Secukinumab Therapy for Netherton Syndrome

Severe congenital ichthyosiform dermatosis in CHIME syndrome successfully treated with ixekizumab

Coloboma, congenital heart disease, ichthyosiform dermatosis, intellectual disability, conductive hearing loss, and epilepsy (CHIME) syndrome is a rare autosomal recessive neuroectodermal disorder caused by PIGL gene mutations. There is emerging literature to support the use of interleukin-17 (IL-17) antagonists in the treatment of certain ichthyosiform dermatoses. Here, we report a case of severe ichthyosiform dermatosis in a child with CHIME syndrome who was recalcitrant to multiple topical medications and dupilumab. This is the first reported case of successful treatment of congenital ichthyosiform dermatosis in a CHIME syndrome patient with ixekizumab, an IL-17A antagonist.

Altered skin microbiome, inflammation, and JAK/STAT signaling in Southeast Asian ichthyosis patients

BACKGROUND

Congenital ichthyosis (CI) is a collective group of rare hereditary skin disorders. Patients present with epidermal scaling, fissuring, chronic inflammation, and increased susceptibility to infections. Recently, there is increased interest in the skin microbiome; therefore, we hypothesized that CI patients likely exhibit an abnormal profile of epidermal microbes because of their various underlying skin barrier defects. Among recruited individuals of Southeast Asian ethnicity, we performed skin meta-genomics (i.e., whole-exome sequencing to capture the entire multi-kingdom profile, including fungi, protists, archaea, bacteria, and viruses), comparing 36 CI patients (representing seven subtypes) with that of 15 CI age-and gender-matched controls who had no family history of CI.

RESULTS

This case-control study revealed 20 novel and 31 recurrent pathogenic variants. Microbiome meta-analysis showed distinct microbial populations, decreases in commensal microbiota, and higher colonization by pathogenic species associated with CI; these were correlated with increased production of inflammatory cytokines and Th17- and JAK/STAT-signaling pathways in peripheral blood mononuclear cells. In the wounds of CI patients, we identified specific changes in microbiota and alterations in inflammatory pathways, which are likely responsible for impaired wound healing.

CONCLUSIONS

Together, this research enhances our understanding of the microbiological, immunological, and molecular properties of CI and should provide critical information for improving therapeutic management of CI patients.

[Inflammatory dermatoses in children and adolescents : Diagnosis and treatment of atopic dermatitis and psoriasis]

Atopic dermatitis (AD) and psoriasis belong to the most common inflammatory dermatoses that we treat in everyday clinical practice. AD manifests in more than 70% of cases before the age of 5 years. Approximately one-third of psoriasis patients report on onset of disease in the first two decades of life. Here, we are going to review both disorders in the light of pediatric dermatology. We are going to discuss selected subtypes and present clues for further examination with respect to the differential diagnoses and comorbidities. The article provides insight into current therapeutic developments that are relevant for the treatment of children and adolescents.

Biologics for inherited disorders of keratinisation: A systematic review

BACKGROUND/OBJECTIVES

Recent literature highlights the potential of biologics in the management of inherited disorders of keratinisation. In this study, we conducted a systematic review of existing literature on treatment outcomes of inherited keratinisation disorders treated with biologics.

METHODS

Eligible records were retrieved through searches of the electronic databases MEDLINE, Embase, PubMed and Scopus. Databases were searched from inception to July 2023 for eligible records. A snowballing method was employed to search the references of the retrieved records for the identification of potentially relevant articles.

RESULTS

One hundred and four eligible studies consisting of a total of 166 patients with an inherited disorder of keratinisation were included. Patients had a median age of 19 years (range: 0.5 to 70 years). The most common disorders were Netherton syndrome (n = 63; 38%), autosomal recessive congenital ichthyoses (n = 27; 16%), CARD14-associated papulosquamous eruptions (n = 17; 10%) and familial pityriasis rubra pilaris (PRP) (n = 15; 9%).Of the 207 times biologics were employed, the three most frequently employed biologics were secukinumab (n = 47; 23%), dupilumab (n = 44; 21%) and ustekinumab (n = 37; 18%). Complete remission was observed in 10 (5%) instances, partial remission in 129 (62%), no or limited response to biologic therapy in 68 (32%) cases, and results are still pending in one case. A total of 33 adverse events were reported.

CONCLUSIONS

Whilst biologics may be considered in cases of inherited keratinisation disorders recalcitrant to standard therapy, definitive conclusions are prohibited by the low-level of evidence and substantial heterogeneity in methodology across the included studies. Establishment of consensus definitions, and randomised clinical trials may help ascertain the efficacy and safety of biologic therapy in this context and establish the best agent and dosing protocol for each disorder.

Staphylococcus aureus proteases trigger eosinophil-mediated skin inflammation

Staphylococcus aureus skin colonization and eosinophil infiltration are associated with many inflammatory skin disorders, including atopic dermatitis, bullous pemphigoid, Netherton's syndrome, and prurigo nodularis. However, whether there is a relationship between S. aureus and eosinophils and how this interaction influences skin inflammation is largely undefined. We show in a preclinical mouse model that S. aureus epicutaneous exposure induced eosinophil-recruiting chemokines and eosinophil infiltration into the skin. Remarkably, we found that eosinophils had a comparable contribution to the skin inflammation as T cells, in a manner dependent on eosinophil-derived IL-17A and IL-17F production. Importantly, IL-36R signaling induced CCL7-mediated eosinophil recruitment to the inflamed skin. Last, S. aureus proteases induced IL-36α expression in keratinocytes, which promoted infiltration of IL-17-producing eosinophils. Collectively, we uncovered a mechanism for S. aureus proteases to trigger eosinophil-mediated skin inflammation, which has implications in the pathogenesis of inflammatory skin diseases.

[A case of neonatal Netherton syndrome]

A male infant, aged 6 days, was admitted to the hospital due to respiratory distress and systemic desquamative rash after birth. The infant presented with erythema and desquamative rash, respiratory failure, recurrent infections, chronic diarrhea, hypernatremic dehydration, and growth retardation. Comprehensive treatment, including anti-infection therapy, intravenous immunoglobulin administration, and skin care, resulted in improvement of the rash, but recurrent infections persisted. Second-generation sequencing revealed a homozygous mutation in the SPINK5 gene, consistent with the pathogenic variation of Netherton syndrome. The family opted for palliative care, and the infant died at the age of 2 months after discharge. This report documents a case of Netherton syndrome caused by the SPINK5 gene mutation in the neonatal period, and highlights multidisciplinary diagnosis and therapy for this condition.

