Immune cell phenotype and functional defects in Netherton syndrome

Netherton syndrome-A therapeutic challenge in childhood

Key Clinical Message

High-dose intravenous immunoglobulin exhibits great potential in the treatment of Netherton syndrome.

Abstract

Netherton syndrome (NS) is a rare autosomal recessive genodermatosis (OMIM #256500) characterized by superficial scaling, atopic manifestations, and multisystemic complications. It is caused by loss-of-function mutations in the SPINK5 gene, which encode a key kallikrein protease inhibitor. There are two subtypes of the syndrome that differ in clinical presentation and immune profile: ichthyosiform erythroderma and ichthyosis linearis circumflexa. NS is a multisystemic disease with numerous extracutaneous manifestations. Current therapy for patients with NS is mainly supportive, as there is no curative or specific treatment, especially for children with NS, but targeted therapies are being developed. We describe an 8-year-old boy with genetically proven NS treated with intravenous immunoglobulin for recurrent skin and systemic infections from infancy, growth retardation, and associated erythroderma. Under this therapy, his skin status, infectious exacerbations, and quality of life all improved. Knowledge of the cytokine-mediated pathogenesis of NS and the development of new biologic drugs open new possibilities for NS patients. However, the different therapeutic options have been applied in a limited number of cases, and variable responses have been shown. Randomized controlled trials with a sufficient number of patients stratified and treated according to their specific immune profile and clinical phenotype are needed to evaluate the safety and efficacy of treatment options for patients with NS.

Infections in Inborn Errors of Immunity with Combined Immune Deficiency: A Review

Enhanced susceptibility to microbes, often resulting in severe, intractable and frequent infections due to usually innocuous organisms at uncommon sites, is the most striking feature in individuals with an inborn error of immunity. In this narrative review, based on the International Union of Immunological Societies' 2022 (IUIS 2022) Update on phenotypic classification of human inborn errors of immunity, the focus is on commonly encountered Combined Immunodeficiency Disorders (CIDs) with susceptibility to infections. Combined immune deficiency disorders are usually commensurate with survival beyond infancy unlike Severe Combined Immune Deficiency (SCID) and are often associated with clinical features of a syndromic nature. Defective humoral and cellular immune responses result in susceptibility to a broad range of microbial infections. Although disease onset is usually in early childhood, mild defects may present in late childhood or even in adulthood. A precise diagnosis is imperative not only for determining management strategies, but also for providing accurate genetic counseling, including prenatal diagnosis, and also in deciding empiric treatment of infections upfront before investigation reports are available.

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.

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.

Significant response to Pembrolizumab for metastatic cutaneous squamous cell carcinoma in patient with Netherton syndrome

Background

Netherton syndrome is a rare autosomal recessive disease that presents with a triad of symptoms which include atopic diathesis, ichthyosis linearis circumflexa, and hair shaft abnormality termed “Bamboo Hair”. Netherton syndrome patients can develop cutaneous squamous cell carcinoma (cSCC) in unusually young age. Pembrolizumab is the first line treatment for locally advanced and recurrent/metastatic cSCC.

Case presentation

A 44-year-old man with a history of Netherton syndrome and multiple skin squamous cell carcinoma was diagnosed with locally advanced and recurrent/metastatic cSCC two years ago. He was started on Pembrolizumab as a treatment for his cSCC. The immunotherapy course was well tolerated with no significant side effects including the expected immune related adverse events seen in patients treated with this medication. PET/CT scan showed significant regression of his disease consistent with partial response according to the response evaluation criteria in solid tumors.

Discussion

Incurable and recurrent cSCC tends to metastasize, leading to an extremely poor long-term prognosis, and the treatment options for locally advanced or metastatic disease are few. Pembrolizumab, an immune checkpoint inhibitors (ICIs) showed a benefit in patients with various tumors including squamous cell carcinoma, but using this drug which is working by enhancing the immunity against tumor in patient with altered immunity like Netherton syndrome was a bit of a challenge, in terms of both effectiveness and safety.

Conclusion

Pembrolizumab had a effective and safe treatment profile when it was used as a monotherapy for treating a Netherton syndrome patient diagnosed with locally advanced and recurrent/metastatic cSCC.

