DNA VIRAL INFECTIONS ASSAY IN KIDNEY TRANSPLANT RECIPIENTS BY A NEW HIGH THROUGHPUT MASS SPECTROMETRY METHOD

Introduction: Infections represent a major complication after renal transplant with an important impact on allograft survival and outcome. Polyomaviruses (PyVs), a group of small and circular dsDNA viruses, mediate a broad spectrum of diseases in immune-compromised patients. NF-jB (nuclear factor kappalight-chain-enhancer of activated B cells) is a key regulator of immune and inflammatory responses and the -94ins/delATTG (rs28362491) polymorphism in the gene promoter has been widely investigated for clinical associations. To date, rs28362491 has been shown to influence the susceptibility to systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease and recently renal transplant rejection. Materials and Methods: We developed a high throughput mass spectrometry (MS)-based method to detect rs28362491 and 18 Py vs. types. Primer pairs of MS assay were designed within the specific large T antigen genes. Viral and human DNAs were extracted from blood samples of 43 kidney transplant recipients, before and after transplantation. Results: We analysed the correlation among Py vs. infections, rs28362491 genotype and post-transplant follow up. Five out of the 18 viral types tested were found in the specimens analysed: BKV, JCV, Merkel cell PyV, Human PyV6 and SV12. In our cohort, 14 patients showed SV12 infection: 10 cases were -94ins/-94ins, 4 were -94ins/-94del. All the patients with the NF-kB-94del/- 94del genotype were characterized by the absence of SV12 strain. No correlation between genotype and viral infection was observed for the other viral types. Conclusions: Our MS assay improved the Py vs. typing and allowed to drive towards the identification of novel biomarkers for the infective management of transplanted patients. The genetic background might modulate the viral infection susceptibility in renal transplant recipients.