Multiple diagnostic examinations are effective for the early diagnosis of scrofuloderma

Although scrofuloderma is the most common subtype of cutaneous tuberculosis, its diagnosis is often delayed. In this case, ciprofloxacin was first administered as only Pseudomonas aeruginosa was detected by initial culture tests. Mycobacterium tuberculosis is usually susceptible to quinolone antibiotics, hence the partial improvement in inflammatory symptoms and subsequent delay in diagnosis. Our case serves as a reminder that we should always be aware of the possibility of cutaneous tuberculosis being the cause of an abscess, especially when the abscess is not completely resolved by antibiotics. Moreover, our case reminds us that it is necessary to conduct repeated culture tests, rather than relying purely on polymerase chain reaction (PCR) results, given that cases of PCR-negative acid-fast bacilli (AFB) culture-positive scrofuloderma have been reported. Fine needle aspiration is a less invasive and useful way to collect culture samples.

Development of pemphigus vegetans and exacerbation of pemphigus foliaceus after secukinumab loading in a patient with complicated generalized pustular psoriasis and pyoderma gangrenosum

In dermatology, biologics that block signaling pathways of TNF-α, IL-4/IL13, IL-17s, and IL-23 are widely used for the treatment of several inflammatory skin diseases, such as atopic dermatitis and psoriasis. They have shown excellent efficacy with an acceptable safety profile. However, these biologics targeting pathogenic cytokines and their receptors could modulate immunological balance, leading to the development of other inflammatory or autoimmune skin diseases in some cases. In this study, we present a patient who suffered pemphigus vegetans and showed an exacerbation of pemphigus foliaceus after secukinumab loading for the treatment of complicated generalized pustular psoriasis and pyoderma gangrenosum.

Prominent dermal accumulation of Russell bodies underlying pseudocarcinomatous hyperplasia with fungal infection

Blockade of the secretion of immunoglobulins leads to their accumulation in plasma cells, resulting in condensed immunoglobulins in the rough endoplasmic reticulum of plasma cells, termed Russell bodies. They are sometimes found in lymphoplasmacellular inflammation of the intestinal mucosa and in lymphoid cell malignancies, but only very rarely in skin diseases. Here, we report an 86-year-old female who presented with a lesion with the prominent accumulation of Russell bodies underlying pseudocarcinomatous hyperplasia with fungal infection in the face. Immunohistochemical staining showed the cells containing Russell bodies to be positive for CD138 and the Russell bodies to be positive for immunoglobulin κ and λ light chains. The present case suggests that when inflammatory cell infiltration with abundant round intracellular eosinophilic materials is observed in the dermis, the dermal accumulation of Russell bodies should be considered in cases with reactive pseudocarcinomatous hyperplasia with fungal infection.

Clustering using unsupervised machine learning to stratify the risk of immune-related liver injury

BACKGROUND AND AIM

Immune-related liver injury (liver-irAE) is a clinical problem with a potentially poor prognosis.

METHODS

We retrospectively collected clinical data from patients treated with immune checkpoint inhibitors between September 2014 and December 2021 at the Nagoya University Hospital. Using an unsupervised machine learning method, the Gaussian mixture model, to divide the cohort into clusters based on inflammatory markers, we investigated the cumulative incidence of liver-irAEs in these clusters.

RESULTS

This study included a total of 702 patients. Among them, 492 (70.1%) patients were male, and the mean age was 66.6 years. During the mean follow-up period of 423 days, severe liver-irAEs (Common Terminology Criteria for Adverse Events grade ≥ 3) occurred in 43 patients. Patients were divided into five clusters (a, b, c, d, and e). The cumulative incidence of liver-irAE was higher in cluster c than in cluster a (hazard ratio [HR]: 13.59, 95% confidence interval [CI]: 1.70-108.76, P = 0.014), and overall survival was worse in clusters c and d than in cluster a (HR: 2.83, 95% CI: 1.77-4.50, P < 0.001; HR: 2.87, 95% CI: 1.47-5.60, P = 0.002, respectively). Clusters c and d were characterized by high temperature, C-reactive protein, platelets, and low albumin. However, there were differences in the prevalence of neutrophil count, neutrophil-to-lymphocyte ratio, and liver metastases between both clusters.

CONCLUSIONS

The combined assessment of multiple markers and body temperature may help stratify high-risk groups for developing liver-irAE.

