Clinicopathologic characteristics and outcome of JC virus-associated nephropathy in renal transplantation(4 cases report)

Abstract

Objective JC virus (JCV) infection is more common than BK virus (BKV) in general population. Systematic studies on the characteristics of JC virus nephropathy (JCVN) in renal transplant recipients are lacking. Therefore, we summarize 4 cases of JCVN in renal transplant recipients, which were diagnosed in our center in recent 10 years. Methods 165 cases of polyomavirus nephropathy (PVN) were diagnosed in our center from 2007 to 2017. Four cases of JCVN were diagnosed through the negative BKV but high JCV load in urine or blood, and positive SV40-T in the biopsy samples. Meanwhile, clinicopathological data were collected. Results At pathological diagnosis documented (87±41 months after transplantation): the median levels of urinary decoy cells and JCV DNA in urine were 1/10 HPF and 5.35×108 copies/mL, respectively; only one patient's JC viremia was positive with 327 copies/mL. The mean level of serum creatinine (Scr) was 144 μmol/L, and the mean level of 24-h urinary protein was 0.94 g. Immunohistological staining showed SV40-T positive region of the 4 cases were all in the renal medulla. Other coexisting pathological features included IgA nephropathy in 2 patients, and suspicious chronic active antibody mediated rejection in one patients. In the latest follow-up, 1 recipient got graft dysfunction while the others were in good function, the mean level of serum creatinine was 134 μmol/L. Conclusion The difference between BK virus nephropathy and JCVN is that most of the JCVN are diagnosed in the late stage after kidney transplantation, the level of serum creatinine is not so high, viremia is very rare, and virus-induced graft injury is not so significant. The overall prognosis of JCVN is relatively good. Key words: Kidney transplantation; JC virus; BK virus; Polyomavirus nephropathy