P4226 - Seronegative Pernicious Anemia from Chronic Atrophic Gastritis Mimicking Thrombotic Thrombocytopenic Purpura

Jordan Woodard, MD¹, Harrison Lapin, BS², Christopher Eckman, DO^1
1Prisma Health, Greenville, SC; ²University of South Carolina School of Medicine, Greenville, SC

Introduction: Vitamin B12 is an essential nutrient required to support hematopoiesis and a neuron function. Severe vitamin B12 deficiency can present as a microangiopathic hemolytic anemia (MAHA) referred to as pseudothrombotic microangiopathy (pseudo-TMA), which can be misdiagnosed as thrombotic thrombocytopenic purpura (TTP) given the constellation of neurological symptoms, MAHA, and thrombocytopenia. Pseudo-TMA is primarily associated with autoimmune gastritis, though has rarely been reported with atrophic gastritis from chronic Helicobacter pylori infection.

Case Description/Methods: A 53-year-old female with gastroesophageal reflux disorder (GERD) and hepatic steatosis presented with generalized fatigue and dyspnea on exertion for two weeks. She had undergone EGD for GERD several months prior and was found to have chronic atrophic gastritis with metaplasia, and H. pylori positive for which she received triple therapy. Notably she denied diarrhea, weight loss, paresthesia, and ataxia.

She had mild generalized abdominal tenderness, with the remainder of the physical exam benign. Initial laboratory assessment revealed platelets 71 k/uL, hemoglobin 5.6 g/dL and MCV 108 fL. Schistocytes were noted on manual differential. Additional workup revealed haptoglobin < 8 mg/dL, lactate dehydrogenase >3,325 IU/L, and total bilirubin 1.9 mg/dL, suggestive of hemolysis. CT abdomen and pelvis revealed mesentery adenopathy and flow cytometry showed myeloid blasts. She was admitted for workup of lymphoma versus TTP. Vitamin B12 level resulted < 109 pg/mL, and intrinsic factor antibodies were not detected. She was initiated on intramuscular (IM) vitamin B12 supplementation and hematology consulted to evaluate, ultimately attributing the etiology of the hematologic abnormalities to severe vitamin B12 deficiency. Following two months of IM vitamin B12 therapy, all hematologic laboratory abnormalities and symptoms resolved.

Discussion: Severe vitamin B12 deficiency can mimic TTP and other MAHAs. Prompt recognition of this rare presentation can prevent the misdiagnosis of TTP and the associated use of high dose steroids and plasmapheresis, preventing potential adverse effects and high cost. The etiology of vitamin B12 deficiency, including H. pylori and atrophic gastritis, should be elucidated for focused treatment. Additionally, all patients with atrophic gastritis should be routinely screened for vitamin B12 deficiency to prevent severe complications such as pseudo-TMA.


Disclosures:


Jordan Woodard, MD¹, Harrison Lapin, BS², Christopher Eckman, DO¹. P4226 - Seronegative Pernicious Anemia from Chronic Atrophic Gastritis Mimicking Thrombotic Thrombocytopenic Purpura, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.