Ichthyosis

The ichthyoses are a large, heterogeneous group of skin cornification disorders. They can be inherited or acquired, and result in defective keratinocyte differentiation and abnormal epidermal barrier formation. The resultant skin barrier dysfunction leads to increased transepidermal water loss and inflammation. Disordered cornification is clinically characterized by skin scaling with various degrees of thickening, desquamation (peeling) and erythema (redness). Regardless of the type of ichthyosis, many patients suffer from itching, recurrent infections, sweating impairment (hypohidrosis) with heat intolerance, and diverse ocular, hearing and nutritional complications that should be monitored periodically. The characteristic clinical features are considered to be a homeostatic attempt to repair the skin barrier, but heterogeneous clinical presentation and imperfect phenotype-genotype correlation hinder diagnosis. An accurate molecular diagnosis is, however, crucial for predicting prognosis and providing appropriate genetic counselling. Most ichthyoses severely affect patient quality of life and, in severe forms, may cause considerable disability and even death. So far, treatment provides only symptomatic relief. It is lifelong, expensive, time-consuming, and often provides disappointing results. A better understanding of the molecular mechanisms that underlie these conditions is essential for designing pathogenesis-driven and patient-tailored innovative therapeutic solutions.

COVID-19 infection- and vaccination-related exacerbation of Darier's disease in a single patient

Darier's disease (DD) is a rare autosomal dominantly inherited disorder. DD patients usually present with widespread keratotic eruptions with itching in the seborrheic regions that are exacerbated by various factors, including heat, sweat, and physical trauma. The SARS-CoV-2 (COVID-19) pandemic has stirred confusion among the medical community, including dermatologists, as this infection has been implicated in various skin conditions. Only a handful of reports have documented DD associated with COVID-19. Here, we report a 30-year-old male with Darier's disease whose symptoms were exacerbated following both COVID-19 vaccination and COVID-19 infection. The patient had noticed slight eruptions 7 years prior, but was not particularly concerned. After COVID-19 vaccination and infection, he had erythematous maculopapular lesions in large areas of the trunk and extremities. The previously reported pathogenic variant c.2255_2257del (p.(Ile752_Tyr753delinsAsn)) in ATP2A2 was detected in the present patient. Oral etretinate greatly improved his DD manifestations. As far as we know, the present patient is the first genetically confirmed DD case who showed both COVID-19 infection- and vaccination-related DD exacerbations independently. We think that the further accumulation of DD cases exacerbated by COVID-19 infection/vaccination is needed to clarify the mechanisms of DD aggravation.

English version of Japanese guidance for the use of oral Janus kinase (JAK) inhibitors in the treatments of atopic dermatitis

This is the English version of guidance for the use of oral Janus kinase (JAK) inhibitors in the treatment of atopic dermatitis. Several cytokines, such as interleukin (IL)-4, IL-13, IL-22, IL-31, thymic stromal lymphopoietin, and interferon-γ, are involved in the pathogenesis of atopic dermatitis. As oral JAK inhibitors hinder the JAK-signal transducers and activators of transcription signal transduction routes involved in the signal transduction of these cytokines, they may be effective for the treatment of atopic dermatitis. In Japan, as oral JAK inhibitors for atopic dermatitis, a JAK1/2 inhibitor, baricitinib, expanded its authorized indications for atopic dermatitis in 2020. Consequentially, a JAK1 inhibitor, upadacitinib, also expanded its indications to atopic dermatitis in 2021, followed by new approval of another JAK1 inhibitor, abrocitinib, for the use under the Japanese health insurance system. Physicians who intend to use them should sufficiently understand and comply with contents of guidelines prepared by the Japanese Ministry of Health, Labour and Welfare to promote optimal use of these drugs. In the treatment with oral JAK inhibitors, it is important to sufficiently consider disease factors, treatment factors and patient backgrounds, and share them with patients to choose treatment options. Points to be considered for drug selection include the efficacy and safety of drugs, age of patients, and dosage and administration of the drug. This guidance was developed for board certified dermatologists, who are specialized in the treatment of atopic dermatitis, and for promoting proper use of oral JAK inhibitors, taking into account a variety of factors in individual patients.

Involvement of hypoxia-inducible factor activity in inevitable air-exposure treatment upon differentiation in a three-dimensional keratinocyte culture

Formation of the human skin epidermis can be reproduced by a three-dimensional (3D) keratinocyte culture system, in which air-exposure is inevitable upon initiation of differentiation. In the continuous submerged culture without air-exposure, even with a differentiation-compatible medium, several keratinocyte-specific proteins were not induced resulting in the formation of aberrant epidermal layers. To clarify the mechanism by which air-exposure promotes keratinocyte differentiation, we performed a comparative analysis on biological properties between submerged and air-liquid interphase culture systems. By transcriptomic analysis, hypoxia-inducible factor (HIF)-related genes appeared to significantly change in these cultured cells. In submerged culture, the transcriptional activity of HIF on its canonical response element was enhanced, while air-exposure treatment drastically reduced the transcriptional activity despite the high HIF protein level. Regulating HIF activity through reagents and genetic manipulation revealed that the reduced but retained HIF-transcriptional activity was essentially involved in differentiation. Furthermore, we showed, for the first time, that artificial supplementation of oxygen in the submerged culture system could restore keratinocyte differentiation as observed in the air-exposed culture. Thus, we mechanistically evaluated how HIF regulates the air-exposure-dependent differentiation of keratinocytes in a 3D culture system.