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Netherton syndrome presents with a triad of symptoms: atopic diathesis, ichthyosis linearis circumflexa, and hair shaft abnormality.

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Patients can also develop cutaneous squamous cell carcinoma (cSCC) in unusually young age.

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KEYTRUDA® (pembrolizumab) used to treat the cancer in this patient.

HPV-Related Skin Phenotypes in Patients with Inborn Errors of Immunity

Patients with inborn errors of immunity (IEI) are prone to develop infections, either due to a broad spectrum of pathogens or to only one microbe. Since skin is a major barrier tissue, cutaneous infections are among the most prevalent in patients with IEI due to high exposures to many microbes. In the general population, human papillomaviruses (HPVs) cause asymptomatic or self-healing infections, but, in patients with IEI, unusual clinical expression of HPV infection is observed ranging from epidermodysplasia verruciformis (EV) (a rare disease due to β-HPVs) to profuse, persistent, and recalcitrant warts (due to α-, γ-, and μ-HPVs) or even tree man syndrome (due to HPV2). Mutations in EVER1, EVER2, and CIB1 are associated with EV phenotype; GATA2, CXCR4, and DOCK8 mutations are typically associated with extensive HPV infections, but there are several other IEI that are less frequently associated with severe HPV lesions. In this review, we describe clinical, immunological, and genetic patterns of IEI related to severe HPV cutaneous infections and propose an algorithm for diagnosis of IEI with severe warts associated, or not, with lymphopenia.

Inborn Errors of Immunity Associated with Elevated IgE

OBJECTIVE

To review the characteristic clinical and laboratory features of inborn errors of immunity that are associated with elevated IgE levels DATA SOURCE: Primary peer-reviewed literature.

STUDY SELECTION

Original research articles reviewed include interventional studies, retrospective studies, case-control studies, cohort studies and review articles related to the subject matter.

RESULTS

An extensive literature review was completed to allow for comprehensive evaluation of several monogenic inborn errors of immunity. This review includes a description of the classic clinical features, common infections, characteristic laboratory findings, specific diagnostic methods (when applicable), and genetic basis of disease of each syndrome. A comprehensive flow diagram was created to assist them in the diagnosis and evaluation of patients with elevated IgE levels who may require evaluation for an IEI.

CONCLUSION

IEI should be considered in patients with elevated IgE levels, especially if they have recurrent infections, eczematous dermatitis, malignancy, lymphoproliferation, autoimmunity, and/or connective tissue abnormalities.

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).

Human Tissue Kallikreins-Related Peptidases Are Targets for the Treatment of Skin Desquamation Diseases

Human tissue Kallikrein-related peptidases (hKLKs) are serine proteases distributed in several tissues that are involved in several biological processes. In skin, many are responsible for skin desquamation in the Stratum Corneum (SC) of the epidermis, specially hKLK5, hKLK7, hKLK6, hKLK8, and hKLK14. In SC, hKLKs cleave proteins of corneodesmosomes, an important structure responsible to maintain corneocytes attached. As part of skin desquamation, hKLKs are also involved in skin diseases with abnormal desquamation and inflammation, such as Atopic Dermatitis (AD), psoriasis, and the rare disease Netherton Syndrome (NS). Many studies point to hKLK overexpression or overactive in skin diseases, and they are also part of the natural skin inflammation process, through the PAR2 cleavage pathway. Therefore, the control of hKLK activity may offer successful treatments for skin diseases, improving the quality of life in patients. Diseases like AD, Psoriasis, and NS have an impact on social life, causing pain, itchy and mental disorders. In this review, we address the molecular mechanisms of skin desquamation, emphasizing the roles of human tissue Kallikrein-related peptidases, and the promising therapies targeting the inhibition of hKLKs.

