ISSN:
1573-2592
Keywords:
Cold agglutination
;
autoimmunity
;
IgG
;
immunosuppression
;
IgG-anti-F(ab′)2
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Previous reports provided evidence of an immunosuppressive role of natural anti-F(ab′)2 antibodies. If suppressive anti-F(ab′)2 antibodies also regulated the autoantibody production in cold agglutination, one would expect high titers of anti-F(ab′)2 to be associated with low titers of cold agglutinins. Indeed, our previous studies revealed an inverse correlation between IgG-anti-F(ab′)2 and cold agglutinins. Many previous experiments focused on anti-F(ab′)2 of an antiidiotypic nature. Recent epitope mapping showed that anti-F(ab′)2 of healthy persons is not an antiidiotype but recognizes a hinge region sequence. We attempted to answer the question whether this IgG-antihinge antibody is responsible for the previously described association between anti-F(ab′)2 and cold agglutinins. IgG-antihinge and IgG-anti-F(ab′)2 antibody was determined and statistically analyzed in the serum of 334 patients with cold agglutination. Our experiments revealed a strong correlation between the concentrations of antihinge and the previously described anti-F(ab′)2 antibody. The anti-F(ab′)2 activity was competitively inhibited by a synthetic hinge peptide. Moreover, patients with high antihinge titers had low cold agglutinin titers, and vice versa. A stratification according to cold agglutinin specificity and disease etiology showed that the inverse correlation is present only in anti-I and anti-i patients suffering from monoclonal B-lymphocyte proliferation. In conclusion, our results confirm the correlation previously described for anti-F(ab′)2 antibody and antierythrocyte autoantibody and define for the first time an association between an idiotype-independent anti-IgG autoantibody and cold agglutinin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1027306511414
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