Pernicious Anemia Unveiled: Unusual Hemolytic Complications and Clinical Implications

• Published in: Curēus (Palo Alto, CA) Vol. 16; no. 4; p. e57901
• Main Authors: Trivedi, Meesha, Areti, Aruni, Venishetty, Nikit, Parikh, Amish, Didia, Claudia
• Format: Journal Article
• Language: English
• Published: United States Cureus Inc 09-04-2024; Cureus
• Subjects: Anemia; Antibodies; Apheresis; Biopsy; Blood; Blood platelets; Colonoscopy; Dehydrogenases; Hematology; Hemoglobin; Hemorrhoids; Internal Medicine; Iron; Oncology; Patients; Vitamin deficiency; pseudo-thrombotic microangiopathy; rare cause of vitamin b12 deficiency; pernicious-anemia; autoimmune gastritis; hemolytic anemia
• ISSN: 2168-8184; 2168-8184
• DOI: 10.7759/cureus.57901

Pernicious anemia (PA) is an autoimmune condition resulting in impaired vitamin B12 absorption that commonly presents with gastritis and neurological symptoms. In rare cases, associated vitamin B12 deficiency can contribute to significant red blood cell lysis, and patients can present with PA-induced pseudo-thrombotic microangiopathy (TMA) hemolytic anemia. This case describes a 59-year-old male presenting with a two-week history of gastrointestinal pain with bleeding who had anemia and hemodynamic instability on initial evaluation. After the endoscopy/colonoscopy did not reveal any active sources of bleeding and packed red blood cells failed to stabilize the patient, it was found that he had low serum B12 with anti-intrinsic factor and anti-parietal cell antibodies. A coordinated clinical approach, including parenteral cyanocobalamin and daily oral folic acid supplementation, stabilized the patient, highlighting the importance of distinguishing PA-induced pseudo-TMA from true TMA hemolytic anemia.