GALLIUM-67 SCINTIGRAPHY AS A PREDICTOR OF RENAL PROGNOSIS IN PRIMARY IMMUNOGLOBULIN-A NEPHROPATHY

From October 1987 to September 1989, 29 patients with newly diagnosed immunoglobulin A nephropathy underwent renal gallium 67 scintigraphy. The radioisotope uptake ratio between left kidney and soft tissue was measured 48 hours after bolus injection of gallium 67, In 25 patients the ratio ranged from 1.30 to 3.56 (mean, 1.95 +/- 0.47), Ratios were not obtained in four patients because strong gastrointestinal isotope excretion, Plots of reciprocal serum creatinine concentration against time and Kaplan-Meier plots of renal survival were used to assess the predictive value of the test in 20 patients for whom long-term follow- up data were available, The radioisotope uptake ratio was negatively c orrelated with the slope of reciprocal serum creatinine against time ( r = -0.64, P < 0.01), When the 20 patients were divided into two group s according to radioisotope uptake ratio (group A, ratio >1.95, nine p atients; group B, ratio <1.95, 11 patients), life table analysis of re nal survival showed group B to have a better prognosis than group A (P < 0.05), The results indicate that increased renal gallium uptake is predictive of a poor prognosis in patients with immunoglobulin A nephr opathy. (C) 1996 by the National Kidney Foundation, Inc.