Jejunal surface pH measurements in tropical sprue.

The mucosal surface pH of jejunal biopsy samples incubated in vitro in Krebs-phosphate buffer was measured. Biopsies from 7 healthy individuals or tropical sprue subjects in complete remission had a mean surface pH of 5.8 +/- 0.09, similar to values for normal Caucasian subjects living in the UK. The mean surface pH of biopsies from 20 sprue patients, 6.0 +/- 0.08, was significantly higher (P less than 0.05) than that of the control subjects. Sprue patients could be sub-divided into those with 2 or more abnormal results in 3 intestinal function tests, and those with one or no abnormal test. The 9 low scorers showed a mean surface pH of 5.75 +/- 0.06 resembling the control mean, whereas the 11 high scorers had a higher (P less than 0.01) mean surface pH of 6.17 +/- 0.08. Mucosal surface pH correlated directly with 3 d mean faecal fat excretion and inversely with xylose and vitamin B12 absorption values but not with the nutritional indicators serum albumen, folate or blood haemoglobin levels. As in coeliac disease, mucosal surface pH in the jejunum is elevated above normal in tropical sprue and may reflect the extent to which normal ion transport processes are affected.