AUTOSOMAL-DOMINANT POLYCYSTIC KIDNEY-DISEASE IN BLACKS - CLINICAL COURSE AND EFFECTS OF SICKLE-CELL HEMOGLOBIN

Autosomal dominant polycystic kidney disease (ADPKD) is a frequent cau se of ESRD, but its frequency in blacks has not been well delineated a nd its course and the effects of sickle hemoglobin in this disease in blacks have not been previously reported. The occurrence of ADPKD in b lacks and whites was determined in two ESRD populations: all ESRD pati ents seen over a 16-yr period in one area of Southeast Tennessee and a ll ESRD patients in 15 hemodialysis units in Tennessee and Atlanta, GA . The frequency of sickle hemoglobin was determined and compared in a group of nonrelated blacks with ESRD with and without ADPKD. The age a t onset of ESRD and factors that might affect ADPKD such as gender, hy pertension, and hemoglobin type were examined. ADPKD was a less freque nt cause of ESRD in blacks than whites (1.4 versus 6.8%). However, aft er adjusting for the population rate, the incidence rates in blacks an d whites were similar (0.48 and 0.47 of 100,000). There was a higher i ncidence of sickle hemoglobin in nonrelated blacks with ADPKD versus o ther black ESRD patients (50 versus 7.5%; P < 0.005). Blacks had an ea rlier onset of ESRD than whites (43.2 versus 55.4 yr; P < 0.0001), as did blacks with sickle-cell trait versus blacks without (38.2 versus 4 8.1 yr; P < 0.003). In this population, hypertension and gender had no effect on the onset of ESRD. ADPKD accounted for a smaller percentage of blacks than whites with ESRD because of the high percentage of bla cks with renal disease from other causes. However, the frequency of ES RD due to ADPKD was similar in blacks and whites. Sickle-cell hemoglob in occurred more frequently than expected, and there was evidence of m ore severe disease as measured by earlier onset of ESRD in blacks when compared with whites and blacks with sickle-cell trait when compared with blacks without the trait.