Pasteurella bettyae Infections in Men Who Have Sex with Men, France.

Pasteurella bettyae is a gram-negative bacillus sporadically involved in human infections; its main reservoirs are cats and dogs. A recent publication suggests the possibility of sexual transmission leading to genital infections in men who have sex with men. We report 9 cases in France of genital infection among this population.

Macrophage-derived CXCL9 and CXCL11, T-cell skin homing, and disease control in mogamulizumab-treated CTCL patients.

Cutaneous T-cell lymphomas (CTCLs) are rare malignancies involving primarily the skin. Responses to treatment are usually short-lived in advanced CTCL. The determinants of long-term CTCL control are unclear. Mogamulizumab, an anti-human CCR4 antibody that acts by antibody-dependent cell cytotoxicity against CCR4+ CTCL tumor cells and peripheral memory blood regulatory T cells, has been associated with long-lasting remissions and immune adverse events. Here, we reported skin rashes in 32% of 44 patients with CTCL treated with mogamulizumab, associated with significantly higher overall survival (hazard ratio, 0.16; 0.04-0.73; P = .01). Rash occurred in patients with Sézary syndrome and was associated with longer time to progression. These rashes were characterized by a CD163+ granulomatous and/or CD8+ lichenoid skin infiltrate. High-throughput sequencing analysis of T-cell receptor ß genes in skin and blood flow cytometry confirmed the depletion of CTCL tumor cells, as well as the recruitment of new reactive T-cell clones in skin at the time of skin rash. CXCL9 and CXCL11, two macrophage-derived chemokines that recruit CXCR3+ T cells to skin, were overexpressed in skin rashes. A higher frequency of TIGIT+ and PD1+ exhausted reactive blood T cells was observed at baseline in patients with rash, and this frequency decreased with mogamulizumab treatment. These data are consistent with mogamulizumab-induced long-term immune CTCL control by activation of the macrophage and T-cell responses in patients with rash.

Two cases of dupilumab-responsive Kimura disease.

Kimura disease (KD) is a rare, chronic angiolymphoproliferative inflammatory disease appearing to be mostly restricted to the skin and soft tissue. Cutaneous involvement of KD includes head and/or neck nodules showing suggestive histological features, frequently associated with an atopic dermatitis-like or prurigo-like presentation. KD is challenging to treat, with high rate of recurrence using current therapeutic strategies. Evidence for involvement of a T-helper type 2 (Th2) immune response in KD pathogenesis has been found in previous studies. Consequently, this study aimed to determine the efficacy and safety of dupilumab, a human monoclonal antibody that inhibits signalling of key Th2 cytokines, interleukin (IL)-4 and IL-13, within a single-centre cohort of patients with cutaneous KD. Two adults with a diagnosis of refractory (failure of at least one treatment line) cutaneous-restricted KD based on clinical, biological, histological, molecular and imaging findings received dupilumab for KD, and showed dramatic response with a good safety profile.

Microenvironment tailors nTreg structure and function.

Natural regulatory T cells (nTregs) ensure the control of self-tolerance and are currently used in clinical trials to alleviate autoimmune diseases and graft-versus-host disease after hematopoietic stem cell transfer. Based on CD39/CD26 markers, blood nTreg analysis revealed the presence of five different cell subsets, each representing a distinct stage of maturation. Ex vivo added microenvironmental factors, including IL-2, TGFß, and PGE2, direct the conversion from naive precursor to immature memory and finally from immature to mature memory cells, the latest being a no-return stage. Phenotypic and genetic characteristics of the subsets illustrate the structural parental maturation between subsets, which further correlates with the expression of regulatory factors. Regarding nTreg functional plasticity, both maturation stage and microenvironmental cytokines condition nTreg activities, which include blockade of autoreactive immune cells by cell-cell contact, Th17 and IL-10 Tr1-like activities, or activation of TCR-stimulating dendritic cell tolerization. Importantly, blood nTreg CD39/CD26 profile remained constant over a 2-y period in healthy persons but varied from person to person. Preliminary data on patients with autoimmune diseases or acute myelogenous leukemia illustrate the potential use of the nTreg CD39/CD26 profile as a blood biomarker to monitor chronic inflammatory diseases. Finally, we confirmed that naive conventional CD4 T cells, TCR-stimulated under a tolerogenic conditioned medium, could be ex vivo reprogrammed to FOXP3 lineage Tregs, and further found that these cells were exclusively committed to suppressive function under all microenvironmental contexts.

