumatoid arthritis (RA), which is also associated with HLA-DRB4*01
and, the main member of this supertypic family, HLA-DRB1*04. The
strongest susceptibility genotype for RA is compound heterozygosity for
HLA-DR4 (HLA-DRB1*0401/*0404), which is a homozygous genotype for
HLA-DRB4*01. In a disease, which predominantly affects females, this
particular genotype occurs preferentially in young males in two
different populations including Britain.47,48 In another
study, homozygosity for HLA-DR53, detected by RFLP analysis, showed a
male-specific decline with age.49 It appears that this
homozygous genotype is associated with deleterious effects only in
young males, the reasons for which are, at present, unknown.
The decreased frequency of the homozygous leukemia susceptibility
genotype in newborn boys suggested an association of reproductive failure with this genotype. If this is the case, prenatal selection against a homozygous HLA genotype is not surprising, as parental sharing of HLA-DR alleles is a known risk factor for both reproductive failure17,18,50,51 and childhood ALL.16 To
date, no particular allele has been shown to be responsible for this
effect. What the present study adds to our knowledge is a possible
gender effect in the influence of HLA-DR homozygosity on reproductive
failure. If our finding is confirmed by larger studies, this would
favor the genetic hypothesis (presence of HLA-linked recessive lethal genes) without arguing against the immunological hypothesis
(deleterious effect of feto-maternal HLA compatibility) of the
immunogenetic background of reproductive failure.
The genetic hypothesis proposes that HLA-linked recessive lethal genes
cause pregnancy failure in the case of homozygosity for them. The
typical example of this is the lethal alleles of the mouse
t-complex. In mice bearing two t-haplotypes from
different complementation groups, some fetus may survive, whereas all
fetuses homozygous for the same lethal t-haplotype die. In the
group of t6/tw5 heterozygotes bearing a double dose of
a recessive lethal allele, sex affects the lethality and a deficit of
males among live births has been noted in independent
studies.52,53 Interestingly, the MHCs embedded into
tw5 and t6-haplotypes share a high level of homology
detected at the DNA level.54 The male-specificity of fetal
loss due to recessive lethals in or around MHC is not then
unprecedented, but our finding remains to be confirmed in human studies.
Because miscarriages and childhood leukemia tend to occur in the same
families5-7 and parental HLA sharing is a risk factor for
each condition separately, it is plausible that the same HLA genotype
may be a risk factor for both conditions. It is particularly important
that the ongoing US Childrens Cancer Group case-control study has so
far identified only the maternal history of fetal loss as a risk factor
for childhood ALL.3,7 This connection is further supported
by the reports that survivors of threatened abortions are at a higher
risk to develop childhood leukemia.5,6 In the most recent
study, mothers had a history of at least one fetal loss almost in one
third of childhood ALL cases.7 Another line of support is
the well-known association of HLA-DR53 or its members (HLA-DR4 and
-DR7) with antiphospholipid antibody syndrome.55 This
antibody is present in 15% of women with a recurrent miscarriage history and usually causes early (first trimester) miscarriages in 90%
of them.56 All of these findings provide circumstantial evidence that the leukemia susceptibility genotype may be responsible for the increased miscarriage incidence in leukemic families. The very
low sex-ratio in newborns homozygous for HLA-DRB4*01 coupled with a
very high ratio in ALL suggested the association of this genotype with
reproductive failure and an increased risk of ALL among those who
survived the prenatal challenge. This scenario is in agreement with the
model proposing that childhood malignancies and reproductive failure
share the same genetic background.12,57,58
Although the human MHC has been extensively examined, it may still be
possible that an unknown gene linked to HLA-DRB4 may be responsible for
the deleterious effects of the susceptibility genotype. The 110-kb to
160-kb extra amount of DNA in the class II region exclusive to the DR53
haplotypes may harbor a recessive lethal/deleterious
gene.59-61 To the best of our knowledge, this area on this
haplotype has not been sequenced as part of the human genome project.
Our results, together with those of the other studies,21,23,24,49 indicate a need for the inclusion of a
DR53 haplotype in the chromosome 6 sequencing project.
