Multicenter Prospective Study for Laboratory Diagnosis of HHV8 Infection in Solid Organ Donors and Transplant Recipients and Evaluation of the Clinical Impact after Transplantation

Background We performed serological and molecular pretransplant screening in solid organ transplant (SOT) donors and recipients in north central Italy and a surveillance program for human herpesvirus 8 (HHV8) infection after transplant, aiming to establish an optimal management of HHV8 infection in SOT recipients. Methods For pretransplant HHV8 screening in both donors and recipients, 6 serological (4 indirect immunofluorescent assays [IFA] and 2 enzyme-linked immunosorbent assays-both HHV8 lytic and latent antigen based) and 2 molecular assays were used. A reference standard to identify HHV8-positive patients was defined by at least 2 positive assays. All transplant patients at risk to develop HHV8-related disease underwent virological posttransplant monitoring by quantitative real-time polymerase chain reaction (PCR) assay. Results Human herpesvirus 8 seroprevalence was 4% (10/249) in donors and 18% (93/517) in organ recipients. The best performance was obtained by 2 lytic antigen-based IFAs that showed almost perfect agreement to the reference standard (0.943 and 0.931 Cohen kappa). Human herpesvirus 8-DNA was detected in 6.8% and 2.9% of HHV8-seropositive donor samples by in-house nested PCR and quantitative real-time PCR assays, respectively. After transplant, 3 (25%) of 12 HHV8-mismatch patients (seropositive donor/seronegative recipient) developed a primary infection, one of whom developed a lethal nonmalignant illness. Two of 93 HHV8-seropositive recipients (2.1%) had viral replication in posttransplant period, one of whom developed Kaposi sarcoma. Conclusions Serological assays, specifically lytic IFAs, were the best methodological approach to identify HHV8-infected SOT donors and recipients. A very low incidence (1.9%) of posttransplant HHV8-related disease was observed.