ABSTRACT
Blood transfusions, pregnancies and previous organ transplantation can cause immunization. Infection and vaccination could alter the recipient sensitization status. Here we evaluated COVID-19 vaccination effect on presensitization status of Pancreas/Renal-Pancreas waitlisted patients in Pisa Hospital (Italy). We enrolled 27 patients (15 female and 12 male) which received a complete vaccination cycle (CVC) of COVID-19 mRNA vaccines (BNT162b2-Pfizer/BioNTech or mRNA-1273-Moderna);15/27 patients received third dose (booster). X-MAP technology (Luminex-beads) was used to identify class I and II anti-HLA antibody specificity. The population was studied before vaccination (BV) and 2 weeks after CVC and booster. Sensitivity status change (qualitative analysis) and mean fluorescence intensity (MFI) changes (semi-quantitative analysis) were calculated by Excel using specific functions created “ad hoc”: AntigenDifference() and AntigenValueSum(). We observed new specificities after CVC in 11/27 patients: class I (29%), class II (33%) and class I + II (22%);after the booster class I, class II and class I + II increased by 35%, 50% and 28%, respectively. No statistically significant differences were observed in the MFI mean value between CVC, booster and BV group (p > 0.05, Mann-Whitney U test). COVID-19 vaccination could induce changes in the percentage of circulating antibodies directed against HLA and should be considered in the pre-transplant risk assessment.