Indirect assessment of renal dysfunction in patients taking cyclosporin A for autoimmune diseases.

Abstract

The reliability of increases in serum creatinine and serum urea above initial values in detecting decreases in glomerular filtration rate below initial values was assessed in patients taking cyclosporin A (CyA) for autoimmune diseases. Both serum creatinine and serum urea provided reasonable estimates of the decline in glomerular filtration rate when measured simultaneously and when compared to patients' own baseline values. Combination of both serum creatinine and serum urea improved the assessment of renal dysfunction, partly by reducing the influence of any analytical errors. Frequent measurements, precise baseline evaluation and standardization of procedures can be expected to increase further the precision of assessing renal dysfunction from serum measurements. Hence, careful evaluation of changes in serum creatinine, with the option to include changes in serum urea, can provide a simple and reliable way of monitoring changes in renal function in patients taking CyA for autoimmune diseases.