B-cell activating factor detected on both naïve and memory B cells in bullous pemphigoid.

B-cell activating factor (BAFF), an important immune regulatory cytokine, is involved in development of autoimmune diseases. Although BAFF is expressed in various cells, including dendritic cells (DCs) and monocytes, BAFF expression on B cells has not been well documented. In the present study, BAFF molecules on DCs and naïve and memory B cells in autoimmune bullous diseases, including pemphigus vulgaris, pemphigus foliaceus and bullous pemphigoid (BP), were analysed by flow cytometry. Compared with healthy controls (HC), BAFF expression on naïve and memory B cells increased significantly in BP. No difference in BAFF receptor expression in naïve and memory B cells was shown among all study groups. Furthermore, BAFF expression in both naïve and memory B cells of BP, but not HC, was detected by confocal microscopic analysis. These results implied that BAFF expressed by B cells may play a pathogenic role in autoimmune bullous diseases, particularly BP.

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.

Guidelines for the management of dermatomycosis (2019).

The "Guidelines for the management of dermatomycosis" of the Japanese Dermatological Association were first published in Japanese in 2009 and the Guidelines Committee of the Japanese Dermatological Association revised it in 2019. The first guidelines was prepared according to the opinions of the Guidelines Committee members and it was of educational value. The revised version is composed of introductory descriptions of the disease concepts, diagnosis, medical mycology and recent advances in treatment, along with clinical questions (CQ), which is intended to help in general practice for dermatologists. The CQ are limited to those involved in therapy but include some of the recently launched antifungal agents. The level of evidence and the degree of recommendation for each item were reviewed by the committee based on clinical studies published by 2018. For rare dermatomycoses, recommendations by the committee are described in the guidelines. In this field, there are still few good quality studies on treatment. Periodic revision in line with new evidence is necessary.

Cutaneous Cryptococcosis

Cutaneous cryptococcosis is classified either as primary or secondary based on the route of infection. The disease can also be classified either as localized cutaneous cryptococcosis or cutaneous manifestations of disseminated cryptococcosis. However, from a physician's point of view, whether lesions are localized to the skin or are disseminated/systemic is more important than the route of infection. The Clinical Practice Guidelines for Diagnosis and Treatment of Cryptococcosis, which was established in 2019 by the Japanese Society for Medical Mycology, adopted the latter classification. Localized cutaneous cryptococcosis is defined as a condition in which lesions are confined within a limited part of the skin, not systemically disseminated at the same time, and are associated with neither cryptococcal fungemia nor antigenemia. This type of cutaneous cryptococcosis is uncommon in Japan. Only 65 cases were reported during the 50-year study period from 1968 to August 2018, with the patients divided into two groups: immunocompromised patients (n=44, 68%) and immunocompetent patients (n=21, 32%). None of the patients were infected with the human immunodeficiency virus (HIV). Localized cutaneous cryptococcosis can also occur in non-HIV-infected patients and well-appearing individuals, therefore, it is considered an important infection in routine dermatology practice. Here, we outline the classification, diagnosis, and treatment of cutaneous cryptococcosis and present a summary of cutaneous cryptococcosis cases reported in Japan.

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.

Mouse bone marrow-derived dendritic cells can phagocytize the Sporothrix schenckii, and mature and activate the immune response by secreting interleukin-12 and presenting antigens to T lymphocytes.

In sporotrichosis, dermal dendritic cells were considered to participate in induction of the immune responses against Sporothrix schenckii infection. However, it is still unclear whether and how dermal dendritic cells were involved in the progress. To clarify the pathogenic role of dermal dendritic cells (DC) in sporotrichosis, we examined the phagocytosis, maturation stages, cytokine production and antigen-presenting ability of mouse bone marrow-derived DC after stimulation with S. schenckii. By analysis of flow cytometry, electron microscope and confocal microscope, mouse bone marrow-derived DC were proved to be able to phagocytize the S. schenckii. The increased expression of CD40, CD80 and CD86 on the surface of S. schenckii-pulsed mouse bone marrow-derived DC was detected by flow cytometer, indicating that the S. schenckii-pulsed mouse bone marrow-derived DC underwent the maturation program. The secretory enhancement of interleukin (IL)-12, but not IL-4, was found in S. schenckii-pulsed mouse bone marrow-derived DC, suggesting the possible activation of T-helper 1 prone immune responses. Furthermore, S. schenckii-pulsed mouse bone marrow-derived DC were demonstrated to be capable of inducing the proliferation of T lymphocytes from BALB/c mice that were pre-sensitized with S. schenckii. Together, all the results implied that dermal DC may participate in the induction of immune responses against S. schenckii infection in sporotrichosis.

[Sporotrichosis and dematiaceous fungal skin infections].

