Mutational analysis of Peroxiredoxin IV: exclusion of a positional candidate for multinodular goitre

BACKGROUND: Multinodular goitre (MNG) is a common disorder characterised by an enlargement of the thyroid, occurring as a compensatory response to hormonogenesis impairment. The incidence of MNG is dependent on sex (female:male ratio 5:1) and several reports have documented a genetic basis for the disease. Last year we mapped a MNG locus to chromosome Xp22 in a region containing the peroxiredoxin IV (Prx-IV) gene. Since Prx-IV is involved in the removal of H(2)O(2) in thyroid cells, we hypothesize that mutations in Prx-IV gene are involved in pathogenesis of MNG. METHODS: Four individuals (2 affected, 2 unrelated unaffected) were sequenced using automated methods. All individuals were originated from the original three-generation Italian family described in previous studies. A Southern blot analysis using a Prx-IV full-length cDNA as a probe was performed in order to exclude genomic rearrangements and/or intronic mutations. In addition a RT-PCR of PRX-IV was performed in order to investigate expression alterations. RESULTS: No causative mutations were found. Two adjacent nucleotide substitutions were detected within introns 1 and 4. These changes were also detected in unaffected individuals, suggesting that they were innocuous polymorphisms. No gross genomic rearrangements and/or restriction fragment alterations were observed on Southern analysis. Finally, using RT-PCR from tissue-specific RNA, no differences of PRX-IV expression-levels were detected between affected and unaffected samples. CONCLUSIONS: Based on sequence and genomic analysis, Prx-IV is very unlikely to be the MNG2 gene

Pericarditis and Autoinflammation: A Clinical and Genetic Analysis of Patients With Idiopathic Recurrent Pericarditis and Monogenic Autoinflammatory Diseases at a National Referral Center.

Background: Idiopathic recurrent pericarditis (IRP) is an orphan disease that carries significant morbidity, partly driven by corticosteroid dependence. Innate immune modulators, colchicine and anti-interleukin-1 agents, pioneered in monogenic autoinflammatory diseases, have demonstrated remarkable efficacy in trials, suggesting that autoinflammation may contribute to IRP. This study characterizes the phenotype of patients with IRP and monogenic autoinflammatory diseases, and establishes whether autoinflammatory disease genes are associated with IRP. Methods and Results: We retrospectively analyzed the medical records of patients with IRP (n=136) and monogenic autoinflammatory diseases (n=1910) attending a national center (London, UK) between 2000 and 2021. We examined 4 genes (MEFV, MVK, NLRP3, TNFRSF1A) by next-generation sequencing in 128 patients with IRP and compared the frequency of rare deleterious variants to controls obtained from the Genome Aggregation Database. In this cohort of patients with IRP, corticosteroid dependence was common (39/136, 28.7%) and was associated with chronic pain (adjusted odds ratio 2.8 [95% CI, 1.3-6.5], P=0.012). IRP frequently manifested with systemic inflammation (raised C-reactive protein [121/136, 89.0%] and extrapericardial effusions [68/136, 50.0%]). Pericarditis was observed in all examined monogenic autoinflammatory diseases (0.4%-3.7% of cases). Rare deleterious MEFV variants were more frequent in IRP than in ancestry-matched controls (allele frequency 9/200 versus 2932/129 200, P=0.040). Conclusions: Pericarditis is a feature of interleukin-1 driven monogenic autoinflammatory diseases and IRP is associated with variants in MEFV, a gene involved in interleukin-1β processing. We also found that corticosteroid dependence in IRP is associated with chronic noninflammatory pain. Together these data implicate autoinflammation in IRP and support reducing reliance on corticosteroids in its management

in-silico and in-vitro analysis of IL36RN mutations reveals critical residues for the function of the interleukin-36 receptor complex