Compelling epidemiological evidence suggests that childhood cALL
develops as a result of a rare response to a common viral infection.4,8,9 It has been also emphasized that an HLA association would implicate a viral involvement.4,8 The
present study found an OR of 14.4 for a newborn boy to develop
childhood cALL, therefore, homozygosity for HLA-DRB4*01 is most likely
to be the HLA genotype responsible for the putative abnormal immune response to a childhood viral infection. This genotype occurred in a
third of boys with cALL. Although there is no direct evidence for any
virus to be the long-suspected link, it has been previously suggested
that the HLA-DR53 homozygous genotype may cooperate with adenovirus in
promotion of preleukemic clones that have arisen spontaneously.10 The putative role of adenovirus in this
model is a nonmutagenic one and involves an interaction with HLA-DR53 in the evasion of an immune response towards the transformed
preleukemic clone. In this context, the very high degree of molecular
mimicry between HLA-DR53 epitope and an adenoviral protein may be
pertinent.62 The large tegument protein of Epstein-Barr
virus (EBV) also shows a seven consecutive amino acid
mimicry with the same HLA-DR53 epitope as well as five amino acids of
the BamHI-M rightward reading frame 2 (BMFR2)
early nuclear protein.62 A recent case control study found
an increased prevalence of antibodies to EBV in leukemic children under
6-years old63 (adenovirus was not considered in that
study). This suggests that the HLA-DR53 association may also point to
EBV as a candidate virus involved in the development of childhood ALL.
In summary, the results of the present study suggest that homozygosity
for HLA-DRB4*01 (-DR53) is a genetic risk factor for childhood ALL in
boys. DRB4*01 homozygosity may also be the common immunogenetic basis
for a proportion of recurrent spontaneous miscarriages observed in
leukemic families. We hope that these results will be used as a guide
for further functional studies and be considered in the ongoing
National Children's Cancer Studies in the US and UK.
| |
ACKNOWLEDGMENT |
The authors thank the manager of the Welsh Leukemia Registry, Z. Whittaker, for providing the data on childhood ALL cases diagnosed in
Wales; and the staff at the Regional Tissue Typing Laboratory in the
Welsh Blood Service and at the HLA Laboratory in Martin Luther
University School of Medicine at Halle, Germany.
| |
FOOTNOTES |
Submitted November 2, 1998; accepted March 16, 1999.
Supported by a research grant from the Leukemia Research Appeal
for Wales. A British Council Academic Research Collaboration grant supported the collaboration between the British and German research groups.
The publication costs of this
article were defrayed in part by
page charge payment. This article
must therefore be hereby marked
"advertisement"
in accordance with 18 U.S.C. section
1734 solely to indicate this fact.
Address reprint requests to M. Tevfik Dorak, MD, Department of
Haematology, University of Wales College of Medicine, Heath Park,
Cardiff CF4 4XN, UK; e-mail: dorak{at}cardiff.ac.uk.
| |
REFERENCES |
1.
Miller RW, Young JL Jr, Novakovic B:
Childhood cancer.
Cancer
75:395, 1995[Medline]
[Order article via Infotrieve]
2.
Shu XO:
Epidemiology of childhood leukemia.
Curr Opin Hematol
4:227, 1997[Medline]
[Order article via Infotrieve]
3.
Robison LL, Buckley JD, Bunin G:
Assessment of environmental and genetic factors in the etiology of childhood cancers: The Childrens Cancer Group epidemiology program (review).
Environ Health Perspect
103:111, 1995 (suppl 6)
4.
Greaves MF:
Aetiology of acute leukaemia.
Lancet
349:344, 1997[Medline]
[Order article via Infotrieve]
5.
Stewart A, Webb J, Hewitt D:
A survey of childhood malignancies.
BMJ
1:1495, 1958
6.
van Steensel-Moll HA, Valkenburg HA, Vandenbroucke JP, van Zanen GE:
Are maternal fertility problems related to childhood leukaemia?
Int J Epidemiol
14:555, 1985[Abstract/Free Full Text]
7.
Yeazel MW, Buckley JD, Woods WG, Ruccione K, Robison LL:
History of maternal fetal loss and increased risk of childhood acute leukemia at an early age. A report from the Childrens Cancer Group.
Cancer
75:1718, 1995[Medline]
[Order article via Infotrieve]
8.
Greaves MF, Alexander FE:
An infectious etiology for common acute lymphoblastic leukemia in childhood?
Leukemia
7:349, 1993[Medline]
[Order article via Infotrieve]
9.
Kinlen LJ:
Epidemiological evidence for an infective basis in childhood leukaemia.
Br J Cancer
71:1, 1995[Medline]
[Order article via Infotrieve]
10.
Dorak MT:
The implications for childhood leukemia of infection with adenovirus.
Trends Microbiol
4:60, 1996[Medline]
[Order article via Infotrieve]
11.