Sporotrichosis is a chronic infectious granuloma of skin. The detection of fungal elements in pathological examination and the isolation of Sporothrix schenckii from the lesion are requisite for diagnosis. The sporotrichin test is useful as an auxiliary examination, but a false-negative reaction might occur in some cases. Oral potassium iodide is first choice of treatment, because of its modest cost and usefulness, although gastrointestinal disorder is a frequent side effect. Itraconazole should be the second selection, and then terbinafine. Local thermotherapy is also effective as an additional therapy. Dematiaceous fungal skin infections are divided into two groups by their parasitic form, chromoblastomycosis and phaeohyphomycosis. Chromoblastomycosis is also called chromomycosis in Japan. It is most important for clinical diagnosis to detect dark brown spores in the scale of chromoblastomycosis and dark brown hyphae in the pus of phaeohyphomycosis by microscopic examination. Both morphological and molecular biological approaches are recommended for identification of fungi. In treatment, the drug appropriate in each case should be selected, and the combination of surgical excision, local thermotherapy, laser therapy or cryotherapy must be considered.

Limitations of CD95 ligand-transduced killer dendritic cells to prevent graft rejections.

As an attempt to experimentally induce antigen (Ag)-specific immunosuppression, we have previously created CD95 ligand (CD95L)-transduced dendritic cells (DC), which delivered apoptotic, but not activation, signals to CD4+ T cells in vitro in an Ag-dependent manner. We have also demonstrated that CD95L-transduced DC (termed killer DC) injected into syngeneic animals suppressed delayed-type hypersensitivity responses to an administered Ag. Based on these findings, we tested whether the injection of killer DC derived from A/J mice (H-2a) into allogeneic BALB/c recipients (H-2d) could prolong the survival of A/J-derived skin grafts by depleting A/J-reactive effector T cells. This attempt has not been successful. In this study, we elucidate the reasons for this failure, especially in terms of in vitro effects of killer DC on in vivo primed alloreactive T cells. We show that killer DC (i) failed to induce the proliferation of naive alloreactive T cells in a CD95/CD95L-dependent fashion, (ii) inhibited the proliferation of in vivo primed alloreactive T cells, (iii) killed relatively small fractions (up to 30%) of these T cells in vitro in a CD95/CD95L-dependent fashion and (iv) significantly, but incompletely, inhibited the generation of cytotoxic T-lymphocyte activities against A/J determinants. Thus, killer DC have significant, but modest, capacities to suppress in vitro alloimmune responses, which may not be sufficient to prolong the survival of alloskin grafts in a stringent allograft model. This study suggests that the current format of killer DC technology requires more modifications for its clinical application to prevent graft rejection.

Dendritic cell-based immunoregulatory strategies.

Dendritic cells (DC) are special subsets of professional antigen-presenting cells that play a dual role in initiating and silencing acquired immune responses. Thus, it should be feasible to control the magnitude and direction of immune responses by experimental manipulation of DC function. We will provide an overview of the recent progress in the development of DC-based immunostimulatory and immunosuppressive strategies, which are potentially applicable to the treatment of cancer, allergy, autoimmune disease, allograft rejection and graft versus host disease.

Killing of naive T cells by CD95L-transfected dendritic cells (DC): in vivo study using killer DC-DC hybrids and CD4(+) T cells from DO11.10 mice.

Dendritic cells (DC) play the dual task of initiating cellular immunity against potentially harmful foreign antigens (Ag), while maintaining immunological tolerance to self-Ag and environmental Ag. As an approach to induce Ag-specific suppression, we and others introduced CD95 ligand (L) cDNA into DC. The resulting "killer" DC delivered apoptotic signals, instead of activation signals, to primed CD4(+) T cells in vitro and induced Ag-specific immunosuppression in vivo. To study the impact of killer DC on naive T cells, the fate of Ag-reactive T cells and the extent of their depletion after killer DC treatment, we performed in vitro and in vivo reconstitution experiments using: (a) killer DC-DC hybrids created between CD95L-transduced XS106 DC clone (A/J origin) and splenic DC from BALB/c mice, (b) CD4(+) T cells isolated from DO11.10 transgenic mice (BALB/c background), and (c) OVA(323-339) peptide as relevant Ag. Ovalbumin (OVA)-pulsed killer DC-DC hybrids inhibited DO11.10 T cell activation triggered by conventional DC, instead of inducing their activation. Rapid apoptosis of T cells was observed after co-culture with OVA-pulsed killer DC-DC hybrids, but not with non-pulsed killer DC-DC hybrids or OVA-pulsed control DC-DC hybrids. For in vivo reconstitution, (BALB/cxA/J)F1 mice received subcutaneous administration of killer DC-DC hybrids, followed by intravenous inoculation of DO11.10 T cells. Killer DC-DC hybrids migrated preferentially to draining lymph nodes albeit with relatively low efficiency (0.5-1% recovery) and they induced significant, but incomplete (30-40%) killing of DO11.10 T cells in this location. These results document the abilities of CD95L-transduced DC to trigger apoptosis of naive T cells in an Ag-specific manner, to overrule T cell activation signals delivered by conventional DC, and to reduce local frequencies of Ag-reactive T cells in vivo. Our data also uncover two major limitations (relatively low homing efficiency and incomplete elimination of Ag-reactive T cells) that remain to be overcome for clinical application of CD95L-transduced DC strategy.