Cross-sectional nationwide epidemiologic survey on quality of life and treatment efficacy in Japanese patients with congenital ichthyoses

BACKGROUND

Congenital ichthyoses sometimes present with severe skin symptoms that significantly affect the patient's quality of life (QOL). Symptomatic treatments are the mainstay therapies, and their efficacy is limited and inadequate.

OBJECTIVE

To assess the disease severity and QOL in patients with congenital ichthyoses, and to investigate the effectiveness of current treatments.

METHODS

We conducted a questionnaire-based Japan-wide epidemiological survey of patients with congenital ichthyosis who received medical care from 1 January 2016-31 December 2020. Effectiveness of past and current treatments was assessed. The outcomes were the physician's assessment, disease severity assessed using the clinical ichthyosis score (CIS), and the disease burden estimated using the Dermatology Life Quality Index (DLQI), the Children's Dermatology Life Quality Index (CDLQI), and the Infants' Dermatitis Quality of Life Index.

RESULTS

One hundred patients with 14 ichthyosis subtypes from 47 institutes were included in the final analysis. The CDLQI score showed a positive correlation with CIS (rs = 0.59, p = 0.004), while the DLQI score showed no significant correlation (rs = 0.13, p = 0.33). All existing medications were effective for many patients. Etretinate improved QOL and reduced CIS, but side effects including bone growth retardation were reported. Decreased treatment willingness was observed in patients with very low and very high CIS.

CONCLUSION

QOL scores were found to correlate with CIS in children, but not in adults. Considering the adverse events, it is speculated that etretinate is not indicated for children with mild cases. Petrolatum was the most commonly used medication, even in patients who were reluctant to receive treatment.

Secukinumab for Netherton syndrome: a Malaysian experience

We described three patients with Netherton syndrome in Malaysia treated with secukinumab with variable outcomes. To date, there have only been reports of about eight patients being treated with secukinumab globally with this condition, with good outcomes. We hope our observation will add to the existing global pool of information about Netherton syndrome treated with secukinumab.

IL-17 in osteoarthritis: A narrative review

Osteoarthritis (OA) is a painful joint disease that is common among the middle-aged and elderly populations, with an increasing prevalence. Therapeutic options for OA are limited, and the pathogenic mechanism of OA remains unclear. The roles of cytokines and signaling pathways in the development of OA is a current research hot spot. Interleukin (IL)-17 is a pleiotropic inflammatory cytokine produced mainly by T helper 17 cells that has established roles in host defense, tissue repair, lymphoid tissue metabolism, tumor progression, and pathological processes of immune diseases, and studies in recent years have identified an important role for IL-17 in the progression of OA. This narrative review focuses on the mechanisms by which IL-17 contributes to articular cartilage degeneration and synovial inflammation in OA and discusses how IL-17 and the IL-17 signaling pathway affect the pathological process of OA. Additionally, therapeutic targets that have been proposed in recent years based on IL-17 and its pathway in OA are summarized as well as recent advances in the study of IL-17 pathway inhibitors and the potential challenges of their use for OA treatment.

Congenital Ichthyosis: A Practical Clinical Guide on Current Treatments and Future Perspectives

Congenital ichthyoses are a group of hereditary disorders of keratinization that are challenging to treat. Affected individuals suffer not only from thickening of the skin but also associated complications such as growth restriction, hearing and eye complications, infections, and thermodysregulation. This clinical review provides a practical roadmap to the longitudinal care of patients with ichthyosis with both general and age- and disease-specific recommendations. The allure of pathogenesis-based and targeted treatments for these monogenetic severe but orphan conditions shines bright as dermatological therapies enter a new era.

Netherton syndrome in a Bulgarian patient : Presentation of a case and an update of therapeutic options

Comel-Netherton syndrome, or Netherton syndrome (NS), is a rare chronic genetic skin condition affecting the daily life of patients, which often results in poorly developed social skills and anxiety. Genetic predisposition plays a key role alongside the clinical findings, and clinicians must be aware of it as it can mimic other well-known skin conditions. Diagnosis is challenging both clinically and histologically. Clinically, it can mimic a severe form of atopic dermatitis, psoriasiform dermatitis overlapping with atopic dermatitis, or erythrokeratodermia variabilis. The difficulties in making histological diagnosis are similar, and it is often necessary to take several biopsies in order to clarify the diagnosis. Although retinoids are used for both psoriasis, erythrokeratodermia variabilis, and other congenital forms of keratodermia, the recommended treatment doses are different. This often results in poor treatment outcome. We present a 16-year-old patient previously diagnosed as erythrokeratodermia variabilis and treated with little to no improvement. Systemic therapy with acitretin 10 mg daily, local pimecrolimus 1%, emollients, and bilastine 20 mg once daily was initiated. Due to the limited application of retinoids and the difficulties in achieving permanent remission, modern medicine is faced with the challenge of seeking innovative therapeutic solutions. New hopes are placed on targeted or anti-cytokine therapy, based on inhibiting the inflammatory component of the disease. This article is mainly focused on innovative therapeutic options, including modern medications such as dupilumab, infliximab, secukinumab, anakinra, omalizumab, and others.

Ichthyosis: presentation and management

PURPOSE OF REVIEW

This review focuses on the presentation and management of ichthyoses and highlights recent advances in treatment that hold promise for better targeted therapy.

RECENT FINDINGS

The ichthyoses are a group of rare genetic diseases with a wide phenotypic spectrum, characterized most often by generalized hyperkeratosis and scaling with variable erythema. The highly visible scaling and frequent itch contribute to decreased quality of life. Management for ichthyosis focuses on symptomatic relief and scale reduction with emollients, keratolytics, and retinoids. Recent advances in immune profiling and genotype-phenotype mapping have increased understanding of ichthyosis and shifted focus to pathogenesis-based targeted therapies with emerging biologics, small molecular inhibitors, and gene therapy.

SUMMARY

This article discusses clinical assessment and genotyping to make the diagnosis of specific forms of ichthyosis, provides guidance for management, and reviews new treatment options with systemic agents.