Persistent deficiency of mucosal-associated invariant T cells during dermatomyositis.

OBJECTIVES: Mucosal-associated invariant T (MAIT) cells are innate-like lymphocytes that are important for antibacterial immunity and may have regulatory roles. MAIT cells are decreased during SLE. However, their frequencies and phenotype have not been investigated in DM. We studied MAIT cell frequencies and phenotype in DM patients with active and inactive disease (after treatment). METHODS: Peripheral blood flow cytometry analysis of MAIT cells was compared between DM (n = 22), SLE (n = 10), psoriasis (n = 7) and atopic dermatitis (n = 5) patients, and healthy controls (n = 19). RESULTS: A dramatic decrease of circulating MAIT cell frequency was observed in active DM and SLE patients compared with healthy controls and other inflammatory skin diseases [active DM: median = 0.25% (interquartile range 0.19-0.6%), P < 0.0001; active SLE: median = 0.61 (0.55-0.77), P < 0.0001 vs healthy controls: 2.32% (1.18-4.45%)]. MAIT cells from active DM patients had an abnormal phenotype including increased expression of CD25 and cytotoxic T-lymphocyte-associated protein 4 that correlated with their low frequency in the blood. CONCLUSION: In DM, peripheral blood MAIT cells are dramatically reduced and have an activated/exhausted phenotype that may be linked to increased activation-induced cell death.

Characteristics of circulating KSHV-infected viroblasts during active KSHV+ multicentric Castleman disease.

Kaposi sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8-associated multicentric Castleman disease (MCD) is a polyclonal B-cell lymphoproliferative disorder that mainly occurs in immunocompromised hosts. The diagnosis relies on lymph node biopsy demonstrating KSHV-infected cells located in the mantle zone with a marked interfollicular plasma cell infiltration. Infected cells are large cells positive for immunoglobulin M (IgM), λ light chain, and CD38, described initially as infected plasmablasts. We show that IgM+λ+CD38high cells were also detectable in the peripheral blood of 14 out of 18 (78%) patients with active KSHV-MCD and absent in 40 controls. Using immunofluorescence and flow-fluorescence in situ hybridization, we demonstrate that these cells are KSHV infected and express both latent and lytic KSHV transcripts. These KSHV-infected viroblasts (KIVs) harbor a distinct phenotype compared with conventional plasmablasts. We also identified several putative mechanisms of immune escape used by KSHV, because KIVs displayed an overall decrease of costimulatory molecules, with a remarkable lack of CD40 expression and are interleukin-10-producing cells. The identification of this specific and easily accessible KSHV+ circulating population brings new elements to the understanding of KSHV-MCD but also raises new questions that need to be clarified.

IL-4/IL-13 Inhibitors for Atopic Dermatitis Induce Psoriatic Rash Transcriptionally Close to Pustular Psoriasis.

