Blood, Vol. 94 No. 12 (December 15), 1999:
pp. 4343-4346
Inverse Association Between IgG-Anti-
and Antierythrocyte
Autoantibodies in Patients With Cold Agglutination
Peter Terness,
Dan Navolan,
Gerhard Opelz, and
Dieter Roelcke
From the Institute of Immunology, University of Heidelberg,
Heidelberg, Germany; and the Ministry of Health, Bucharest, Romania.
It has been known for a long time that
IgG-anti-F(ab')2 antibodies (Abs) are able to
suppress the B-cell response. We showed that natural
IgG-anti-F(ab')2 autoantibodies appear in the serum of patients with cold agglutination. If the anti-F(ab')2 Ab
suppresses cold agglutinin (CA)-producing B cells, one would expect an
inverse correlation between the titers of these two Abs. Our study
confirmed this correlation. Subsequent experiments showed that some
anti-F(ab')2 Abs bind to the hinge region of IgG. It
was difficult to explain how this Ab suppresses CA-producing B cells,
which are of IgM isotype. Here we show that patients with cold
agglutination have an IgG-anti-
light chain autoantibody in their
serum. This is another member of the anti-F(ab')2 Ab
group. Because the vast majority of CAs are IgM- Abs, the anti-
Ab might suppress CA-producing B cells. If this is the case, there
should be an inverse association between the titer of anti- Ab and
CA. In a group of 302 patients, we found that high titers of the
anti- Ab correlate with low titers of CA and vice versa (P
= .009). Interestingly, this association is found only in patients
whose disease is caused by noninfectious agents, including mainly
B-cell proliferations (P = .0058). Our data show that the
inverse correlation is not confined to a particular CA autoantibody
specificity. The results are discussed in the light of recent findings
showing that anti-IgM Abs may either inactivate or kill tumoral B cells
by apoptosis.
