Folate Deficiency-Induced Pseudo-Thrombotic Microangiopathy

Pseudo-thrombotic microangiopathy is commonly linked with cyanocobalamin (vitamin B12) deficiency, but its association with folate deficiency is rare. This report details a case involving a 60-year-old man with a background of chronic alcohol use who presented with pancytopenia and schistocytes on his blood smear. Bone marrow aspiration showed erythroblastic hyperplasia with megaloblastic changes indicative of folate deficiency. Both cyanocobalamin and methylmalonic acid levels were normal, and there was no evidence of thrombotic thrombocytopenic purpura. Notably, the patient's haemoglobin and platelet counts improved after folate supplementation.

Pseudo-thrombotic microangiopathy related to folate deficiency is extremely rare and is defined by the presence of non-immune haemolytic anaemia, thrombocytopenia, and schistocytes observed in peripheral blood smears.The pathophysiology of pseudo-thrombotic microangiopathy associated with folate deficiency remains incompletely understood. Folate deficiency elevates homocysteine levels, which in turn cause endothelial dysfunction and activate platelets, thereby promoting micro thrombosis and intravascular haemolysis. Additionally, homocysteine has been suggested to act as a haemolytic toxin by generating free radicals within erythrocytes, potentially leading to intramedullary haemolysis.This case demonstrates that although the clinical presentation of folate deficiency-induced pseudo-thrombotic microangiopathy can be severe and may occasionally necessitate intensive care admission, prompt improvement was achieved following folate supplementation.