Cold Agglutinin Disease Prevalence and Immunoglobulin M levels in Patients with Splenomegaly from Endemic Areas for Malaria in Rwanda

Abstract

Background: Inhabitants from malaria endemic zones often present with enlarged spleen, mainly due to hyper reactive malarial splenomegaly (HMS), and it is seen more commonly associated with elevated levels of Immunoglobulin M (IgM). Cold agglutinin disease is an acquired autoimmune hemolytic anemia (AIHA) that is usually due to cold-reacting IgM autoantibodies directed against red cell antigens. The study was conducted in response to the observed high frequency of transfusion dependent anemia in patients with splenomegaly from malaria endemic zones in southern province of Rwanda. The objectives of this study were to determine the prevalence of cold agglutinin disease and to assess the distribution of IgM antibodies among these patients. Methodology: This was a descriptive, cross-sectional study conducted over a period of six months from June 2016 to December 2016. The study enrolled adult population from malaria endemic areas of the southern province of Rwanda with unexplained splenomegaly. Blood samples for testing IgM levels, cold agglutinin, FBC, and markers of hemolysis were collected from peripheral health settings and analyzed at the laboratory of Butare University Teaching Hospital. Results: During the study period, we enrolled 188 participants with enlarged spleen. One hundred twenty-five (66%) were females and 34% were males. The mean (±SD) age of the study participants was 35.6 ± 15.2 years. Out of 188 participants, only 4.8% were found with significantly positive Cold Agglutinin Titer (CAT) (≥1:64) and 84% of participants were found to have elevated serum IgM level. Hemoglobin level, white blood count and platelets count decrease with severity of splenomegaly, while IgM level increases with spleen size. Conclusion: Among patients with splenomegaly from malaria endemic areas, IgM levels correlate with the stages of splenomegaly while cold agglutinin disease plays a small role in the etiology of anemia.