Enterocyte function in progressive systemic sclerosis as estimated by the deconjugation of pteroyltriglutamate to folic acid.

As a measure of enterocyte function, the deconjugation of pteroyl-L-glutamyl-gamma-L-glutamyl-gamma-L-glutamic acid to folic acid and subsequent active absorption was measured in 19 patients with progressive systemic sclerosis and compared with 14 controls. The absorption step of folic acid was identical in the two groups, while deconjugation of pteroyl-L-glutamyl-gamma-L-glutamyl-gamma-L-glutamic acid was significantly decreased in the patients with progressive systemic sclerosis. This observation suggests a primary epithelial defect of the small intestine in patients with progressive systemic sclerosis.