Lilly F, Boyse EA, Old LJ:
Genetic basis of susceptibility to viral leukaemogenesis.
Lancet
2:1207, 1964[Medline]
[Order article via Infotrieve]
12.
Dorak MT, Burnett AK:
Major histocompatibility complex, t-complex, and leukemia (review).
Cancer Causes Control
3:273, 1992[Medline]
[Order article via Infotrieve]
13.
Tiwari JL, Terasaki PI:
HLA and Disease Associations. New York, NY, Springer-Verlag, 1985.
14.
Dorak MT, Owen G, Galbraith I, Henderson N, Webb D, Mills KI, Darke C, Burnett AK:
Nature of HLA-associated predisposition to childhood acute lymphoblastic leukemia.
Leukemia
9:875, 1995[Medline]
[Order article via Infotrieve]
15.
Taylor GM, Robinson MD, Binchy A, Birch JM, Stevens RF, Jones PM, Carr T, Dearden S, Gokhale DA:
Preliminary evidence of an association between HLA-DPB1*0201 and childhood common acute lymphoblastic leukaemia supports an infectious aetiology.
Leukemia
9:440, 1995[Medline]
[Order article via Infotrieve]
16.
Von Fliedner VE, Merica H, Jeannet M, Barras C, Feldges A, Imbach P, Wyss M:
Evidence for HLA-linked susceptibility factors in childhood leukemia.
Hum Immunol
8:183, 1983[Medline]
[Order article via Infotrieve]
17.
Thomas ML, Harger JH, Wagener DK, Rabin BS, Gill TJ III:
HLA sharing and spontaneous abortion in humans.
Am J Obstet Gynecol
151:1053, 1985[Medline]
[Order article via Infotrieve]
18.
Jin K, Ho HN, Speed TP, Gill TJ III:
Reproductive failure and the major histocompatibility complex.
Am J Hum Genet
56:1456, 1995[Medline]
[Order article via Infotrieve]
19.
Leen MP, Gorski J:
DRB4 promoter polymorphism in DR7 individuals: Correlation with DRB4 pre-mRNA and mRNA levels.
Immunogenetics
45:371, 1997[Medline]
[Order article via Infotrieve]
20.
Knowles RW, Flomenberg N, Horibe K, Winchester R, Radka SF, Dupont B:
Complexity of the supertypic HLA-DRw53 specificity: Two distinct epitopes differentially expressed on one or all of the DR beta-chains depending on the HLA-DR allotype.
J Immunol
137:2618, 1986[Abstract]
21.
Seremetis S, Cuttner J, Winchester R:
Definition of a possible genetic basis for susceptibility to acute myelogenous leukemia associated with the presence of a polymorphic Ia epitope.
J Clin Invest
76:1391, 1985
22.
Dyer PA, Ridway JC, Flanagan NG:
HLA-A,B and DR antigens in chronic lymphocytic leukaemia.
Dis Markers
4:231, 1986[Medline]
[Order article via Infotrieve]
23.
Dorak MT, Chalmers EA, Gaffney D, Wilson DW, Galbraith I, Henderson N, Worwood M, Mills KI, Burnett AK:
Human major histocompatibility complex contains several leukemia susceptibility genes.
Leuk Lymphoma
12:211, 1994[Medline]
[Order article via Infotrieve]
24.
Dorak MT, Machulla HK, Hentschel M, Mills KI, Langner J, Burnett AK:
Influence of the major histocompatibility complex on age at onset of chronic lymphoid leukaemia.
Int J Cancer
65:134, 1996[Medline]
[Order article via Infotrieve]
25.
Miller SA, Dykes DD, Polesky HF:
A simple salting out procedure for extracting DNA from human nucleated cells.
Nucleic Acids Res
16:1215, 1988[Free Full Text]
26.
Yoshida M, Kimura A, Numano F, Sasazuki T:
Polymerase-chain-reaction-based analysis of polymorphism in the HLA-B gene.
Hum Immunol
34:257, 1992[Medline]
[Order article via Infotrieve]
27.
Dressel R, Gunther E:
A pentanucleotide tandem duplication polymorphism in the 3' untranslated region of the HLA-linked heat-shock protein 70-2 (HSP70-2) gene.
Hum Genet
94:585, 1994[Medline]
[Order article via Infotrieve]
28.
Kogan SC, Doherty M, Gitschier J:
An improved method for prenatal diagnosis of genetic diseases by analysis of amplified DNA sequences. Application to hemophilia A.
N Engl J Med
317:985, 1987[Abstract]
29.
