Efficacy and safety of ritlecitinib, an oral JAK3/TEC family kinase inhibitor, in adolescent and adult patients with alopecia totalis and alopecia universalis.

This post-hoc analysis of the ALLEGRO phase 2b/3 study (NCT03732807) evaluated the efficacy and safety of ritlecitinib, an oral Janus kinase 3/TEC family kinase inhibitor, in patients with alopecia totalis (AT) and alopecia universalis (AU). Patients aged ≥ 12 years with alopecia areata (AA) and ≥50% scalp hair loss received once-daily ritlecitinib 50 or 30 mg (± 4-week 200-mg loading dose) or placebo for 24 weeks. In a subsequent 24-week extension period, the ritlecitinib groups continued their doses and patients initially assigned to placebo switched to ritlecitinib (200/50 or 50 mg daily). In this analysis, clinician- and patient-reported hair regrowth outcomes were assessed at weeks 24 and 48 in four AA subgroups: AT/AU, AT, AU, and non-AT/AU. Safety was monitored throughout. Of the 718 randomized patients, 151 (21%) and 147 (20%) were defined as having AT or AU, respectively. At week 24, Severity of Alopecia Tool (SALT) score ≤20 (≤20% scalp hair loss) response rates were higher in the ritlecitinib-treated AT/AU, AT, and AU groups (7%-14%, 7%-21%, and 4%-10%, respectively) vs the placebo group (0% in the AT/AU, AT, and AU groups). The proportions of patients with a SALT score of ≤20 increased through week 48 (AT/AU, 13%-31%; AT, 11%-27%; AU, 6%-41%). Additionally, at week 24, 25%-43%, 32%-42%, and 12%-50% of patients with AT/AU, AT, and AU, respectively, who received ritlecitinib achieved a moderately or greatly improved response based on the Patient Global Impression of Change scale. Response rates generally increased through week 48 and were similar across AA subgroups. In patients with AT/AU, ritlecitinib was well tolerated with a safety profile consistent with that of the overall AA population. Ritlecitinib demonstrated clinical efficacy, patient-reported improvement, and an acceptable safety profile in patients with AT and AU through week 48. A plain language summary of this study is available at https://doi.org/10.25454/pfizer.figshare.26879161. Clinicaltrials.gov: NCT03732807.

Comparison of interleukin-17- producing cells in different clinical types of alopecia areata.

T helper 17 cells, characterized by interleukin-17 (IL-17) production, play a critical role in the pathogenesis of autoimmune disease, including alopecia areata (AA). In this report, we employed immunohistochemical staining for IL-17-producing cells, as well as interferon-γ-producing cells, granulysin-bearing cells and Foxp3+ regulatory T cells, and performed a quantitative analysis of IL-17-producing cells in the lesional skin of several clinical forms of AA by TissueFAXS analysis. Among them, interestingly, the ratio of IL-17-producing cells in acute, diffuse and total alopecia was significantly lower than those of multiple types of AA. Our study sheds light on one of the possible immunological mechanisms of AA.

Successful treatment of syringotropic CD8+ mycosis fungoides accompanied by hypohidrosis with vorinostat and retinoids.

We describe a 34-year-old Japanese man with syringotropic CD8+ mycosis fungoides (MF) accompanied by hypohidrosis who was treated with vorinostat and retinoids. Interestingly, immunohistochemical staining for dermcidin revealed a decrease of sweat in the eccrine glands, and a sweat test by the iodine starch method proved hypohidrosis in the MF-affected areas. Six months after treatment with this combination therapy, the patient's advanced MF was under control.

Staphylococcus aureus skin colonization promotes SLE-like autoimmune inflammation via neutrophil activation and the IL-23/IL-17 axis.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by inflammation of various organs such as skin, kidneys, bones, and brain and the presence of autoantibodies. Although the cause of SLE is not completely understood, environmental factors, genetic susceptibility, hormone factors, and environmental factors are thought to play essential roles in the pathogenesis of SLE. Among environmental factors, the microbiota are linked to the development of different autoimmune diseases. The microbiota in the nasal cavity and gut are involved in SLE development, but the influence of skin microbiota is still unclear. Here, we demonstrated that epithelial cell-specific IκBζ-deficient (NfkbizΔK5) mice showed spontaneous skin inflammation with increased abundance of Staphylococcus aureus on the skin. When S. aureus was epicutaneously applied on NfkbizΔK5 mice, NfkbizΔK5 mice developed SLE-associated autoantibodies, anti-dsDNA antibodies, anti-Sm antibodies, and glomerulonephritis with IgG deposition. Epicutaneous S. aureus application significantly increased staphylococcal colonization on the skin of NfkbizΔK5 mice with reduced expression of several antimicrobial peptides in the skin. This staphylococcal skin colonization promoted caspase-mediated keratinocyte apoptosis and neutrophil activation, inducing the interleukin-23 (IL-23)/IL-17 immune response by activating dendritic cells and T cells. Furthermore, the subcutaneous administration of anti-IL-23p19 and anti-IL-17A antibodies alleviated the systemic autoimmune response. Together, these findings underscore epithelial-immune cross-talk disturbances caused by skin dysbiosis as an essential mediator inducing autoimmune diseases.

