Granular C3 dermatosis-A report of two cases and a mini-review of literature

Granular C3 dermatosis (GCD) is characterized by bullous, erythematous, and eczematous skin lesions similar to dermatitis herpetiformis, and granular deposition of complement C3 and C5b-9 along the epidermal basement membrane zone (BMZ) by direct immunofluorescence (IF). Here, we present two cases of GCD with different clinical features. Case 1, a 49-year-old man, showed pruritic blisters and erythema of the extremities. Case 2, a 53-year-old woman, showed severely pruritic papules, erythema, and erosions on the entire body with scattered blisters, mainly on the lower extremities. Both patients showed mild eosinophilia on blood tests, subepidermal blisters and prominent eosinophilic infiltration in the upper dermis on histopathological examination, and granular BMZ deposition of C3, but not of immunoglobulins or other complement components, on direct IF. No circulating autoantibodies were detected on enzyme-linked immunosorbent assays, chemiluminescent enzyme immunoassays, indirect IF using 1 mol/L NaCl-split normal human skin, or immunoblotting. Diagnosis of GCD was made in both cases. Case 1 was successfully treated with topical steroids, oral minocycline, and nicotinamide without any recurrence of symptoms. Case 2 was treated with oral steroids and showed remarkable improvement, although mild pruritic papules remained. We reviewed 30 reported GCD cases, including the two cases presented here, since Hashimoto et al. first described GCD in 2016. GCD should be more widely recognized, and further accumulation and validation of cases are required.

The ability of biomarkers to assess the severity of atopic dermatitis

Background

To develop precision medicine for atopic dermatitis (AD), it is critical to establish relevant biomarkers. However, the characteristics of various biomarkers have not been fully understood. We previously carried out the Biomarkers to Predict Clinical Improvement of AD in Patients Treated with Dupilumab (B-PAD) study, a comprehensive nationwide study in Japan, to explore biomarkers for AD.

Objective

The aim of this study is to find biomarkers associated with objective and subjective clinical findings in patients with moderate-to-severe AD based on the B-PAD study and to identify biomarkers sensitive enough to assess the severity of AD.

Methods

We performed the B-PAD study as a consortium composed of 19 medical facilities in Japan, enrolling 110 patients with moderate-to-severe AD. We evaluated the Eczema Area and Severity Index (EASI) for objective assessment as well as the Patient-Oriented Eczema Measure (POEM) and a numeric rating scale for pruritus (pruritis-NRS) for subjective assessment, measuring 19 biomarkers at baseline.

Results

We found that 12, 6, and 7 biomarkers showed significant and positive associations with the EASI, POEM, and pruritis-NRS, respectively. Most of the biomarkers associated with either the POEM or the pruritis-NRS were included among the biomarkers associated with EASI. Of the biomarkers examined, CCL26/eotaxin-3 and SCCA2 were the most capable of assessing severity for EASI, as shown by the 2 kinds of receiver operating characteristic analyses, respectively, whereas lactate dehydrogenase was the best for both the POEM and pruritis-NRS, again using the 2 analyses.

Conclusion

We found biomarkers associated with the EASI, POEM, and pruritis-NRS, respectively, based on the B-PAD study. Moreover, we identified CCL26/eotaxin-3 and/or SCCA2 as the biomarkers having the greatest ability to assess severity in the EASI; lactate dehydrogenase did the same for the POEM and pruritis-NRS. These findings will be useful in treating patients with moderate-to-severe AD.

Gorlin Syndrome and Cowden Syndrome

Gorlin syndrome and Cowden syndrome are hereditary diseases that are characterized by multiple malignancies, cutaneous symptoms, and various other abnormalities. Both disorders are caused by a mutation of the gene that regulates cell proliferation and growth, resulting in tumorigenesis. Representative mutations are mutation in the patched 1 gene (PTCH1) in Gorlin syndrome and mutation in the phosphatase and tensin homolog deleted from chromosome 10 (PTEN) gene in Cowden syndrome. Making a diagnosis of these diseases in the early years of life is important because detection of malignancies at an early stage is linked to improved prognosis. Both Gorlin syndrome and Cowden syndrome have cutaneous findings in the early phase in childhood, and the role of dermatologists is therefore important. These diseases are generally diagnosed by clinical criteria, but some patients who do not meet the criteria need genetic examinations including a genetic diagnostic panel and next-generation sequencing. The most important treatment and management are detection and resection of malignancies in the early stage, and targeted therapies have recently been used for treatment of tumors and other symptoms in these diseases. Although evidence of the effectiveness of targeted therapies has been limited, they are promising therapeutic options and further clinical trials are needed in the future.

