{"id":"intrinsic-factor-blocking-antibody","name":"Intrinsic Factor Blocking Antibody","shortName":"IF Blocking Ab","aliases":["Intrinsic Factor Antibody","IF Blocking Ab","Intrinsic Factor Ab, Blocking","IFBA","Intrinsic Factor Blocking Antibodies","Intrinsic Factor Antibody, Blocking","IF Blocking Antibody","Anti-Intrinsic Factor Antibody","Anti-Intrinsic Factor","IF Antibody","Type 1 Intrinsic Factor Antibody","IFAB","Intrinsic Factor Blocking Antibody, Serum","Intrinsic Factor Ab","IF AB Type 1"],"abbreviations":["IFBA","IFAB","IF Ab"],"loinc":[{"code":"31443-5","primary":true},{"code":"9537-2","primary":false},{"code":"31444-3","primary":false},{"code":"31445-0","primary":false}],"specimen":"serum","units":[{"ucum":"[arb'U]/mL","display":"AU/mL"}],"referenceRanges":[{"population":"Adults","low":0,"high":1.1,"unit":"[arb'U]/mL","unitDisplay":"AU/mL","note":"Labcorp's immunochemiluminometric assay reports 0.0 to 1.1 AU/mL, as listed by Northwell Health Laboratories for its Labcorp send-out. Labcorp's own cutoffs for equivocal and positive results above 1.1 were not confirmed. ARUP's qualitative ELISA and the Mayo-based send-out listed by UW Medicine report only negative, positive or indeterminate, so use the flag printed on your own report. AU/mL values from different kits are not interchangeable.","sources":[{"title":"Intrinsic Factor Blocking Antibodies (Northwell Health Laboratories test 56184, Labcorp send-out)","url":"https://labs.northwell.edu/epic/test/56184","publisher":"Northwell Health Laboratories"}]}],"review":{"status":"ai-draft","label":"AI-drafted. Awaiting verification","lastReviewed":"2026-10-03"},"summary":"Looks for antibodies that block intrinsic factor, a stomach protein needed to absorb vitamin B12; a positive result supports pernicious anemia.","url":"https://bloodtesttracker.com/markers/intrinsic-factor-blocking-antibody","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}