Objective: Assessment of the usefulness of the intrinsic factor antibody (IF Ab) test in comparison to the Schilling test in diagnosing pernicious anaemia (PA) in patients with vitamin B12 deficiency.
Design: This study was designed to compare the If Ab test to the Schilling test using results obtained of patients presenting with megaloblastic anaemia and low serum vitamin B12 levels to a large referral hospital.
Setting: The Chris Hani Baragwanath Hospital, Soweto, Gauteng, South Africa.
Subjects: Results from 77 patients with megaloblastic anaemia, low serum vitamin B12 levels and with both Schilling and IF Ab test results available were included.
Main outcome measures: The sensitivity and specificity of the IF Ab test was compared to the Schilling test with regard to making a diagnosis of PA in patients presenting with megaloblastic anaemia and low serum vitamin B12 levels.
Results: Relevant statistical analysis showed that in the correct clinical setting, a confident diagnosis of PA could be made without Schilling tests in patients with megaloblastic anaemia, vitamin B12 deficiency and positive IF Ab tests. In a small proportion of patients in whom the IF Ab is negative, Schilling tests still need to be performed.
Conclusion: With the increased concern over rising medical costs and where limited facilities are available, the IF Ab, in the correct clinical setting, is a cost effective and reliable test for diagnosis of PA.