Two sporadic cases of childhood-onset Hailey-Hailey disease with superimposed mosaicism

A prenatal second-hit genetic change that occurs on the wild-type allele in an embryo with a congenital pathogenic variant allele results in mosaicism of monoallelic and biallelic defect of the gene, which is called superimposed mosaicism. Superimposed mosaicism of Hailey-Hailey disease (HHD) has been demonstrated in one familial case. Here, we report two unrelated HHD cases with superimposed mosaicism: a congenital monoallelic pathogenic variant of ATP2C1, followed by a postzygotic copy-neutral loss of heterozygosity. Uniquely, neither patient had a family history of HHD at the time of presentation. In the first case, the congenital pathogenic variant had occurred de novo. In the second case, the father had the pathogenic variant but had not yet developed skin symptoms. Our cases showed that superimposed mosaicism in HHD can lack a family history and that genetic analysis is crucial to classify the type of mosaicism and evaluate the risk of familial occurrence.

Classification and Antigen Molecules of Autoimmune Bullous Diseases

Autoimmune bullous diseases (AIBDs), which are a group of tissue-specific autoimmune diseases of the skin, present with various blistering lesions on the skin and mucous membranes, and show autoantibodies of IgG, IgA and IgM against epidermal cell surfaces and basement membrane zone. To date, AIBDs have been classified into a number of distinct subtypes by clinical and histopathological findings, and immunological characteristics. In addition, various biochemical and molecular biological studies have identified various novel autoantigens in AIBDs, which has resulted in proposals of new subtypes of AIBDs. In this article, we summarized various distinct AIBDs, and proposed the latest and most comprehensive classification of AIBDs with their autoantigen molecules.

Efficacy and safety of apremilast and phototherapy versus phototherapy only in psoriasis vulgaris

Phototherapy and apremilast (oral phosphodiesterase-4 inhibitor) are well-known in the treatment of moderate to severe psoriasis vulgaris. However, current evidence on the efficacy and safety of their combination is not sufficient. This multicenter, randomized controlled study compared the efficacy and safety between phototherapy as monotherapy and phototherapy and apremilast as combination therapy in patients with psoriasis vulgaris. Patients with moderate to severe psoriasis vulgaris were assigned to combination (n = 29) and monotherapy (n = 13) groups. All patients underwent an 8-week phototherapy regimen comprising irradiation with narrowband UV-B. The patients in the combination group were also administered 10 mg to 60 mg of oral apremilast. We evaluated the improvement percentage based on the Psoriasis Area and Severity Index (PASI) score from baseline to week 8. Additionally, we evaluated the percentage of patients who achieved ≥75% improvement; changes in body surface area (BSA) and scores of EuroQol 5-dimensions 5-level, Dermatology Life Quality Index, and visual analog scale for pruritis from baseline to 4 and 8 weeks; and adverse events. Compared with the monotherapy group, the combination group had significantly lower PASI scores at 4 and 8 weeks and more patients who achieved a PASI score improvement of ≥75% at 8 weeks. Both groups exhibited a significant decrease in BSA; at 8 weeks, no significant difference was observed between the two groups, although the combination group tended toward a greater reduction in BSA. The intergroup differences in the changes at the three time points were not significant. Adverse events were more frequent in the combination group than in the monotherapy group. Our findings suggest that an 8-week combined apremilast and phototherapy regimen may not be adequate in patients for improvements in their subjective assessment of psoriasis, and longer treatment periods may be necessary.

Bexarotene-induced central hypothyroidism assessed by TRH stimulation test in cutaneous T-cell lymphoma patients

Bexarotene-induced central hypothyroidism (CH), for which levothyroxine (LT4) replacement is recommended, has been shown to be caused by pituitary but not hypothalamic disorder experimentally, though the underlying mechanism in humans remains unclear. Here, the pathophysiology of bexarotene-induced CH was examined using a TRH stimulation test in cutaneous T-cell lymphoma (CTCL) patients. In this retrospective longitudinal observational study, serum TSH and free T4 (F-T4) levels were measured in 10 euthyroid patients with CTCL during 24 weeks of bexarotene treatment. TRH stimulation testing was performed following CH diagnosis, with LT4 replacement dosage adjusted to maintain F-T4 at the pre-treatment level. After one week of bexarotene administration, all 10 patients developed CH, based on combined findings of low or low-normal F-T4 with low or normal TSH levels. TSH peak response after a stimulation test at one week was reached at 30 minutes. However, that was <4 μIU/mL in all patients, indicating a blunted though not exaggerated and delayed TSH response. In eight who continued bexarotene for 24 weeks, median LT4 replacement dosage was 125 (range, 75-150) μg/day. TSH level at 30 as well as 15, 60, 90, and 120 minutes after TRH stimulation was significantly correlated with LT4 replacement dosage (ρ = -0.913, p = 0.002), whereas TSH and F-T4 basal levels at one week were not. These results suggest that pituitary hypothyroidism is responsible for bexarotene-induced CH, while TSH levels after TRH stimulation precisely reflect residual pituitary-thyroid function in patients receiving bexarotene.