Dermal melanocytosis of the helix.

A 2-year-old Japanese boy had a congenital gray-blue macule involving the right helix along with a few melanotic spots on both sclerae. Histopathology showed dermal melanocytosis. Q-switched alexandrite laser treatment induced a good cosmetic response. This patient shows the overlap between Ota and Ito nevi, and we suggest dermal melanocytosis is better used as a generic term for these unusual pigmentations.

TGF-beta1 dampens the susceptibility of dendritic cells to environmental stimulation, leading to the requirement for danger signals for activation.

In contrast to its favourable effects on Langerhans cell (LC) differentiation, transforming growth factor (TGF)-beta1 has been reported to prevent dendritic cells from maturing in response to tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, or lipopolysaccharide (LPS). We first characterized the effects of TGF-beta1 on dendritic cell function by testing the response of TGF-beta1-treated monocyte-derived dendritic cells (MoDCs) to maturation stimuli that LCs receive in the epidermis, namely, haptens, ATP and ultraviolet (UV). TGF-beta1 treatment, which augmented E-cadherin and down-regulated dendritic cell-specific ICAM3-grabbing non-integrin on MoDCs, significantly suppressed their CD86 expression and hapten-induced expression of IL-1beta and TNF-alpha mRNA and protein. As TGF-beta1-treated MoDCs lacked Langerin expression, we demonstrated the suppressive effects of TGF-beta1 on haematopoietic progenitor cell-derived dendritic cells expressing both CD1a and Langerin. These suppressive effects of TGF-beta1 increased with the duration of treatment. Furthermore, TGF-beta1-treated MoDCs became resistant to apoptosis/necrosis induced by high hapten, ATP or UV doses. This was mainly attributable to dampened activation of p38 mitogen-activated protein kinase (MAPK) in TGF-beta1-treated MoDCs. Notably, although ATP or hapten alone could only induce CD86 expression weakly and could not augment the allogeneic T-cell stimulatory function of TGF-beta1-treated MoDCs, ATP and hapten synergized to stimulate these phenotypic and functional changes. Similarly, 2,4-dinitro, 1-chlorobenzene (DNCB) augmented the maturation of TGF-beta1-treated MoDCs upon co-culture with a keratinocyte cell line, in which ATP released by the hapten-stimulated keratinocytes synergized with the hapten to induce their maturation. These data may suggest that TGF-beta1 protects LCs from being overactivated by harmless environmental stimulation, while maintaining their ability to become activated in response to danger signals released by keratinocytes.

Molecular events in human T cells treated with diesel exhaust particles or formaldehyde that underlie their diminished interferon-gamma and interleukin-10 production.

BACKGROUND: A series of epidemiological and experimental studies have suggested that diesel exhaust particles (DEP) and formaldehyde (FA) may help trigger T helper type 2 (Th2)-mediated allergic responses. METHODS: To identify the molecular events by which DEP and FA induce a Th2-skewed immune response, we stimulated T cells from healthy subjects with anti-CD3/anti-CD28 monoclonal antibodies and examined the effect of pretreatment with DEP or FA on mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-kappaB by Western blotting and colorimetric NF-kappaB assays. We also examined the mRNA expression profiles of the T cells by microarray and real-time PCR analyses. RESULTS: FA selectively suppressed interferon (IFN)-gamma and interleukin-10 mRNA expression and protein production in stimulated T cells, as we previously reported with DEP. In the present study, we found that both DEP and FA suppressed NF-kappaB signaling and activated MAPKs. Both also significantly suppressed the mRNA expression of T-bet, Txk and c-Maf. Microarrays revealed significant augmentation of the expression of 2 FoxO3a-dependent genes, namely glucocorticoid-induced leucine zipper and growth arrest and DNA damage-inducible gene 45 alpha (Gadd45a), which are known to modulate T cell immune responses. Treatment with N-acetylcysteine reversed the augmented Gadd45a mRNA response and caused the suppressed IFN-gamma mRNA response to recover. CONCLUSIONS: DEP and FA have similar transcriptional and nontranscriptional effects on T cell signaling that together promote a Th2-skewed immune response.

