High incidence of serum monoclonal Igs detected by a sensitive
immunoblotting technique in B-cell chronic lymphocytic leukemia
A Beaume, A Brizard, B Dreyfus and JL Preud'homme
Laboratory of Immunology and Immunopathology (CNRS URA 1172), Poitiers,
France.
In a prospective study in 65 untreated patients with early-stage B-cell
chronic lymphocytic leukemia (B-CLL), serum monoclonal Igs (moIg) were
evidenced in 80% of cases by a sensitive immunoblotting procedure. These
low-abundance moIg were generally undetectable by immunoelectrophoresis and
individual sera often contained several of them. Their kappa/lambda ratio
was close to 1 instead of 2.8 for the lymphocyte surface Igs. A monoclonal
IgM of the same light-chain type as the lymphocyte surface IgM was found in
26 sera only. The distribution of the heavy-chain classes and subclasses
and light-chain types of the serum moIg was similar to those observed in
aging (with a higher incidence and no correlation with age in B-CLL) and
conditions with defective T-cell functions. Using a specific filter
affinity- transfer assay, rheumatoid factors were detected in 58.5% of
sera. However, homogeneous anti-IgG antibodies corresponding to a
monoclonal IgM of the same light-chain type as the surface IgM were found
in 10 patients only. These data suggest that the majority of discrete serum
moIg in B-CLL are not secretion products of the leukemic clones and likely
result from the immunodeficiency state inherent in the disease.
Volume 84,
Issue 4,
pp. 1216-1219,
08/15/1994
Copyright © 1994 by The American Society of Hematology
