Increasing of the interferon-γ gene expression during polyomavirus BK infection in kidney transplant patients

Polyomavirus BK infection is a common complication and a major cause of morbidity after kidney transplantation. Surveillance of kidney transplant recipients was threatened by reactivation of polyomavirus BK infection can lead to polyomavirus BK-associated nephropathy (PVN). Antiviral immunoregulatory markers like Gamma interferon (IFN-γ) might also affect the polyomavirus BK pathogenesis for its role in antiviral host defense, graft rejection, and regulative of the adaptive immune responses. After screening polyomavirus BK infection, using Real time PCR (Taq-Man), the possible association between polyomavirus BK infection with IFN-γ gene expression was assessed. The mRNA levels of IFN-γ was examined in (n = 23) polyomavirus BK infected and (n = 23) non-infected kidney transplant patients in comparison with healthy controls (n = 23), using an in-house Real time PCR (SYBR Green) assay. The correlation of IFN-γ expression with viral load as well as other variables was also performed. The mRNA expression level of IFN-γ was significantly higher in polyomavirus BK infected patients (fold = 58.47) compared with non-infected ones (fold = 4.62), and healthy controls (p = 0.002). IFN-γ expression was higher in patients with higher viral load (p = 0.001). IFN-γ expression was correlated with viral load (r = 0.7, p < 0.0001). Accordingly, polyomavirus BK infection can induce IFN-γ gene over expression in kidney transplant infected patients. The results emphasized on the determinative role of IFN-γ in the pathogenesis of activated polyomavirus BK infection and also its importance in managing the clinical complications after kidney transplantation due to virus reactivation, requiring further investigation.