IgA anti-red blood cell auto-antibodies in Evans syndrome.
In Evans syndrome, IgG auto-antibodies (Abs) and/or complement components are frequently detected on red blood cells (RBC) in the direct antiglobulin test (DAT). A 70-year-old man with Evans syndrome diagnosed four years previously presented with a persistent autoimmune haemolytic anaemia, despite immunosuppressive treatment and normalization of platelet count. The RBC allo- and auto-Abs screening and identification were performed by indirect antiglobulin test (IAT) and DAT. In March 2006, no circulating anti-RBC auto-Abs were found in IAT but the DAT was positive with anti-IgG (++), -C3d (weak) and -IgA (++). Follow up for 11 months revealed anti-RBC IgA auto-Abs on five out of six samples. IAT was positive for RBC auto-Abs on three samples. No correlation between the haemoglobin level and the strength of reactivity of IgG and IgA auto-Abs was observed. IgA anti-RBC auto-Abs are present in Evans syndrome. To detect these Abs and characterize their role, DAT procedures should systematically include anti-IgA.
Moncharmont
P
P
Etablissement français du Sang - Rhône-Alpes, Site de Lyon, Lyon Cedex 07, France. pierre.moncharmont@efs.sante.fr
Troncy
J
J
Rigal
D
D
D000368:Aged; D000744:Anemia, Hemolytic, Autoimmune / Q000175:diagnosis*; D001323:Autoantibodies / Q000097:blood*; D003298:Coombs Test; D004912:Erythrocytes / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D008297:Male; D013577:Syndrome
D001323:Autoantibodies; D007070:Immunoglobulin A