Hidradenitis suppurativa (HS) is a chronic, inflammatory, debilitating, follicular disease of the skin. Despite a high prevalence in the general population, the physiopathology of HS remains poorly understood. The use of antibiotics and immunosuppressive agents for therapy suggests a deregulated immune response to microflora. Using cellular and gene expression analyses, we found an increased number of infiltrating CD4(+) T cells secreting IL-17 and IFN-γ in perilesional and lesional skin of patients with HS. By contrast, IL-22-secreting CD4(+) T cells are not enriched in HS lesions contrasting with increased number of those cells in the blood of patients with HS. We showed that keratinocytes isolated from hair follicles of patients with HS secreted significantly more IL-1β, IP-10, and chemokine (C-C motif) ligand 5 (RANTES) either constitutively or on pattern recognition receptor stimulations. In addition, they displayed a distinct pattern of antimicrobial peptide production. These findings point out a functional defect of keratinocytes in HS leading to a balance prone to inflammatory responses. This is likely to favor a permissive environment for bacterial infections and chronic inflammation characterizing clinical outcomes in patients with HS.

The identification of COVID-19 patients with high-risk of severe disease is a challenge in routine care. We performed cell phenotypic, serum and RNA-seq gene expression analyses in severe hospitalized patients (n = 61). Relative to healthy donors, results showed abnormalities of 27 cell populations and an elevation of 42 cytokines, neutrophil chemo-attractants, and inflammatory components in patients. Supervised and unsupervised analyses revealed a high abundance of CD177 , a specific neutrophil activation marker, contributing to the clustering of severe patients. Gene abundance correlated with high serum levels of CD177 in severe patients. Higher levels were confirmed in a second cohort and in ICU than non-ICU patients (P< 0.001). Longitudinal measurements discriminated between patients with the worst prognosis, leading to death, and those who recovered (P = 0.01). These results highlight neutrophil activation as a hallmark of severe disease and CD177 assessment as a reliable prognostic marker for routine care.

ObjectivesRecent data showed the selection of mutations in the integrase gene, mainly involving position 148 or 155, in patients displaying virological failure (VF) on raltegravir (RAL) therapy. Here, we describe the development of RAL resistance, in both plasmatic and cellular compartments, in three heavily pretreated HIV-infected patients failing RAL-containing regimens. MethodsThree of 17 patients receiving RAL displayed VF. The entire integrase gene, isolated from plasma and peripheral blood mononuclear cells (PBMC), was sequenced. A clonal analysis was performed in one patient at the time of VF. ResultsAt the time of VF, RAL-resistance mutations were selected: (i) Q148R in patients 1 and 3; (ii) T66A and E92Q in patient 2. A gradual accumulation of new mutations was observed in all patients, including G140S, Q148H and N155H in patient 1, L74I in patient 2, and G140S in patient 3. Clonal analysis showed the coexistence, in patient 1, of the two common resistance pathways (mutations Q148R/H and N155H) found in distinct quasi-species. In addition, RAL-resistance mutations were detected in HIV DNA in all patients. ConclusionsHaving rapidly established, resistance to RAL evolves and diversifies, and is likely to impact the efficacy of subsequently used second-generation integrase inhibitors. Moreover, RAL-resistance mutations can be archived early in PBMC.