Immunologic abnormalities in hemodialysis patients: improvement after pyridoxine therapy.

8 male patients undergoing maintenance hemodialysis were studied to determine the effect of administering supplements of pyridoxine hydrochloride, 50 mg/day for 3-5 weeks, on tests of immune function. In the 3 patients who initially had abnormal nitroblue tetrazolium reduction tests, the values returned to normal with therapy (p less than 0.05). The generation of chemotactic factors from plasma was defective in all evaluated patients and improved after pyridoxine therapy in 4 of 5 patients (p less than 0.01). The lymphocyte subpopulations changed with a rise in the populations of null cells after supplementation with pyridoxine. In addition, lymphocyte transformation in response to mitogens improved in the 3 patients who initially showed low values in these assays. The improvements occurred with pyridoxine therapy even though some patients who responded had no evidence for vitamin B6 deficiency before therapy, as indicated by a normal erythrocyte glumatic-pyruvic transaminase index. We conclude that several parameters of immune function are improved with pyridoxine supplementation. Studies are necessary to establish the minimum daily intake of pyridoxine which will maintain improved values of these tests of immune function in hemodialysis patients.