[MACULOPAPULAR CUTANEOUS MASTOCYTOSIS HARBORING A KIT MUTATION (ASP419DEL): A CASE REPORT].

A 2-year-old, male patient presented with an 18-month history of scattered, brown macules and nodules up to 2 cm in size on his trunk and extremities. These macules were accompanied by pruritus and were positive for Darier's sign. A skin biopsy of a brown macule on the left thigh revealed a dense accumulation of CD117-positive, round or oval cells with amphophilic cytoplasm within the upper to middle dermis. The patient was otherwise healthy and had normal laboratory and imaging test results. Sequence analysis of genomic DNA from a skin biopsy demonstrated the presence of an Asp419del mutation in exon 8 of the KIT gene. Based on these findings, maculopapular cutaneous mastocytosis (MPCM) was diagnosed. The patient received H 1-antihistamine. Although the pruritus resolved, the brown macules remained for one year after the initial treatment. To the best of our knowledge, only three cases of cutaneous mastocytosis (CM) with an Asp419del mutation, including the present case, have been reported in the Japanese literature to date; moreover, while the previous two cases were of DCM, the present case was the first instance of MPCM. Normally, the symptoms of childhood-onset MPCM are dormant until puberty. However, a recent study reported that many MPCM patients may experience persistent or exacerbated symptoms. The present study therefore evaluated 53 Japanese cases of childhood onset MPCM with a KIT gene mutation and discussed the patients' clinical outcomes.

High migratory activity of dermal sheath cup cells associated with the clinical efficacy of autologous cell-based therapy for pattern hair loss.

BACKGROUND: Autologous cell-based therapy using dermal sheath cup (DSC) cells was reported as a new treatment for male and female pattern hair loss. However, the mechanisms underlying its action remain unclear. OBJECTIVE: We investigated the mechanisms underlying the efficacy of DSC cells in cell-based therapy. METHODS: We conducted multivariate analysis to categorize individuals based on treatment response as responders and non-responders. The differentially expressed genes in DSC cells from the two groups were evaluated using bulk transcriptome, quantitative polymerase chain reaction, and single-cell transcriptome analyses. We performed live cell imaging combined with immunostaining to characterize the DSC subpopulation associated with responders. RESULTS: We identified nine and three genes as high efficacy (HE) and low efficacy (LE) marker genes, respectively. The HE subpopulations were enriched for cell migration-related genes in single-cell analysis. In contrast, the LE subpopulation was enriched for basement membrane and vasculature-related genes. Moreover, DSC cells in culture were immunocytochemically and morphologically heterogeneous, expressing characteristic factors. Furthermore, live cell imaging showed that DSC cells expressing integrin subunit alpha 6 (ITGA6), an HE subpopulation gene, had markedly higher mobility than those expressing the LE subpopulation genes collagen type IV or CD36. CONCLUSIONS: ITGA6-positive DSC cells, with superior migratory activity, may contribute to cell-based therapy by promoting cell migration into nearby hair follicles.

Efficacy and safety of ritlecitinib in adolescents with alopecia areata: Results from the ALLEGRO phase 2b/3 randomized, double-blind, placebo-controlled trial.

BACKGROUND/OBJECTIVES: This subgroup analysis of the ALLEGRO phase 2b/3 trial (NCT03732807) evaluated the efficacy and safety of ritlecitinib, an oral, selective dual JAK3/TEC family kinase inhibitor, for the treatment of alopecia areata (AA) in patients aged 12-17 years. METHODS: In ALLEGRO-2b/3, patients aged ≥12 years with AA and ≥50% scalp hair loss received once-daily ritlecitinib 50 or 30 mg (±4-week 200-mg loading dose) or 10 mg or placebo for 24 weeks. In a subsequent 24-week extension period, ritlecitinib groups continued their doses, and patients initially assigned to placebo switched to 200/50 or 50 mg daily. Clinician- and patient-reported hair regrowth outcomes and safety were assessed. RESULTS: In total, 105 adolescents were randomized. At Week 24, 17%-28% of adolescents achieved a Severity of Alopecia Tool (SALT) score ≤20 (≤20% scalp without hair) in the ritlecitinib 30 mg and higher treatment groups versus 0% for placebo. At Week 48, 25%-50% of patients had a SALT score ≤20 across ritlecitinib treatment groups (30 mg and higher). Adolescents reporting that their AA "moderately" or "greatly" improved were 45%-61% in the ritlecitinib groups (30 mg and higher) (vs. 10%-22% for placebo) at Week 24 and 44%-80% at Week 48. The most common adverse events in adolescents were headache, acne, and nasopharyngitis. No deaths, major adverse cardiovascular events, malignancies, pulmonary embolisms, opportunistic infections, or herpes zoster infections were reported. CONCLUSION: Ritlecitinib treatment demonstrated clinician-reported efficacy, patient-reported improvement, and an acceptable safety profile through Week 48 in adolescents with AA with ≥50% scalp hair loss.

