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JCI Insight ; 7(9)2022 May 09.
Article in English | MEDLINE | ID: covidwho-1765224


Transplant recipients exhibit an impaired protective immunity after SARS-CoV-2 vaccination, potentially caused by mycophenolate (MPA) immunosuppression. Recent data from patients with autoimmune disorders suggest that temporary MPA hold might greatly improve booster vaccination outcomes. We applied a fourth dose of SARS-CoV-2 vaccine to 29 kidney transplant recipients during a temporary (5 weeks) MPA/azathioprine hold, who had not mounted a humoral immune response to previous vaccinations. Seroconversion until day 32 after vaccination was observed in 76% of patients, associated with acquisition of virus-neutralizing capacity. Interestingly, 21/25 (84%) calcineurin inhibitor-treated patients responded, but only 1/4 belatacept-treated patients responded. In line with humoral responses, counts and relative frequencies of spike receptor binding domain-specific (RBD-specific) B cells were markedly increased on day 7 after vaccination, with an increase in RBD-specific CD27++CD38+ plasmablasts. Whereas overall proportions of spike-reactive CD4+ T cells remained unaltered after the fourth dose, frequencies were positively correlated with specific IgG levels. Importantly, antigen-specific proliferating Ki67+ and in vivo-activated programmed cell death 1-positive T cells significantly increased after revaccination during MPA hold, whereas cytokine production and memory differentiation remained unaffected. In summary, antimetabolite hold augmented all arms of immunity during booster vaccination. These data suggest further studies of antimetabolite hold in kidney transplant recipients.

Antimetabolites , COVID-19 Vaccines , COVID-19 , Kidney Transplantation , Antibodies, Viral , Antimetabolites/therapeutic use , COVID-19/prevention & control , COVID-19 Vaccines/immunology , Humans , Immunity, Cellular , Immunity, Humoral , Immunosuppressive Agents/therapeutic use , SARS-CoV-2 , Transplant Recipients , Vaccination
J Am Soc Nephrol ; 32(3): 708-722, 2021 03.
Article in English | MEDLINE | ID: covidwho-1496675


BACKGROUND: Late antibody-mediated rejection (ABMR) is a leading cause of transplant failure. Blocking IL-6 has been proposed as a promising therapeutic strategy. METHODS: We performed a phase 2 randomized pilot trial to evaluate the safety (primary endpoint) and efficacy (secondary endpoint analysis) of the anti-IL-6 antibody clazakizumab in late ABMR. The trial included 20 kidney transplant recipients with donor-specific, antibody-positive ABMR ≥365 days post-transplantation. Patients were randomized 1:1 to receive 25 mg clazakizumab or placebo (4-weekly subcutaneous injections) for 12 weeks (part A), followed by a 40-week open-label extension (part B), during which time all participants received clazakizumab. RESULTS: Five (25%) patients under active treatment developed serious infectious events, and two (10%) developed diverticular disease complications, leading to trial withdrawal. Those receiving clazakizumab displayed significantly decreased donor-specific antibodies and, on prolonged treatment, modulated rejection-related gene-expression patterns. In 18 patients, allograft biopsies after 51 weeks revealed a negative molecular ABMR score in seven (38.9%), disappearance of capillary C4d deposits in five (27.8%), and resolution of morphologic ABMR activity in four (22.2%). Although proteinuria remained stable, the mean eGFR decline during part A was slower with clazakizumab compared with placebo (-0.96; 95% confidence interval [95% CI], -1.96 to 0.03 versus -2.43; 95% CI, -3.40 to -1.46 ml/min per 1.73 m2 per month, respectively, P=0.04). During part B, the slope of eGFR decline for patients who were switched from placebo to clazakizumab improved and no longer differed significantly from patients initially allocated to clazakizumab. CONCLUSIONS: Although safety data indicate the need for careful patient selection and monitoring, our preliminary efficacy results suggest a potentially beneficial effect of clazakizumab on ABMR activity and progression.

Antibodies, Monoclonal, Humanized/therapeutic use , Graft Rejection/therapy , Interleukin-6/antagonists & inhibitors , Kidney Transplantation/adverse effects , Adult , Allografts , Antibodies, Monoclonal, Humanized/adverse effects , Double-Blind Method , Female , Glomerular Filtration Rate , Graft Rejection/immunology , Graft Rejection/physiopathology , Humans , Infections/etiology , Interleukin-6/immunology , Isoantibodies/blood , Male , Middle Aged , Tissue Donors , Treatment Outcome , Young Adult
J Clin Invest ; 131(14)2021 07 15.
Article in English | MEDLINE | ID: covidwho-1311203


Novel mRNA-based vaccines have been proven to be powerful tools in combating the global pandemic caused by SARS-CoV-2, with BNT162b2 (trade name: Comirnaty) efficiently protecting individuals from COVID-19 across a broad age range. Still, it remains largely unknown how renal insufficiency and immunosuppressive medication affect development of vaccine-induced immunity. We therefore comprehensively analyzed humoral and cellular responses in kidney transplant recipients after the standard second vaccination dose. As opposed to all healthy vaccinees and the majority of hemodialysis patients, only 4 of 39 and 1 of 39 transplanted individuals showed IgA and IgG seroconversion at day 8 ± 1 after booster immunization, with minor changes until day 23 ± 5, respectively. Although most transplanted patients mounted spike-specific T helper cell responses, frequencies were significantly reduced compared with those in controls and dialysis patients and this was accompanied by a broad impairment in effector cytokine production, memory differentiation, and activation-related signatures. Spike-specific CD8+ T cell responses were less abundant than their CD4+ counterparts in healthy controls and hemodialysis patients and almost undetectable in transplant patients. Promotion of anti-HLA antibodies or acute rejection was not detected after vaccination. In summary, our data strongly suggest revised vaccination approaches in immunosuppressed patients, including individual immune monitoring for protection of this vulnerable group at risk of developing severe COVID-19.

COVID-19 Vaccines/administration & dosage , COVID-19/immunology , COVID-19/prevention & control , Kidney Transplantation/adverse effects , SARS-CoV-2 , Adult , Aged , Antibodies, Viral/biosynthesis , COVID-19 Vaccines/immunology , Case-Control Studies , Cohort Studies , Cytokines/immunology , Female , Humans , Immunity, Cellular , Immunity, Humoral , Immunization, Secondary , Immunoglobulin A/biosynthesis , Immunoglobulin G/biosynthesis , Immunologic Memory , Immunosuppressive Agents/adverse effects , Lymphocyte Activation , Male , Middle Aged , Monitoring, Immunologic , Renal Dialysis/adverse effects , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes/immunology , Transplantation Immunology