Systematic kidney biopsies after acute allograft pyelonephritis

Area of Science:

• Nephrology
• Transplant Surgery
• Pathology

Background:

• Limited data exist on the renal histological impact of acute graft pyelonephritis post-kidney transplant.
• Assessing early histological changes and long-term function is crucial for patient outcomes.

Purpose of the Study:

• To evaluate kidney histology one month after acute graft pyelonephritis.
• To assess kidney function one year after acute graft pyelonephritis in kidney transplant recipients.

Main Methods:

• A cohort of 28 kidney transplant patients with acute graft pyelonephritis underwent biopsy at 1 month post-infection.
• Histological findings were compared to a control group of 28 patients who had protocol biopsies at 1 year without pyelonephritis.
• Patients were matched for age, sex, and immunosuppression.

Main Results:

• Kidney function was impaired post-acute graft pyelonephritis; 40% had not recovered estimated glomerular filtration rate (eGFR) by 1 month.
• Tubulitis was more frequent in the pyelonephritis group, particularly in those with incomplete eGFR recovery.
• Significant inflammatory infiltrate (>20%) at 1 month predicted worse kidney function at 1 year.

Conclusions:

• Kidney biopsies post-acute graft pyelonephritis can diagnose graft rejection.
• Biopsy findings, especially persistent eGFR impairment at 1 month, predict long-term kidney function recovery after transplant.