Topical application of imatinib mesylate ameliorated psoriasis-like skin lesions in imiquimod-induced murine model via angiogenesis inhibition.

Psoriasis is a chronic skin disorder characterized by a skin rash with scaly patches. Microvascular abnormalities are a characteristic feature of psoriasis and play a crucial role in the pathogenesis of psoriatic lesions. Angiogenic factors are upregulated in psoriatic skin lesions and are thought to induce angiogenesis. Platelet-derived growth factor (PDGF) induces vascular endothelial growth factor (VEGF), and PDGF is upregulated in keratinocytes in psoriatic skin lesions. The present study aimed to investigate the effect of topical imatinib mesylate (IMT) in inhibiting the activation of PDGF signalling in the pathogenesis of psoriasis. When topically applied to the skin of mice with imiquimod (IMQ)-induced psoriasis, IMT ameliorated skin symptoms similar to those of human psoriasis. Hyperproliferation of keratinocytes, hyperkeratosis, inflammatory cell infiltration and hypervascularity were histologically suppressed by topical IMT. The expression of angiogenic factors including fibroblast growth factor (FGF) and VEGF was decreased. The expression of FGF and VEGF in a PDGF-stimulated fibroblast cell line was inhibited by IMT. PDGF is required for the signalling pathway producing angiogenic factors in fibroblast. Thus, topically applied IMT inhibits PDGFR activation in fibroblast and suppresses the production of angiogenic factors, thereby mitigating the symptoms of psoriasis. The inhibitory effect of IMT on angiogenesis suggests that topical application IMT may be a viable treatment option for psoriasis.

Topical application of imatinib mesylate suppresses vitamin D3 analog-induced dermatitis in Balb/c mice.

Atopic dermatitis (AD) is an allergic disease mediated by Th2 cells. In AD, externally stimulated keratinocytes release inflammatory cytokines, such as IL-33 and TSLP. Inflammatory cells infiltrate skin tissue and increase vascular permeability. Therefore, we hypothesized that imatinib mesylate (IMT), which suppresses vascular permeability, may be a candidate therapeutic agent for AD. A vitamin D3 analog (MC903) was administered daily to both ears of Balb/c mice to create a murine AD model to which IMT was applied. The skin lesions were evaluated histopathologically and by immunostaining. Cytokine expression in the skin was assessed by using real-time polymerase chain reaction (PCR) and immunostaining and was investigated using Evans Blue to determine whether IMT suppressed vascular permeability due to histamine. The suppressive effect of TNF-α/IL-4-induced TSLP expression in primary mouse keratinocytes (MKCs) treated with IMT was then investigated. Tslp gene and protein expression in the lesion was measured using real-time PCR and ELISA. The activation of signal transduction was analysed by western blotting. Topical application of IMT significantly reduced ear thickness, Evans blue leakage, and scratch onset. IMT suppressed the number of infiltrating cells (CD4+ T cells, eosinophils, and basophils), and the expression of IL-13, IL-33, and TSLP in a MC903-induced, murine AD model and inhibited TNF-α/IL-4-induced TSLP expression via downregulation of ERK phosphorylation in MKCs. IMT reduced the skin symptoms in a MC903-induced, murine AD model, suggesting that it may have potential as a new treatment for AD.

