Hemolytic Anemia and Pancytopenia Secondary to Vitamin B12 Deficiency: Evaluation and Clinical Significance

Severe vitamin B12 deficiency presents a diagnostic challenge due to its diverse clinical manifestations, which can mimic serious hematologic disorders such as thrombotic thrombocytopenic purpura (TTP) or leukemia. The case we present here illustrates the unique characteristics of severe B12 deficiency, highlighting key differentiators from other conditions, including decreased reticulocyte counts and markedly elevated lactate dehydrogenase levels indicative of suppressed erythropoiesis. Advanced cobalamin deficiency affects all cell lines, leading to peripheral pancytopenia. Proposed mechanisms include fragile red blood cells prone to shearing, resulting in schistocyte formation, and hyperhomocysteinemia-induced oxidative stress exacerbating hemolysis. Prompt recognition and treatment with B12 replacement are critical, as illustrated by this case of hemolytic anemia and pancytopenia secondary to pernicious anemia, to prevent severe hematologic complications.

Et Tu, B12? Cobalamin Deficiency Masquerading As Pseudo-Thrombotic Microangiopathy

Vitamin B12 deficiency is classically associated with megaloblastic anemia. Possible cobalamin deficiency is not investigated once hemolysis is seen. Around 2.5% of cases can present as pseudo-thrombotic microangiopathy (TMA). A swift identification of this means the difference between an easy solution and a protracted one for the patient. A 74-year-old man with no past medical history presented with exertional dyspnea, fatigue, and increasing anorexia over two weeks. Physical examination including a neurological examination was normal. Laboratory tests revealed pancytopenia, unconjugated hyperbilirubinemia, elevated LDH (lactate dehydrogenase), low haptoglobin, and fragmented red blood cells (RBCs) on the peripheral smear, but normal FDP (fibrinogen degradation product) and fibrinogen. The absolute reticulocyte count was reduced as opposed to the expected elevation. Vitamin B12 levels were undetectable, and severe cobalamin deficiency from pernicious anemia was found to be the paramount etiology. Cobalamin deficiency causing pseudo-TMA baffles most physicians. Advanced pernicious anemia is thought to cause intramedullary hemolysis, resulting in peripheral pancytopenia. The fragile RBCs are easily sheared, producing schistocytosis without platelet microthrombi. In contrast to hemolytic anemias, reticulocyte count is low given the unavailability of B12 for erythropoiesis. Reticulocytopenia is a universal finding in cases of pseudo-TMA. Around 38.8% of cases with pseudo-TMA are misdiagnosed as thrombotic thrombocytopenic purpura and treated with plasma product therapy. Keeping an eye out for reticulocytopenia in cases of hemolysis could mean a world of difference for the patient.

An Exceedingly Rare Presentation of Severe Folate Deficiency-Induced Non-Immune Hemolytic Anemia

Macrocytic anemia is usually associated with vitamin B12 or folate deficiency. However, folate deficiency was rarely reported as a cause of hemolytic anemia. We present a case of a young man with a history of alcohol abuse who initially presented with an acute on chronic abdominal pain and was found to have jaundice and scleral icterus. His liver enzymes were unremarkable, and his abdominal imaging did not reveal any acute pathology. However, he was found to have a severe non-immune hemolytic anemia secondary to folate deficiency.

A case of asymptomatic pancytopenia with clinical features of hemolysis as a presentation of pernicious anemia

Pernicious anemia is an autoimmune disease with a variety of clinical presentations. We describe a case of pernicious anemia presenting with pancytopenia with hemolytic features. Further workup revealed very low vitamin B12 levels and elevated methylmalonic acid. It is important for a general internist to identify pernicious anemia as one of the cause of pancytopenia and hemolytic anemia to avoid extensive workup. Pernicious anemia can present strictly with hematological abnormalities without neurological problems or vice versa as in our case.