Immune Function Assay (Immunknow) Drop Over First 6 Months After Renal Transplant: A Predictor of Opportunistic Viral Infections?

Abstract Background The Immuknow assay (IKA; Cylex) is a T-cell immune function assay that evaluates immunoreactivity in immunocompromised patients. The aim of this study was to analyze IKA values in a cohort of kidney transplantation (KT) recipients to investigate correlations between single–time point low IKA values and their trend over time with cytomegalovirus (CMV) or BK virus (BKV) reactivation. Methods A total of 118 adult patients receiving deceased-donor KT were enrolled (55.6 ± 11.9 years old; 79 [66.9%] male). IKA CMV and BKV viremia determinations and were performed at months 1, 3, and 6 after surgery. Results Overall, 272 IKA determinations were performed: IKA values significantly decreased from month 1 (422 ± 184 ng/mL) to month 3 (330 ± 159 ng/mL; P P  = .030). IKA values did not correlate with renal function or viral reactivation at any time. However, patients with either CMV or BKV viremia had a trend to higher IKA values at month 1 and lower IKA values at month 6, even if the difference did not reach a statistical significance ( P  = .115). Conclusions Our study suggests that presence of low immunologic reactivity (IKA