[A CHILD CASE OF DIFFUSE CUTANEOUS MASTOCYTOSIS].

Cutaneous mastocytosis (CM) usually appears in childhood and improves substantially before adolescence. The c-KIT mutation of D816V is present in 36% and 20% of patients with childhood-onset CM and diffuse cutaneous mastocytosis (DCM), respectively. In some cases of childhood-onset DCM, the disease can progress to systemic mastocytosis; in others, it resolves spontaneously. Thus, assessing the prognosis is difficult. Herein, we described a case of DCM in an 11-month-old, male patient without a c-KIT mutation. The patient presented with dark brown macules and sporadic erythema topped by bullous lesions. A skin biopsy of the macule on the abdomen revealed accumulation of mast cells which were round to oval-shaped with amphophilic cytoplasm within the upper dermis. The patient had received H1 inhibitor until age 3 years and continued to experience blisters on the trunk. However, no severe symptoms, such as anaphylaxis, occurred. Included in this manuscript is a review of previous reports of childhood-onset DCM in Japan and cases specifically seen at our dermatology clinic.

Low-Dose MST-16/VP-16 Combination Chemotherapy in 9 Patients with Tumor Stage Mycosis Fungoides.

BACKGROUND/AIM: MST-16 and VP-16, both of which are topoisomerase II inhibitors, are antitumor agents regularly used to treat malignant lymphoma and small cell lung carcinoma. New therapeutic agents for tumor stage mycosis fungoides (MF) have recently been developed, but their efficacy is limited. We herein retrospectively reported the use of MST-16/VP-16 combination therapy for tumor stage MF at multiple treatment centers and examined their antitumor effect. METHODS: Five male and four female patients with tumor stage MF were enrolled. Age at the start of therapy ranged from 33 to 80 years (average: 54.5 years), and the previous treatment consisted of R-CHOP, CAVOP-IFN, etc. The protocol for low-dose MST-16/VP-16 combination chemotherapy consisted of 800 mg MST-16 and 25 mg VP-16 administered 5 days per month. RESULTS: Three of the 9 patients died, but two of the three fatalities were unrelated to MF. A treatment effect was seen in three and 6 patients who showed a complete response and a partial response, respectively. The 5-year and 10-year overall survival rate was 85.7% and 57.1%, respectively. Adverse reactions consisted of 4 cases of nausea and 1 case of leukopenia. CONCLUSION: The present study demonstrated that the response rate to MST-16/VP-16 combination therapy was 100% and that the treatment effect was relatively long, suggesting that this therapy may be a viable option for treating tumor stage MF.

Treatment of intra-anal warts with imiquimod 5% cream: A single-center prospective open study.

Intra-anal warts are frequently recalcitrant to surgical removal, but imiquimod 5% cream is not formulated to use in clinical practice due to the risk of mucosal inflammation. In the present, prospective, open study examining the efficacy and safety of imiquimod 5% cream, the drug was applied to the entire inner surface of the anal canal with a cotton swab under anoscopy three times weekly for 16 weeks. If complete remission was not achieved, the treatment was continued until week 28. Electrocautery was applied once in a poorly responsive case. In total, 21 patients with intra-anal warts, of whom 16 were HIV-positive, were enrolled. Two patients withdrew before week 16, and nine more patients withdrew before week 28. The complete clearance rate was 36.8% (7/19) at week 16 and 70% (7/10) at week 28. Four patients achieved complete clearance at week 16 and maintained clearance at week 28 without further treatment. Three of four patients resistant to previous electrocautery achieved clearance with imiquimod 5% cream treatment. Adverse events occurred in 81% (17/21) of the patients mainly at the application site, but serious or previously unencountered adverse events were not observed. Imiquimod 5% cream applied to intra-anal warts was nearly as efficacious and safe as when applied to external anogenital warts. Since treatment modalities for intra-anal warts are very limited, application of imiquimod 5% cream alone with careful and frequent observation or in combination with electrocautery is a useful option for refractory cases of intra-anal wart.

Recent reductions in the size of facial pigmented basal cell carcinoma at diagnosis and the surgical margin: A retrospective and comparative study.