The role of IL-17 in acute kidney injury

Acute kidney injury (AKI) is a common clinical kidney disease with a high mortality rate. AKI is caused by a variety of factors, including sepsis, ischemia, and nephrotoxic drugs, and can progress to chronic kidney disease and end-stage renal disease. Numerous studies have suggested that cytokines can be used as therapeutic targets for AKI. IL-17 is a pro-inflammatory cytokine that not only participates in the host defense and the development of autoimmune diseases but also is linked to AKI due to a variety of factors. This review will give an overview of the structure, signaling pathways, and biological functions of IL-17, as well as its role in AKI, to show that IL-17 is a potential target for the prevention and treatment of AKI.

Treatment of Netherton Syndrome With Abrocitinib

This case report describes a 28-year-old woman with Netherton syndrome who had large erythematous migratory patches with serpiginous double-edged scales on her face, neck, trunk, and extremities.

Interleukin-18 as a severity marker and novel potential therapeutic target for epidermolytic ichthyosis

BACKGROUND

Epidermolytic ichthyosis (EI) is a major form of nonsyndromic inherited ichthyosis, characterized by erythroderma, marked hyperkeratosis and scale, bulla and erosion at birth, associated with KRT1/KRT10 mutations. The cytokine and chemokine profiles in EI are poorly understood, and specific treatment options have not been established.

AIM

To explore novel biomarkers and therapeutic targets in patients with EI.

METHODS

We analysed cytokine levels in serum and skin samples from 10 patients with inherited ichthyosis, including seven patients with EI. Wild-type and mutant KRT1 constructs were established and transfected into HaCaT cells, an immortalized keratinocyte cell line, for in vitro immunoblotting and immunocytochemistry analyses.

RESULTS

Multiplex cytokine/chemokine analysis revealed that 10 cytokines/chemokines [interleukin (IL)-1β, IL-4, IL-17A, IL-16, IL-18, IL-1 receptor-α, macrophage colony-stimulating factor, interferon-α2, basic fibroblast growth factor and monocyte chemotactic protein-3] were significantly increased in patients with EI. Furthermore, IL-18 levels were significantly higher in patients with EI [n = 7; 2714.1 (1438.0) pg mL-1] than in healthy controls [n = 11; 218.4 (28.4) pg mL-1, P < 0.01]. Immunohistochemical analyses showed that IL-18 expression was elevated in skin samples from patients with EI. Serum IL-18 levels correlated with the severity of ichthyosis, as measured by the Ichthyosis Scoring System. Immunoblotting analysis revealed that mature IL-18 levels were increased in the supernatant of mutant KRT1 expressing HaCaT cells. Additionally, these cells showed NLRP3 aggregation in the cytoplasm and ASC clustered around mutant keratin aggregations. These findings suggest that mutant keratin might promote the activation of the NLRP3 inflammasome and its downstream caspase-1-mediated IL-18 release in keratinocytes from patients with EI.

CONCLUSIONS

Our results suggest that serum IL-18 is a severity marker released from the skin of patients with EI. Blockade of IL-18 may be a useful novel therapeutic option for patients with EI.

Secukinumab responses vary across the spectrum of congenital ichthyosis in adults

IMPORTANCE

Treatment of congenital ichthyoses primarily focuses on reversing skin scaling and is not pathogenesis based. Recent studies showed Th17 immune skewing, as in psoriasis, across the spectrum of ichthyosis, suggesting that targeting this pathway might broadly reduce disease severity.

OBJECTIVE

To determine whether secukinumab, an IL-17A inhibitor, can improve ichthyosis across several congenital ichthyosis subtypes.

DESIGN

Exploratory 16-week double-blind, randomized, placebo-controlled trial comparing secukinumab 300 mg every 4wks to placebo (1:1 randomization) in adults with the four major congenital ichthyosis subtypes (NCT03041038), followed by a 16-week open-label phase to evaluate response of the placebo-first group and a 20-week extension for safety. Significant differences in secukinumab- vs. placebo-treated subjects at Wk16 in the Ichthyosis Area Severity Index (IASI) score and lack of increased mucocutaneous bacterial and/or fungal infections were the co-primary efficacy and safety endpoints, respectively.

SETTING

Two tertiary referral centers: Northwestern University Feinberg School of Medicine, Chicago, and Mount Sinai Icahn School of Medicine, New York.

PARTICIPANTS

Twenty subjects ≥ 18 yo with genotype-confirmed epidermolytic ichthyosis, Netherton syndrome, lamellar ichthyosis, or congenital ichthyosiform erythroderma with at least moderate erythroderma.

RESULTS

IL-17A inhibition did not significantly reduce severity or increase mucocutaneous infections among the 18 who completed the 16-week double-blind phase. Five patients with 29-50% clinical improvement at Wk32 requested drug continuation. Th17-related biomarkers were not significantly reduced vs. baseline or placebo-treated levels.

LIMITATIONS

Small sample size; heterogeneous ichthyosis subsets.

CONCLUSION

IL-17 inhibition with secukinumab is safe, but not efficacious across the spectrum of adult ichthyoses.

CLINICALTRIALS

GOV REGISTRATION NUMBER

NCT03041038; first posted on 02/02/2017.

Treatment Experiences with Intravenous Immunoglobulins, Ixekizumab, Dupilumab, and Anakinra in Netherton Syndrome: A Case Series

BACKGROUND

Netherton syndrome (NS) is a rare potential life-threatening disorder that causes severe defects to the skin barrier. No effective treatment options are available for patients with NS and current therapy is mostly supportive. The effects of intravenous immunoglobulins (IVIGs), ixekizumab, and dupilumab have scarcely been reported. Additionally, the role of anakinra in patients with NS has never been investigated.

OBJECTIVES

The objective was to report our experiences of treatment with IVIG, ixekizumab, dupi-lumab, and anakinra in patients with NS.

METHODS

A retrospective case series, including 5 patients with NS, was performed in a tertiary referral hospital between 2016 and 2021. Patients were treated with IVIG, ixekizumab, dupilumab, and/or anakinra. Long-term experiences with treatment regimens and adverse events requiring medical attention were reported.

