Slaheddine Marrakchi

BACKGROUND: Generalized pustular psoriasis is a life-threatening disease of unknown cause. It is characterized by sudden, repeated episodes of high-grade fever, generalized rash, and disseminated pustules, with hyperleukocytosis and elevated serum levels of C-reactive protein, which may be associated with plaque-type psoriasis. METHODS: We performed homozygosity mapping and direct sequencing in nine Tunisian multiplex families with autosomal recessive generalized pustular psoriasis. We assessed the effect of mutations on protein expression and conformation, stability, and function. RESULTS: We identified significant linkage to an interval of 1.2 megabases on chromosome 2q13-q14.1 and a homozygous missense mutation in IL36RN, encoding an interleukin-36-receptor antagonist (interleukin-36Ra), an antiinflammatory cytokine. This mutation predicts the substitution of a proline residue for leucine at amino acid position 27 (L27P). Homology-based structural modeling of human interleukin-36Ra suggests that the proline at position 27 affects both the stability of interleukin-36Ra and its interaction with its receptor, interleukin-1 receptor-like 2 (interleukin-1 receptor-related protein 2). Biochemical analyses showed that the L27P variant was poorly expressed and less potent than the nonvariant interleukin-36Ra in inhibiting a cytokine-induced response in an interleukin-8 reporter assay, leading to enhanced production of inflammatory cytokines (interleukin-8 in particular) by keratinocytes from the patients. CONCLUSIONS: Aberrant interleukin-36Ra structure and function lead to unregulated secretion of inflammatory cytokines and generalized pustular psoriasis. (Funded by Agence Nationale de la Recherche and Société Française de Dermatologie.).

BACKGROUND: Generalized pustular psoriasis (GPP) is a rare, life-threatening, inflammatory skin disease characterized by widespread eruption of sterile pustules. Interleukin-36 signaling is involved in the pathogenesis of this disorder. Spesolimab, a humanized anti-interleukin-36 receptor monoclonal antibody, is being studied for the treatment of GPP flares. METHODS: In a phase 2 trial, we randomly assigned patients with a GPP flare in a 2:1 ratio to receive a single 900-mg intravenous dose of spesolimab or placebo. Patients in both groups could receive an open-label dose of spesolimab on day 8, an open-label dose of spesolimab as a rescue medication after day 8, or both and were followed to week 12. The primary end point was a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) pustulation subscore of 0 (range, 0 [no visible pustules] to 4 [severe pustulation]) at the end of week 1. The key secondary end point was a GPPGA total score of 0 or 1 (clear or almost clear skin) at the end of week 1; scores range from 0 to 4, with higher scores indicating greater disease severity. RESULTS: A total of 53 patients were enrolled: 35 were assigned to receive spesolimab and 18 to receive placebo. At baseline, 46% of the patients in the spesolimab group and 39% of those in the placebo group had a GPPGA pustulation subscore of 3, and 37% and 33%, respectively, had a pustulation subscore of 4. At the end of week 1, a total of 19 of 35 patients (54%) in the spesolimab group had a pustulation subscore of 0, as compared with 1 of 18 patients (6%) in the placebo group (difference, 49 percentage points; 95% confidence interval [CI], 21 to 67; P<0.001). A total of 15 of 35 patients (43%) had a GPPGA total score of 0 or 1, as compared with 2 of 18 patients (11%) in the placebo group (difference, 32 percentage points; 95% CI, 2 to 53; P = 0.02). Drug reactions were reported in 2 patients who received spesolimab, in 1 of them concurrently with a drug-induced hepatic injury. Among patients assigned to the spesolimab group, infections occurred in 6 of 35 (17%) through the first week; among patients who received spesolimab at any time in the trial, infections had occurred in 24 of 51 (47%) at week 12. Antidrug antibodies were detected in 23 of 50 patients (46%) who received at least one dose of spesolimab. CONCLUSIONS: In a phase 2 randomized trial involving patients with GPP, the interleukin-36 receptor inhibitor spesolimab resulted in a higher incidence of lesion clearance at 1 week than placebo but was associated with infections and systemic drug reactions. Longer and larger trials are warranted to determine the effect and risks of spesolimab in patients with pustular psoriasis. (Funded by Boehringer Ingelheim; Effisayil 1 ClinicalTrials.gov number, NCT03782792.).

Interleukin-36 Blockade in Pustular Psoriasis Seven patients with pustular psoriasis, three with mutations in IL36RN, were treated with a monoclonal antibody against interleukin-36 receptor and had...

The face showed anatomical variation on reaction to chemicals, which could be related to differences in biophysical specificities of the skin. The aim of this study was to establish a map of the face for 6 biophysical parameters.10 young human volunteers (24-34 years) and 10 old volunteers (66-83 years) were studied to prepare a map of the human face based on regional variations and age-related differences by measuring various biophysical parameters. 7 locations on the face, neck, and forearm were investigated. Skin blood flow, transepidermal water loss (TEWL), stratum corneum hydration (capacitance), temperature, pH, and sebum content of the skin surface were measured. In both groups, skin blood flow in the nose showed the highest value. Perioral and nasolabial areas showed the highest TEWL values. The neck showed the highest capacitance value. The highest skin temperature was detected in the neck in the young group and in the nasolabial area in the old group. The chin showed the most alkaline pH in both groups. Nasolabial area showed the highest sebum content in the young group, as did the chin in the old group. These baseline values provide a framework to build on for ascertaining disease and intervention-related effects.

Autosomal recessive congenital ichthyosis (ARCI) is a rare genetic disorder of the skin characterized by abnormal desquamation over the whole body. In this study we report four patients from three consanguineous Tunisian families with skin, eye, heart, and skeletal anomalies, who harbor a homozygous contiguous gene deletion syndrome on chromosome 15q26.3. Genome-wide SNP-genotyping revealed a homozygous region in all affected individuals, including the same microdeletion that partially affects two coding genes (ADAMTS17, CERS3) and abolishes a sequence for a long non-coding RNA (FLJ42289). Whereas mutations in ADAMTS17 have recently been identified in autosomal recessive Weill-Marchesani-like syndrome in humans and dogs presenting with ophthalmologic, cardiac, and skeletal abnormalities, no disease associations have been described for CERS3 (ceramide synthase 3) and FLJ42289 so far. However, analysis of additional patients with non-syndromic ARCI revealed a splice site mutation in CERS3 indicating that a defect in ceramide synthesis is causative for the present skin phenotype of our patients. Functional analysis of patient skin and in vitro differentiated keratinocytes demonstrated that mutations in CERS3 lead to a disturbed sphingolipid profile with reduced levels of epidermis-specific very long-chain ceramides that interferes with epidermal differentiation. Taken together, these data present a novel pathway involved in ARCI development and, moreover, provide the first evidence that CERS3 plays an essential role in human sphingolipid metabolism for the maintenance of epidermal lipid homeostasis.