Platelet Dysfunction in Patients with Vitamin B₁₂ Deficiency

Abstract

10 cases of pernicious anaemia are reported in which 6 had abnormal aggregation with epinephrine, 3 with fibrinogen, 2 with ADP, and 2 with ristocetin. 5 patients had thrombocytopenia and 3 of these had a prolongation of the bleeding time. These abnormalities were normalized after vitamin B₁₂ treatment. After treatment, platelet size changed toward a smaller diameter, but platelet size, however, was not significantly different from the normal platelet size distribution.

Tremors and thrombocytosis during treatment of megaloblastic anaemia

“…In most instances, such reactive thrombocytosis is described as asymptomatic but various thrombo-embolic complications, including deep vein thrombosis, coronary infarction and cerebral venous thrombosis, have been reported. 17,19 During follow-up, one of our patients had sudden-onset altered consciousness with features of raised intracranial pressure. He rapidly deteriorated and died.…”

“…Ingeberg & Stoffersen, while reporting platelet dysfunction in Cbl deficiency, also noticed thrombocytosis in three of ten cases. 19 The mechanism by which thrombocytosis develops following thrombocytopenia is thought to be a feedback process controlling thrombopoiesis. 17 During thrombocytopenia, the thrombopoietin levels are increased, which might be responsible for the brisk rise in the platelet count once the deficiency is corrected.…”

Multiple vascular abnormalities and a paradoxical combination of vitamin B 12 deficiency and thrombocytosis in a case with POEMS syndrome

“…In addition to several single case reports [1,2,7,8,10,17,19,20,22,23,29], two larger series have demonstrated the high frequency of moderate thrombocytosis in POEMS syndrome [4,24]. Nevertheless, the unique and paradoxical combination of vitamin B 12 deficiency, which is usually associated with thrombocytopenia [9], and thrombocytosis has been reported only once in POEMS syndrome before [28]. PO-EMS syndrome is characterised by a massive increase in serum VEGF levels, which originates from platelets [7,21].…”

Hemorrhagic manifestation of megaloblastic anemia: report of two cases and literature review

“…Both of our patients had pancytopenia with bleeding manifestations. Bleeding manifestations in megaloblastosis have been reported to be up to 25% by various workers [3,4] The commonly described hemorrhages are retinal hemorrhages and purpuric spots. Bleeding in the form of hemtemesis, hemoptysis and even life-threatening bleeding was described by Marwaha et al [5].…”

“…Hemorrhage can occur even with high platelet counts because of platelet dysfunction associated with megaloblastosis. Abnormal platelet aggregation with epinephrine, adenosine diphosphate (ADP) and ristocetin was demonstrated in six out of 10 patients by Ingeberg and Stoffersen [3]. Ghosh et al [4] also demonstrated impaired aggregation to ADP, collagen epinephrine and ristocetin in four out of 17 patients in their series with megaloblastic anemia.…”