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 There has been no relapse of AIHA since, even after steroid medication was withdrawn and even though the monospecific IgA-DAT has remained positive.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.

IgA-mediated human autoimmune hemolytic anemia as a result of hemagglutination in the spleen, but independent of complement activation and FcαRI

“…3 However, wAIHA associated exclusively with IgA antibodies, reacting optimally at 37°C, remains rare. 1,[4][5][6][7][8] Some of the features of these reported cases, including disease severity, high binding potency of IgA for RBCs with very little free antibody detectable in the serum, no strong evidence of blood group specificity, and in some cases, refractoriness to first-line treatment (administration of high doses of glucocorticosteroids), seem to be characteristic. 1 IgA antibodies exist in several forms, monomeric IgA, dimeric IgA, and polymeric IgA, all of which interact to some extent with the human IgA Fc receptor (Fc␣RI/CD89).…”

How I treat autoimmune hemolytic anemia

“…The IgA isotype is much less commonly involved in AIHA but may cause severe hemolysis. 14,15 The ability of the anti-erythrocyte antibody to bind to the erythrocyte antigen at specific temperatures is fundamental to the diagnosis in terms of whether it is designated as warm (reacts maximally at 37°C) or cold (reacts maximally at ,4°C) AIHA. The pathologic and clinical features of AIHA relate to the autoantibody class, thermal amplitude, and their efficiency in activating complement.…”

Diagnostik und Therapie der Anämie in der Praxis

“…Die hämoiytischen Anämien können weiter in Coombspositive oder Coombs-negative Anämien unterteilt werden [24] oder in erworbene und vererbte Formen [4]. Eine hämolytische Anämie kann selten auch aus labortechnischen Gründen Coombsnegativ sein [25] …”