No abstract

The description of protective humoral and T cell immune responses specific against SARS‐CoV‐2 has been reported among immunocompetent (IC) individuals developing COVID‐19 infection. However, its characterization and determinants of poorer outcomes among the at‐risk solid organ transplant (SOT) patient population have not been thoroughly investigated. Cytokine‐producing T cell responses, such as IFN‐γ, IL‐2, IFN‐γ/IL‐2, IL‐6, IL‐21, and IL‐5, against main immunogenic SARS‐CoV‐2 antigens and IgM/IgG serological immunity were tracked in SOT (n = 28) during acute infection and at two consecutive time points over the following 40 days of convalescence and were compared to matched IC (n = 16) patients admitted with similar moderate/severe COVID‐19. We describe the development of a robust serological and functional T cell immune responses against SARS‐CoV‐2 among SOT patients, similar to IC patients during early convalescence. However, at the infection onset, SOT displayed lower IgG seroconversion rates (77% vs. 100%; p = .044), despite no differences on IgG titers, and a trend toward decreased SARS‐CoV‐2‐reactive T cell frequencies, especially against the membrane protein (7 [0–34] vs. 113 [15–245], p = .011, 2 [0–9] vs. 45 [5–74], p = .009, and 0 [0–2] vs. 13 [1–24], p = .020, IFN‐γ, IL‐2, and IFN‐γ/IL‐2 spots, respectively). In summary, our data suggest that despite a certain initial delay, SOT population achieve comparable functional immune responses than the general population after moderate/severe COVID‐19.

Background We analyzed the prevalence, etiology, and risk factors of culture-positive preservation fluid and their impact on the management of solid organ transplant recipients. Methods From July 2015 to March 2017, 622 episodes of adult solid organ transplants at 7 university hospitals in Spain were prospectively included in the study. Results The prevalence of culture-positive preservation fluid was 62.5% (389/622). Nevertheless, in only 25.2% (98/389) of the cases were the isolates considered “high risk” for pathogenicity. After applying a multivariate regression analysis, advanced donor age was the main associated factor for having culture-positive preservation fluid for high-risk microorganisms. Preemptive antibiotic therapy was given to 19.8% (77/389) of the cases. The incidence rate of preservation fluid–related infection was 1.3% (5 recipients); none of these patients had received preemptive therapy. Solid organ transplant (SOT) recipients with high-risk culture-positive preservation fluid receiving preemptive antibiotic therapy presented both a lower cumulative incidence of infection and a lower rate of acute rejection and graft loss compared with those who did not have high-risk culture-positive preservation fluid. After adjusting for age, sex, type of transplant, and prior graft rejection, preemptive antibiotic therapy remained a significant protective factor for 90-day infection. Conclusions The routine culture of preservation fluid may be considered a tool that provides information about the contamination of the transplanted organ. Preemptive therapy for SOT recipients with high-risk culture-positive preservation fluid may be useful to avoid preservation fluid–related infections and improve the outcomes of infection, graft loss, and graft rejection in transplant patients.