Native kidney BK virus nephropathy, a systematic review

Background There is a growing base of literature describing BK nephropathy (BKVN) in patients outside of the setting of kidney transplant. Previous systematic reviews of the literature have been limited by methodology or by the scope of patients included. Study Design and Methods Systematic Review (Prospero # CRD42018088524). Setting & Population Patients without kidney transplant who had biopsy-proven BKVN. Selection Criteria for Studies Full-text articles that describe native BKVN patient cases. Analytical Approach Descriptive synthesis. Results The search identified 630 unique articles of which 51 were included in the final review. Sixty-five cases (including two new cases presented in this review) were identified, all but one occurred in the setting of known immunosuppression. Limitations The primary limitation was the exclusion of studies that did not fulfill the stringent review criteria. We excluded reports with only a clinical diagnosis of BKVN, such as those with viruria and/or viremia without biopsy. Conclusions As of May 2018, there are 65 reported cases of BKVN in native kidneys. This represents the most comprehensive description of biopsy-proven BKVN in native kidneys to date. Evaluation for BK nephropathy should be considered in immunocompromised patients who exhibit unexplained renal failure.