Evidence map›Paper›PMID 40964663›Full record

ArticleSAGE open medical case reports2025

Masked vitamin B12 deficiency in pernicious anaemia: A diagnostic trap due to assay interference-Case report.

Mohammed Abdulgayoom, Elabbass Abdelmahmuod, Abdulrahman F Al-Mashdali, Yara R Abuazab, Aliaa Amer, Ibrahim Ganwo, Shehab Mohamed

Abstract readCase Reports
In one paragraph

Article in SAGE open medical case reports, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Mohammed AbdulgayoomDepartment of Haematology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha, Qatar.ORCID https://orcid.org/0000-0003-0622-8455
Elabbass AbdelmahmuodEndocrine Section, Department of Medicine, Hamad Medical Corporation, Doha, Qatar.ORCID https://orcid.org/0000-0001-9330-5740
Abdulrahman F Al-MashdaliDepartment of Haematology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha, Qatar.
Yara R AbuazabDepartment of Family Medicine, Hamad Medical Corporation, Doha, Qatar.
Aliaa AmerDepartment of Laboratory Medicine and Pathology, Department of Hematopathology, Hamad Medical Corporation, Doha, Qatar.
Ibrahim GanwoDepartment of Laboratory Medicine and Pathology, Department of Hematopathology, Hamad Medical Corporation, Doha, Qatar.
Shehab MohamedDepartment of Haematology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha, Qatar.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Megaloblastic anaemia is mainly caused by vitamin B12 or folate deficiency. However, rare cases present with discordant laboratory findings, particularly falsely elevated vitamin B12 levels due to assay interference from anti-intrinsic factor antibodies, complicating diagnosis and management. We describe a 64-year-old woman with macrocytic anaemia, pancytopaenia, and megaloblastic changes on the blood smear, yet with a markedly elevated serum B12 (>2000 pmol/L). A strongly positive anti-intrinsic factor antibody titre explained the paradoxical result. Empirical parenteral B12 therapy led to rapid haematological recovery, confirming masked B12 deficiency secondary to pernicious anaemia. This case highlights the critical pitfall of anti-intrinsic factor antibody-mediated assay interference in vitamin B12 testing, which can mask true deficiency. Clinicians must maintain a high index of suspicion for masked B12 deficiency in patients with megaloblastic anaemia and incongruent laboratory results, particularly in the presence of anti-intrinsic factor antibodies.

Indexed as

anti-intrinsic factor antibodyassay interferenceB12 deficiencymegaloblastic anaemiapernicious anaemia

Identifiers

PMID40964663
PMCPMC12437156

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