The present, retrospective, single-center study analyzed various factors associated with primary basal cell carcinoma (BCC) in the period before and after the introduction of dermoscopy (BD and AD, respectively). The demographic data of patients with primary BCC between 2001 and 2005 (BD: 84 patients, 90 cases) and 2011 and 2018 (AD: 297 patients, 320 cases) were analyzed. In the pigmented BCC-predominant cohort (94%), the proportion of smaller tumors as well as the total number of tumors significantly increased during AD (median tumor size, 10.0 mm in BD, 8.0 mm in AD; Mann-Whitney U-test, p = 0.011). BCC were excised with a significantly narrower margin during AD (median, 2.0 mm) than during BD (median, 3.0 mm; Mann-Whitney U-test, p < 0.001; odds ratio, 0.30; multivariate logistic regression analysis, p < 0.001); the incomplete excision rate was 1.9%, and the recurrence rate was 0%. The present study suggests that the introduction of dermoscopy might have aided in the early diagnosis of smaller BCC, especially in the face region, and determining the appropriate surgical margin. The smaller pigmented BCC can be excised with a narrower margin than stated in the guidelines (4 mm).

Histopathologic and dermoscopic features of 42 cases of folliculitis decalvans: A case series.

BACKGROUND: Folliculitis decalvans (FD) is a form of inflamed primary cicatricial alopecia (PCA). FD is classified as a neutrophilic PCA; however, only a few previous studies have described its histopathology, including the assessment of systematically evaluated and quantified follicular changes in horizontally sectioned biopsy specimens with clinical and dermoscopic findings of the early and advanced stages. OBJECTIVE: We aimed to clarify the histopathologic and dermoscopic features of early and advanced active stage FD. METHODS: We conducted a case series study of 42 patients with FD by dermoscopy and both horizontally and vertically sectioned biopsy specimens. RESULTS: The histopathologic findings of the early-stage lesions included loss of sebaceous glands; interfollicular acanthosis; and fibrosis with depressed, fused follicular infundibula showing thickened interfollicular keloid-like areas with tufted hairs on dermoscopy. Active lesions showed a greater number of hair clusters, clefting, and fused infundibula with dense inflammation predominantly in the upper follicles. Neutrophil-predominant infiltrates were observed in fewer than half of the patients, including those with early-stage lesions. LIMITATIONS: This was a retrospective study. CONCLUSION: FD has the features of mixed-cell PCA. The features of early-stage FD are thickened interfollicular keloid-like areas with tufted hairs and loss of sebaceous glands.

Downregulation of integrin-αvß6 on keratinocytes in the scar of lichen planopilaris and folliculitis decalvans: Relevance for the disappearance of epidermal Langerhans cells.

Primary cicatricial alopecia (PCA) is a group of poorly understood mechanisms in which the destruction of hair follicles leads to permanent hair loss. Lichen planopilaris (LPP) is a type of lymphocytic PCA and it has been known for epidermal Langerhans cells (LC) to disappear in the scar of LPP. We also found that epidermal LC also disappeared in the scar of folliculitis decalvans (FD), a type of neutrophilic PCA. Of note was that epidermal LC did not disappear in the scar of discoid lupus erythematosus, another type of lymphocytic PCA, suggesting that LC disappearance in the scar was not always a common feature of PCA. We found that the expression of integrin (ITG)-αvß6 in scar epidermis was significantly diminished in LPP and FD, but not in other PCA and disorders accompanied with scar formation. We also found that exogenous interleukin-1ß and α-interferon downregulated ITG-αvß6 expression in normal human epidermal keratinocytes. These data suggest that downregulation of ITG-αvß6 may be one of the causes of LC disappearance in the scar of LPP and FD.

Cytotoxic T-lymphocyte-associated protein 4 expressed by melanoma cells does not affect melanoma-specific cytotoxic T lymphocytes in the effector phase.

