To the Editor.
—Several recent reports have brought attention to the problem of tuberculosis (TB) in patients with chronic renal failure (CRF).1-4 They suggest that the incidence of active TB is increased in maintenance hemodialysis patients,1-3 as well as in patients with less severe renal insufficiency.4 Of particular note is the frequency of extrapulmonary and difficult-to-diagnose cases reported and the fact that many of the patients had anergy to skin tests.Increased susceptibility to mycobacterial disease is not surprising in view of the defects in cell-mediated immunity that have been demonstrated in dialysis patients.5 As part of routine surveillance, our patients have PPD skin tests every six months. Our present population of in-center and home peritoneal and hemodialysis patients shows an 18% incidence (19/ 107) of positive PPD reactivity. Of these 19, pulmonary TB developed in three after beginning dialysis. In one of these patients, recurrent