RESULTS

IVIG, ixekizumab, dupilumab, and anakinra were well tolerated with no severe adverse events. The 2 patients that received IVIG showed clinical response for 6 months and 2.5 years. Ixekizumab was effective in 1 of our patients for 3.5 years, while in another patient ixekizumab lost its effect after 1.5 years. Dupilumab treatment did not result in persistent improvement of NS-related skin symptoms in 1 patient. Anakinra showed physician-assessed clinical response during the first months of treatment in 4 patients with NS. During anakinra treatment, no changes in blood levels of IL-1β, IL-6, and TNF-α levels were measured at routine blood examinations.

CONCLUSIONS

This case series suggests that the use of IVIG, ixekizumab, dupilumab, and anakinra in NS is safe and moderately effective on the short term. On the long term, a decline in effect was observed. Our experiences may help clinicians and researchers to provide adequate care and develop treatment for these severely affected patients. More international research, especially on the long term, is needed to determine if and which patients benefit most from the emerging therapies for NS.

Tailored treatments in inborn errors of immunity associated with atopy (IEIs-A) with skin involvement

Inborn errors of immunity associated with atopy (IEIs-A) are a group of inherited monogenic disorders that occur with immune dysregulation and frequent skin involvement. Several pathways are involved in the pathogenesis of these conditions, including immune system defects, alterations of skin barrier and metabolism perturbations. Current technological improvements and the higher accessibility to genetic testing, recently allowed the identification of novel molecular pathways involved in IEIs-A, also informing on potential tailored therapeutic strategies. Compared to other systemic therapy for skin diseases, biologics have the less toxic and the best tolerated profile in the setting of immune dysregulation. Here, we review IEIs-A with skin involvement focusing on the tailored therapeutic approach according to their pathogenetic mechanism.

Report of two sisters with Netherton syndrome successfully treated with dupilumab and review of the literature

Different monoclonal antibodies have been used for the treatment of Netherton's syndrome (NS); secukinumab (anti-IL17A), infliximab (anti-TNF-α), ustekinumab (anti p40 subunit of IL-12 and IL-23), omalizumab (anti-IgE), and dupilumab (anti-IL4 and IL13). We report two sisters with severe NS who were treated with omalizumab in one and with secukinumab in the other. In view of the therapeutic failure, treatment with dupilumab was started in both sisters. The data were analyzed 16 weeks after starting treatment with dupilumab. Treatment response was assessed using the Severity Scoring Atopic Dermatitis (SCORAD); Eczema Area and Severity Index (EASI); Pruritus Numeric Rating Scale (NSR); Netherton Area Severity Assessment (NASA) and Dermatology Life Quality Index Ichthyosis. All scores were reduced after 16 weeks of treatment with dupilumab in both patients. She maintains improvement after 18 months and 12 months of treatment, respectively. No severe adverse events were reported. Treatment with dupilumab in two sisters with NS and atopic diseases produced a marked cutaneous improvement after a failed attempt with omalizumab and secukinumab. Further studies are needed to determine which biologic therapy is the most effective in NS.

Prevalence of and risk factors for nutritional deficiency and food allergy in a cohort of 21 patients with Netherton syndrome

BACKGROUND

Netherton syndrome (NS; OMIM: 256500) is a rare autosomal recessively inherited disease due to SPINK5 mutations. Hair and inflammatory skin involvement are variable along with allergies. Morbidity and mortality are high, particularly in infancy. A detailed clinical analysis of a NS patient cohort should broaden the understanding of nutritional challenges and allergic comorbidities.

METHODS

In this retrospective monocentric cohort study, medical and dietetic records of pediatric NS patients, presenting between 1999 and 2018, were reviewed. The severity of skin involvement was assessed according to the extent of the body surface area (BSA) affected by erythema.

RESULTS

We identified 21 patients with NS (median age 11.6 years). Within the first 6 months of life, requirements for fluid and kcals/protein were high for all patients (average 228 ml/kg/day) and infants had an average of 1.9 feed changes (range 0-4) due to food intolerance. Clinical evidence for IgE-mediated food allergy was present in 84.2% (16/19 children, 2 no data) with a range of 1-12 food allergies per patient. In 75%, more than one food had to be avoided. Specific IgE levels were falsely positive in 38.3% and 8/18 patients (44.4%). One-third (5/15; 6 no data) of patients, all with severe disease, had anaphylactic reactions following ingestion of fish (n = 2), sesame (n = 1), cow's milk (n = 1), and both peanut and egg (n = 1).

CONCLUSIONS

Our data emphasize feeding difficulties in children with NS and reveal an unexpectedly higher prevalence of food allergies that gives evidence to the importance of early coordinated multidisciplinary care for overcoming these challenges in NS.

Dupilumab improves clinical symptoms in children with Netherton syndrome by suppressing Th2-mediated inflammation

Background

Netherton syndrome is a rare, life-threatening autosomal recessive genetic disorder with no effective treatment yet. Skin barrier dysfunction caused by SPINK5 gene mutations is a hallmark of the disease. Antigen penetration through the defective skin and nonspecific inflammation provide a pro-T helper 2 (Th2) immune microenvironment in the disease. Therefore, Th2 cytokines are considered to be candidate therapeutic targets.

Objective

To evaluate the clinical responses of patients with Netherton syndrome to dupilumab, an IL-4Rα antagonist, and identify changes in the Th1/2/17 pathway activity, skin barrier defect protein LEKTI expression after treatment.

Methods

Four children with severe Netherton syndrome (aged 2 y to 4 y and 6 m) who were treated with dupilumab from January to June 2022 were evaluated at baseline, and at 4, 8, 12, 16, and 20 weeks after the start of dupilumab administration. Treatment response was assessed using the Eczema Area and Severity Index (EASI), the Numerical Rating Scale (NRS), the Dermatology Life Quality Index (CDLQI), and the Dermatitis Family Impact-questionnaire (DFI). Blood eosinophil counts, serum IgE levels and inflammatory cytokines were measured. The immunotyping of Th1/2/17 cells was performed by flow cytometry and cytokine expressions in T cell subsets were analyzed by single-cell RNA sequencing. In addition, expression of the LEKTI in skin lesions was evaluated by immunohistochemical analysis.

