Skin Manifestations of Micafungin Breakthrough Disseminated Trichosporonosis in Acute Megakaryoblastic Leukemia.

Disseminated trichosporonosis is a rare fungal infection whose risk factors are hematological malignancies and neutropenia. Recently, breakthrough Trichosporon infections after administration of micafungin, the first-line systemic antifungal agent in compromised hosts, have been widely recognized. A man in his seventies about 1 month into chemotherapy for acute megakaryoblastic leukemia presented with a worsening fever and dyspnea. The patient was being administered with empirical micafungin therapy for suspected candidiasis. As the symptoms progressed, scattered erythema appeared on the trunk, some with a dark red vesicle at the center. Blood cultures identified Trichosporon asahii, as did the specimen of the skin biopsy. On the basis also of the presence of pneumonia on chest computed tomography, we confirmed the diagnosis of disseminated trichosporonosis and changed the antifungal agent from micafungin to voriconazole. Blood culture turned out to be negative 1 month after administrating voriconazole. However, the patient died of the leukemia. Our review of previous reports on cutaneous manifestations of disseminated trichosporonosis revealed that despite their morphological diversity, erythema with a red papule or vesicle at the center, implying necrosis, was also observed in previous cases. Our case report suggests that dermatologists should be aware of skin manifestations of disseminated trichosporonosis after micafungin administration, especially in cases of hematological malignancies.

Clinical effectiveness of efinaconazole 10% solution for treatment of onychomycosis with longitudinal spikes.

Onychomycosis with longitudinal spikes in the nail plate has been reported to be refractory to oral drugs as with dermatophytoma. We evaluated the efficacy of 10% efinaconazole solution in the treatment of onychomycosis with longitudinal spikes. Of the 223 subjects who were enrolled in a previous study, a post-hoc analysis of 82 subjects with longitudinal spikes was performed in this study. The opacity ratio of longitudinal spikes was decreased over time from 8.1 to 0.9 at the final assessment. In addition, the longitudinal spike disappearance rate increased early after the application to 81.7% at the final assessment. Therefore, 10% efinaconazole solution can be a first-line drug for longitudinal spikes, which have been regarded as refractory to oral drugs.

Efficacy of long-term treatment with efinaconazole 10% solution in patients with onychomycosis, including severe cases: A multicenter, single-arm study.

We evaluated the efficacy of efinaconazole 10% topical solution in long-term use, for up to 72 weeks, for onychomycosis, including severe cases. Among 605 participants, 219 patients diagnosed as having onychomycosis were evaluated for the efficacy of efinaconazole. The treatment success rate (<10% clinical involvement of the target toenail) at the final assessment time point was 56.6%, the complete cure rate was 31.1% and the mycological cure rate was 61.6%, all of which increased over time, demonstrating that continuous application contributed to the improvement of cure rate. Even in severe cases, reduction of the affected nail area was observed, showing the potential efficacy of the treatment. Responses to a quality of life questionnaire among patients with onychomycosis, OnyCOE-t, suggested that efinaconazole treatment improved the patients' quality of life. The incidence of adverse drug reaction in the patients eligible for the assessment was 6.3%, and this developed only in the administration site in all cases. No systemic adverse event was observed. In addition, no increase in the incidence of adverse drug reaction due to long-term use was found. Efinaconazole therapy was proved to exhibit excellent balance between efficacy and safety, and thus may serve as a useful treatment option for onychomycosis.

Th17 cells carrying TCR recognizing epidermal autoantigen induce psoriasis-like skin inflammation.

Psoriasis is considered a Th17-type autoimmune skin inflammatory disease; however, involvement of an autoantigen-specific TCR has not been established. In this study, we show that psoriasis-like skin inflammation can be induced by autoreactive Th17 cells. We previously developed the desmoglein 3-specific TCR-transgenic (Dsg3H1) mouse, in which CD4⁺ T cells recognize physiological epidermal autoantigen. T cells from Dsg3H1 mice were polarized into Th17 cells in vitro and then adoptively transferred into Rag2⁻/⁻ mice. Dsg3H1-Th17 cells induced severe psoriasis-like skin inflammation within 2 wk after transfer in the tissues in which desmoglein 3 is expressed. Such pathology was not observed when wild-type Th17 cells or Th1-skewed Dsg3H1 T cells were transferred, and it was strongly suppressed by anti-IL-12/23 and anti-IL-17 Abs. Although IFN-γ⁺/IL-17⁺ T cells accumulated in the skin lesions of mice that received Dsg3H1-Th17 cells, IFN-γ-deficient Dsg3H1-Th17 cells were fully pathogenic. These results demonstrate that cutaneous psoriasis-like immunopathology can be developed by epidermis-specific recognition of Th17 cells, which is strictly dependent on IL-17 but not IFN-γ.

Ectopic expression of epidermal antigens renders the lung a target organ in paraneoplastic pemphigus.

