Purpose: To describe clinical, biological characteristics and associated diseases of cold agglutinins in adults.
Methods: Retrospective study in a single department of internal medicine from 1997 to 2002. The inclusion criteria were a positive direct Coombs test and a positive research for cold-reactive autoantibodies. We recorded for each patient: clinical presentation at onset and during follow-up, biological parameters of haemolysis, biological characteristics of the cold agglutinin and associated diseases.
Results: Fifty-eight patients (34 females, 24 males), with medium age of 58.8 were included in the study. Clinical presentation was highly variable between acute life-threatening haemolysis and absence of symptoms. Results of direct antiglobulin test were C3 (74%), IgG + C3 (22.4%), IgG (3.4%). Titer, thermal amplitude, strength and specificity of Coombs test were correlated, in all cases except 6, with cold agglutinin haemolytic activity. In 77.6% of cases cold agglutinin was secondary; related to: autoimmune disorders (n = 19), lymphoproliferative disorders (n = 11) and infections (n = 10).
Conclusion: Clinical presentation of cold agglutinin is highly variable and not always related to the biological characteristics of the bound antibody (titer, thermal amplitude, specificity). In our single center study, diseases associated with cold agglutinin were various with the highest frequency of auto-immune disorders. Our study underlined also the high frequency of lymphoproliferative disorders and justifies a close follow-up of these patients. Finally, we reported a high frequency of hepatitis C virus infection among the infectious aetiologies.