Comparison of the Efficacy and Safety of Bexarotene and Photo(Chemo)Therapy Combination Therapy and Bexarotene Monotherapy for Cutaneous T-Cell Lymphoma

Introduction

Cutaneous T-cell lymphoma (CTCL) is a chronic condition with low malignancy. The combined use of therapeutic agents and photo(chemo)therapy is widely applied for the treatment of CTCL. The efficacy and safety of bexarotene and photo(chemo)therapy combination therapy were previously confirmed in Japanese patients with CTCL. The efficacy and safety of the bexarotene and photo(chemo)therapy combination therapy was compared with bexarotene monotherapy in Japanese patients with CTCL.

Methods

This was a randomized, open-label, two-parallel-group, active-control specified clinical study in Japanese patients diagnosed with CTCL carried out over 8 weeks with a study extension conducted at two institutions. This study was registered in Japan Registry of Clinical Trials (jRCTs041180094).

Results

In the combination therapy group, 22 subjects received oral bexarotene (300 mg/m² body surface area) once daily, followed by bath-psoralen and ultraviolet (UV) A or narrowband UVB. In the monotherapy group, 24 subjects received oral bexarotene (300 mg/m²) once daily. The efficacy analysis using the modified Severity-Weighted Assessment Tool, which included 39 patients, showed a response rate of 81.0% (17/21) in the combination therapy group and 83.3% (15/18) in the monotherapy group. No statistically significant difference was detected between groups. In the combination therapy group, four subjects showed a complete clinical response or complete response, and subjects with a partial response exhibited a high rate of skin lesion resolution, significantly better than in the monotherapy group. In the safety analysis, which included 46 treated subjects (22 in the combination therapy group and 24 in the monotherapy group), no adverse events or adverse drug reactions were reported in either group.

Conclusion

Both bexarotene and photo(chemo)therapy combination therapy and bexarotene monotherapy were therapeutically effective in Japanese patients with CTCL and well tolerated. Combination therapy led to a higher skin lesion resolution rate and greater therapeutic effects compared with monotherapy.

Trial Registration

jRCTs041180094.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-021-00655-0.

This study evaluated the efficacy and safety of bexarotene monotherapy compared with bexarotene and photo(chemo)therapy combination therapy in Japanese patients with cutaneous T-cell lymphoma (CTCL). The study was a randomized, open-label, two-parallel-group, active-control specified clinical study in patients diagnosed with CTCL performed over an 8-week period with a study extension conducted in two institutions. In the combination therapy group, bexarotene (300 mg/m² body surface area) was administered orally once daily to 22 subjects, followed by treatment with bath-psoralen and ultraviolet A (bath-PUVA) or narrowband UVB. In the bexarotene monotherapy group, bexarotene (300 mg/m²) was administered orally once daily to 24 subjects. Efficacy was assessed using the modified Severity-Weighted Assessment Tool. Among the 39 subjects analyzed for treatment efficacy, the response rate of the combination therapy group was 81.0% (17/21) and that of the monotherapy group was 83.3% (15/18). Differences between the two treatment groups were not statistically significant. Of the 21 subjects in the combination therapy group, 4 had a complete clinical response or complete response, and those with a partial response showed a higher skin lesion resolution rate than in the monotherapy group. The safety analysis revealed no reports of adverse events or adverse drug reactions among the 46 treated subjects (combination therapy group = 22; monotherapy group = 24). Thus, both bexarotene and photo(chemo)therapy combination therapy and bexarotene monotherapy were therapeutically effective and well tolerated in Japanese patients with CTCL. Patients receiving the combined therapy, however, showed a higher rate of skin lesion resolution.

The Second Study of Clinical and Immunological Findings in Anti-laminin 332-Type Mucous Membrane Pemphigoid Examined at Kurume University-Diagnosis Criteria Suggested by Summary of 133 Cases

Background

Recently, we published an article retrospectively summarizing the results in 55 anti-laminin 332 (LM332)-type mucous membrane pemphigoid (MMP) cases examined at Kurume University, which were diagnosed by strict inclusion criteria, including positive reactivity in direct immunofluorescence and absence of antibodies to non-LM332 autoantigens. However, indirect immunofluorescence using 1M-NaCl-split normal human skin (ssIIF) is also valuable for diagnosis of anti-LM332-type MMP.

