Chronic atrophic gastritis as rare cause and manifestation of vitamin B12 deficiency: Case report

USA: Researchers have reported a rare case of chronic atrophic gastritis presenting as hemolytic anemia due to severe vitamin B12 deficiency, which has been published in the journal Case Reports in Hematology.

Food-bound cobalamin malabsorption occurs when the release of vitamin B12 from ingested food is hindered due to an underlying factor blocking the nutrient from its transport protein. This is now the most prevalent cause of vitamin B12 insufficiency.

Chronic atrophic gastritis is a rare autoimmune cause that results in pernicious anemia. The mechanism of hemolysis is thought to be related to both intramedullary and extramedullary malfunction. It's essential to get this diagnosis as early as possible to avoid needless treatments like plasmapheresis.

Doctors from Hackensack Meridian Health, USA compiled a case report of a 46-year-old Haitian man who presented with chest discomfort, increasing weakening, and exhaustion that prevailed for a month. These complaints led him to lose his appetite, resulting in an accidental weight reduction of 30 pounds during the preceding weeks.

The case report summary

Pancytopenia was discovered on the first complete blood count (CBC), which indicated a reduced white blood cell count of 2.4uL, hemoglobin level of 4.9 g/dL, and platelet count of 5710 3/uL.

Blood tests indicated normal serum electrolytes and renal function, as well as an increase in AST, total bilirubin, direct bilirubin, and LDH, as well as a reduction in haptoglobin. A hemolytic anemia test was also performed.

Additionally, the patient had an upper endoscopy (EGD) and a colonoscopy. EGD revealed a solitary nonbleeding erosion at the gastroesophageal junction, as well as widespread atrophic mucosa in the stomach body and antrum, which was biopsied. Internal hemorrhoids were discovered during a colonoscopy, which was otherwise normal.

The patient was given two units of packed red blood cells and brought to the hospital for additional testing. The patient's posttransfusion hemoglobin improved to 8.2 g/dL (13.2–17.5 g/dL) the day after admission.

Given the first direct positive Coombs test, the patient was eventually treated with 4 days of intravenous dexamethasone 40 mg daily for suspected autoimmune hemolytic anemia and was then started on daily intramuscular injections of cyanocobalamin 1000 mcq for a total of 10 days.

Bone marrow biopsy was postponed since the patient's cell numbers improved with vitamin B12 treatment. The patient was discharged with a hemoglobin level of 9.8 g/dL (13.2–17.5 g/dL).

He was discharged with oral vitamin B12 supplements and instructions to return to the hematology clinic the following month for weekly intramuscular vitamin B12 injections.

Important takeaway points:

• The pathogenesis of dysmorphic red blood cells in severe vitamin B12 deficiency is thought to be a combination of intramedullary and extramedullary malfunction.

• Pernicious anemia caused significant vitamin B12 deficiency and hence hemolytic anemia in the patient.

• Seronegativity was not linked with higher severity of gastric atrophy or clinical symptoms, while seropositivity did not correspond with atrophy severity.

• In the case of hemolytic anemia induced by vitamin B12 deficiency, an initial positive direct antiglobulin test (DAT) can be noticed.

• Patients with pernicious anemia have been documented to have a positive Coombs test for a short period of time, but subsequent testing is usually negative if the patient is started on vitamin B12 treatment. Repeat DAT was negative in this patient after he was started on vitamin B12 supplementation as well as a course of steroids.

"Vitamin B12 deficiency usually presents with neurologic and hematologic symptoms. Rarely, it will cause hemolytic anemic and thrombocytopenia, best described as a pseudothrombotic microangiopathy, as demonstrated in this case. It is critical to establish this diagnosis early on to prevent unnecessary treatment, such as plasmapheresis," shared Dr. Amanda in conclusion.

This article was published online in the Journal of Case Reports in Hematology, July 2021 Issue as "Chronic Atrophic Gastritis Presenting as Hemolytic Anemia due to Severe Vitamin B12 Deficiency."

Reference

Amanda M. Woodford, Rabhea Chaudhry, Gabriella A. Conte, Varsha Gupta, Madhurima Anne, "Chronic Atrophic Gastritis Presenting as Hemolytic Anemia due to Severe Vitamin B12 Deficiency", Case Reports in Hematology, vol. 2021, Article ID 9571072, 5 pages, 2021. https://doi.org/10.1155/2021/9571072