Renal scintigraphy and survival of indium-111-labelled platelets in patients with diabetic nephropathy.

Nine patients with overt diabetic nephropathy underwent renal scintigraphy and measurement of platelet survival time using indium-111-labelled platelets after treatment for six weeks with aspirin-dipyridamole (990 mg/225 mg/day) or placebo in a double-blind cross-over study. External scanning of the renal areas at 16 and 40 h post-injection showed no excess activity of indium-111 relative to background. Mean platelet survival was within the published normal range at 9.1 +/- 0.6 days and 7.6 +/- 1.4 days using linear and gamma function analyses respectively. Treatment with aspirin-dipyridamole was without effect. The results suggest that significant platelet deposition in renal blood vessels is not an important factor in the pathogenesis of diabetic nephropathy.