Methods

In this second study, we selected 133 anti-LM332-type MMP cases, which were diagnosed by our different inclusion criteria: (i) immunoglobulin G (IgG) deposition to basement membrane zone (BMZ) by direct immunofluorescence or IgG reactivity with dermal side of split skin by ssIIF, (ii) positivity for at least one of the three subunits of LM332 by immunoblotting of purified human LM332, and (iii) the presence of mucosal lesions. Clinical, histopathological, and immunological findings were summarized and analyzed statistically. Although these cases included the 55 previous cases, the more detailed study for larger scale of patients was conducted for further characterization.

Results

Clinically, among the 133 patients, 89% and 43% patients had oral and ocular mucosal lesions, respectively, 71% had cutaneous lesions, and 17% had associated malignancies. Histopathologically, 93% patients showed subepidermal blisters. The sensitivities of ssIIF and direct immunofluorescence are similar but are significantly higher than indirect immunofluorescence using non-split human skin (both p < 0.001). In immunoblotting of purified LM332, patient IgG antibodies most frequently reacted with LMγ2 subunit (58%), followed by LMα3 (49%) and LMβ3 (36%). Thirty-four percent patients recognized additional non-LM332 autoantigens. Statistical analysis revealed that autoantibodies against non-LM332 autoantigens might stimulate the production of anti-LMγ2 antibodies.

Conclusions

This retrospective study further characterized in more detail the clinical and immunological features of 133 cases of anti-LM332-type MMP, in which the new diagnostic criteria without positive direct immunofluorescence reactivity were useful for the diagnosis. Higher frequency with anti-LMγ2 antibodies suggested more significant pathogenic role of this subunit. Additional autoantibodies to non-LM332 autoantigens detected in one-third of the patients may contribute to complexity in anti-LM332-type MMP, including the induction of anti-LMγ2 antibodies.

Safety and efficacy of bexarotene for Japanese patients with cutaneous T-cell lymphoma: Real-world experience from post-marketing surveillance

To establish real-world evidence about the safety and efficacy of bexarotene for Japanese patients with cutaneous T-cell lymphoma, we conducted a nationwide cohort study using data from post-marketing surveillance for bexarotene treatment. In total, 294 patients with cutaneous T-cell lymphoma were identified between June 2016 and June 2018. Of these, 267 patients were included as the safety analysis set. Of the 267 patients, 175 were included in the efficacy analysis set. Of these, 139 patients had mycosis fungoides, including 46 with early stage disease and 93 with advanced stage disease. Among the 139 patients with mycosis fungoides, the objective response rate was 46.8%. A significant difference in objective response rate was detected between patients who started with bexarotene at 300 mg/m² (61.6%) and patients who started with bexarotene at less than 300 mg/m² (22.6%, p < 0.001). Of the 139 patients with mycosis fungoides, 92 were treated with a combination of bexarotene plus photo(chemo)therapy. A significant difference in objective response rate was seen between bexarotene with a combination of photo(chemo)therapy (57.6%) and bexarotene without a combination of photo(chemo)therapy (25.5%, p < 0.001). Starting bexarotene at 300 mg/m² and combination with photo(chemo)therapy were detected as independent factors influencing response. Common treatment-related adverse events included hypothyroidism (85.8%), hypertriglyceridemia (68.5%), hypercholesterolemia (43.8%), and neutropenia (21.3%). Hypertriglyceridemia, hypercholesterolemia, and neutropenia occurred more frequently in patients who started with bexarotene at 300 mg/m² than patients who started with bexarotene at less than 300 mg/m² (hypertriglyceridemia, 76.4% vs. 57.0%, p = 0.001; hypercholesterolemia, 49.0% vs. 36.4%, p = 0.045; neutropenia, 28.0% vs. 12.1%, p = 0.002; respectively). The present study indicates that starting bexarotene at 300 mg/m² and combination of photo(chemo)therapy offer a promising efficacy for the treatment of patients with mycosis fungoides. Efficacy of low-dose bexarotene plus photo(chemo)therapy should be evaluated in future.

Effect of adalimumab on axial manifestations in Japanese patients with psoriatic arthritis: a 24 week prospective, observational study

OBJECTIVES

PsA is characterized by enthesitis, synovitis and osseous involvement in the peripheral and axial joints. Few studies have examined axial involvement in PsA using imaging techniques. Here we examined axial involvement in PsA patients using MRI. In addition, we determined the efficacy of 24 week adalimumab treatment in improving the MRI findings of spondylitis and sacroiliitis.

METHODS

This was a prospective, open-label, single-arm study in patients with PsA. Adalimumab was administered to patients for a total of 24 weeks. MRI examinations were conducted at baseline and at week 24 of adalimumab treatment.