Daly LE, Bourke GJ, McGilvray J:
Interpretation and Uses of Medical Statistics. Oxford, UK, Blackwell, 1991.
30.
Svejgaard A, Ryder LP:
HLA and disease associations: Detecting the strongest association.
Tissue Antigens
43:18, 1994[Medline]
[Order article via Infotrieve]
31.
de Moerloose P, Chardonnens X, Vassalli P, Jeannet M:
[HL-A D antigens from B-lymphocytes and susceptibility to certain diseases].
Schweiz Med Wochenschr
107:1461, 1977[Medline]
[Order article via Infotrieve]
32.
Casper JT, Duquesnoy RJ, Borella L:
Transient appearance of HLA-DRw-positive leukocytes in peripheral blood after cessation of antileukemia therapy.
Transplant Proc
12:130, 1980[Medline]
[Order article via Infotrieve]
33.
Von Fliedner VE, Sultan-Khan Z, Jeannet M:
HLA-DRw antigens associated with acute leukemia.
Tissue Antigens
16:399, 1980[Medline]
[Order article via Infotrieve]
34.
Michel K, Hubbel C, Dock NL, Davey FR:
Correlation of HLA-DRw3 with childhood acute lymphocytic leukemia (letter).
Arch Pathol Lab Med
105:560, 1981[Medline]
[Order article via Infotrieve]
35.
Chan KW, Pollack MS, Braun D Jr, O'Reilly RJ, Dupont B:
Distribution of HLA genotypes in families of patients with acute leukemia. Implications for transplantation.
Transplantation
33:613, 1982[Medline]
[Order article via Infotrieve]
36.
de Jongh BM, van der Dose-van den Berg A, Schreuder GM:
Random HLA-DR distribution in children with acute lymphocytic leukaemia in long-term continuous remission.
Br J Haematol
52:161, 1982[Medline]
[Order article via Infotrieve]
37.
Navarrete C, Alonso A, Awad J, McCloskey D, Ganesan TS, Amess J, Lister TA, Festenstein H:
HLA class I and class II antigen associations in acute leukaemias.
J Immunogenet
13:77, 1986[Medline]
[Order article via Infotrieve]
38.
Bortin MM, D'Amaro J, Bach FH, Rimm AA, van Rood JJ:
HLA associations with leukemia.
Blood
70:227, 1987[Abstract/Free Full Text]
39.
Orgad S, Cohen IJ, Neumann Y, Vogel R, Kende G, Ramot B, Zaizov R, Gazit E:
HLA-A11 is associated with poor prognosis in childhood acute lymphoblastic leukemia (ALL).
Leukemia
2:79S, 1988[Medline]
[Order article via Infotrieve]
40.
Caruso C, Cammarata G, Sireci G, Modica MA:
HLA-Cw4 association with acute lymphoblastic leukaemia in Sicilian patients.
Vox Sang
54:57, 1988[Medline]
[Order article via Infotrieve]
41.
Dearden SP, Taylor GM, Gokhale DA, Robinson MD, Thompson W, Ollier W, Binchy A, Birch JM, Stevens RF, Carr T, Bardsley WG:
Molecular analysis of HLA-DQB1 alleles in childhood common acute lymphoblastic leukaemia.
Br J Cancer
73:603, 1996[Medline]
[Order article via Infotrieve]
42.
Boyse EA, Old LJ, Stockert E:
The relation of linkage group IX to leukemogenesis in the mouse, in
Emmelot P,
Bentvelzen P
(eds):
RNA Viruses and Host Genome in Oncogenesis. Amsterdam, The Netherlands, North Holland, 1972, p 171.
43.
Lilly F, Pincus T:
Genetic control of murine viral leukemogenesis.
Adv Cancer Res
17:231, 1973
44.
Vasmel WL, Zijlstra M, Radaszkiewicz T, Leupers CJ, de Goede RE, Melief CJ:
Major histocompatibility complex class II-regulated immunity to murine leukemia virus protects against early T- but not late B-cell lymphomas.
J Virol
62:3156, 1988[Abstract/Free Full Text]
45.
Miyazawa M, Nishio J, Chesebro B:
Genetic control of T cell responsiveness to the Friend murine leukemia virus envelope antigen. Identification of class II loci of the H-2 as immune response genes.
J Exp Med
168:1587, 1988[Abstract/Free Full Text]
46.
Matsuyama T, Schwenzer J, Silver J, Winchester R:
Structural relationships between the DR beta 1 and DR beta 2 subunits in DR4, 7, and w9 haplotypes and the DRw53 (MT3) specificity.