Skin Microbiota and Clinical Associations in Netherton Syndrome

Netherton syndrome (NS) is a rare, life-threatening syndrome caused by serine protease inhibitor Kazal-type 5 gene (SPINK5) mutations, resulting in skin barrier defect, bacterial skin infections, and allergic sensitization in early childhood. Recent data on adult patients with NS suggest that the presence of Staphylococcus aureus further promotes barrier disruption and skin inflammation. We analyzed the skin microbiota by shotgun sequencing in 12 patients with NS from eight Finnish families with healthy family controls as the reference and correlated the findings with allergen-specific IgE prevalence, immune cell phenotype, and infection history of the patients. Compared with healthy family controls, skin microbiome diversity and normal skin site variability were measurably decreased in patients with NS. No correlation was found between allergic sensitization and skin microbiota as such, but low circulating CD57+ and/or CD8+ T cells significantly correlated with lower microbial diversity and less abundance of S. aureus (P < 0.05). S. aureus was the most prevalent species in patients with NS but also Streptococcus agalactiae was abundant in four patients. The genomic DNA relative abundance of S. aureus secreted virulence peptides and proteases PSMα, staphopain A, and staphopain B were increased in most of the samples of patients with NS, and their abundance was significantly (P < 0.05) associated with recurrent childhood skin infections, confirming the clinical relevance of S. aureus dominance in the NS skin microbiome.

A novel SPINK5 mutation and successful subcutaneous immunoglobulin replacement therapy in a child with Netherton syndrome

We report a 2-year-old patient with Netherton syndrome presenting with generalized exfoliative erythroderma, ichthyosiform dermatitis, trichorrhexis invaginata, hypernatremic dehydration, failure to thrive, and recurrent respiratory infections. Molecular analysis of SPINK5 identified a novel mutation (c.1530CA). Our case report also verifies and supports the safety and efficacy of subcutaneous immunoglobulin substitution in chronic generalized skin disorders associated with primary immunodeficiencies such as Netherton syndrome.

The challenging management of a series of 43 infants with Netherton syndrome: unexpected complications and novel mutations

BACKGROUND

Netherton syndrome (NS) is a rare disease caused by SPINK5 mutations, featuring variable skin and hair involvement and, in many cases, allergic manifestations with a risk of lethality, particularly in infants. The clinical management of NS is challenging.

OBJECTIVES

To analyse the clinical manifestations of a cohort of infants with NS managed in a reference centre and to draw up recommendations for management.

METHODS

We conducted a monocentric analysis of patients with NS. The inclusion criteria were management in our reference centre, a histologically or molecularly confirmed diagnosis of NS and available epidemiological, clinical and laboratory data.

RESULTS

A total of 43 patients with NS were included. Hypernatraemia was reported in 23 cases (54%) and associated with a greater likelihood of enteral and/or parenteral nutritional support (P < 0.001). Moreover, hypernatraemia was more frequent in patients with skin manifestations at birth (P = 0.026) and in patients bearing the c.153delT mutation in SPINK5 exon 3 (P = 0.014). The need for enteral and/or parenteral nutritional support was associated with a history of hypernatraemic dehydration (P < 0.001). Several unexpected extracutaneous complications were recorded, and new mutations were reported. The death rate (9% overall) was higher among the subset of patients bearing the c.153delT deletion.

CONCLUSIONS

Our data emphasize that neonatal NS is a severe and sometimes lethal multisystem disorder. Patients have a high risk of variable metabolic anomalies (i.e. lethal hypernatraemia) and therefore have major nutritional needs. Cases of NS associated with c.153delT are particularly severe. Unexpected clinical manifestations broadened the phenotypic spectrum of NS. We provide recommendations on the management of the life-threatening manifestations of NS in neonates based on our multidisciplinary experience.

Genodermatoses with malignant potential

The hereditary nature of some forms of cancer was recognized long ago. Over time, recognition of associated findings led to the delineation of numerous hereditary cancer syndromes. Many of these syndromes also have cutaneous manifestations, the recognition of which can lead to their early identification. Recognition of these syndromes allows vigilant surveillance and preemptive treatment, which can dramatically impact the risks of morbidity and mortality for affected patients. The rise of rapid and accurate genetic testing now allows the early identification of asymptomatic at risk family members so that monitoring can be initiated as early as possible. The dermatologist plays a critical role in early identification of these syndromes and, in many cases, their treatment. This review summarizes many known hereditary cancer syndromes with cutaneous findings, their etiology, identification, evaluation, and management. Importantly, this is an ever evolving topic and new findings and syndromes will continue to be recognized. The dermatologist must be always alert to ensure they are detected.