Red cell aplasia following prolonged D-penicillamine therapy.

Red cell aplasia developed in a case of Wilson's disease following an increase in D-penicillamine dosage after 14 years' treatment. In vitro study of the effect of D-penicillamine on 59Fe incorporation by marrow cells did not suggest that the patient's erythropoiesis was particularly sensitive to D-penicillamine or determine the mechanism of drug toxicity. However, three weeks after the drug was withdrawn, evidence of marrow regeneration was apparent, and within 10 weeks the haemoglobin had returned to normal. The patient has subsequently remained asymptomatic on an alternative chelating agent, triethylenetetramine dihydrochloride.