Dupilumab is a therapeutic antibody targeting IL-4 and IL-13 receptor subunit alpha used for the treatment of patients with atopic dermatitis (AD). Cases of psoriasis-like reactions induced under dupilumab treatment (dupilumab-induced psoriatic eruption [DI-Pso]) for AD were recently reported. To understand the pathogenesis of DI-Pso, we performed gene expression profiling studies on skin biopsies of DI-Pso (n = 7) compared with those of plaque psoriasis, AD, and healthy controls (n = 4 each). Differential gene expression was performed using enrichment and Gene Ontology analysis. Gene expression was validated by qPCR, and protein levels were assessed by immunohistochemistry. Transcriptomic and protein analysis of DI-Pso compared with that of healthy controls, plaque psoriasis, and AD skins revealed activation of T helper 17/IL-23 pathways associated with a significant expression of IL-36, surrogate marker of pustular psoriasis. By contrast, T helper 2 representative genes' expression was strongly decreased in DI-Pso across comparison. Matching analysis with public data of pustular psoriasis skin corroborated that DI-Pso and pustular psoriasis upstream regulators overlap, greater than the overlap with plaque psoriasis. Furthermore, DI-Pso showed strongly decreased expression of many barrier skin genes compared with healthy controls, plaque psoriasis, and AD. Our data indicate that the pathogenesis of DI-Pso relied on a shift of skin immune responses from a T helper 2 to an IL-36 and T helper 17 polarization and on intensified skin barrier alterations.

Disease patterns and specific trajectories of anti-MDA5-related disease: a multicentre retrospective study of 70 adult patients.

Introduction: This study aimed to provide an updated analysis of the different prognostic trajectories of patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibodies. Methods: Among a cohort of 70 patients, baseline characteristics and phenotypes, treatments and outcomes were analyzed. A Cox proportional hazards model was used to identify factors associated with poor outcomes, i.e., death or progressive disease at the last follow-up. Results: Among the 70 patients, 45 were women, and 54 were Caucasian. A dermatologic involvement was observed in 58 (83%) patients, including 40 with MDA5 vasculopathy-related skin lesions. Muscular involvement was observed in 39 (56%) patients. Interstitial lung disease (ILD) was observed at baseline in 52 (74%) patients, including 23 (44%) who developed rapidly progressive (RP) ILD. Seven (10%) patients showed thromboembolic complications within the first weeks of diagnosis, and eight (11%) other patients developed a malignancy (4 before the diagnosis of anti-MDA5 disease). Poor outcomes were observed in 28 (40%) patients, including 13 (19%) deaths. Among the 23 patients with RP-ILD, 19 (79%) showed poor outcomes, including 12 (63%) who died. In multivariate analyses, RP-ILD (hazard ratio (HR), 95% CI: 8.24 [3.21-22], p<0.0001), the occurrence of thromboembolic events (HR: 5.22 [1.61-14.77], p=0.008) and the presence of any malignancy (HR: 19.73 [6.67-60], p<0.0001) were the three factors independently associated with poor outcomes. Discussion: This new independent cohort confirms the presence of different clinical phenotypes of anti-MDA5 diseases at baseline and the poor prognosis associated with RP-ILD. Thromboembolic events and malignancies were also identified as prognostic factors.

Humoral and cellular responses to SARS-CoV-2 BNT162b2 vaccination in allogeneic hematopoietic stem cell transplantation recipients.

Previous studies reporting the response to SARS-CoV-2 mRNA vaccination in alloHSCT recipients used serological and/or cellular assays, but no study has evaluated vaccine-induced neutralizing antibodies. We prospectively studied 28 alloHSCT recipients who received two BNT162b2 doses. Two patients groups were defined according to time from alloHSCT and immunosuppressive treatment, and had different baseline immunologic status. Study end-point was the evaluation of humoral and cellular responses one month after the second vaccine. All patients seroconverted. Anti-S IgG levels and neutralizing antibodies percentages were not significantly different between both groups. Using IFNγ ELISpot assay, five patients showed a strong increase, without correlation with the humoral response. Using flow cytometry lymphocyte proliferation assay, 14 patients exhibited responding T cells, without difference between both groups or correlation with anti-S IgG levels. A few low serological responders had a detectable CD4 + T cell proliferative response. This finding should be confirmed in a larger cohort.

RNA sequencing of chronic GVHD skin lesions defines shared and unique inflammatory pathways characterizing lichen planus and morphea.