RESULTS

Thirty-seven patients with PsA were included in this study. Spondylitis was observed in at least one site of the positive scan in 91% (n = 31) of patients with PsA. The number of arthritic sites in the cervical, thoracic and lumbar regions of the spine was 48, 67 and 53, respectively. All patients had MRI-determined sacroiliitis of grade ≥1 severity while 28 patients (82%) had grade ≥2 sacroiliitis in at least one sacroiliac region. Sacroiliac arthritis was statistically more severe on the right side than on the left side (P < 0.05). In 34 patients with PsA, the thoracic spine was the most common site of spondylitis. In addition, 24 week adalimumab treatment led to an improvement in the mean number of spondylitis sites and the mean grade of sacroiliitis.

CONCLUSION

Treatment with adalimumab for 24 weeks resulted in improvement in spondylitis and sacroiliitis.

A multicenter, open-label, uncontrolled, single-arm phase 2 study of tirabrutinib, an oral Bruton's tyrosine kinase inhibitor, in pemphigus

BACKGROUND

The treatment of pemphigus is based on systemic corticosteroid use and adjuvant therapies, but some patients are resistant to conventional therapy. Tirabrutinib is a highly selective oral Bruton's tyrosine kinase inhibitor that may be clinically effective in treating pemphigus by suppressing B-cell signaling.

OBJECTIVE

We investigated the efficacy and safety of tirabrutinib in patients with refractory pemphigus.

METHODS

This was a multicenter, open-label, single-arm phase 2 study of Japanese patients with refractory pemphigus receiving appropriate treatment with an oral corticosteroid and adjuvant therapies. Patients received postprandial oral tirabrutinib 80 mg once daily for 52 weeks. After 16 weeks of tirabrutinib treatment, the corticosteroid dose was tapered to ≤10 mg/day of prednisolone equivalent.

RESULTS

In total, 16 patients were evaluated (mean age, 52.5 years; 50 % male). The complete remission rate after 24 weeks of treatment (primary endpoint) was 18.8 % (3/16; 95 % confidence interval, 6.6 %-43.0 %). By Week 52, eight patients (50.0 %) achieved complete remission and 10 patients (62.5 %) achieved remission. Over 52 weeks of treatment, the mean prednisolone dose decreased from 17.03 to 7.65 mg/day. Incidences of adverse events (AEs) and adverse drug reactions were 87.5 % and 43.8 %, respectively. A relationship with tirabrutinib was ruled out for all serious AEs and Grade ≥3 AEs.

CONCLUSION

Treatment with tirabrutinib enabled remission and reduced oral corticosteroid exposure over time and did not result in any major safety concerns in patients with refractory pemphigus. Thus, oral tirabrutinib may be a new treatment option for patients with refractory pemphigus.

POS1059 ULTRASOUND SYNOVITIS, UNLIKE ENTHESITIS OR CLINICAL JOINT ASSESSMENT, IS ASSOCIATED WITH JOINT DAMAGE PROGRESSION IN PATIENTS WITH PSORIATIC ARTHRITIS

Background:

We previously reported that ultrasound assessment of enthesitis (US enthesitis) is not consistent with tenderness of the enthesis (clinical enthesitis) in patients with psoriatic arthritis (PsA). Although US enthesitis reflects inflammatory condition and clinical enthesitis is associated with disease activity and physical function, each of them was not associated with joint destruction by cross-sectional analysis1. It is reported that the utility of US for predicting joint destruction remains unclear among patients with PsA2.

Objectives:

This study is aimed to longitudinally investigate the relationships between enthesitis or synovitis and joint damage progression in patients with PsA.

Methods:

Forty-seven patients with PsA (average age of 56.5 years) underwent US and clinical examination of wrist and finger joints and 14 entheses (the bilateral humeral medial epicondyles and insertions of the triceps, distal quadriceps, proximal/distal patella, Achilles tendons, and plantar fascia). Tender or swollen joint count (TJC/SJC), Gray Scale (GS) and Power Doppler (PD) score of the joints, and US/clinical enthesitis counts were calculated. The relationships between the yearly progression in modified total sharp score (ΔmTSS) at two-time points (baseline and average follow-up of 20.4 months) and US or clinical findings were investigated.

Results:

ΔmTSS was significantly correlated with age (r=0.44, p=0.01), joint GS score (r=0.44, p=0.01), and joint PD score (r=0.38, p=0.03). TJC, SJC, inflammatory marker, and disease activity showed no associations with ΔmTSS. US/clinical enthesitis counts also showed no associations with ΔmTSS (Table 1). The joint PD score, adjusted by age, was significant factor for ΔmTSS by multiple regression analysis (b=0.50, p<0.001).

Conclusion:

The joint PD score or US synovitis, unlike clinical joint assessment, was significant predictive factor for joint damage progression. It is important to assess joints by US as well as clinical examination.

References:

1) Yutaro Yamada et al. Ultrasound assessment, unlike clinical assessment, reflects enthesitis in patients with psoriatic arthritis. Clin Exp Rheumatol. 2020 Apr 17. Online ahead of print.