Results

All four patients experienced clinical improvement, with significantly reduced EASI scores (by 75.0-83.9%) and NRS (by 87.5-90.0%) from baseline to 20 weeks of treatment. Improved quality of life scores were also seen for all patients, as measured by CDLQI and DFI. Serum IgE levels also fell by 75.6-86.9%. The serum Th2 cytokines IL-4, IL-5 and IL-13 were found at low level, with no significant changes during the treatment. However, Th2 cytokines expressed by T cells, especially IL-4, decreased at single-cell level after treatment (P = 0.029). The baseline percentage of Th2 cells (among total CD3⁺CD4⁺ T cells) was significantly higher in patients than that in healthy controls (HC) (P < 0.0001); this percentage fell from 8.25% ± 0.75% to 4.02% ± 0.62% after 20 weeks dupilumab treatment. There was no noticeable change in LEKTI protein expression in skin lesions pre- and post-treatment. Two patients reported mild ocular adverse effects, but there were no severe adverse events.

Conclusion

Dupilumab may be an effective and safe treatment option in a subset of pediatric patients with Netherton syndrome, especially in improving itch and the quality of life. These effects were achieved in part by suppression of the Th2-mediated inflammation.

Ustekinumab therapy for Netherton syndrome

Netherton syndrome (NS) is a rare disorder of cornification associated with high morbidity. It is caused by bi-allelic mutations in SPINK5 encoding the serine protease inhibitor LEKTI. Previous studies have shown Th17 skewing with IL-23 upregulation in NS, raising the possibility that targeting these inflammatory pathways may alleviate disease manifestations. We ascertained the therapeutic efficacy of six doses of ustekinumab administered to three patients with NS over a period of 13 months using the Ichthyosis Area and Severity Index (IASI), the Dermatology Life Quality Index (DLQI), a visual analogue scale (VAS) for itch and the peak-pruritus numeric rating scale (PP-NRS). Histopathology analysis including CD3, CD4, CD8 and interleukin 17 (IL-17) immunostaining, was performed at baseline and 4 weeks following the last ustekinumab dose. Total IASI scores were reduced by 28% in two patients at week 16 with sustained response by week 56. No consistent improvement in DLQI, VAS for itch and PP-NRS scores was observed. The inflammatory infiltrate and the degree of acanthosis were slightly reduced at week 56 as compared to baseline. No significant change in immunostaining of the various inflammatory markers was observed at week 56. In conclusion, this case series did not demonstrate a significant therapeutic effect of ustekinumab in NS.

Transcriptomic Analysis of the Major Orphan Ichthyosis Subtypes Reveals Shared Immune and Barrier Signatures

Preliminary work suggested upregulation of inflammatory pathways in patients with common forms of ichthyosis. However, a comprehensive characterization of skin from various ichthyosis subtypes is unavailable, precluding the development of targeted treatments. Thus, we sought to characterize the immune and barrier profiles of common and subtype-specific skin transcriptomes in a large group of patients with ichthyosis. We performed a global RNA-sequencing analysis in 54 patients with ichthyosis (7 with Netherton syndrome, 13 with epidermolytic ichthyosis, 16 with lamellar ichthyosis, and 18 with congenital ichthyosiform erythroderma) and 40 healthy controls. Differentially expressed genes were defined on the basis of fold changes > 2 and false discovery rate < 0.05 criteria. We found robust and significant T helper (Th) 22/Th17 skewing in all subtypes (e.g., IL-17A/C/F, S100A7/8/9/12; P < 0.001) with modest changes in Th2 pathway, primarily in Netherton syndrome, and Th1 skewing in congenital ichthyosiform erythroderma. Across all subtypes (less evident in epidermolytic ichthyosis), lipid metabolism and barrier junction markers were downregulated (e.g., FA2H, CDH10/11/12/2; P < 0.05), whereas epidermal cornification and proliferation measures were upregulated (e.g., SPRR1A/1B/2C/2G, EREG; P < 0.05). Our findings suggest that the common ichthyosis variants share aberrations in Th17/Th22 and barrier function, with minimal Th2 modulation. This may help to elucidate the pathogeneses of these subtypes and inform the development of subtype-specific treatments.

Revertant Mosaicism in Genodermatoses: Natural Gene Therapy Right before Your Eyes

Revertant mosaicism (RM) is the intriguing phenomenon in which nature itself has successfully done what medical science is so eagerly trying to achieve: correcting the effect of disease-causing germline variants and thereby reversing the disease phenotype back to normal. RM was molecularly confirmed for the first time in a genodermatosis in 1997, the genetic skin condition junctional epidermolysis bullosa (EB). At that time, RM was considered an extraordinary phenomenon. However, several important discoveries have changed this conception in the past few decades. First, RM has now been identified in all major subtypes of EB. Second, RM has also been identified in many other genodermatoses. Third, a theoretical mathematical exercise concluded that reverse mutations should be expected in all patients with a recessive subtype of EB or any other genodermatosis. This has shifted the paradigm from RM being an extraordinary phenomenon to it being something that every physician working in the field of genodermatoses should be looking for in every patient. It has also raised hope for new treatment options in patients with genodermatoses. In this review, we summarize the current knowledge on RM and discuss the perspectives of RM for the future treatment of patients with genodermatoses.

New developments in the molecular treatment of ichthyosis: review of the literature

Ichthyosis covers a wide spectrum of diseases affecting the cornification of the skin. In recent years, new advances in understanding the pathophysiology of ichthyosis have been made. This knowledge, combined with constant development of pathogenesis-based therapies, such as protein replacement therapy and gene therapy, are rather promising for patients with inherited skin diseases. Several ongoing trials are investigating the potency of these new approaches and various studies have already been published. Furthermore, a lot of case series report that biological therapeutics are effective treatment options, mainly for Netherton syndrome and autosomal recessive congenital ichthyosis. It is expected that some of these new therapies will prove their efficacy and will be incorporated in the treatment of ichthyosis.

Atopy as Immune Dysregulation: Offender Genes and Targets

Allergic diseases are a heterogeneous group of disorders resulting from exaggerated type 2 inflammation. Although typically viewed as polygenic multifactorial disorders caused by the interaction of several genes with the environment, we have come to appreciate that allergic diseases can also be caused by monogenic variants affecting the immune system and the skin epithelial barrier. Through a myriad of genetic association studies and high-throughput sequencing tools, many monogenic and polygenic culprits of allergic diseases have been described. Identifying the genetic causes of atopy has shaped our understanding of how these conditions occur and how they may be treated and even prevented. Precision diagnostic tools and therapies that address the specific molecular pathways implicated in allergic inflammation provide exciting opportunities to improve our care for patients across the field of allergy and immunology. Here, we highlight offender genes implicated in polygenic and monogenic allergic diseases and list targeted therapeutic approaches that address these disrupted pathways.

