CUTANEOUS ABNORMALITIES AND METABOLIC DISTURBANCE OF PORPHYRINS IN PATIENTS ON MAINTENANCE HEMODIALYSIS

Blistering disorders may occur in patients with chronic renal failure. Photoactive medication may account for some, and others may be attrib utable to porphyria cutanea tarda (PCT), but most appear idiopathic. S eventy haemodialysis patients at the National Renal Transplant Centre were therefore screened to determine the prevalence of cutaneous disea se and to establish a reference range for plasma porphyrins in this po pulation. The possible contribution of hepatitis C virus (HCV) infecti on to increased porphyrin levels in this group was also investigated. Ninety four percent of patients on haemodialysis had dermatoses associ ated with chronic uraemia, and the plasma porphyrin levels in those pa tients (mean +/- 2 S.D: 19.1 +/- 13.5 nmol/L) were significantly highe r than those of a normal population (n = 40; mean +/- 2 S.D.: 5.5 +/- 3.2 nmol/L) (p < 0.05). Only 2 patients (2.9%), however, had antibodie s to HCV and although three others had blistering on light-exposed ski n, none of these had PCT or was on photoactive medication, nor did the y differ from the rest of the haemodialysis population with regard to erythropoietin or alcohol ingestion. For patients on haemodialysis, th erefore, in whom urinary porphyrin estimation is impossible or unrelia ble, it is recommended that plasma porphyrin profiles be checked where necessary with reference to the range for a haemodialysis population, in addition to assessment of the faecal porphyrin profile. Abnormal p orphyrin levels in this group may not, however, be explained by HCV in fection, but the occurrence of blistering on the sun-exposed sites of 3 patients suggests that ultraviolet radiation may be implicated in th ose instances.