Generalized pustular psoriasis (GPP) is a potentially life-threatening skin disease, associated with IL36RN mutations. IL36RN encodes the interleukin (IL)-36 receptor antagonist (IL-36Ra), a protein that downregulates the activity of IL-36 cytokines by blocking their receptor (IL-36R). While GPP can be treated with IL-36R inhibitors, the structural underpinnings of the IL-36Ra/IL-36R interaction remain poorly understood. Here, we sought to address this question by systematically investigating the effects of IL36RN mutations. We experimentally characterized the effects of 30 IL36RN variants on protein stability. In parallel, we used a machine-learning tool (Rhapsody) to analyse the IL-36Ra three-dimensional structure and predict the impact of all possible amino acid substitutions. This integrated approach identified 21 amino acids that are essential to IL-36Ra stability. We next investigated the effects of IL36RN changes on IL-36Ra/IL-36R binding and IL-36R signalling. By combining in-vitro assays and machine-learning with a second programme (mCSM), we identified 13 amino acids that are critical to IL-36Ra/IL36R engagement. Finally, we experimentally validated three representative predictions, further confirming the reliability of Rhapsody and mCSM. These findings shed light on the structural determinants of IL-36Ra activity, with potential to facilitate the design of new IL-36 inhibitors and aid the interpretation of IL36RN variants in diagnostic settings

IL-36 Promotes Systemic IFN-I Responses in Severe Forms of Psoriasis

Psoriasis is an immune-mediated skin disorder associated with severe systemic comorbidities. Whereas IL-36 is a key disease driver, the pathogenic role of this cytokine has mainly been investigated in skin. Thus, its effects on systemic immunity and extracutaneous disease manifestations remain poorly understood. To address this issue, we investigated the consequences of excessive IL-36 activity in circulating immune cells. We initially focused our attention on generalized pustular psoriasis (GPP), a clinical variant associated with pervasive upregulation of IL-36 signaling. By undertaking blood and neutrophil RNA sequencing, we demonstrated that affected individuals display a prominent IFN-I signature, which correlates with abnormal IL-36 activity. We then validated the association between IL-36 deregulation and IFN-I over-expression in patients with severe psoriasis vulgaris (PV). We also found that the activation of IFN-I genes was associated with extracutaneous morbidity, in both GPP and PV. Finally, we undertook mechanistic experiments, demonstrating that IL-36 acts directly on plasmacytoid dendritic cells, where it potentiates toll-like receptor (TLR)-9 activation and IFN-α production. This effect was mediated by the upregulation of PLSCR1, a phospholipid scramblase mediating endosomal TLR-9 translocation. These findings identify an IL-36/ IFN-I axis contributing to extracutaneous inflammation in psoriasis.</p

The interleukin 1 receptor antagonist anakinra to reduce disease severity of palmoplantar pustulosis in adults: APRICOT RCT and PLUM mechanistic study