Two novel anti-aminoacyl tRNA synthetase antibodies: Autoantibodies against cysteinyl-tRNA synthetase and valyl-tRNA synthetase

Anti-aminoacyl-tRNA synthetase (anti-ARS) antibodies are useful for identifying a clinical subset of patients with inflammatory myopathies. Since the myositis of anti-ARS-positive patients is characterized by a unique set of non-myopathic manifestations, including interstitial lung disease, mechanic's hands, and arthralgia, the patients are classified as having anti-synthetase syndrome. Autoantibodies have been identified to eight kinds of ARSs. Of the other 12 ARSs, eight are components of the "OJ" multi-synthetase complex. Autoantibodies to the four remaining ARSs (CysARS, ValARS, SerARS, and TrpARS) have not been reported to be present in patients with inflammatory myopathies. In this study, we first screened samples from more than 300 Japanese patients majorly consisting of those with dermatomyositis (DM) by our established in-house ELISA to find autoantibodies against the four ARSs described above. Since sera from two DM patients specifically reacted to CysARS or ValARS, we determined their reactivities by immunoprecipitation (IP) with the corresponding recombinant proteins and IP-Western blotting with cellular extract. One patient had several features found in anti-synthetase syndrome, but the other did not. The clinical differences among the various anti-ARS antibodies should be explored in a future work.

Ceramide Analysis in Combination With Genetic Testing May Provide a Precise Diagnosis for Self-Healing Collodion Babies

Self-healing collodion baby (SHCB), also called "self-improving collodion baby", is a rare mild variant of autosomal recessive congenital ichthyosis and is defined as a collodion baby who shows the nearly complete resolution of scaling within the first 3 months to 1 year of life. However, during the neonatal period, it is not easy to distinguish SHCB from other inflammatory forms of autosomal recessive congenital ichthyosis, such as congenital ichthyosiform erythroderma. Here, we report a case study of two Japanese SHCB patients with compound heterozygous mutations, c.235G>T (p.(Glu79∗))/ c.1189C>T (p.(Arg397Cys)) and c.1295A>G (p.(Tyr432Cys))/ c.1138delG (p.(Asp380Thrfs∗3)), in CYP4F22, which encodes cytochrome P450, family 4, subfamily F, polypeptide 22 (CYP4F22). Immunohistochemically, inflammation with the strong expression of IL-17C, IL-36γ, and TNF-α was seen in the skin at birth. CYP4F22 is an ultra-long-chain FA ω-hydroxylase responsible for ω-O-acylceramide (acylceramide) production. Among the epidermal ceramides, acylceramide is a key lipid in maintaining the epidermal permeability barrier function. We found that the levels of ceramides with ω-hydroxy FAs including acylceramides and the levels of protein-bound ceramides were much lower in stratum corneum samples obtained by tape stripping from SHCB patients than in those from their unaffected parents and individuals without SHCB. Additionally, our cell-based enzyme assay revealed that two mutants, p.(Glu79∗) and p.(Arg397Cys), had no enzyme activity. Our findings suggest that genetic testing coupled with noninvasive ceramide analyses using tape-stripped stratum corneum samples might be useful for the early and precise diagnosis of congenital ichthyoses, including SHCB.

Siglec-5 and Siglec-14 mediate the endocytosis of ADAMTS13

BACKGROUND

The plasma metalloprotease ADAMTS13 regulates the thrombotic activity of the von Willebrand factor (VWF). ADAMTS13 is highly glycosylated and its carbohydrate chains are capped with sialic acid (SA). Thus, ADAMTS13 may interact with carbohydrate- and/or SA-binding plasma membrane receptors that are involved in the clearance of various plasma proteins. We have investigated ADAMTS13 endocytosis via Siglecs, which were originally identified as SA-binding immunoreceptor family proteins expressed on leukocytes and are also known as endocytic receptors.

