Vitamin B12 Deficiency and Metabolism-Mediated Thrombotic Microangiopathy (MM-TMA)

Thrombotic microangiopathies (TMA) are characterized by microangiopathic hemolytic anemia, thrombocytopenia and organ damage resulting from mechanical factors, accumulation of the ultra-large von Willebrand factor multimers or complement-mediated abnormalities. Severe acquired vitamin B12 (Cobalamin - Cbl) deficiency or congenital defective Cbl metabolism could lead to a picture that mimics TMA. The later has been termed metabolism-mediated TMA (MM- TMA). This confusing picture is mediated partly by the large red cell fragmentation coupled with reduced platelet production in the absence of vitamin B12 and partly by the accumulated byproducts and metabolites that induce endothelial injury and hence organ damage.

Source: Transfusion and Apheresis Science - December 30, 2019 Category: Hematology Authors: Waleed Sabry, Mohamed Elemary, Thierry Burnouf, Jerard Seghatchian, Hadi Goubran Tags: Review Source Type: research