Hemolysis and schistocytosis in the emergency department: consider pseudothrombotic microangiopathy related to vitamin B12 deficiency

Abstract

In a context of mechanical hemolysis with thrombocytopenia in a patient admitted to the emergency department, very high LDH levels and a low reticulocyte count are strongly suggestive of pseudo-TMA and should prompt the physician to screen for cobalamin deficiency.

Cobalamin Deficient Thrombotic Microangiopathy: a case of TTP or Pseudo-TTP

“…Both are microangiopathies that result in hemolytic anemias. 1,2,3,4,7,13,15 This is evident by diminished Hgb/Hct, elevated bilirubin, elevated LDH and schistocytes in the peripheral circulation denoting fragmented cells. Thrombocytopenia occurs from platelet aggregation, with the resultant debris eventually causing organ ischemia leading to dysfunction and failure, especially in the brain, heart, kidney and gastrointestinal system.…”

“…8,11,14,15 The megaloblastic features of the larger erythrocytes are seen as an elevated MCV. 1,11,12 Ineffective erythropoiesis also contributes to intramedullary hemolysis, causing LDH to be significantly more elevated than intravascular cell destruction only. 1,6,7,8,9,10,13,14,15 Finally, age can be a clue with most TTP occurring prior to fifty years old 13 while pseudo-TTP predominately occurs in seniors.…”

“…1,11,12 Ineffective erythropoiesis also contributes to intramedullary hemolysis, causing LDH to be significantly more elevated than intravascular cell destruction only. 1,6,7,8,9,10,13,14,15 Finally, age can be a clue with most TTP occurring prior to fifty years old 13 while pseudo-TTP predominately occurs in seniors. 1,6,9,12 This patient didn't present with a clear picture for pseudo-TTP (Table 1).…”

“…1,2,3,4 TMAs are rare, with an estimated incidence of 4 per 1 million, 1,5,6 but have a mortality rate of 10-20%. 1 Hemolytic Uremic Syndrome, cancer, HIV, hemopoetic stem cell transplant, connective tissue disorders and medications, like oxymorphone, Quinine, calcinuerin inhibitors and antineoplastic agents, can result in TMA. 3,5,7,8 The most common TMA is thrombotic thrombocytopenic purpura (TTP), or Moschowitz disease, with 2-3 individuals per million incidence.…”

“…3,7,9,10 Cobalamin (Vitamin B12) deficiency has a prevalence of 4-15%, which is higher in the elderly. 1,6,9,11,12 Most symptomatology is mild, but lifethreatening manifestations can occur. Cobalamin deficiency related TMA, which accounts for 2.5% of all TMA cases and called pseudo-TTP.…”