MATERIALS AND METHODS

Endocytic internalization of fluorescently labeled ADAMTS13 into HEK293 cells expressing Siglecs was examined via fluorescence microscopy. In vitro binding of ADAMTS13 to the extracellular region of Siglec-5 was examined. Plasma ADAMTS13 activity in human Siglec-5-expressing mice was measured.

RESULTS AND CONCLUSIONS

Siglec-5- and Siglec-14-expressing cells internalized not only full-length ADAMTS13 (FL) but also the truncated form (MDTCS) at least partly in an SA-independent manner. Replacement of the V-set domain of Siglec-14 with that of Siglec-3 abrogated the internalization of ADAMTS13. ADAMTS13 directly bound to the extracellular region of Siglec-5 in vitro. Expression of Siglec-5 in the mouse liver resulted in a significant decrease in plasma ADAMTS13 activity. These results suggest that Siglec-5 and Siglec-14, which have nearly identical ligand-binding domains, may contribute to the regulation of plasma ADAMTS13 levels as endocytic receptors for ADAMTS13.

Ceramide profiling of stratum corneum in Sjögren-Larsson syndrome

BACKGROUND

Sjögren-Larsson syndrome (SLS) is a neurocutaneous disorder whose causative gene is the fatty aldehyde dehydrogenase ALDH3A2 and of which ichthyosis is the major skin symptom. The stratum corneum contains a variety of ceramides, among which ω-O-acylceramides (acylceramides) and protein-bound ceramides are essential for skin permeability barrier formation.

OBJECTIVES

To determine the ceramide classes/species responsible for SLS pathogenesis and the enzymes that are impaired in SLS.

METHODS

Genomic DNA was collected from peripheral blood samples from an SLS patient and her parents, and whole-genome sequencing and Sanger sequencing were performed. Lipids were extracted from stratum corneum samples from the SLS patient and healthy volunteers and subjected to ceramide profiling via liquid chromatography coupled with tandem mass spectrometry.

RESULTS

A duplication (c.55_130dup) and a missense mutation (p.Lys447Glu) were found in the patient's ALDH3A2 gene. The patient had reduced levels of all acylceramide classes, with total acylceramide levels at 25 % of healthy controls. Reductions were also observed for several nonacylated ceramides: ceramides with phytosphingosine or 6-hydroxysphingosine in the long-chain base moiety were reduced to 24 % and 41 % of control levels, respectively, and ceramides with an α-hydroxy fatty acid as the fatty acid moiety were reduced to 29 %. The fatty acid moiety was shortened in many nonacylated ceramide classes.

CONCLUSION

These results suggest that reduced acylceramide levels are a primary cause of the ichthyosis symptoms of SLS, but reductions in other ceramide classes may also be involved.

Neutrophil extracellular traps are involved in enhanced contact hypersensitivity response in IL-36 receptor antagonist-deficient mice

Loss-of-function homozygous or compound heterozygous mutations in IL36RN, which encodes interleukin-36 receptor antagonist (IL-36Ra), have been implicated in the pathogenesis of skin disorders. We previously reported that Il36rn^−/− mice exhibit an enhanced contact hypersensitivity (CHS) response through increased neutrophil recruitment. In addition, Il36rn^−/− mice show severe imiquimod-induced psoriatic skin lesions and enhanced neutrophil extracellular trap (NET) formation. We hypothesized that NETs may play an important role in the CHS response. To confirm this, we examined the CHS response and NET formation in Il36rn^−/− mice. Il36rn^−/− mice showed enhanced CHS responses, increased infiltration of inflammatory cells, including neutrophils, CD4⁺ T cells, and CD8⁺ T cells, NET formation, and enhanced mRNA expression of cytokines and chemokines, including IL-1β, C-X-C motif chemokine ligand (CXCL)1, CXCL2, and IL-36γ. Furthermore, NET formation blockade improved the CHS response, which consequently decreased inflammatory cell infiltration and NET formation. Consistently, we observed decreased expression of these cytokines and chemokines. These findings indicate that IL-36Ra deficiency aggravates the CHS response caused by excessive inflammatory cell recruitment, NET formation, and cytokine and chemokine production, and that NET formation blockade alleviates the CHS response. Thus, NET formation may play a prominent role in the CHS response.