2) van der Heijde et al. Assessing structural damage progression in psoriatic arthritis and its role as an outcome in research. Arthritis Res Ther. 2020, 22(1): 18.

Table 1.

Univariate analysis of predictive factors for joint damage progression in PsA patients.

mTSS at baselineΔmTSSR valuep valueR valuep valueage0.55<0.0010.440.01PASE0.040.810.120.52PASI-0.250.15-0.010.96DAS28CRP-0.050.750.070.71DAPSA-0.010.94-0.010.97HAQ0.170.27-0.070.73CRP-0.130.380.230.20MMP-30.040.800.290.12biologics use0.190.19-0.110.54Clinical enthesitis counts-0.010.97-0.190.30TJC-0.050.76-0.100.58SJC0.210.180.130.48US enthesitis counts0.120.44-0.130.48joint GS score0.080.600.440.01joint PD score0.080.600.380.03

PsA: psoriatic arthritis, mTSS: modified Total Sharp Score, PASE: Psoriatic Arthritis Screening and Evaluation, PASI: Psoriasis Area Severity Index, DAPSA: Disease Activity in Psoriatic Arthritis, DAS: Disease Activity Score, CRP: C-reactive protein, HAQ: Health Assessment Questionnaire, MMP-3: matrix metalloproteinase 3, TJC: tender joint counts, SJC: swollen joint counts, GS: Gray Scale, PD: Power Doppler

Disclosure of Interests:

Yutaro Yamada: None declared, Kentaro Inui Speakers bureau: Abbvie, Eisai, Eli Lilly, Grant/research support from: Abbvie, Eisai, Chigai, Eli Lilly, Daiichi Sankyo, Mitusbishi Tanabe, Pfizer, UCB, Tadashi Okano Speakers bureau: Abbvie, Koji Mandai: None declared, Kenji Mamoto: None declared, Tatsuya Koike Grant/research support from: Abbvie, Chugai, Chiharu Tateishi: None declared, Daisuke Tsuruta Speakers bureau: Abbvie, Astellas, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen, Novartis, Sanofi, Grant/research support from: Abbvie, Eli Lilly, Bristol-Myers Squibb, UCB, Hiroaki Nakamura Grant/research support from: Astellas, Asahi Kasei

Granzyme B inhibition reduces disease severity in autoimmune blistering diseases

Pemphigoid diseases refer to a group of severe autoimmune skin blistering diseases characterized by subepidermal blistering and loss of dermal-epidermal adhesion induced by autoantibody and immune cell infiltrate at the dermal-epidermal junction and upper dermis. Here, we explore the role of the immune cell-secreted serine protease, granzyme B, in pemphigoid disease pathogenesis using three independent murine models. In all models, granzyme B knockout or topical pharmacological inhibition significantly reduces total blistering area compared to controls. In vivo and in vitro studies show that granzyme B contributes to blistering by degrading key anchoring proteins in the dermal-epidermal junction that are necessary for dermal-epidermal adhesion. Further, granzyme B mediates IL-8/macrophage inflammatory protein-2 secretion, lesional neutrophil infiltration, and lesional neutrophil elastase activity. Clinically, granzyme B is elevated and abundant in human pemphigoid disease blister fluids and lesional skin. Collectively, granzyme B is a potential therapeutic target in pemphigoid diseases.

Exploration of biomarkers to predict clinical improvement of atopic dermatitis in patients treated with dupilumab: A study protocol

BACKGROUND

Atopic dermatitis (AD) is a common eczematous skin disorder that profoundly reduces the quality of life due to intractable pruritus. Excellent therapeutic success of the anti-interleukin 4 receptor-α antibody dupilumab in clinical trials and a real-world clinical context indicates the crucial roles of interleukin (IL)-4 and IL-13 in the pathogenesis of AD. Along with the clinical improvement in skin scores and pruritus, dupilumab significantly and progressively reduces and normalizes the upregulated expression of T helper type 2 signatures such as Chemokine (C-C motif) ligand (CCL)17, CCL18, CCL22, and CCL26 in the lesional skin of AD. However, no blood/serum biomarkers are known to predict good or poor outcome in patients with AD treated with dupilumab.

