Pepsinogens and other serum markers in pernicious anemia.

Pepsinogen (PG) I and PG II levels were determined in sera from 147 patients with pernicious anemia. Race, sex, age, gastrin level, and antibody status did not influence pepsinogen levels. PG I values less than 30 micrograms/L were found in 92% of cases and PG I to PG II ratios less than 3.0 in 82% of cases. At least one of these two results was abnormal in 97% of all patients with pernicious anemia. In comparison, results of other blood tests used in the investigation of pernicious anemia were less often abnormal. Serum gastrin level exceeded 200 ng/L in 90% of patients with pernicious anemia and was second to pepsinogen abnormality in diagnostic sensitivity. Results for anti-intrinsic factor antibody were positive in 73% of cases and anti-parietal cell antibody in only 52%. Although its specificity is limited, the presence of low PG I level and/or low PG I-PG II ratio is currently the most sensitive serum indicator for pernicious anemia, and absence of both can be taken as a strong argument against the diagnosis. This highly sensitive test can be combined further with the highly specific serum anti-intrinsic factor antibody test for the presumptive diagnosis of pernicious anemia when definitive tests (the Schilling test or gastric analysis for intrinsic factor) cannot be done or results are inconclusive.