Browsing by Author "Ulloa, Camilo"
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Publication A Third Dose of SARS-CoV-2 mRNA Vaccine Improves Immune Response in Chronic Kidney Disease Patients(2023) Poli Harlowe, María Cecilia; Vial Cox, María Cecilia; Rey, Emma; González, Natalia; Cortés, Lina; Hormazabal, Juan; Ramírez, Carolina; De la Cruz, Javiera; Ulloa, CamiloChronic kidney disease (CKD) patients have an increased risk of morbidity and mortality following SARS-CoV-2 infection. Vaccination in these patients is prioritized, and monitoring of the immune response is paramount to define further vaccination strategies. This prospective study included a cohort of 100 adult CKD patients: 48 with kidney transplant (KT) and 52 on hemodialysis without prior COVID-19. The patients were assessed for humoral and cellular immune responses after four months of an anti-SARS-CoV-2 primary two-dose vaccination scheme (CoronaVac or BNT162b2) and one month after a booster third dose of BNT162b2 vaccine. We identified poor cellular and humoral immune responses in the CKD patients after a primary vaccination scheme, and these responses were improved by a booster. Robust polyfunctional CD4+ T cell responses were observed in the KT patients after a booster, and this could be attributed to a higher proportion of the patients having been vaccinated with homologous BNT162b2 schemes. However, even after the booster, the KT patients exhibited lower neutralizing antibodies, attributable to specific immunosuppressive treatments. Four patients suffered severe COVID-19 despite three-dose vaccination, and all had low polyfunctional T-cell responses, underscoring the importance of this functional subset in viral protection. In conclusion, a booster dose of SARS-CoV-2 mRNA vaccine in CKD patients improves the impaired humoral and cellular immune responses observed after a primary vaccination scheme.Item Conversion From Calcineurin Inhibitors to Belatacept in HLA-sensitized Kidney Transplant Recipients With Low-level Donor-specific Antibodies(2019) Ulloa, Camilo; Anglicheau, Dany; Snanoudj, Renaud; Scemla, Anne; Martinez, Frank; Timsit, Marc-Olivier; Legendre, Christophe; Sberro, RebeccaBackground: Belatacept could be the treatment of choice in renal-transplant recipients with renal dysfunction attributed to calcineurin inhibitor (CNI) nephrotoxicity. Few studies have described its use in patients with donor-specific antibody (DSA). Methods: We retrospectively evaluated conversion from CNIs to belatacept in 29 human leukocyte antigen-immunized renal-transplant recipients. Data about acute rejection, DSA, and renal function were collected. These patients were compared with 42 nonimmunized patients treated with belatacept. Results: Patients were converted from CNIs to belatacept a median of 444 days (interquartile range, 85-1200) after transplantation and were followed up after belatacept conversion, for a median of 308 days (interquartile range, 125-511). At conversion, 16 patients had DSA. Nineteen DSA were observed in these 16 patients, of which 11/19 were <1000 mean fluorescence intensity (MFI), 7/19 were between 1000 and 3000 MFI, and one was >3000 MFI. At last follow-up, preexisting DSA had decreased or stabilized. Seven patients still had DSA with a mean MFI of 1298 ± 930 at the last follow-up. No patient developed a de novo DSA in the DSA-positive group. In the nonimmunized group, one patient developed de novo DSA (A24-MFI 970; biopsy for cause did not show biopsy-proven acute rejection or microinflammation score). After belatacept conversion, one antibody-mediated rejection was diagnosed. The mean estimated glomerular filtration rate improved from 31.7 ± 14.2 mL/min/1.73 m to 40.7 ± 12.3 mL/min/1.73 m (P < 0.0001) at 12 months after conversion. We did not find any significant difference between groups in terms of renal function, proteinuria, or biopsy-proven acute rejection. Conclusions: We report on a safe conversion to belatacept in human leukocyte antigen-immunized patients with low DSA levels.