METHODS

Patients are at least 18 years of age and have moderate-to-severe AD with Eczema Area and Severity Index (EASI) ≥16, Investigator's Global Assessment ≥3, and body surface area ≥10%. We are going to enroll more than 130 subjects from 18 medical facilities. Clinical objective findings will be evaluated by EASI. Subjective symptoms will be assessed by Patient-Oriented Eczema Measure, Numerical Rating Scale for Pruritus (Pruritus-NRS), Skin Comfort-NRS, and Treatment Satisfaction-NRS. We will measure 18 blood/serum biomarkers including % eosinophils in blood cell count, lactate dehydrogenase, total IgE, soluble interleukin 2 receptor, CCL17, CCL18, CCL22, CCL26, CCL27, IL-13, IL-22, IL-24, IL-25, IL-31, IL-33, thymic stromal lymphopoietin, periostin, and squamous cell carcinoma antigen-2. The clinical evaluation and biomarker sampling will be performed at 0, 2, 4, 8, and 16 weeks of dupilumab treatment. We will also perform proteomic analysis (of roughly 300 proteins) of the patients' sera obtained at 0 and 2 weeks of treatment. The primary endpoint is the association between "baseline levels of 18 biomarkers" and "% change from baseline of EASI at 16 weeks of dupilumab treatment."

DISCUSSION

This is the first clinical trial to explore the biomarkers, including potential proteomic markers, most strongly associated with improvement in EASI in patients with moderate-to-severe AD treated with dupilumab for 16 weeks (B-PAD study). A limitation is that we will only enroll Japanese patients.

Efficacy and safety of bexarotene combined with photo(chemo)therapy for cutaneous T-cell lymphoma

Cutaneous T‐cell lymphoma (CTCL) is a chronic condition with low malignancy. International treatment guidelines for CTCL are widely followed in Europe and the USA. Combination therapy with therapeutic agents for CTCL and phototherapy is effective on the basis of European data. The efficacy and safety of combination therapy for Japanese CTCL patients are not established. We investigated the efficacy and safety of combination therapy with photo(chemo)therapy and bexarotene in Japanese CTCL patients. Twenty‐five patients received daily oral bexarotene (300 mg/m² body surface), followed by bath‐psoralen plus ultraviolet (UV)‐A (PUVA) or narrowband UV‐B. Treatment results were evaluated using the modified Severity‐Weighted Assessment Tool (mSWAT) and the Physician Global Assessment of Clinical Condition (PGA) up to week 24. Safety was also assessed. Twenty‐four weeks after initiating treatment, the total response rate was 80.0% (mSWAT) and 84.0% (PGA). Response rates did not differ when stratified by disease stage. Number of days (mean ± standard deviation) for time to response, duration of response and time to progression determined by the mSWAT were 20.7 ± 9.62, 117.0 ± 43.0 and 163.6 ± 28.8, respectively. T‐helper 2 chemokine levels in patients at stage IIA or more decreased significantly at weeks 12 and 24. All patients experienced adverse events and adverse drug reactions. Serious adverse drug reactions included sepsis, anemia and congestive cardiac insufficiency (n = 1 each). Other adverse drug reactions were of mild to moderate severity. Combination therapy with bexarotene and PUVA was safe and effective in Japanese CTCL patients.

Systemic lupus erythematosus with refractory ulcerated livedoid vasculopathy: Successful treatment with intravenous immunoglobulin and warfarin

We reported a patient with systemic lupus erythematosus complicated by livedoid vasculopathy (LV), who responded well to intravenous immunoglobulin and warfarin. Cutaneous lesions of LV resemble those of cutaneous vasculitis. LV should be included in the differential diagnosis of leg ulcerations even in the presence of autoimmune disorders.

Herpetiform pemphigus with characteristic transmission electron microscopic findings of various-sized ballooning vacuoles in keratinocytes without acantholysis

We report a unique case of a Japanese woman with herpetiform pemphigus (HP) who had IgG autoantibodies reactive with nondesmosomal sites of keratinocytes and presented characteristic transmission electron microscopic (TEM) findings of various-sized vacuoles in keratinocytes without acantholysis. The patient presented with pruritic annular oedematous erythemas with small blisters lining the margins on the trunk and extremities. Histopathological examinations showed intraepidermal blisters with prominent infiltrations of eosinophils. Direct and indirect immunofluorescence tests revealed the presence of in vivo bound and circulating IgG autoantibodies to the keratinocyte cell surfaces. However, enzyme-linked immunosorbent assays for desmoglein (Dsg) 1, Dsg3 and desmocollins 1-3 showed negative results. Immunoblotting using the full-length human Dsg1 recombinant protein showed a positive band. TEM examination showed various-sized vacuoles squashing the nuclei in many keratinocytes, resulting in rupture of the cells. Immunoelectron microscopic examination revealed IgG deposition over the entire keratinocyte cell surfaces, which spared the desmosomes. IgG antibodies were also present on the inside walls of the vacuoles around the nuclei of keratinocytes and on the cell surfaces of infiltrating eosinophils. This patient also had marked eosinophilia and high levels of thymus and activation-regulated chemokine and interleukin-5 in the serum. These results indicated a novel autoantigen on the nondesmosomal keratinocyte cell surfaces and the pathogenesis of bullous spongiotic change with inflammation in HP.