J Immunol
137:934, 1986[Abstract]
47.
Weyand CM, Hicok KC, Conn DL, Goronzy JJ:
The influence of HLA-DRB1 genes on disease severity in rheumatoid arthritis.
Ann Intern Med
117:801, 1992
48.
MacGregor A, Ollier W, Thomson W, Jawaheer D, Silman A:
HLA-DRB1*0401/0404 genotype and rheumatoid arthritis: Increased association in men, young age at onset, and disease severity.
J Rheumatol
22:1032, 1995[Medline]
[Order article via Infotrieve]
49.
Dorak MT, Mills KI, Gaffney D, Wilson DW, Galbraith I, Henderson N, Burnett AK:
Homozygous MHC genotypes and longevity.
Hum Hered
44:271, 1994[Medline]
[Order article via Infotrieve]
50.
Ober C, Elias S, Kostyu DD, Hauck WW:
Decreased fecundability in Hutterite couples sharing HLA-DR.
Am J Hum Genet
50:6, 1992[Medline]
[Order article via Infotrieve]
51.
Ober C, Hyslop T, Elias S, Weitkamp LR, Hauck WW:
Human leukocyte antigen matching and fetal loss: Results of a 10 year prospective study.
Hum Reprod
13:33, 1998[Abstract/Free Full Text]
52.
Bechtol KB:
Lethality of heterozygotes between t-haplotype complementation groups of mouse: Sex-related effect on lethality of t6/tw5 heterozygotes.
Genet Res
39:79, 1982[Medline]
[Order article via Infotrieve]
53.
King TR:
Partial complementation by murine t haplotypes: Deficit of males among t6/tw5 double heterozygotes and correlation with transmission-ratio distortion.
Genet Res
57:55, 1991[Medline]
[Order article via Infotrieve]
54.
Silver LM:
Genomic analysis of the H-2 complex region associated with mouse t haplotypes.
Cell
29:961, 1982[Medline]
[Order article via Infotrieve]
55.
Sebastiani GD, Galeazzi M, Morozzi G, Marcolongo R:
The immunogenetics of the antiphospholipid syndrome, anticardiolipin antibodies, and lupus anticoagulant (review).
Semin Arthritis Rheum
25:414, 1996[Medline]
[Order article via Infotrieve]
56.
Rai R, Clifford K, Regan L:
The modern preventative treatment of recurrent miscarriage.
Br J Obstet Gynaecol
103:106, 1996[Medline]
[Order article via Infotrieve]
57.
Gill TJ III:
The borderland of embryogenesis and carcinogenesis. Major histocompatibility complex-linked genes affecting development and their possible relationship to the development of cancer.
Biochim Biophys Acta
738:93, 1984[Medline]
[Order article via Infotrieve]
58.
Gill TJ III:
Role of the major histocompatibility complex region in reproduction, cancer, and autoimmunity.
Am J Reprod Immunol
35:211, 1996
59.
Kendall E, Todd JA, Campbell RD:
Molecular analysis of the MHC class II region in DR4, DR7, and DR9 haplotypes.
Immunogenetics
34:349, 1991[Medline]
[Order article via Infotrieve]
60.
Niven MJ, Hitman GA, Pearce H, Marshall B, Sachs JA:
Large haplotype-specific differences in inter-genic distances in human MHC shown by pulsed field electrophoresis mapping of healthy and type 1 diabetic subjects.
Tissue Antigens
36:19, 1990[Medline]
[Order article via Infotrieve]
61.
Inoko H, Ando A, Kawai J, Trowsdale J, Tsuji K:
Mapping of the HLA-D region by pulsed-field gel electrophoresis: Size variation in subregion intervals, in
Silver J
(ed):
Molecular Biology of HLA Class II Antigens. Boca Raton, FL, CRC, 1990, p 1.
62.
Dorak MT, Burnett AK:
Molecular mimicry of an HLA-DR53 epitope by viruses (letter).
Immunol Today
15:138, 1994[Medline]
[Order article via Infotrieve]
63.
Schlehofer B, Blettner M, Geletneky K, Haaf HG, Kaatsch P, Michaelis J, Mueller-Lantzsch N, Niehoff D, Winkelspecht B, Wahrendorf J, Schlehofer JR:
Sero-epidemiological analysis of the risk of virus infections for childhood leukaemia.
Int J Cancer
65:584, 1996[Medline]
[Order article via Infotrieve]
TOP
ABSTRACT
INTRODUCTION