Postoperative radiation therapy improves prognoses in extramammary Paget's disease presenting with multiple lymph node metastases

Invasive extramammary Paget's disease may cause lymph node and distant metastases. Complete lymph node dissection is generally performed for extramammary Paget's disease presenting with lymph node metastases. Patients with extramammary Paget's disease and multiple lymph node metastases typically have poor prognoses, and there is no effective postoperative treatment to prevent recurrence or further metastases in such patients to date. This study aimed to evaluate the efficacy of postoperative radiotherapy in patients with extramammary Paget's disease and multiple lymph node metastases. We enrolled 26 patients with extramammary Paget's disease with ≥3 lymph node metastases who were treated at the National Cancer Center Hospital in Japan between January 2000 and June 2021. The patients were divided into those who underwent complete lymph node dissection only or with postoperative radiotherapy. We evaluated recurrence-free survival, distant metastasis-free survival, and overall survival outcomes with Kaplan-Meier curves. Among the 26 enrolled patients, 16 underwent complete lymph node dissection only and 10 underwent complete lymph node dissection with postoperative radiotherapy. The median follow-up period was 16 months. The 5-year recurrence-free, distant metastasis-free, and overall survival values were 47.3%, 63.0%, and 90% in those with complete lymph node dissection and postoperative radiotherapy, while these outcomes were all 0% (p = 0.001, 0.004, and 0.009, respectively) in those with only complete lymph node dissection. Thus, survival was significantly prolonged with postoperative radiotherapy. Additional postoperative radiotherapy may substantially improve the prognoses of patients with extramammary Paget's disease and ≥3 lymph node metastases, and undergoing curative surgery.

UVB-Induced Skin Autoinflammation Due to Nlrp1b Mutation and Its Inhibition by Anti-IL-1β Antibody

NLRP1 (NACHT and leucine-rich repeat-containing protein family, pyrin domain-containing protein 1) is an innate immune sensor that is involved in the formation of inflammasome complexes. NLRP1 hyperactivity has been reported to cause inherited autoinflammatory diseases including familial keratosis lichenoides chronica and NLRP1-associated autoinflammation with arthritis and dyskeratosis. We generated Nlrp1b (the mouse homologue of human NLRP1) gain-of-function knock-in (Nlrp1b KI) mice with UVB irradiation-induced autoinflammatory skin lesions. We demonstrated that UVB irradiation induces IL-1β upregulation and IL-1β-dependent inflammation via caspase-1 activation in these Nlrp1b KI mice. RNA sequencing revealed the upregulation of inflammasome pathway-related genes, keratinocyte stress marker genes, and keratinocyte differentiation marker genes in the Nlrp1b KI mice after UVB irradiation. The skin inflammation and hyperkeratosis from UVB irradiation in the Nlrp1b KI mice were inhibited by both intraperitoneal and subcutaneous administration of anti-IL-1β antibodies before UVB irradiation. UVB irradiation and the IL-1β pathway are important in the pathogenesis of NLRP1-associated autoinflammatory skin lesions.

POS1424 RISK FACTORS FOR ADVERSE EVENTS OF SULFAMETHOXAZOLE-TRIMETHOPRIM PROPHYLAXIS IN PATIENTS WITH SYSTEMIC RHEUMATIC DISEASES

Background

The prophylactic use of sulfamethoxazole-trimethoprim (SMX/TMP) can reduce the risk for developing pneumocystis pneumonia in immunosuppressed patients with systemic rheumatic diseases, whereas discontinuation of SMX/TMP prophylaxis is frequent due to adverse events (AEs) with this drug.

Objectives

The purpose of this study was to identify risk factors for AEs of SMX/TMP in patients with systemic rheumatic diseases.

Methods

All consecutive patients who were admitted in our hospital for induction treatment between 2012 and 2019 and newly received prophylactic SMX/TMP were included in the study. We divided them into two groups according to the presence or absence of AEs of SMX/TMP leading to discontinuation of the drug and compared clinical characteristics between the AE and non-AE groups. Multivariable analysis was performed to identify risk factors for AEs of SMX/TMP prophylaxis.

Results

A total of 438 patients were included in the study. Rheumatic diseases of the patients were systemic lupus erythematosus (25.3%), anti-neutrophil cytoplasmic antibody associated vasculitis (15.5%), rheumatoid arthritis (11.6%), polymyositis/dermatomyositis (10.7%), IgG4-related disease (8.5%), large vessel vasculitis (7.1%), adult-onset Still’s disease (AOSD; 4.1%), and others (17.2%). Among them, 82 patients (18.7%) stopped SMX/TMP due to AEs. Most frequent AEs were skin rash (36.6%), followed by liver dysfunction (29.3%), thrombocytopenia (19.5%), elevation in serum creatinine levels (15.9%), hyperkalemia (14.6%), hyponatremia (11%), leukopenia (6.1%), and fever (6.1%). Baseline age (61.4±16.4 vs 56.3±16.9 years, p=0.014) and prednisolone dose for remission induction treatment (0.97 vs 0.91 mg/kg/day, p=0.03) were significantly higher in the AE group than in the non-AE group, respectively. In terms of disease type, significantly higher rates of AEs were observed in patients with AOSD than in those with the other diseases (66.7% vs 16.7%, p<0.001; Figure 1). Blood tests at SMX/TMP initiation demonstrated lower lymphocyte counts (10.1 vs 10.8 x102/μl, p=0.049), lower platelet counts (20.9 vs 25.8 x104/μl, p=0.045), lower albumin levels (3.2 vs 3.4 g/dl, p=0.007), higher AST levels (26 vs 23 U/L, p=0.04), higher creatinine levels (0.71 vs 0.67 mg/dl, p=0.047), and higher ferritin levels (167 vs 154 ng/ml, p=0.047) in the AEs group compared with the non-AEs group, respectively. Multivariable analysis identified an older age (OR 1.03, p=0.002) and AOSD (OR 9.72, p<0.001) as independent risk factors for AEs leading to SMX/TMP withdrawal (Table 1).