Unique mouse monoclonal antibodies reactive with maturation-related epitopes on type VII collagen

In this study, we generated a new set of monoclonal antibodies (mAbs) to bovine and human type VII collagen (COL7) by immunizing mice with bovine cornea-derived basement membrane zone (BMZ) fraction. The four mAbs, tentatively named as COL7-like mAbs, showed speckled subepidermal staining in addition to linear BMZ staining of normal human skin and bovine cornea, a characteristic immunofluorescence feature of COL7, but showed no reactivity with COL7 by in vitro biochemical analyses. Taking advantage of the phenomenon that COL7-like mAbs did not react with mouse BMZ, we compared immunofluorescence reactivity between wild-type and COL7-rescued humanized mice and found that COL7-like mAbs reacted with BMZ of COL7-rescued humanized mice. In ELISAs, COL7-like mAbs reacted with intact triple-helical mammalian recombinant protein (RP) of COL7 but not with bacterial RP. Furthermore, COL7-like mAbs did not react with COL7 within either cultured DJM-1 cells or basal cells of skin of a bullous dermolysis of the newborn patient. These results confirmed that COL7-like mAbs reacted with human and bovine COL7. The epitopes for COL7-like mAbs were considered to be present only on mature COL7 after secretion from keratinocytes and deposition to BMZ and to be easily destroyed during immunoblotting procedure. Additional studies indicated association of the speckled subepidermal staining with both type IV collagen and elastin. These unique anti-COL7 mAbs should be useful in studies of both normal and diseased conditions, particularly dystrophic epidermolysis bullosa, which produces only immature COL7.

A case of subepidermal blistering disease with autoantibodies to multiple laminin subunits who developed later autoantibodies to alpha-5 chain of type IV collagen associated with membranous glomerulonephropathy

We report a 68-year-old Japanese female patient with subepidermal blistering disease with autoantibodies to multiple laminins, who subsequently developed membranous glomerulonephropathy. At skin disease stage, immunofluorescence demonstrated IgG anti-basement membrane zone antibodies reactive with dermal side of NaCl-split skin. Immunoblotting of human dermal extract, purified laminin-332, hemidesmosome-rich fraction and laminin-521 trimer recombinant protein (RP) detected laminin γ-1 and α-3 and γ-2 subunits of laminin-332. Three years after skin lesions disappeared, nephrotic symptoms developed. Antibodies to α-3 chain of type IV collagen (COL4A3) were negative, thus excluding the diagnosis of Goodpasture syndrome. All anti-laminin antibodies disappeared. Additional IB and ELISA studies of RPs of various COL4 chains revealed reactivity with COL4A5, but not with COL4A6 or COL4A3. Although diagnosis of anti-laminin γ-1 (p200) pemphigoid or anti-laminin-332-type mucous membrane pemphigoid could not be made, this case was similar to previous cases with autoantibodies to COL4A5 and/or COL4A6.

Anti-desmocollin autoantibodies in nonclassical pemphigus

BACKGROUND

Despite the established pathogenic role of anti-desmoglein (Dsg) antibodies in classical pemphigus, the significance of autoantibodies to another desmosomal cadherin, desmocollin (Dsc) is at present unknown. No consistent immunoassay for immunoglobulin (Ig) G autoantibodies to Dscs has been developed.

OBJECTIVES

The aim of this study was to develop reliable assays to detect anti-Dsc autoantibodies.

METHODS

We expressed soluble recombinant proteins (RPs) of human Dsc1-3 in mammalian cells and examined sera of various types of pemphigus, including 79 paraneoplastic pemphigus (PNP) sera, by novel enzyme-linked immunosorbent assays (ELISAs) using the RPs. We also performed ELISAs of Dsc baculoproteins and used the complementary DNA (cDNA) transfection method, and compared the results with those of mammalian ELISAs.

RESULTS

Through mammalian ELISAs, IgG autoantibodies to Dsc1, Dsc2 and Dsc3 were detected in 16.5%, 36.7% and 59.5% of PNP sera, respectively, and considerable numbers of pemphigus herpetiformis (PH) and pemphigus vegetans (PVeg) sera reacted strongly with Dsc1 and Dsc3. Mammalian ELISAs were highly specific and more sensitive than baculoprotein ELISAs or the cDNA transfection method. Several Dsc-positive sera, particularly PH sera, showed no reactivity with Dsgs. The reactivity of PNP serum and PVeg serum with Dscs was not abolished by pre-absorption with Dsg RPs.

CONCLUSIONS

The results of these novel ELISAs indicated that IgG anti-Dsc autoantibodies were frequently detected and potentially pathogenic in nonclassical pemphigus.