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Published on: July 13, 2019
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Granulomatous inflammation in BK polyomavirus-associated nephropathy
Yang Zhang1, Hiba Ahmed2, Abdolreza Haririan2
1Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA.
Summary
Granulomatous BK polyomavirus-associated nephropathy (BKPyVAN) can mimic allograft rejection but may resolve spontaneously or with reduced immunosuppression. This presentation should be considered in immunosuppressed patients with granulomatous tubulointerstitial nephritis.
Area of Science:
- Nephrology
- Transplant Pathology
- Virology
Background:
- BK polyomavirus-associated nephropathy (BKPyVAN) typically presents as tubulointerstitial inflammation.
- Significant tubulitis in BKPyVAN can mimic acute T-cell-mediated allograft rejection.
- Less common presentations include histiocyte predominance and granuloma formation.
Purpose of the Study:
- To describe the clinicopathological features of granulomatous BKPyVAN.
- To highlight the differential diagnosis of granulomatous tubulointerstitial nephritis in transplant recipients.
- To present cases of granulomatous BKPyVAN in the first year post-transplantation.
Main Methods:
- Retrospective analysis of three kidney transplant recipients with granulomatous BKPyVAN.
- Review of allograft biopsies at 4, 6, and 12 months post-transplant.
- Clinicopathological correlation of inflammatory patterns and patient outcomes.
Main Results:
- Three cases of granulomatous BKPyVAN were identified within the first year post-transplantation.
- Biopsies demonstrated varying stages: spontaneously resolving, resolving after immunosuppression reduction, and early disease.
- Granulomatous inflammation in BKPyVAN can be a sign of evolving or resolving infection.
Conclusions:
- Granulomatous BKPyVAN is an uncommon but important presentation of BKPyVAN.
- It should be included in the differential diagnosis of granulomatous tubulointerstitial nephritis in immunosuppressed patients.
- Careful clinicopathological assessment is crucial for diagnosis and management.