Conclusion

Old age and AOSD were associated with AEs of SMX/TMP prophylaxis in patients with systemic rheumatic diseases.

Disclosure of Interests

None declared

AB0621 Characteristics of Anti-Neutrophil Cytoplasmic Antibody Associated Vasculitis With Severe Peripheral Neuropathy

Background

Peripheral neuropathy is one of major manifestations of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and has a significant impingement on patients’ quality of life.1,2

Objectives

The aim of this study was to clarify clinical features of AAV patients with peripheral neuropathy and identify risk factors for severe motor neuropathy.

Methods

All consecutive patients with active, treatment-naïve AAV who were admitted to our hospital between April, 2012 and October, 2021 were reviewed. Patients were divided into two groups according to the presence or absence of peripheral neuropathy, and their baseline clinical characteristics were compared.

Results

A total of 76 patients (microscopic polyangiitis, MPA, n=37, granulomatosis with poly angiitis, GPA, n=24, eosinophilic GPA, EGPA, n=15) were included in the study. Among them, 28 patients (36.8%) had peripheral neuropathy including 12 with MPA, 4 with GPA, and 12 with EGPA. The clinical characteristics of all patients with peripheral neuropathy were younger age (66.0 years versus 74.5 years, p<0.05) and showed higher white blood cell counts (11500/μL versus 8800/μL, p<0.05), higher blood eosinophil counts (788.5/μL versus 139.0/μL, p<0.05), higher creatinine clearance (77.3 mL/min versus 56.3 mL/min, p<0.05), higher levels of serum immunoglobulin (Ig)E (660 IU/mL versus 125 IU/mL, p<0.05), and IgG4 (361.5 mg/dL versus 84.0 mg/dL, p <0.05). In patients with EGPA, the most susceptible type to peripheral neuropathy, 80% of the patients had peripheral neuropathy. Comparison between patients with EGPA with peripheral neuropathy and those without demonstrated significantly younger age (56.0 years versus 80.0 years, p<0.05) and higher blood eosinophil counts (7832/μL versus 2340/μL, p<0.05) were characteristic for the presence of peripheral neuropathy. Patients with EGPA with motor neuropathy (n=8) showed higher white blood cell counts (26850//μL versus 8650//μL, p <0.05) and higher blood eosinophil counts (13134//μL versus 3436//μL, p<0.05) compared with those with only sensory neuropathy (n=4).

Conclusion

Our current study has shown that patients with EGPA are more prone to peripheral neuropathy than patients with MPA or GPA. Severe motor neuropathy was observed only in patients with EGPA and associated with more intense eosinophilic inflammation. Our results suggest that molecular targeted therapy that improves eosinophilic inflammation such as anti-IL-5 therapy is beneficial for peripheral neuropathy.

References

[1]RUTGERS, Abraham; KALLENBERG, Cees GM. Peripheral neuropathy in AAV—when vasculitis hits a nerve. Nature Reviews Rheumatology, 2012, 8.3: 127-128.

[2]NAKAZAWA, Daigo, et al. Pathogenesis and therapeutic interventions for ANCA-associated vasculitis. Nature Reviews Rheumatology, 2019, 15.2: 91-101.

