title: Association of acquired thrombotic thrombocytopaenic purpura in a patient with pernicious anaemia.
abstract: Pernicious anaemia is an autoimmune disease caused by intrinsic factor antibody; it leads to vitamin B12 deficiency and is marked by ineffective erythropoiesis. Haematological features reveal macrocytosis, hyperchromasia and hypersegmented neutrophils. Schistocytes are typically seen in microangiopathy, such as in thrombotic thrombocytopaenic purpura (TTP)/haemolytic uraemic syndrome or disseminated intravascular haemolysis (DIC). We report a case of a patient with severe anaemia who presented to the emergency room. Peripheral smear revealed macrocytosis, hypersegmented neutrophils and marked schistocytosis. The patient also had high reticulocyte count with high serum lactate dehydrogenase, elevated D-dimer, low fibrinogen and low haptoglobin. Vitamin B12 level came back low and the presence of intrinsic factor antibody confirmed pernicious anaemia. ADAMTS13 level was noted to be mildly reduced, which raised the suspicion of the association of acquired TTP with pernicious anaemia. Acquired TTP is another autoimmune disorder and its association with pernicious anaemia needs further evaluation.
authors.affiliation: Department of Internal Medicine, Jamaica Hospital Medical Center, Jamaica, New York, USA.
authors.forename: Sidhertha
authors.initials: S
authors.lastname: Podder
authors.affiliation: Department of Hematology-Oncology, Jamaica Hospital Medical Centre, Jamaica, New York, USA.
authors.forename: Jose
authors.initials: J
authors.lastname: Cervates
authors.affiliation: Department of Hematology-Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Bimalangshu R
authors.initials: BR
authors.lastname: Dey
mesh_terms: D051722:ADAM Proteins / Q000097:blood*; D000071120:ADAMTS13 Protein; D000368:Aged; D000748:Anemia, Macrocytic / Q000097:blood / Q000150:complications / Q000175:diagnosis; D000752:Anemia, Pernicious / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000097:blood; D004906:Erythrocyte Count; D004913:Erythrocytes, Abnormal; D004920:Erythropoiesis; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D006242:Haptoglobins / Q000378:metabolism; D006463:Hemolytic-Uremic Syndrome / Q000097:blood / Q000150:complications; D006801:Humans; D007437:Intrinsic Factor / Q000097:blood*; D007770:L-Lactate Dehydrogenase / Q000097:blood; D009504:Neutrophils; D011697:Purpura, Thrombotic Thrombocytopenic / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D001323:Autoantibodies; D005338:Fibrin Fibrinogen Degradation Products; D006242:Haptoglobins; C036309:fibrin fragment D; D005340:Fibrinogen; D007437:Intrinsic Factor; D007770:L-Lactate Dehydrogenase; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human; D014805:Vitamin B 12