title: Severe IgA-mediated auto-immune haemolytic anaemia in a 48-yr-old woman.
abstract: Auto-immune haemolytic anaemia (AIHA) is characterised by haemolysis associated with the presence of the immunoglobulins IgG, IgM or IgA, and/or components of the complement system on the red cell membrane. The immunoglobulins react as auto-antibodies against the red cell antigens of the patient. IgG antibodies and the complement component C3d can be detected by the direct antiglobulin test (DAT); however, IgM and particularly IgA antibodies may not necessarily be detected by the broad-spectrum anti-human-globulin serum. We present the case of a 48-yr-old woman with severe AIHA. The initial polyspecific direct antiglobulin test (DAT), using a broad-spectrum antiserum, was negative. Testing with monospecific antisera led to the diagnosis of AIHA due to warm-acting auto-antibodies solely of the IgA class, which is a very rare finding. As therapy with steroids alone did not lead to a lasting remission, splenectomy was performed 10 months after initial diagnosis. There has been no relapse of AIHA since, even after steroid medication was withdrawn and even though the monospecific IgA-DAT has remained positive. This case demonstrates the importance of performing a monospecific antiglobulin test if there is a strong suspicion of AIHA in apparently "Coombs-negative" haemolytic anaemia. In AIHA caused by solely IgA antibodies, the polyspecific direct antiglobulin test may be negative or only weakly positive because of a limited content of anti-IgA antibodies in the polyspecific anti-human-globulin serum. First-line treatment of warm-type AIHA is the administration of high-dose glucocorticosteroids; splenectomy is indicated in steroid-refractory patients.
authors.affiliation: Department of Internal Medicine, Kantonsspital, CH-6000 Lucerne 16, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Bardill
authors.forename: C
authors.initials: C
authors.lastname: Mengis
authors.forename: M
authors.initials: M
authors.lastname: Tschopp
authors.forename: W A
authors.initials: WA
authors.lastname: Wuillemin
mesh_terms: D000744:Anemia, Hemolytic, Autoimmune / Q000175:diagnosis* / Q000276:immunology / Q000628:therapy; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood; D003298:Coombs Test / Q000592:standards; D005188:False Negative Reactions; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008875:Middle Aged; D013156:Splenectomy
chemical_list: D000888:Antibodies, Anti-Idiotypic; D001323:Autoantibodies; C049937:anti-IgA