Antibody to Gastric Intrinsic Factor in Blood Donors and Hospital Patients

SUMMARY Antibody to gastric intrinsic factor was detected in the serum of five of 700 hospital patients (0·7%) aged over 50 years, but in none of 400 hospital patients aged below 50 years and in none of 500 blood donors aged below 60 years. Four of these five patients were further investigated : all four had latent pernicious anæmia and two of the patients had extremely low serum levels of vitamin B12 (30 and 60 pg. per millilitre). It is suggested that the presence of circulating intrinsic factor antibody in five of 700 hospital patients could indicate an overall incidence of latent pernicious anæmia in the vicinity of 1% in hospital patients aged over 50 years.