Lack of evidence of association between IFNG and IL28B polymorphisms and QuantiFERON-CMV test results in seropositive transplant patients

The aim of this study was to analyze the relationship between the IFNG +874 T/A and IL28B (rs12979860) C/T polymorphisms and the secretion of IFNG by CD8+ T cells after stimulation with cytomegalovirus (CMV) peptides, measured using QuantiFERON-CMV (QF-CMV) assay. A total of 184 CMV-seropositive solid organ transplant patients (108 kidney, 68 liver and 8 lung) were recruited. Of them, 151 patients were QF-CMV Reactive (IFNG ≥ 0.2 UI/mL) and 33 were Non-reactive. Genotype frequencies in the study population were TT (26.6%), AT (50.0%) and AA (23.4%) for IFNG +874 and CC (52.7%), CT (39.1%) and TT (8.2%) for IL28B (rs12979860). These frequencies did not significantly differ between QF-CMV Reactive and Non-reactive patients. Nor were any significant differences observed in the quantitative IFNG level among the genotypes in either the IFNG or the IL28 genes. When we analyzed whether these polymorphisms had any impact on the risk of CMV replication after transplantation, the adjusted analysis showed no association. In summary, our results showed that IFNG +874 T/A and IL28B (rs12979860) C/T polymorphisms are not associated with the IFNG response to CMV measured by the QuantiFERON-CMV assay, although these results should be confirmed with a higher number of patients.