Three patients with disseminated lymphosarcoma and 3 cases of acute leukemia were placed on a pyridoxine deficient diet together with desoxypyridoxine for periods of four to fourteen days. Although there was evidence of malnutrition in the form of weight loss and weakness, none of the signs of specific pyridoxine deficiency described in animals was observed in the human. There was no unequivocal evidence of depression of hemopoiesis, no significant atrophy of lymphoid tissue, no signs of demyelinization of nerves, and no abnormality of tryptophane metabolism determined by urinary xanthurenic acid excretion. The possibility that the dietary restriction of pyridoxine was too brief for the development of a deficiency syndrome was considered, but it was pointed out that the rigors of the procedure were too great to justify more protracted periods of observation.
Two patients had acute toxic manifestations following the administration of large doses of desoxypyridoxine. These were characterized by transient epileptiform convulsions. There were no sequelae and no recurrence of the symptoms when the dose of the drug was reduced.
There was no evidence that the restriction of pyridoxine in the diet together with desoxypyridoxine for periods up to two weeks had any therapeutic effect in lymphosarcoma or acute leukemia. Also, no potentiation of the cytotoxic effect of nitrogen mustard was observed in the patients with lymphosarcoma when chemotherapy was given after the completion of the pyridoxine deficient regimen. It is to be emphasized that this does not absolutely exclude the possibility that pyridoxine deficiency may adversely affect lymphosarcoma in man. The short duration of the experiment and the well known refractoriness to any form of therapy of the tumors in these patients are factors which may have militated against a satisfactory outcome of the regimen.