Kidney biopsies for research: safety and feasibility

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Additional kidney cores for research purposes can be successfully and safely obtained from 90% of diabetic patients undergoing clinically indicated kidney biopsy, according to a research letter in CJASN.

The authors report an interim analysis from the multicenter Transforming Research in Diabetic Nephropathy (TRIDENT) study, a longitudinal cohort study using direct analysis of kidney tissue to identify biomarkers and new therapeutic targets for diabetic kidney disease. The analysis included data on 176 patients enrolled in TRIDENT. All had clinical indications for kidney biopsy and consented to undergo collection of an additional biopsy core for the study.

Biopsy was performed in 160 patients, and a research biopsy core was successfully obtained from 144 patients. The reasons for not obtaining an additional core were operator’s decision or needing all tissue for clinical purposes in 10 cases and bleeding/hematoma in six cases. The mean number of biopsy passes was 3.6. The indications for biopsy were excessive proteinuria in 65% of cases and rapid loss of kidney function in 24%.

Diabetic glomerulosclerosis was present in 82% of eligible research cores. Eleven patients (7%) experienced a total of 19 complications. Hematomas >5 cm occurred in seven patients, gross hematuria in three patients, and unplanned blood transfusion in three patients. Six patients had a prolonged hospital stay or readmission, but none required surgery or radiologic intervention.

Diabetic kidney disease is usually a clinical diagnosis, based on blood and urine test results rather than direct analysis of kidney tissue. There are limited data on the feasibility and safety of obtaining kidney biopsy cores for research purposes, as planned by the TRIDENT study.

This interim analysis shows a high rate of successful research core recovery in diabetic patients undergoing clinically indicated kidney biopsy, with low rates of adverse events. “These data will help to potentiate the safety of obtaining kidney tissue for research, ultimately improving care for patients with DKD,” the researchers write. They plan a full analysis of biopsy complications and risk factors once TRIDENT recruitment is completed [Hogan JJ, et al. The feasibility and safety of obtaining research kidney biopsy cores in patients with diabetes: An interim analysis of the TRIDENT study. Clin J Am Soc Nephrol doi: 10.2215/CJN.13061019].