Light microscopy of the patient’s renal biopsy tissue. We found that 18 glomeruli were present in the sample. The glomeruli show an almost normal appearance. The capillary lumina are patent. The basement membranes are intact and not duplicated. The mesangium is not widened and not proliferated. The interstitial space shows a multifocal, mild mononuclear cell infiltration. The tubules are minimally atrophic. The vessels are unremarkable. There is no obvious chronic damage in the kidney. Hematoxylin and eosin stain; original magnification, ×200.