Cytokines and chemokines modulation of itch

Itch (pruritus) is a common cutaneous symptom widely associated with many skin complaints, and chronic itch can be a severe clinical problem. The onset and perpetuation of itch are linked to cytokines, such as interleukin (IL)-31, IL-4, IL-13, IL-33, thymic stromal lymphopoietin, and tumor necrosis factor-alpha, and chemokines, such as chemokine (C-C motif) ligand 2 and C-X-C motif chemokine ligand 10. This review highlights research that has attempted to determine the attributes of various cytokines and chemokines concerning the development and modulation of itch. Through such research, clinical approaches targeting cytokines and/or chemokines may arise, which may further the development of itch therapeutics.

Secukinumab use in the treatment of Netherton's syndrome

Netherton syndrome is a rare, severe genetic disorder of cornification without specific treatment. We describe two cases who demonstrated marked cutaneous improvement with secukinumab and suggest a role for IL-17 therapy in treating this condition.

Biologic Therapies for the Management of Cutaneous Findings in Genodermatoses: A Review

Genodermatoses are genetically inherited dermatologic conditions. The management of cutaneous findings in genodermatoses is challenging, and first-line therapies, such as steroids and/or retinoids, are often inadequate. In recent years, research on the molecular basis of genodermatoses has led to the use of biologic therapies for intractable disease. Here, we review the evidence regarding the use of available biologic therapies for the management of dermatologic findings in genodermatoses. Biologic therapies appear to be promising therapeutic options for several recalcitrant genodermatoses, especially those with underlying immune dysregulation. However, not all genodermatoses are amenable to biologic therapies, and some have been shown to paradoxically worsen under treatment. Biologic therapies offer a novel avenue to target refractory genodermatoses. However, evidence supporting the use of biologic therapies in the management of genodermatoses is mostly limited to case reports and case series. Further studies are warranted to determine the safety and efficacy of biologic therapies for the management of cutaneous findings in genodermatoses.

Loricrin at the Boundary between Inside and Outside

Cornification is a specialized mode of the cell-death program exclusively allowed for terrestrial amniotes. Recent investigations suggest that loricrin (LOR) is an important cornification effector. As the connotation of its name (“lorica” meaning an armor in Latin) suggests, the keratin-associated protein LOR promotes the maturation of the epidermal structure through organizing covalent cross-linkages, endowing the epidermis with the protection against oxidative injuries. By reviewing cornification mechanisms, we seek to classify ichthyosiform dermatoses based on their function, rather than clinical manifestations. We also reviewed recent mechanistic insights into the Kelch-like erythroid cell-derived protein with the cap “n” collar homology-associated protein 1/nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway in skin health and diseases, as LOR and NRF2 coordinate the epidermis-intrinsic xenobiotic metabolism. Finally, we refine the theoretical framework of cross-talking between keratinocytes and epidermal resident leukocytes, dissecting an LOR immunomodulatory function.

Outcomes of Systemic Treatment in Children and Adults With Netherton Syndrome: A Systematic Review

Background

Comèl-Netherton syndrome (NS) is a rare disease caused by pathogenic variants in the SPINK5 gene, leading to severe skin barrier impairment and proinflammatory upregulation. Given the severity of the disease, treatment of NS is challenging. Current treatment regimens are mainly topical and supportive. Although novel systemic treatment options for NS have been suggested in recent literature, little is known about their outcomes.

Objective

to provide an overview of systemic treatment options and their outcomes in adults and children with NS.

Methods

Embase, MEDLINE, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar were searched up to July 22, 2021. Empirical studies published in English language mentioning systemic treatment in NS were enrolled. Studies that did not define a treatment period or report at least one outcome were excluded. Methodological quality was evaluated by the Joanna Briggs Institute critical appraisal checklist for case reports or case series. Overall quality of evidence of the primary outcome, skin, was assessed by the GRADE approach.

Results

36 case series and case reports were included. The effects of 15 systemic therapies were described in 48 patients, of which 27 were children. Therapies included retinoids, prednisolone, cyclosporine, immunoglobulins, and biologicals. In retinoids both worsening (4/15 cases) and improvement (6/15 cases) of the skin was observed. Use of prednisolone and cyclosporine was only reported in one patient. Immunoglobulins (13/15 cases) and biologicals (18/21 cases) showed improvement of the skin. Certainty of evidence was rated as very low.

Conclusion

NS is a rare disease, which is reflected in the scarce literature on systemic treatment outcomes in children and adults with NS. Studies showed large heterogeneity in outcome measures. Adverse events were scarcely reported. Long-term outcomes were reported in a minority of cases. Nonetheless, a general beneficial effect of systemic treatment was found. Immunoglobulins and biologicals showed the most promising results and should be further explored. Future research should focus on determining a core outcome set and measurement instruments for NS to improve quality of research.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=217933, PROSPERO (ID: 217933).

Netherton syndrome subtypes share IL-17/IL-36 signature with distinct IFN-α and allergic responses

BACKGROUND

Netherton syndrome (NS) is a rare recessive skin disorder caused by loss-of-function mutations in SPINK5 encoding the protease inhibitor LEKTI (lymphoepithelial Kazal-type-related inhibitor). NS patients experience severe skin barrier defects, display inflammatory skin lesions, and have superficial scaling with atopic manifestations. They present with typical ichthyosis linearis circumflexa (NS-ILC) or scaly erythroderma (NS-SE).

OBJECTIVE

We used a combination of several molecular profiling methods to comprehensively characterize the skin, immune cells, and allergic phenotypes of NS-ILC and NS-SE patients.

METHODS

We studied a cohort of 13 patients comprising 9 NS-ILC and 4 NS-SE.

RESULTS

Integrated multiomics revealed abnormal epidermal proliferation and differentiation and IL-17/IL-36 signatures in lesion skin and in blood in both NS endotypes. Although the molecular profiles of NS-ILC and NS-SE lesion skin were very similar, nonlesion skin of each disease subtype displayed distinctive molecular features. Nonlesion and lesion NS-SE epidermis showed activation of the type I IFN signaling pathway, while lesion NS-ILC skin differed from nonlesion NS-ILC skin by increased complement activation and neutrophil infiltration. Serum cytokine profiling and immunophenotyping of circulating lymphocytes showed a T_H2-driven allergic response in NS-ILC, whereas NS-SE patients displayed mainly a T_H9 axis with increased CCL22/MDC and CCL17/TARC serum levels.

