Renal biopsy was broadly used for research in some institutions of the former Soviet Union: it was performed
in patients with amyloidosis, renovascular hypertension (both kidneys), pyelonephritis and chronic alcoholism. When
renal biopsy was performed in accordance with clinical indications, a part of the tissue cylinder was sometimes consumed
for scientific purposes. Renal biopsy was performed in clinically inactive or latent glomerulonephritis, isolated proteinuria
and/or hematuria. Semithin sections, silver and trichrome stains were not used in the routine, while electron microscopy
was applied infrequently. In isolated proteinuria and/or hematuria, histologically are often found only minor glomerular
abnormalities: slight mesangial widening and hypercellularity, scarce deposits of immunoglobulins and complement.
Under such conditions, this picture can be misinterpreted as glomerulonephritis, which can entail overtreatment. In some
studies, patients with the inactive or latent glomerulonephritis, isolated proteinuria or hematuria, were treated with
corticosteroids and/or cytotoxic drugs. Today, the upturn in Russian economy enables acquisition of modern equipment;
and medical research is on the increase. Under these circumstances, the main purpose of this letter was to remind that,
performing renal biopsy, the risk-to-benefit ratio should be kept as low as possible.