Cutaneous involvement of chronic graft-versus-host disease (cGVHD) has a wide range of manifestations including a lichenoid form with a currently assumed mixed Th1/Th17 signature and a sclerotic form with Th1 signature. Despite substantial heterogeneity of innate and adaptive immune cells recruited to the skin and of the different clinical manifestations, treatment depends mainly on the severity of the skin involvement and relies on systemic, high-dose glucocorticoids alone or in combination with a calcineurin inhibitor. We performed the first study using RNA sequencing to profile and compare the transcriptome of lichen planus cGVHD (n = 8), morphea cGVHD (n = 5), and healthy controls (n = 6). Our findings revealed shared and unique inflammatory pathways to each cGVHD subtype that are both pathogenic and targetable. In particular, the deregulation of IFN signaling pathway was strongly associated with cutaneous cGVHD, whereas the triggering receptor expressed on myeloid cells 1 pathway was found to be specific of lichen planus and likely contributes to its pathogenesis. The results were confirmed at a protein level by performing immunohistochemistry staining and at a transcriptomic level using real-time quantitative polymerase chain reaction.

Systemic sclerosis is associated with lower limb vascular stiffness and microvascular impairment: results from a prospective study.

OBJECTIVE: Systemic sclerosis (SSc) is a connective tissue disease characterized by microangiopathy. Peripheral arterial disease, increasingly studied during SSc, is responsible for digital ulcers, associated with a high risk of amputation. The aim of our study was to assess the frequency of lower limb arterial impairment in SSc patients by measuring ankle-brachial index (ABI), toe pressure (TP), and toe-brachial index (TBI). METHODS: Systemic sclerosis patients were included prospectively during 1 year in Tenon and Saint-Antoine Hospitals, Paris. Clinical and biological data were recorded. For each patient, ABI, TP, and TBI were measured and an arterial duplex ultrasonography was prescribed in case of abnormal results. RESULTS: Eighty-six patients were included (94% women, median age 62 years). Only 24% of them had no lower limb hemodynamic vascular abnormalities; 44% had an isolated microvascular abnormality (normal ABI and TBI<0.75); 31% had at least a macrovascular injury associated or not with microvascular impairment (abnormal ABI) and 12.6% had a TP<50 mmHg. During follow-up, there was a trend towards association of low TBI with more major adverse event (all-cause mortality, non-fatal stroke, non-fatal myocardial infarction, and lower limb ischemic manifestations) than normal TBI. CONCLUSION: By measuring ABI and TP, we showed that 76% of SSc patients had hemodynamic arterial lower limb abnormalities related to macro- and/or microvascular impairment and that 28% had vascular stiffness. In SSc patients, ABI is not an accurate tool to detect lower limb arterial disease, likely due to underlying micro- and macrovascular changes. Key Points • The presence of lower limb macro-and/or microvascular involvement was detected in 76% of SSc patients. • In SSc patients, ABI is not an accurate tool to detect lower limb arterial disease, likely due to underlying microvascular changes and frequent arterial stiffness.

Immune checkpoint inhibitors increase T cell immunity during SARS-CoV-2 infection.

The COVID-19 pandemic has spread worldwide, yet the role of antiviral T cell immunity during infection and the contribution of immune checkpoints remain unclear. By prospectively following a cohort of 292 patients with melanoma, half of which treated with immune checkpoint inhibitors (ICIs), we identified 15 patients with acute or convalescent COVID-19 and investigated their transcriptomic, proteomic, and cellular profiles. We found that ICI treatment was not associated with severe COVID-19 and did not alter the induction of inflammatory and type I interferon responses. In-depth phenotyping demonstrated expansion of CD8 effector memory T cells, enhanced T cell activation, and impaired plasmablast induction in ICI-treated COVID-19 patients. The evaluation of specific adaptive immunity in convalescent patients showed higher spike (S), nucleoprotein (N), and membrane (M) antigen-specific T cell responses and similar induction of spike-specific antibody responses. Our findings provide evidence that ICI during COVID-19 enhanced T cell immunity without exacerbating inflammation.