CONCLUSIONS

This study confirms IL-17/IL-36 as the predominant signaling axes in both NS endotypes and unveils molecular features distinguishing NS-ILC and NS-SE. These results identify new therapeutic targets and could pave the way for precision medicine of NS.

Stratum corneum as polymer sheet: concept and cornification processes

The skin barrier protects our body from external insults and water loss through a specialized layer, the stratum corneum. The stratum corneum, an accumulation of dead keratinocytes (corneocytes), comprises lipids and supporting cell bodies. We propose a framework of lipid-filled polymer sheet of corneocytes, a unique structure that achieves flexibility and robustness, updating the rigid image of the historical bricks-and-mortar model. The polymerization of polymer sheet (cornification) by cell death of keratinocytes (corneoptosis) is delicately and dynamically controlled by cytoplasmic calcium ion and pH. Understanding the structure and formation of the stratum corneum can lead to better treatments for skin diseases and a better understanding of the evolution of the stratum corneum.

Dupilumab Improves Pruritus in Netherton Syndrome: A Case Study

The patient was a 26-year-old male. He had red and scaling skin of the entire body since birth, as well as an elevated level of serum IgE. Genetic testing revealed a mutation in the SPINK5 gene, which had confirmed the diagnosis with Netherton syndrome. He has had significant pruritis since birth, and subsequently had symptoms of sleeping disorders and concentration difficulty throughout the day. Since treatment with various antihistamines were not effective, we administered dupilumab and found that it was effective in immediate elimination of pruritus and gradual reduction of the rash. Dupilumab has been administered for one year without any adverse events or recurrence of symptoms. Although studies have previously described cases who used dupilumab for Netherton syndrome, reported effects have been limited or transient. Additional studies are needed to confirm the effect of dupilumab for Netherton syndrome, which currently lack any effective treatment strategies.

Challenges in Treating Genodermatoses: New Therapies at the Horizon

Genodermatoses are rare inherited skin diseases that frequently affect other organs. They often have marked effects on wellbeing and may cause early death. Progress in molecular genetics and translational research has unravelled many underlying pathological mechanisms, and in several disorders with high unmet need, has opened the way for the introduction of innovative treatments. One approach is to intervene where cell-signaling pathways are dysregulated, in the case of overactive pathways by the use of selective inhibitors, or when the activity of an essential factor is decreased by augmenting a molecular component to correct disequilibrium in the pathway. Where inflammatory reactions have been induced by a genetically altered protein, another possible approach is to suppress the inflammation directly. Depending on the nature of the genodermatosis, the implicated protein or even on the particular mutation, to correct the consequences or the genetic defect, may require a highly personalised stratagem. Repurposed drugs, can be used to bring about a "read through" strategy especially where the genetic defect induces premature termination codons. Sometimes the defective protein can be replaced by a normal functioning one. Cell therapies with allogeneic normal keratinocytes or fibroblasts may restore the integrity of diseased skin and allogeneic bone marrow or mesenchymal cells may additionally rescue other affected organs. Genetic engineering is expanding rapidly. The insertion of a normal functioning gene into cells of the recipient is since long explored. More recently, genome editing, allows reframing, insertion or deletion of exons or disruption of aberrantly functioning genes. There are now several examples where these stratagems are being explored in the (pre)clinical phase of therapeutic trial programmes. Another stratagem, designed to reduce the severity of a given disease involves the use of RNAi to attenuate expression of a harmful protein by decreasing abundance of the cognate transcript. Most of these strategies are short-lasting and will thus require intermittent life-long administration. In contrast, insertion of healthy copies of the relevant gene or editing the disease locus in the genome to correct harmful mutations in stem cells is more likely to induce a permanent cure. Here we discuss the potential advantages and drawbacks of applying these technologies in patients with these genetic conditions. Given the severity of many genodermatoses, prevention of transmission to future generations remains an important goal including offering reproductive choices, such as preimplantation genetic testing, which can allow selection of an unaffected embryo for transfer to the uterus.

Biological treatments for pediatric Netherton syndrome

Netherton syndrome (NS) is a rare and potentially life-threatening genetic skin disease responsible for skin inflammation and scaling, hair abnormalities and severe allergic manifestations. NS is caused by loss-of-function variants in Serine Peptidase Inhibitor Kazal-Type 5 (SPINK5), encoding the serine protease inhibitor LEKTI. NS patients have a profound skin barrier defect caused by unopposed kallikrein-related proteases activity (KLKs). They develop severe skin inflammation with eczematous-like lesions and high serum IgE levels. Multiomics studies have revealed that the IL-17/IL-36 pathway is the most predominant upregulated pathway in NS. It is associated with a Th2 signature with complement activation in the ichthyosis linearis circumflexa subtype, and with interferon and Th9 activation in the scaly erythrodermic form. Several case reports proved the efficacy of different biotherapies targeting IL-17A, IL-12/IL-23, IL-4R and IL-13R, TNF-a and IL-1β in pediatric NS patients. Intravenous immunoglobulins (IVIG) have also shown efficacy. These studies showed no severe side effects. At present, IL-17 blockade seems to be the most efficient treatment, but case reports remain limited with small numbers of patients and no placebo-control. Additional pathways must also be explored, and more efficient strategies could be used to block IL-17 and IL-23 pathways. In the future, the combination of specific strategies aiming at repairing the initial skin barrier defect could potentiate the efficacy of biologics. The current reports suggest that biological therapy is safe and often effective at pediatric age. However, controlled clinical trials that include a larger number of patients need to be conducted to reach more reliable conclusions.

Successful treatment of Netherton syndrome with dupilumab: A case report and review of the literature

Netherton syndrome (NS) is a rare autosomal recessive genetic disease caused by SPINK5 gene mutation without specific effective therapies available. We report a case of NS confirmed by whole exome sequencing of DNA using peripheral blood, and Sanger sequencing found two new mutations associated with her clinical presentation located at SPINK5 gene c.1220+5G>A from her father and c.1870delA from her mother. The patient was treated with dupilumab (600 mg at week 0, then 300 mg every 2 weeks, s.c.). The clinical manifestation and dermoscopic images of the patient's hair showed remarkable improvement after dupilumab treatment with no adverse effects. We also reviewed previous reports to learn more about the therapeutic effect and adverse reactions of NS treated with dupilumab.

