RT info:eu-repo/semantics/article T1 Optimizing a Protocol to Assess Immune Responses after SARS-CoV-2 Vaccination in Kidney-Transplanted Patients: In Vivo DTH Cutaneous Test as the Initial Screening Method A1 Barrios del Pino, Yvelise A1 Rodriguez, Aurelio A1 Franco, Andrés A1 Alava-Cruz, Cristina A1 Marrero-Miranda, Domingo A1 Perez-Tamajon, Lourdes A1 Matheu, Victor AB Previously, the delayed-type hypersensitivity (DTH) cutaneous test with the spike proteinof SARS-CoV-2 has been shown to be a simple in vivo method to measure T-cell functionality afternatural infection and in vaccinated individuals. Methods: Twenty-five kidney-transplanted recipientswere immunized with two doses of the mRNA-based Pfizer–BioNTech COVID19 vaccine three weeksapart. Cell-immune response (CIR) was evaluated ten weeks later using an in vivo DTH skin testand in vitro with an interferon gamma release assay (IGRA). Humoral Immune Response (HIR)was determined by the measurement of specific IgG anti-S1 SARS-CoV-2. Results: Ten weeks afterthe second dose of the vaccine, 23 out of 25 transplanted patients had a positive DTH skin test,while in vitro CIR was considered positive in 20 patients. Unspecific stimulation was positive inall 25 patients, showing no T-cell defect. Seven out of twenty-five patients had a negative specificanti-spike IgG. CIR was positive in all immune-competent control patients. Conclusions: DTH is auseful, simple, and cheaper tool that can be used to assess cellular immune response, with an excellentcorrelation with the in vitro CIR. CIR assessment after vaccination in these immunocompromisedpatients is an excellent complement to HIR-based methods. This skin test could be used if classicalin vitro methods cannot be applied SN 2076-393X YR 2021 FD 2021 LK http://riull.ull.es/xmlui/handle/915/34890 UL http://riull.ull.es/xmlui/handle/915/34890 LA en DS Repositorio institucional de la Universidad de La Laguna RD 16-jun-2024