Purpose: To describe the main characteristics and outcome of adult's acquired immune hemolytic anemias (AIHA). To analyse the relevance of the complementary tests performed for the search of an underlying disease.
Methods: Retrospective (1980-2000) monocentric study.
Inclusion criteria: age above 16, AIHA defined by an hemoglobin level below 12 g/dl in men and 11 g/dl in women, with hemolysis and/or a positive direct Coombs test and/or the presence of cold agglutinins (threshold 1/500) and/or in the absence of any other cause.
Results: Eighty three patients included (56 women and 27 men), with a mean age of 56 years (+/- 22) at AIHA onset including: 72 patients (87%) with warm antibody AIHA and 11 (13%) with cold agglutinin disease. The mean follow-up was 48 months (median 22 months). Among the 72 patients with warm antibody AIHA, the specificity of autoantibodies was: IgG + complement (43%), IgG (32%) or complement alone (25%); cold agglutinins (titre from 1/60 to 1/512) were detected in 15 (20%) of the patients. Antinuclear antibodies were detected (threshold: 1/80) in 33% of the cases. Hypogammaglobulinemia on serum protein electrophoresis (SPE) was significantively associated with the presence of an underlying non-Hogkin lymphoma (NHL). The CT-scan of the the chest and abdomen which was performed in 50% of the patients, showed abnormalities other than a spleen enlargement in 25% of the cases. The medullar biopsy (MB) was abnormal in 7 of 26 cases (27%) but lead by itself to the diagnosis of NHL in a single case. Thrirty seven (51%) of warm antibody AIHA cases were finally considered to be "secondary" to an underlying disease namely: NHLs (n = 14), Hogkin's disease (n = 1) connective tissue disease (CTD) (n = 14), drug-induced AIHA (n = 3), miscellaneous (n = 5). In 6 out of 14 cases (43%) of NHL's associated AIHA, the onset of AIHA precedes the NHL from 22 to 66 months. The response rates to different therapeutic regimens did not significatively differ when "secondary" and "idiopathic" AIHA were compared. Overall, 13 patients (15.6%) died mainly from infectious complications (n = 5) or an underlying NHL (n = 5).
Conclusions: In more than half of the cases AIHA are associated with an underlying disease and AIHA may precede the onset of a NHL for a long period. In the absence of a clinically apparent underlying disorder, testing for the presence of antinuclear antibodies, a SPE and a CT-scan must be systematic. Conversely, if no abnormalities are found, the relevance of a systematic MB at AIHA onset seems very low.