Sarcoidosis-Lymphoma Syndrome Associated with Folliculotropic Peripheral T Cell Lymphoma Not Otherwise Specified.

Sarcoidosis is occasionally accompanied by hematologic malignancies, including cutaneous T-cell lymphoma, called sarcoidosis-lymphoma syndrome. Although the mechanism underlying the induction of lymphomas is still unknown, understanding the immunological background of sarcoidosis could help explain the possible mechanisms of the induction of lymphomas. In this report, we describe a case of sarcoidosis-lymphoma syndrome associated with folliculotropic peripheral T cell lymphoma not otherwise specified, which caused dense infiltration of CD30+ CD163+ tumor-associated macrophages (TAMs) only in the lesional skin. Our present case might suggest the significance of TAMs in developing sarcoid-lymphoma syndrome.

A randomized double-blind trial of intravenous immunoglobulin for bullous pemphigoid.

BACKGROUND: Patients with steroid-resistant bullous pemphigoid (BP) require an appropriate treatment option. OBJECTIVE: A multicenter, randomized, placebo-controlled, double-blind trial was conducted to investigate the therapeutic effect of high-dose intravenous immunoglobulin (IVIG; 400mg/kg/day for 5days) in BP patients who showed no symptomatic improvement with prednisolone (≥0.4mg/kg/day) administered. METHODS: We evaluated the efficacy using the disease activity score on day15 (DAS15) as a primary endpoint, and changes in the DAS over time, the anti-BP180 antibody titer, and safety for a period of 57days as secondary endpoints. RESULTS: We enrolled 56 patients in this study. The DAS15 was 12.5 points lower in the IVIG group than in the placebo group (p=0.089). The mean DAS of the IVIG group was constantly lower than that of the placebo group throughout the course of observation, and a post hoc analysis of covariance revealed a significant difference (p=0.041). Furthermore, when analyzed only in severe cases (DAS≥40), the DAS15 differed significantly (p=0.046). The anti-BP180 antibody titers showed no difference between the two groups. CONCLUSION: IVIG provides a beneficial therapeutic outcome for patients with BP who are resistant to steroid therapy.

Periostin in the Cancer Stroma of Mycosis Fungoides Palmaris et Plantaris: A Case Report and Immunohistochemical Study.

Mycosis fungoides palmaris et plantaris (MFPP) is a rare variant of mycosis fungoides limited to the palms and soles. Although little is known about the pathogenesis of MFPP, this variant of mycosis fungoides presents a relatively good prognosis. In this report, we describe an 85-year-old Japanese man with MFPP. Immunohistochemical staining revealed the dense deposition of periostin in the cancer stroma, as well as infiltration of CD163(+)CD206(-) tumor-associated macrophages (TAMs), which suggested the phenotypes of TAMs were not polarized to the M2 phenotype in the lesional skin of MFPP. Our present case might suggest one of the possible reasons for the good prognosis of MFPP.

Redox imbalance induced by contact sensitizers triggers the maturation of dendritic cells.

Although p38 mitogen-activated protein kinases (MAPK) play a crucial role in the activation of monocyte-derived dendritic cells (MoDC) by contact sensitizers, the upstream signals of p38 MAPK remain undetermined. To examine whether sensitizers induce redox or oxidative stress in dendritic cells (DC), which subsequently stimulate p38 MAPK, we measured the ratio of the oxidized (GSSG) versus reduced (GSH) form of cellular glutathione in MoDC stimulated with five sensitizers including NiCl2 and 2,4-dinitrochlorobenzene (DNCB) and three non-sensitizers including sodium dodecyl sulfate using colorimetric assays. All the sensitizers, but none of the non-sensitizers at sublethal concentration, reduced the GSH/GSSG ratio, which was accompanied by phosphorylation of p38 MAPK. Treatment with the antioxidant, N-acetyl-L-cysteine, which suppressed the reduction of the GSH/GSSG ratio, abrogated both the phosphorylation of p38 MAPK and the augmentation of CD86 expression. A similar response pattern was observed in THP-1 macrophage-monocyte cells. Unexpectedly, however, formaldehyde (HCHO) reduced the GSH/GSSG ratio in MoDC, but not in THP-1. This finding, in conjunction with the observation that DNCB and NiCl2 reduced the GSH/GSSG ratio at different kinetics, indicated that the sensitizers reduced the GSH/GSSG ratio by a different mechanism. These data suggest that the GSH/GSSG imbalance plays a crucial role in triggering DC maturation by sensitizers.

H1 and H2 histamine receptors are absent on Langerhans cells and present on dermal dendritic cells.

