BK virus renal infection in a patient with the acquired immunodeficiency syndrome

Background.-We describe herein a patient with the acquired immunodeficiency syndrome and renal failure due to biopsy-proven BK virus (BKV) infection. Three months after the diagnosis of the renal viral infection, his conditio n remained unchanged. Although BKV has previously been shown to be associat ed with ureteral stenosis and renal damage in renal transplant patients, to our knowledge, the literature contains only 3 cases describing the presenc e of BKV lesions in the kidneys of immunosuppressed patients who had not un dergone transplantation. Methods.-The presence of BKV infection was demonstrated by means of histolo gy, immunohistochemistry with polyclonal anti-SV40 antibody, immunoelectron microscopy, polymerase chain reaction, and enzymatic cleavage with BamHI. Results.-Histologic examination revealed interstitial inflammatory infiltra tes and tubules with enlarged and eosinophilic nuclei. Conclusions.-The high frequency of latent BKV infection and its reactivatio n during immunosuppression suggest that the possibility of its involvement in renal damage should be considered in immunocompromised patients.