Disclosure of Interests

None declared

Darier disease successfully treated with a topical agent containing vitamin A (retinyl palmitate), vitamin E, and urea

Darier disease (DD), also called keratosis follicularis, is an autosomal dominant hereditary keratinization disorder that manifests as keratotic papules with plaques in seborrheic areas. There are no validated curative treatments for DD, with the majority of cases treated symptomatically. We report the efficacy of a topical over-the-counter agent which contains retinyl palmitate, vitamin E, and urea for a patient with DD. A 13-year-old girl had brown papules on her scalp, neck, shoulders, and axillae since entering elementary school. A skin biopsy revealed hyperkeratosis, suprabasal acantholysis, and dyskeratosis manifested as corps ronds and grains in the epidermis. Sanger sequencing found the previously reported heterozygous mutation c.1484C>T in ATP2A2. The application of an over-the-counter topical agent containing retinyl palmitate 2750 μg/g (5000 IU/g), tocopheryl acetate 20 mg/g, urea 200 mg/g, and monoammonium glycyrrhizinate 5 mg/g twice daily for 2 months improved the papules without serious adverse events. Oral or topical aromatic vitamin A analogs (retinoids) are often used to treat DD. However, several adverse events are associated with retinoid treatment, and many patients only undergo their intermittent use or discontinue the treatments. Retinyl palmitate is more stable and has a lower irritative profile than other retinoic acids. When applied topically, however, retinyl palmitate cannot penetrate the skin as well as retinol can. Some reports have noted that vitamin E increases the biological availability of vitamin A and that urea helps mechanical percutaneous drug delivery. Our case suggests that retinyl palmitate has a sufficient therapeutic effect when combined with vitamin E and urea. In conclusion, we propose that topical agents containing retinyl palmitate, vitamin E, and urea might have a satisfactory effect on the skin lesions of DD patients, without the serious risks of adverse events.

Clinical utility of botulinum toxin type A local injection therapy for head and forehead hyperhidrosis

Head and forehead hyperhidrosis (HFH) is a disease that causes a large amount of sweating from the head region, and it significantly reduces patients' quality of life. Only a few reports have shown the effectiveness of botulinum toxin type A (BTX-A) local injection therapy (BTX-A therapy) for HFH. To clarify the benefits of BTX-A for HFH, BTX-A therapy was performed in 15 patients, and its efficacy was evaluated. The amount of sweating was measured by the ventilation capsule method and Minor's iodine-starch test. Evaluation was also performed using the Hyperhidrosis Disease Severity Scale (HDSS) and the Dermatology Life Quality Index (DLQI). In most cases, a remarkable antiperspirant effect was observed from 2 weeks after the injection, and the effect lasted for approximately 30 weeks. HDSS and DLQI improved along with the decrease in sweating. Two patients (13.3%) complained of transient mild ptosis. There were no serious side-effects. This study showed that BTX-A therapy is a safe and effective treatment for HFH.

Increased Risk of Thyroid Dysfunction by PD-1 and CTLA-4 Blockade in Patients Without Thyroid Autoantibodies at Baseline

BACKGROUND

Previous studies showed that although the risk of thyroid dysfunction [thyroid immune-related adverse events (irAEs)] induced by anti-programmed cell death-1 antibodies (PD-1-Ab) was as low as 2% to 7% in patients negative for anti-thyroid antibodies (ATAs) at baseline, it was much higher (30%-50%) in patients positive for ATAs. However, whether a similar increase occurs with combination therapy using PD-1-Ab plus anti-cytotoxic T-lymphocyte antigen-4 antibody (CTLA-4-Ab) is unknown.

METHODS

A total of 451 patients with malignancies treated with PD-1-Ab, CTLA-4-Ab, or a combination of PD-1-Ab and CTLA-4-Ab (PD-1/CTLA-4-Abs) were evaluated for ATAs at baseline and for thyroid function every 6 weeks for 24 weeks after treatment initiation and then observed until the last clinical visit.

RESULTS

Of the 451 patients, 51 developed thyroid irAEs after immunotherapy [41 of 416 (9.9%) treated with PD-1-Ab, 0 of 8 (0%) treated with CTLA-4-Ab, and 10 of 27 (37.0%) treated with PD-1/CTLA-4-Abs]. The cumulative incidence of thyroid irAEs was significantly higher in patients who were positive vs negative for ATAs at baseline after both PD-1-Ab [28/87 (32.2%) vs 13/329 (4.0%), P < 0.001] and PD-1/CTLA-4-Abs [6/10 (60.0%) vs 4/17 (23.5%), P < 0.05] treatments. The risk of thyroid irAEs induced by PD-1/CTLA-4Abs, which was significantly higher than that induced by PD-1-Ab, in patients negative for ATAs at baseline was not statistically different from that induced by PD-1-Ab in patients positive for ATAs at baseline.

CONCLUSIONS

This study showed that the incidence of thyroid irAEs was high and not negligible after PD-1/CTLA-4-Abs treatment even in patients negative for ATAs at baseline.

