CAN FINGERNAIL CREATININE CONCENTRATIONS BE USED TO PREDICT DURATION OF AZOTEMIA

Clinical use of fingernail creatinine estimation to predict duration o f azotemia is yet to be validated. We studied the fingernail creatinin e concentrations in 48 subjects: seven controls, nine with acute renal failure, five with rapidly progressive glomerulonephritis, 12 with ch ronic renal failure and 15 with end-stage renal failure on maintenance hemodialysis. The creatinine concentration in aqueous eluates of powd ered nail clippings was determined by the alkaline picrate reaction. T he mean finger-nail creatinine concentration was significantly higher in patients with chronic renal failure (93.7 +/- 83.7 mu g/g), and end -stage renal disease on maintenance hemodialysis (118.4 +/- 46.8 mu g/ g) as compared to those with acute renal failure (36.6 +/- 23.7 mu g/g ) and rapidly progressive glomeruionephritis (35.8 +/- 20.6 mu g/g). T he creatinine concentrations did not differ significantly between norm al subjects (27.2 +/- 28.7 mu g/g) and those with acute renal failure and rapidly progressive glomerulonephritis. However because of large v ariability in the values of fingernail creatinine concentrations withi n each group, the test lacked specificity. Therefore, this investigati on is an unreliable indicator of duration of azotemia in individual pa tients and is not likely to be of much clinical use.