Role of HLA matching and donor specific antibody development in long-term survival, acute rejection and cardiac allograft vasculopathy.

Although there are different data supporting benefits of HLA matching in kidney transplantation, its role in heart transplantation is still unclear. HLA mismatch (MM) between donor and recipient can lead to the development of donor-specific antibodies (DSA) which produces negative events on the outcome of heart transplantation. Moreover, DSAs are involved in the development of antibody-mediated rejection (AMR) and are associated with an increase in cardiac allograft vasculopathy (CAV). In this study it is analyzed retrospectively the influence of HLA matching and anti-HLA antibodies on overall survival, AMR and CAV in heart transplantation. For this retrospective study are recruited heart transplanted patients at the Cardiac Transplantation Centre of Naples between 2000 and 2019. Among the 155 heart transplant patients, the mean number of HLA-A, B, -DR MM (0 to 6) between donor and recipient was 4.5 ± 1.1. The results show a negative association between MM HLA-DR and survival (p = 0.01). Comparison of patients with 0-1 MM at each locus to all others with 2 MM, for both HLA class I and class II, has not showed significant differences in the development of CAV. Our analysis detected DSA in 38.1% of patients. The production of de novo DSA reveals that there is not an influence on survival (p = 0.72) and/or AMR (p = 0.39). Instead, there is an association between the production of DSA class II and the probability of CAV development (p = 0.03). Mean fluorescence intensity (MFI) values were significantly higher in CAV-positive patients that CAV-negative patients (p = 0.02). Prospective studies are needed to evaluate HLA class II matching as an additional parameter for heart allocation, especially considering the increment of waiting list time.

Reduced levels of hepcidin associated with lower ferritin concentration and increased number of previous donations in periodic blood donors: A pilot study.

BACKGROUND: Hepcidin is one of the major negative regulators of iron balance. Periodic blood donors are highly susceptible to iron deficiency. Our goal was to evaluate the possible association between serum hepcidin levels and iron homeostasis parameters in periodic blood donors. MATERIALS AND METHODS: We enrolled a total of n = 39 periodic healthy blood donors (n = 24 M and n = 15 F). A solid phase enzyme-linked immunosorbent assay (ELISA) was performed to measure endogenous hepcidin-25 levels in serum biospecimens collected from each study participant. Statistical analysis evaluated possible associations between hepcidin levels and ferritin, transferrin, total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC), transferrin saturation (TSAT), and number of previous donations. RESULTS: Reduced serum hepcidin levels significantly correlated with lower ferritin concentration (r = 0.56, IC 95%: 0.51-0.60, p < 0.01). A multiple linear regression analysis showed that hepcidin levels were independently and negatively correlated with ferritin (p < 0.01). In addition, the number of previous blood donations was significantly associated with reduced hepcidin levels, independently of the other covariates (p < 0.01). CONCLUSION: Reduced serum hepcidin levels were significantly associated with reduced levels of ferritin and with increased number of previous donations suggesting its possible clinical role as non-invasive "point-of-care" in predicting iron deficiency among periodic blood donors.

Novel insights in the clinical management of hyperimmune patients before and after transplantation.

Despite improvements in anti-Human Leucocyte Antigens antibody detection, identification, and characterization offer a better in peri-operative management techniques, antibodies remain a serious cause of morbidity and mortality for patients both before and after organ transplantation. Hyperimmune patients are disadvantaged by having to wait longer to receive an organ from a suitably matched donor. They could benefit from desensitization protocols in both pre- and post-transplantation period. Clinical studies are underway to highlight which best desensitization strategies could be assure the best outcome in both heart and kidney transplantation. Although most clinical evidence about desensitization strategies by using anti-CD20 monoclonal antibodies, proteasome inhibitors, anti-CD38 monoclonal antibodies, interleukin-6 blockade, cysteine protease and complement inhibitors, comes from kidney transplantation studies, many of the debated novel concepts can be easily applied to desensitization also in heart transplantation. Here, we discuss the candidates and recipients' management by using most common standard of care and novel therapeutics, desensitization endpoints, and strategies for future studies.

Evaluation of circulating leucocyte populations both in subjects with previous SARS-COV-2 infection and in healthy subjects after vaccination.

Innate immune mechanisms are central players in response to the binding of pathogens to pattern-recognition receptors providing a crucial initial block on viral replication. Moreover, innate immune response mobilizes cells of the cellular-mediated immune system, which develop into effector cells that promote viral clearance. Here, we observed circulating leukocyte T cell response in healthy subjects, COVID-19 infected, and in healthy vaccinated subjects. We found a significant CD8+ T cells (p < 0,05) decrease and an augmented CD4+/CD8+ ratio (p < 0,05) in COVID-19 infected group compared with vaccinated subjects. In addition, healthy vaccinated subjects have a significant increased expression of CD8+ T cells, and a reduction of CD4+/CD8+ ratio with respect to subjects previously COVID-19 infected. Central Memory and Terminal Effector Memory cells (TEMRA) increased after vaccine but not among groups.