Autoinflammatory Keratinization Disease With Hepatitis and Autism Reveals Roles for JAK1 Kinase Hyperactivity in Autoinflammation

Heterozygous mutations in JAK1 which result in JAK-STAT hyperactivity have been implicated in an autosomal dominant disorder that features multi-organ immune dysregulation. This study identifies another previously unreported heterozygous missense JAK1 mutation, H596D, in an individual with a unique autoinflammatory keratinization disease associated with early-onset liver dysfunction and autism. Using CRISPR-Cas9 gene targeting, we generated mice with an identical Jak1 knock-in missense mutation (Jak1^{H595D/+;I596I/+;Y597Y/+} mice) that recapitulated key aspects of the human phenotype. RNA sequencing of samples isolated from the Jak1^{H595D/+;I596I/+;Y597Y/+} mice revealed the upregulation of genes associated with the hyperactivation of tyrosine kinases and NF-κB signaling. Interestingly, there was a strong correlation between genes downregulated in Jak1^{H595D/+;I596I/+;Y597Y/+} mice and those downregulated in the brain of model mice with 22q11.2 deletion syndrome that showed cognitive and behavioral deficits, such as autism spectrum disorders. Our findings expand the phenotypic spectrum of JAK1-associated disease and underscore how JAK1 dysfunction contributes to this autoinflammatory disorder.

Anti-Zo antibodies in Japanese myositis patients detected by a newly developed ELISA

OBJECTIVES

The myositis-specific autoantibodies that characterise certain forms of idiopathic inflammatory myopathy (IIM) are useful for diagnosing dermatomyositis (DM) / polymyositis (PM) and predicting its prognosis. The autoantibody to phenylalanyl-tRNA synthetase (anti-Zo) has been identified as a disease marker antibody for anti-synthetase syndrome only in a UK cohort. Here we aim to establish an ELISA for the measurement of anti-Zo and to characterise the clinical features of Japanese patients who have this autoantibody.

METHODS

Anti-Zo was investigated by immunoprecipitation with recombinant phenylalanyl-tRNA synthetase α/β proteins. The results were confirmed by immunoprecipitation-Western blotting with cell extract. Sera from patients with DM/PM (n=224) were screened by an ELISA with the recombinant proteins. Medical records were retrospectively reviewed to obtain detailed information on the clinical phenotypes of the anti-Zo-positive patients.

RESULTS

Only two male patients were confirmed to have anti-Zo. Both patients had fever, myopathy, interstitial lung disease, and mechanic's hands, and these clinical features are consistent with those of anti-synthetase syndrome. Another patient's serum showed a higher level than the cut-off value for anti-phenylalanyl-tRNA synthetase α by our in-house ELISA, but was judged to be negative for anti-Zo by immunoprecipitation-Western blotting.

CONCLUSIONS

This is the first report of anti-Zo-positive IIM patients from Asia. Although Japanese patients with anti-Zo have a clinical phenotype similar to that of Caucasian patients, further large cohort studies are necessary to confirm the frequency of anti-Zo in Japanese IIM patients. Our newly developed ELISA should be validated for sensitivity and specificity in large cohorts.

Differential Pathomechanisms of Desmoglein 1 Transmembrane Domain Mutations in Skin Disease

Dominant and recessive mutations in the desmosomal cadherin, desmoglein (DSG) 1, cause the skin diseases palmoplantar keratoderma (PPK) and severe dermatitis, multiple allergies, and metabolic wasting (SAM) syndrome, respectively. In this study, we compare two dominant missense mutations in the DSG1 transmembrane domain (TMD), G557R and G562R, causing PPK (DSG1_PPK-TMD) and SAM syndrome (DSG1_SAM-TMD), respectively, to determine the differing pathomechanisms of these mutants. Expressing the DSG1_TMD mutants in a DSG-null background, we use cellular and biochemical assays to reveal the differences in the mechanistic behavior of each mutant. Super-resolution microscopy and functional assays showed a failure by both mutants to assemble desmosomes due to reduced membrane trafficking and lipid raft targeting. DSG1_SAM-TMD maintained normal expression levels and turnover relative to wildtype DSG1, but DSG1_PPK-TMD lacked stability, leading to increased turnover through lysosomal and proteasomal pathways and reduced expression levels. These results differentiate the underlying pathomechanisms of these disorders, suggesting that DSG1_SAM-TMD acts dominant negatively, whereas DSG1_PPK-TMD is a loss-of-function mutation causing the milder PPK disease phenotype. These mutants portray the importance of the DSG TMD in desmosome function and suggest that a greater understanding of the desmosomal cadherin TMDs will further our understanding of the role that desmosomes play in epidermal pathophysiology.