Background: Palmoplantar pustulosis is a rare, debilitating, chronic skin disease involving the hands and feet, and there are limited treatment options. Mechanistic findings suggest that interleukin 1 may be a pathogenic driver. // Objective: To determine whether or not anakinra [Sobi (Swedish Orphan Biovitrum AB), Stockholm, Sweden], an interleukin 1 receptor antagonist, delivers therapeutic benefit in palmoplantar pustulosis. // Design: A Phase IV, randomised, double-blind, placebo-controlled study with two stages and an adaptive element (24 participants in stage 1, 64 participants in total) with an open-label extension. // Setting: Sixteen hospitals across England, Scotland and Wales. // Participants: Adults (aged ≥ 18 years) with a diagnosis of palmoplantar pustulosis and a disease duration of > 6 months and of sufficient impact and severity to require systemic therapy. // Interventions Participants were randomised (1 : 1) to daily self-administered subcutaneous injection of either anakinra or a placebo for 8 weeks. Main outcome measures The primary outcome was the Palmoplantar Pustulosis Area and Severity Index score measured at 0, 1, 4, 8 and 12 weeks, with the primary end point at 8 weeks adjusted for baseline. Secondary outcomes included other investigator-assessed efficacy measures of disease severity, safety measures and participant-reported measures of efficacy and impact. Results A total of 64 participants (mean baseline Palmoplantar Pustulosis Area and Severity Index score of 17.8, standard deviation 10.5) received anakinra (n = 31) or the placebo (n = 33). In the primary intention-to-treat analysis, which estimated the effect of the treatment policy, the mean treatment group difference at 8 weeks after adjustment for baseline Palmoplantar Pustulosis Area and Severity Index score was –1.65 (95% confidence interval –4.77 to 1.47; p = 0.300), in favour of anakinra relative to placebo, but was not statistically significant. Similarly, secondary investigator-assessed outcomes did not show statistical superiority of anakinra: the baseline-adjusted mean difference in fresh pustule count (palms and soles) between the anakinra group and the placebo group was 2.94 (95% confidence interval –26.44 to 32.33), in favour of placebo, and the mean difference in total pustule count was –30.08 (95% confidence interval –83.20 to 23.05), in favour of anakinra. Participant-assessed outcomes were consistent with these objective findings: the baseline-adjusted mean difference in Dermatology Life Quality Index between the anakinra group and the placebo group was 0.52 (95% confidence interval –2.04 to 3.07), in favour of placebo, and the mean difference in Palmoplantar Quality-of-Life Index was 1.27 (95% confidence interval –3.04 to 5.57), in favour of placebo. However, the proportion of participants who strongly agreed that treatment was worthwhile was greater in the anakinra group (12/29, 41%) than in the placebo group (4/28, 14%), a difference in proportion of 27% (95% confidence interval 5% to 49%). In the complier-average causal effect analysis, the baseline-adjusted mean treatment group difference in the week 8 Palmoplantar Pustulosis Area and Severity Index score in individuals who received ≥ 50% of injections was –2.30 (95% confidence interval –6.54 to 1.93; p = 0.287) and in those who received ≥ 90% of injections was –3.80 (95% confidence interval –10.76 to 3.16; p = 0.285), in favour of anakinra. No serious infections, significant neutropenia or other serious adverse events occurred. Injection site reactions were more frequent for those receiving anakinra (19/31, 61%) than for those receiving placebo (1/33, 3%). // Conclusions: There was no evidence that anakinra was superior to placebo. For the treatment of palmoplantar pustulosis, interleukin 1 blockade is not a useful intervention. // Limitations: The sample size was calculated to detect a large effect size. Treatment adherence was lower than expected. It cannot be ruled out that there was some selection bias towards less severe or unstable participants entering the trial given that the trial was placebo controlled with a required washout period. // Future work: Palmoplantar pustulosis remains an area of high unmet need and further research is recommended to (1) identify new drug targets, (2) determine the contributory role of drug exposure (including pharmacokinetics and adherence) and (3) validate outcome measures in palmoplantar pustulosis. // Trial registration: This trial is registered as ISCRTN13127147 and EudraCT 2015-003600-23. // Funding: This project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a MRC and National Institute for Health Research (NIHR) partnership. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 9, No. 2. See the NIHR Journals Library for further project information

Association of Clinical and Demographic Factors With the Severity of Palmoplantar Pustulosis.

