Serum vitamin B12 levels in chronic atrophic gastritis.

SUMMARY Thirteen cases of severe chronic atrophic gastritis were studied over a period ranging from five to 12 years. Diagnosis was established by a history of flatulent dyspepsia, depleted acid secretion and serial gastric biopsies using the suction biopsy tube. There was no evidence of peptic ulcer or cancer. During the last three years of the study serial assays were made of the serum vitamin B12 levels in these cases. In the majority there was a fall in the level. Also, the mean level was lower than that in a control group in which normal acid secretion was found on histamine stimulation. Absorption studies were made with 58Co labelled vitamin B12. These studies indicated the following three clinical states : (i) pre-pernicious anaenia, with serum vitamin B12 levels between 100 and 250 μμg. per millilitre and normoblastic bone marrow, but no symptoms or perhaps minimal weakness ; (ii) latent pernicious anaemia, with a serum vitamin B12 level less than 100 μμg. per millilitre, but still a normoblastic bone marrow, and either no symptoms or, at the most, minimal weakness ; (iii) overt pernicious anaemia, with a serum vitamin B12 level of less than 100 per millilitre and the classical clinical and bone-marrow changes of pernicious anemia and/or subacute combined degeneration of the spinal cord. The findings after a histamine test meal and on gastric biopsy and particularly the serum vitamin B12 level are of considerable value to the physician who suspects prepernicious anaemia, latent pernicious anaemia or the early manifestations of overt pernicious anaemia or subacute combined degeneration of the cord. He may thus save the patient from the severe forms of the disease.