Ustekinumab in bio-naïve and bio-failure Crohn's disease patients: Results from a « real-life ¼ monocentric cohort.

BACKGROUND: The pivotal clinical trials have largely demonstrated the efficacy and safety of ustekinumab in Crohn's disease. Real-life cohorts published so far only include very few bio-naïve patients. This study assesses effectiveness and safety of ustekinumab in bio-naïve and bio-failure patients treated with ustekinumab in routine practice and look for predictors of response. METHODS: We performed a retrospective monocentric study. Initial response was assessed by maintenance therapy beyond week 16. Sustained response was assessed by the continuation or cessation of therapy over time for another reason than stopping in sustained remission. Treatment persistence was assessed by Kaplan Meier curves and predictors of treatment persistence were studied by univariate and multivariate Cox model. RESULTS: Out of 156 recorded patients, three patients were still in their induction phase at time of analysis and 5 patients were lost to follow-up, leaving 148 patients for clinical effectiveness analyses, including 35 bio-naïve when starting ustekinumab. A maintenance therapy was initiated in 79.7%. At one year, the probability to be still treated with ustekinumab was 73.8%. Treatment cessation increased with smoking in multivariate analysis. Previous biologic failure (as a whole), CRP and fecal calprotectin baseline levels did not influence initial response and treatment persistence. CONCLUSION: A large proportion of CD patients initially respond to ustekinumab and continue this treatment beyond one year. Treatment persistence is as high in bio-failure as in bio-naïve patients.

γδ T cells compose a developmentally regulated intrauterine population and protect against vaginal candidiasis.

This most comprehensive analysis to date of γδ T cells in the murine uterus reveals them to compose a unique local T-cell compartment. Consistent with earlier reports, most cells expressed a canonical Vγ6Vδ1 TCR, and produced interleukin (IL)-17A upon stimulation. Nonetheless, contrasting with earlier reports, uterine γδ T cells were not obviously intraepithelial, being more akin to sub-epithelial Vγ6Vδ1+ T cells at several other anatomical sites. By contrast to other tissues however, the uterine compartment also included non-Vγ6+, IFN-γ-producing cells; was strikingly enriched in young mice; expressed genes hitherto associated with the uterus, including the progesterone receptor; and did not require microbes for development and/or maintenance. This notwithstanding, γδ T-cell deficiency severely impaired resistance to reproductive tract infection by Candida albicans, associated with decreased responses of IL-17-dependent neutrophils. These findings emphasise tissue-specific complexities of different mucosal γδ cell compartments, and their evident importance in lymphoid stress-surveillance against barrier infection.

Immune requirements for protective Th17 recall responses to Mycobacterium tuberculosis challenge.

Tuberculosis (TB) vaccine development has focused largely on targeting T helper type 1 (Th1) cells. However, despite inducing Th1 cells, the recombinant TB vaccine MVA85A failed to enhance protection against TB disease in humans. In recent years, Th17 cells have emerged as key players in vaccine-induced protection against TB. However, the exact cytokine and immune requirements that enable Th17-induced recall protection remain unclear. In this study, we have investigated the requirements for Th17 cell-induced recall protection against Mycobacterium tuberculosis (Mtb) challenge by utilizing a tractable adoptive transfer model in mice. We demonstrate that adoptive transfer of Mtb-specific Th17 cells into naive hosts, and upon Mtb challenge, results in Th17 recall responses that confer protection at levels similar to vaccination strategies. Importantly, although interleukin (IL)-23 is critical, IL-12 and IL-21 are dispensable for protective Th17 recall responses. Unexpectedly, we demonstrate that interferon-γ (IFN-γ) produced by adoptively transferred Th17 cells impairs long-lasting protective recall immunity against Mtb challenge. In contrast, CXCR5 expression is crucial for localization of Th17 cells near macrophages within well-formed B-cell follicles to mediate Mtb control. Thus, our data identify new immune characteristics that can be harnessed to improve Th17 recall responses for enhancing vaccine design against TB.