Basics of kidney biopsy: A nephrologist's perspective.

The introduction of the kidney biopsy is one of the major events in the history of nephrology. Primary indications of kidney biopsy are glomerular hematuria/proteinuria with or without renal dysfunction and unexplained renal failure. Kidney biopsy is usually performed in prone position but in certain situations, supine and lateral positions may be required. Biopsy needles have changed with times from Vim-Silverman needle to Tru-cut needle to spring-loaded automatic gun. The procedure has also changed from blind bedside kidney biopsy to ultrasound marking to real-time ultrasound guidance to rarely computerized tomography guidance and laparoscopic and open biopsy. In very specific situations, transjugular kidney biopsy may be required. Most of the centers do kidney biopsy on short 1-day admission, whereas some take it as an outdoor procedure. For critical interpretation of kidney biopsy, adequate sample and clinical information are mandatory. Tissue needs to be stained with multiple stains for delineation of various components of kidney tissue. Many consider that electron microscopy (EM) is a must for all kidney biopsies, but facilities for EM are limited even in big centers. Sophisticated tests such as immunohistochemistry and in-situ hybridization are useful adjuncts for definitive diagnosis in certain situations.