Paraneoplastic pemphigus (PNP) is an autoimmune disease of the skin and mucous membranes that can involve fatal lung complications. IgG autoantibodies target the cell adhesion molecules desmoglein (Dsg)3 and plakins, but the nature and targets of infiltrating T cells are poorly characterized. Moreover, the lung involvement in this skin Ag-specific autoimmune condition represents a paradox. To mimic autoimmunity in PNP, we grafted wild-type skin onto Dsg3(-/-) mice, which resulted in graft rejection and generation of anti-Dsg3 IgG and Dsg3-specific T cells. Transfer of splenocytes from these mice into Rag2(-/-) mice induced a combination of suprabasilar acantholysis and interface dermatitis, a histology unique to PNP. Furthermore, the recipient mice showed prominent bronchial inflammation of CD4(+) and CD8(+) T cells with high mortality. Intriguingly, ectopic Dsg3 expression was observed in the lungs of PNP mice, mirroring the observation that squamous metaplasia is often found in the lungs of PNP patients. Dsg3 and other epidermal Ags were ectopically expressed in the lungs after pulmonary injuries by naphthalene, which was sufficient for recruitment of Dsg3-specific CD4(+) T cells. These findings demonstrate that squamous metaplasia after pulmonary epithelial injury may play a crucial role in redirecting the skin-specific autoimmune reaction to the lungs in PNP.

SOCS1 is essential for regulatory T cell functions by preventing loss of Foxp3 expression as well as IFN-{gamma} and IL-17A production.

Regulatory T cells (T(reg) cells) maintain immune homeostasis by limiting inflammatory responses. SOCS1 (suppressor of cytokine signaling 1), a negative regulator of cytokine signaling, is necessary for the suppressor functions of T(reg) cells in vivo, yet detailed mechanisms remain to be clarified. We found that Socs1(-/-) T(reg) cells produced high levels of IFN-γ and rapidly lost Foxp3 when transferred into Rag2(-/-) mice or cultured in vitro, even though the CNS2 (conserved noncoding DNA sequence 2) in the Foxp3 enhancer region was fully demethylated. Socs1(-/-) T(reg) cells showed hyperactivation of STAT1 and STAT3. Because Foxp3 expression was stable and STAT1 activation was at normal levels in Ifnγ(-/-)Socs1(-/-) T(reg) cells, the restriction of IFN-γ-STAT1 signaling by SOCS1 is suggested to be necessary for stable Foxp3 expression. However, Ifnγ(-/-)Socs1(-/-) T(reg) cells had hyperactivated STAT3 and higher IL-17A (IL-17) production compared with Ifnγ(-/-)Socs1(+/+) T(reg) cells and could not suppress colitis induced by naive T cells in Rag2(-/-) mice. In vitro experiments suggested that cytokines produced by Socs1(-/-) T(reg) cells and Ifnγ(-/-)Socs1(-/-) T(reg) cells modulated antigen-presenting cells for preferential Th1 and Th17 induction, respectively. We propose that SOCS1 plays important roles in T(reg) cell integrity and function by maintaining Foxp3 expression and by suppressing IFN-γ and IL-17 production driven by STAT1 and STAT3, respectively.

Desmoglein 3-specific CD4+ T cells induce pemphigus vulgaris and interface dermatitis in mice.

Pemphigus vulgaris (PV) is a severe autoimmune disease involving blistering of the skin and mucous membranes. It is caused by autoantibodies against desmoglein 3 (Dsg3), an adhesion molecule critical for maintaining epithelial integrity in the skin, oral mucosa, and esophagus. Knowing the antigen targeted by the autoantibodies renders PV a valuable model of autoimmunity. Recently, a role for Dsg3-specific CD4+ T helper cells in autoantibody production was demonstrated in a mouse model of PV, but whether these cells exert cytotoxicity in the tissues is unclear. Here, we analyzed 3 Dsg3-specific TCRs using transgenic mice and retrovirus induction. Dsg3-specific transgenic (Dsg3H1) T cells underwent deletion in the presence of Dsg3 in vivo. Dsg3H1 T cells that developed in the absence of Dsg3 elicited a severe pemphigus-like phenotype when cotransferred into immunodeficient mice with B cells from Dsg3-/- mice. Strikingly, in addition to humoral responses, T cell infiltration of Dsg3-expressing tissues led to interface dermatitis, a distinct form of T cell-mediated autoimmunity that causes keratinocyte apoptosis and is seen in various inflammatory/autoimmune skin diseases, including paraneoplastic pemphigus. The use of retrovirally generated Dsg3-specific T cells revealed that interface dermatitis occurred in an IFN-γ- and TCR avidity-dependent manner. This model of autoimmunity demonstrates that T cells specific for a physiological skin-associated autoantigen are capable of inducing interface dermatitis and should provide a valuable tool for further exploring the immunopathophysiology of T cell-mediated skin diseases.

A case of blastomycosis-like pyoderma caused by mixed infection of Staphylococcus epidermidis and Trichophyton rubrum.

Blastomycosis-like pyoderma (BLP) is a type of chronic pyoderma characterized histologically by specific epidermal changes namely: pseudoepitheliomatous hyperplasia and intraepithelial abscesses. These epidermal changes are also seen in blastomycosis (referred to as deep dermatophytosis in North America). Here, we describe the case of a 53-year-old male with prurigo nodularis, diabetes, and chronic lymphocytic leukemia who presented with multiple yellowish-red colored papules that coalesced to form a vegetating plaque. In addition to the typical features of BLP, spores with budding were seen histopathologically in a biopsy specimen. Cultures of a skin specimen grew Staphylococcus epidermidis and Trichophyton rubrum. Antibiotic therapy was effective but failed to eliminate the lesion until antifungal therapy using terbinafine was administered concurrently. Past reports suggest that BLP is mainly caused by bacterial infection, but our case suggests that fungal infection can also be involved as the causative organism in BLP.