Associations of high anti-CMV IgG titer with renal function decline and allograft rejection in kidney transplant patients.

Background: An anti-cytomegalovirus (CMV) immunoglobulin G (IgG) antibody is produced after primary CMV infection and generally persists after the primary infection. However, it is not well-known about the relationship between anti-CMV IgG titer and outcomes in kidney transplant recipients. We, therefore, aimed to explore the role of anti-CMV IgG titer on the risks of CMV disease development, allograft rejection, renal function decline, and mortality.

Methods: In a hospital-based study, we identified 179 CMV-seropositive kidney transplant recipients between January 2013 and December 2017. These patients were divided into low and high anti-CMV IgG titer groups, respectively. The cutoff level of anti-CMV IgG titer was determined by receiver operating characteristic curve analysis. The outcomes evaluated included CMV disease, decrease of ≥15% in estimated glomerular filtration rate (eGFR), biopsy-proven allograft rejection, and all-cause mortality.

Results: The high anti-CMV IgG titer group (≥846.2 AU/mL) exhibited a higher risk of CMV disease (adjusted hazard ratio [aHR], 3.77; 95% CI, 1.47-9.68; p = 0.006), eGFR decline ≥15% (aHR, 2.00; 95% CI, 1.19-3.35; p = 0.009), and renal allograft rejection (aHR, 2.95; 95% CI, 1.11-7.87; p = 0.030) than the low titer group (<846.2 AU/mL).

Conclusion: In kidney transplant recipients, a high anti-CMV IgG titer was associated with higher risks for developing CMV disease, undergoing allograft rejection, and eGFR decline.