Itgb3-integrin-deficient mice may not be a sufficient model for patients with Glanzmann thrombasthenia

Itgb3-integrin-deficient (Itgb3(−/−)) mice have been reported as a Glanzmann thrombasthenia (GT) model and have been used for platelet research. However, it remains unclear whether this mouse model can fully simulate patients with GT or whether it has different characteristics from these patients. The present study aimed to answer this question. Itgb3(−/−) mice were tested for platelet function, tail bleeding, whole-blood count, bone marrow hematopoiesis and organ enlargement. Itgb3(−/−) platelets showed impaired functions, including fibrinogen binding, aggregation, adhesion or spreading. Itgb3(−/−) mice demonstrated decreased platelet count and microcytic hypochromic anemia. Reduced iron staining of bone marrow and decreased plasma ferritin level confirmed the diagnosis of iron deficiency anemia. Evident splenomegaly was observed in Itgb3(−/−) mice. Immunohistochemical analysis of spleen biopsy revealed normal expression of CD3 and CD19, but elevated expression of CD71, which suggested that the splenomegaly in Itgb3(−/−) mice may be associated with extramedullary hematopoiesis. In conclusion, Itgb3(−/−) mice exhibited some unique characteristics that differed from those of human patients with GT and thus cannot completely simulate patients with GT.