Netherton syndrome plus atopic dermatitis: Two new genetic mutations in the same patient

A child who comes to our attention for the appearance of erythematous, scaly lesions localized to the upper and lower limbs for 2 months. Histological features suggested ichthyosiform disease and concomitant mutations in the SPINK5 and FLG2 genes confirmed Netherton syndrome with severe atopic manifestations.

Netherton Syndrome: Case Report and Review of the Literature

Netherton syndrome (NS) is a rare genodermatosis with an autosomal recessive pattern of inheritance caused by pathogenic variants in the SPINK5 gene. It is characterized by a triad consisting of atopic diathesis, ichthyosis linearis circumflexa, and hair shaft abnormalities. Ichthyosis linearis circumflexa can be confused with atopic dermatitis leading to a delayed diagnosis. Furthermore, difficulty in making the differential diagnosis with other atopiform, erythrodermic, and ichthyosiform entities that exhibit hair shaft abnormalities represent a challenge. Trichoscopy is an accessible and noninvasive auxiliary diagnostic tool in these cases; the hair shaft abnormalities found in NS are bamboo, golf tee, and matchstick hairs. Identification of a pathogenic variant in the SPINK5 gene through genetic testing is necessary to confirm the diagnosis. Multiple treatment options are available including topical therapy with emollients, corticosteroids, calcineurin inhibitors, antiseptics, and narrowband UVB phototherapy. Systemic treatments comprehend intravenous immunoglobulins, and advances in the understanding of the pathophysiology of NS have led to more directed therapies with biologics such as infliximab, ixekizumab, secukinumab, ustekinumab, and dupilumab. Treatments currently under investigation include inhibitors of kallikrein 5, cathelicidins, drugs activating the transcription factor nuclear factor erythroid-derived 2-like 2, and gene therapy using autologous keratinocytes induced with a lentiviral vector encoding SPINK5.

Alarmins/stressorins and immune dysregulation in intractable skin disorders

Unlike other barrier epithelia of internal organs, the stratified squamous epithelium of the skin is always exposed to the external environment. However, the robust barrier structure and function of the skin are highly resistant against external insults so as to not easily allow foreign invasions. Upon sensing danger signals, the innate immunity system is promptly activated. This process is mediated by alarmins, which are released passively from damaged cells. Nuclear alarmins or stressorins are actively released from intact cells in response to various cellular stresses. Alarmins/stressorins are deeply involved in the disease processes of chronic skin disorders of an unknown cause, such as rosacea, psoriasis, and atopic dermatitis. Furthermore, alarmins/stressorins are also induced in the congenital skin disorders of ichthyosis and keratoderma due to defective keratinization. Studies on alarmin activation and its downstream pathways may help develop novel therapeutic agents for intractable skin disorders.

Scalp roof tiles.: A new diagnostic sign in neonates with Netherton Syndrome

A 2-month-old baby boy, of full-term spontaneous vaginal delivery, presented to the dermatology outpatient clinic with generalized erythroderma, which had been noted since birth. Family history was positive for similar disease in his eldest sister, who died at 6 months of age without a diagnosis. On examination, the patient looked ill with generalized erythroderma, yet there were no signs of ectropion, eclabium, or deformed ears. Diffuse scalp scaling was observed with interlocking tessellation scales over the scalp (Figure 1). Hair microscopy showed in Figure 2. All laboratory results were normal.

Eczematous Drug Eruptions

Eczematous drug eruptions are a heterogenous group of skin reactions that resemble eczema both clinically and histologically. We reviewed the literature and cataloged the systemically administered medications that cause these eruptions, along with their characteristic clinical presentations. We identified three primary pathophysiologic etiologies: (1) cutaneous immunomodulation, (2) skin dehydration, and (3) delayed hypersensitivity. Notably, eczematous eruptions caused by altered immunity in the skin may be increasing in incidence as some responsible drugs, in particular biologic therapies (such as tumor necrosis factor-α and interleukin-17 inhibitors) and targeted cancer treatments (including immune checkpoint inhibitors and epidermal growth factor receptor inhibitors), become more commonly employed in clinical practice. Other notable causes of eczematous eruptions include antiviral agents for hepatitis C virus and cardiovascular medications in elderly individuals, and notable subtypes of eczematous reactions include systemic contact dermatitis and photoallergic reactions, which are also discussed. The diagnostic gold standard is drug rechallenge and most reactions may be treated effectively with emollients, topical corticosteroids, and oral antihistamines.

A Potent and Selective Kallikrein-5 Inhibitor Delivers High Pharmacological Activity in Skin from Patients with Netherton Syndrome

Regulation of proteolytic activity in the skin plays a pivotal role in epidermal homeostasis. This is best exemplified in Netherton syndrome, a severe genetic skin condition caused by loss-of-function mutations in the gene serine protease inhibitor Kazal-type 5 encoding lympho-epithelial Kazal-type-related inhibitor, a serine protease inhibitor that regulates kallikrein (KLK)-related peptidase 5, 7, and 14 activities. KLK5 plays a central role in stratum corneum shedding and inflammatory cell signaling, activates KLK7 and KLK14, and is therefore an optimal therapeutic target. We aimed to identify a potent and selective small-molecule inhibitor of KLK5 amenable to epidermal delivery. GSK951 was identified using a structure-based design strategy and showed a half maximal inhibitory concentration of 250 pM for KLK5 and greater than 100-fold selectivity over KLK7 and KLK14. Cocrystal structure analysis identified the critical catalytic site interactions to a surrogate for KLK5. Topical application of GSK951-containing cream inhibited KLK5 activity in TgKLK5 mouse skin, reduced transepidermal water loss, and decreased proinflammatory cytokine expression. GSK951 achieved high concentrations in healthy human epidermis following topical application in a cream formulation. Finally, KLK5 protease activity was increased in stratum corneum of patients with Netherton syndrome and significantly inhibited by GSK951. These findings unveil a KLK5-specific small-molecule inhibitor with a high therapeutic potential for patients with Netherton syndrome.