Importance: Although palmoplantar pustulosis (PPP) can significantly impact quality of life, the factors underlying disease severity have not been studied. Objective: To examine the factors associated with PPP severity. Design, Setting, and Participants: An observational, cross-sectional study of 2 cohorts was conducted. A UK data set including 203 patients was obtained through the Anakinra in Pustular Psoriasis, Response in a Controlled Trial (2016-2019) and its sister research study Pustular Psoriasis, Elucidating Underlying Mechanisms (2016-2020). A Northern European cohort including 193 patients was independently ascertained by the European Rare and Severe Psoriasis Expert Network (2014-2017). Patients had been recruited in secondary or tertiary dermatology referral centers. All patients were of European descent. The PPP diagnosis was established by dermatologists, based on clinical examination and/or published consensus criteria. The present study was conducted from October 1, 2014, to March 15, 2020. Main Outcomes and Measures: Demographic characteristics, comorbidities, smoking status, Palmoplantar Pustulosis Psoriasis Area Severity Index (PPPASI), measuring severity from 0 (no sign of disease) to 72 (very severe disease), or Physician Global Assessment (PGA), measuring severity as 0 (clear), 1 (almost clear), 2 (mild), 3 (moderate), and 4 (severe). Results: Among the 203 UK patients (43 men [21%], 160 women [79%]; median age at onset, 48 [interquartile range (IQR), 38-59] years), the PPPASI was inversely correlated with age of onset (r = -0.18, P = .01). Similarly, in the 159 Northern European patients who were eligible for inclusion in this analysis (25 men [16%], 134 women [84%]; median age at onset, 45 [IQR, 34-53.3] years), the median age at onset was lower in individuals with a moderate to severe PGA score (41 years [IQR, 30.5-52 years]) compared with those with a clear to mild PGA score (46.5 years [IQR, 35-55 years]) (P = .04). In the UK sample, the median PPPASI score was higher in women (9.6 [IQR, 3.0-16.2]) vs men (4.0 [IQR, 1.0-11.7]) (P = .01). Likewise, moderate to severe PPP was more prevalent among Northern European women (57 of 134 [43%]) compared with men (5 of 25 [20%]) (P = .03). In the UK cohort, the median PPPASI score was increased in current smokers (10.7 [IQR, 4.2-17.5]) compared with former smokers (7 [IQR, 2.0-14.4]) and nonsmokers (2.2 [IQR, 1-6]) (P = .003). Comparable differences were observed in the Northern European data set, as the prevalence of moderate to severe PPP was higher in former and current smokers (51 of 130 [39%]) compared with nonsmokers (6 of 24 [25%]) (P = .14). Conclusions and Relevance: The findings of this study suggest that PPP severity is associated with early-onset disease, female sex, and smoking status. Thus, smoking cessation intervention might be beneficial

Damaging alleles affecting multiple CARD14 domains are associated with palmoplantar pustulosis

No abstract available

Single-cell analysis implicates Th17-to-Th2 cell plasticity in the pathogenesis of palmoplantar pustulosis

Background Palmoplantar pustulosis (PPP) is a severe inflammatory skin disorder, characterised by eruptions of painful, neutrophil-filled pustules on the palms and soles. While PPP has a profound effect on quality of life, it remains poorly understood and notoriously difficult to treat. Objective We sought to investigate the immune pathways that underlie the pathogenesis of PPP. Methods We applied bulk- and single-cell RNA-sequencing methods to the analysis of skin biopsies and peripheral blood mononuclear cells. We validated our results by flow cytometry and immune fluorescence microscopy Results Bulk RNA-sequencing of patient skin detected an unexpected signature of T-cell activation, with a significant overexpression of several Th2 genes typically upregulated in atopic dermatitis. To further explore these findings, we carried out single-cell RNA-sequencing in peripheral blood mononuclear cells of healthy and affected individuals. We found that the memory CD4+T-cells of PPP patients were skewed towards a Th17 phenotype, a phenomenon that was particularly significant among CLA+ skin-homing cells. We also identified a subset of memory CD4+ T-cells which expressed both Th17 (KLRB1/CD161) and Th2 (GATA3) markers, with pseudo-time analysis suggesting that the population was the result of Th17 to Th2 plasticity. Interestingly, the GATA3+/CD161+ cells were over-represented among the PBMCs of affected individuals, both in the scRNA-seq dataset and in independent flow-cytometry experiments. Dual positive cells were also detected in patient skin by means of immune fluorescence microscopy. Conclusions These observations demonstrate that PPP is associated with complex T-cell activation patterns and may explain why biologics that target individual T-helper populations have shown limited therapeutic efficacy. Clinical implications The simultaneous activation of Th17 and Th2 responses in PPP supports the therapeutic use of agents that inhibit multiple T-cell pathways