ImportanceAutoimmune disorders can affect various organs and if refractory, can be life threatening. Recently, CD19-targeting–chimeric antigen receptor (CAR) T cells were efficacious as an immune suppressive agent in 6 patients with refractory systemic lupus erythematosus and in 1 patient with antisynthetase syndrome.ObjectiveTo test the safety and efficacy of CD19-targeting CAR T cells in a patient with severe antisynthetase syndrome, a complex autoimmune disorder with evidence for B- and T-cell involvement.Design, Setting, and ParticipantsThis case report describes a patient with antisynthetase syndrome with progressive myositis and interstitial lung disease refractory to available therapies (including rituximab and azathioprine), who was treated with CD19-targeting CAR T cells in June 2022 at University Hospital Tübingen in Tübingen, Germany, with the last follow-up in February 2023. Mycophenolate mofetil was added to the treatment to cotarget CD8+ T cells, hypothesized to contribute to disease activity.ExposurePrior to treatment with CD19-targeting CAR T cells, the patient received conditioning therapy with fludarabine (25 mg/m2 [5 days before until 3 days before]) and cyclophosphamide (1000 mg/m2 [3 days before]) followed by infusion of CAR T cells (1.23×106/kg [manufactured by transduction of autologous T cells with a CD19 lentiviral vector and amplification in the CliniMACS Prodigy system]) and mycophenolate mofetil (2 g/d) 35 days after CD19-targeting CAR T-cell infusion.Main Outcomes and MeasuresThe patient’s response to therapy was followed by magnetic resonance imaging of the thigh muscle, Physician Global Assessment, functional muscle and pulmonary tests, and peripheral blood quantification of anti-Jo-1 antibody levels, lymphocyte subsets, immunoglobulins, and serological muscle enzymes.ResultsRapid clinical improvement was observed after CD19-targeting CAR T-cell infusion. Eight months after treatment, the patient’s scores on the Physician Global Assessment and muscle and pulmonary function tests improved, and there were no detectable signs of myositis on magnetic resonance imaging. Serological muscle enzymes (alanine aminotransferase, aspartate aminotransferase, creatinine kinase, and lactate dehydrogenase), CD8+ T-cell subsets, and inflammatory cytokine secretion in the peripheral blood mononuclear cells (interferon gamma, interleukin 1 [IL-1], IL-6, and IL-13) were all normalized. Further, there was a reduction in anti-Jo-1 antibody levels and a partial recovery of IgA (to 67% of normal value), IgG (to 87%), and IgM (to 58%).Conclusions and RelevanceCD19-targeting CAR T cells directed against B cells and plasmablasts deeply reset B-cell immunity. Together with mycophenolate mofetil, CD19-targeting CAR T cells may break pathologic B-cell, as well as T-cell responses, inducing remission in refractory antisynthetase syndrome.

Therapy resistant viral reactivations significantly contribute to mortality after hematopoietic stem cell transplantation. Adoptive cellular therapy with virus-specific T cells has shown efficacy in various single center trials. However, scalability of this therapy is hampered by laborious production methods. In this study we describe the in-house production of virus-specific T cells (VST) in a closed system (CliniMACS Prodigy® system by Miltenyi Biotec). In addition, we report the efficacy in 26 patients with viral disease post HSCT in a retrospective analysis (ADV n=7, CMV n=8, EBV n=4, multi-viral n=7). Production of VST was successful in 100% of cases. Safety profile of VST therapy was favorable (n=2 adverse event grade 3, n=1 grade 4; all three were reversible). A response was seen in 20 of 26 patients (77%). Responding patients had a significantly better OS than patients without response (p

The PI3Kδ-inhibitor Idelalisib is approved for the treatment of Non-Hodgkin lymphoma. However, its use has been decreased within the last years due to deleterious infections such as cytomegalovirus and pneumocystis jirovecii. Here, we have investigated the effect of Idelalisib on human monocyte-derived dendritic cells (DCs) as important players in the induction of immune responses. We found that Idelalisib-treated DCs displayed impaired T cell stimulatory function. PI3Kδ inhibition during differentiation resulted in decreased Interleukin-12, Interleukin-13 and TNFα production by DCs after lipopolysaccharide stimulation. Moreover, DCs showed decreased expression of the activation marker CD83 after Idelalisib treatment. Further, in line with this was the failure of Idelalisib-treated DCs to properly induce allogeneic T cells in a dose-dependent manner. Finally, activation of the NFκB pathway was also ablated in Idelalisib-treated DCs. Our results implicate that severe infectious complications may not only result from direct PI3Kδ-inhibition in T cells, but also from impaired DC function in Idelalisib-treated patients. Here, we provide new insight into the pathogenesis of Idelalisib-associated infectious complications. Our study may further provide a rationale for the use of Idelalisib as a novel therapeutic option in inflammatory diseases.

Adenovirus infection (ADV) after allogeneic hematopoietic stem cell transplantation (HSCT) is an emerging pathogen causing relevant morbidity and mortality, with preponderance in children. Since a sufficient host T-cell response has been shown essential to clear the virus, diagnostic procedures for detection of virus-specific T-cells have recently developed to asses the specific cellular immune response. Furthermore adoptive immunotherapy is a new treatment option for patients with absent specific T-cell response and present systemic adenoviral infection. The possibility of an adoptive T-cell transfer depends on the availability of GMP compatible protocols and reagents. The adenoviral hexon protein was shown a immunodominant T-cell target within the viral capsid. In the present study we investigate the presence of Hexon-specific T-cell responses in HSCT donors, i.e. the availability of donors for an adoptive T-cell transfer. Secondly, the emergence of Hexon-specific T-cells in recipients post HSCT was analyzed. Thirdly, a protocol was established under GMP-conditions for adoptive T-cell immunotherapy through isolation of IFN-γ secreting T-cells after ex-vivo stimulation with the adenoviral Hexon protein. This procedure resulted in a mixed population of CD4 and CD8 positive T-cells with an effector memory phenotype and Th1 cytokine pattern (n=8). Isolated Hexon-specific T-cells show a strong expansion potential in vitro as well as specific cytotoxic activity. The availability of a donor was evaluated in 76 HSCT donors. Only 17.1% of donors had no ADV-specific T-cell response and 72.4% of donors were eligible for an adoptive T-cell transfer using the presented approach. The Hexon protein was responsible for almost the complete response to ADV, since no significant difference was seen against ADV lysate and the Hexon protein. In 76% HSCT recipients Hexon directed T-cell responses were evaluated and were shown to be responsible for clearance of the viral infection. In conclusion feasibility of an adoptive T-cell transfer for the treatment of ADV infection post HSCT is shown in accordance to current GMP regulations.