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is one of the important molecules that regulate the anti-melanoma T-cell response. Currently, there are some reports showing that CTLA-4 is expressed not only by T cells but also by various kinds of tumor cells, including melanoma cells. However, there is no report that shows the role of CTLA-4 expressed by melanoma cells in melanoma-specific cytotoxic T-lymphocyte (CTL) response. In this report, we confirmed substantial CTLA-4 expression and the localization of CTLA-4 in melanoma cell lines and tissues. Also, we examined its impact on melanoma-specific CTL in vitro, and found that CTLA-4 expressed by melanoma cells does not affect melanoma-specific CTL in the effector phase. Our findings suggest the importance of elucidating the role of CTLA-4 expressed by melanoma cells, particularly in anti-CTLA-4 antibody therapy.

Acquisition of resistance to vemurafenib leads to interleukin-10 production through an aberrant activation of Akt in a melanoma cell line.

Serine/threonine-protein kinase B-Raf (BRAF) inhibitors are very effective in treating melanoma with BRAF mutations. BRAF inhibitors suppress aberrant growth of melanoma cells caused by BRAF mutations. BRAF mutations reportedly result in melanoma cells releasing immunosuppressive factors, and BRAF inhibitors elicit anti-melanoma immune responses by reducing such factors. However, immunological characteristics of tumor cells that acquire resistance to BRAF inhibitors remain unknown. Here, we compared immunological characteristics between a melanoma cell line and its vemurafenib-resistant subline. No differences were observed in the status of BRAF mutations, expression of surface molecules related to antitumor T-cell responses or recognition by human leukocyte antigen-A*0201-matched melanoma-specific cytotoxic T lymphocytes in a short-term co-culture assay. However, resistant tumor cells released high amounts of interleukin-10 depending on aberrant activation of Akt signaling, and dendritic cell functions were considerably suppressed by culture supernatants of the resistant cells. Our findings demonstrated a novel immunological mechanism contributing to tumor growth owing to drug resistance to BRAF inhibitors.

Key component of inflammasome, NLRC4, was identified in the lesional epidermis of psoriatic patients.

Inflammasomes are multimolecular complexes that control the inflammatory response. The function of inflammasomes in the pathogenesis of psoriasis is still unclear. To clarify the relationship between inflammasomes and the pathophysiology of psoriasis, and in particular, to identify molecules interacting with caspase-1, a crucial component of inflammasomes, scale extracts obtained from patients with psoriasis were immunoprecipitated with anti-caspase-1 antibody and analyzed by liquid chromatography coupled with electrospray tandem mass spectrometry (LC-MS/MS). The expression of the inflammasome component was assessed by immunohistochemical analysis and an in vitro assay. We identified several candidates for caspase-1-interacting proteins from the psoriatic scale extracts by immunoprecipitation and LC-MS/MS. Nucleotide-binding oligomerization domain-containing protein-like receptor family CARD domain-containing protein 4 (NLRC4) was the only inflammasome component among the candidates; thus, the protein is considered to be a key factor of inflammasomes in psoriasis. No inflammasome component was found in the extracts of atopic dermatitis or normal skin by LC-MS/MS. Immunohistochemical analysis demonstrated upregulation of NLRC4 in the lesional epidermis of some psoriatic patients whereas weak expression of NLRC4 was detected in the normal and non-lesional epidermis. The mRNA expression of the NLRC4 gene increased in keratinocytes at confluency, 48 h after air exposure and after the addition of 1.5 mmol/L calcium chloride. Our findings suggest that NLRC4 may be involved in the exacerbation or modification of psoriatic lesions.

A pulmonary metastatic model of murine melanoma assessed by magnetic resonance imaging.

Immune checkpoint inhibitors and kinase inhibitors have improved prognosis of malignant melanoma (MM) patients. However, these therapies cannot completely overcome the metastasis of MM. Thus, development of new therapy against metastasis should be required. A first step towards this goal, the aim of this study, is to establish a model of pulmonary metastasis from primary cutaneous MM and a monitoring system. B16-F10, a murine melanoma cell line, was subcutaneously injected into the pinna of mice. The pinna was excised when the lesion was detected. A metastatic nodule on T2-weighted imaging was detected 4 weeks after resection of the pinna. Lung metastases were observed in 37.5% (6/16) of the specimens. We established a novel murine model of the high pulmonary metastasis of MM. The MRI was useful for observations of the growth of the metastatic lesions in the lungs without dissection.