Human monocyte-derived dendritic cells (MoDC) have both histamine H1 and H2 receptors and can induce CD86 expression by histamine. Nevertheless, it has not been reported whether human epidermal Langerhans cells (LC) have histamine receptors or not. In this study, using RT-PCR, we investigated the expression of H1 and H2 receptor mRNA on DC with the features of LC (LC-like DC) that were generated in vitro from peripheral blood monocytes, LC derived from CD34+ hematopoietic progenitor cells, and LC obtained from human epidermis. We compared the histamine-induced CD86 expression among these cells. In contrast to MoDC, LC and LC-like DC did not express H1 or H2 receptors. In addition, they could not augment the CD86 expression by histamine. Interestingly, when transforming growth factor-beta1 (TGF-beta1) was added to the culture of MoDC, the expression of H1 and H2 receptors and the histamine-induced CD86 expression were abrogated in a concentration-dependent fashion. Finally, in the assessment of the cell surface expression of histamine receptors using fluorescence-labeled histamine, histamine could bind to MoDC and dermal dendritic cells obtained from the skin, whereas there was no specific binding of histamine to LC-like DC or LC obtained from the skin. These data suggest that LC do not express either H1 or H2 receptors, mainly because of the effect of TGF-beta1. This made a striking contrast with the expression of the functional H1 and H2 receptors on MoDC and dermal dendritic cells.

Interleukin-3 in cooperation with transforming growth factor beta induces granulocyte macrophage colony stimulating factor independent differentiation of human CD34+ hematopoietic progenitor cells into dendritic cells with features of Langerhans cells.

Recently, we have reported that M-CSF in cooperation with TGF-beta1 can induce Langerhans cell (LC) development from hematopoietic progenitor cells (HPCs) without GM-CSF. In the present study, we examined whether TGF-beta1 changes the differentiation of HPCs induced by IL-3 towards LC development. We cultured HPCs in a serum-free medium in the presence of IL-3 and a combination cytokines including Flt3L, SCF, and TNF-alpha with or without TGF-beta1. DCs induced by the IL-3 culture (IL-3 DCs) did not significantly differ from those induced by the GM-CSF culture (GM-CSF DCs). Namely, both expressed CDla, F-cadherin, and Langerin in the presence of TGF-beta1 and stimulated allogeneic T cells at a similar magnitude. In contrast to GM-CSF DCs, IL-3 DCs lacked the expression of Birbeck granules (BGs) in spite of their expression of Langerin. When we compared the expression of Langerin between these two DCs, however, it became clear that both Langerin protein and mRNA were significantly lower in IL-3 DCs than in GM-CSF DCs. These studies again demonstrated the ability of TGF-beta1 to polarize the differentiation of HPCs induced by IL-3 towards LC development, although IL-3 DCs were unable to form BGs partly because of their poor ability to induce Langerin.

p38 Mitogen-Activated protein kinase mediates dual role of ultraviolet B radiation in induction of maturation and apoptosis of monocyte-derived dendritic cells.

Although ultraviolet B (UVB) induces apoptosis and functional perturbations in dendritic cells (DC), for example, Langerhans cells (LC), it also stimulates some LC into maturation after irradiation in vivo. To analyze its reciprocal effects on DC, we elucidated the direct effect of UVB on DC in vitro using human monocyte-derived DC (MoDC). UVB from 50 to 200 J per m2 stimulated the maturation of MoDC with (1) augmented expression of CD86 and HLA-DR, (2) enhanced production of IL-1beta, IL-6, IL-8, and TNF-alpha at both the mRNA and protein levels, and (3) enhanced allostimulatory capacity on a per-cell basis, whereas the exceeded doses induced apoptotic cell death. Western-blot analysis of MoDC after UVB demonstrated a concentration-dependent phosphorylation of p38- and c-JUN N-terminal kinase (JNK)-mitogen-activated protein kinases (MAPK), but not that of extracellular signal-regulated kinases. p38 MAPK-inhibitor, SB203580, inhibited both UVB-induced maturation and apoptosis of MoDC. Interestingly, MoDC that had undergone apoptosis exhibited an augmented expression of HLA-DR without upregulation of CD86 antigen, suggesting their tolerogenic phenotype. Thus, our study revealed a dual effect of UVB, to stimulate maturation or to induce apoptosis in MoDC, depending on the dosage, via p38 MAPK pathway.

p38 Mitogen-activated protein kinase and extracellular signal-regulated kinases play distinct roles in the activation of dendritic cells by two representative haptens, NiCl2 and 2,4-dinitrochlorobenzene.

Previous studies have demonstrated that haptens induce several phenotypic and functional changes of dendritic cells in vivo as well as in vitro. Although recently, the crucial role of p38 mitogen-activated protein kinase has been reported in the activation of dendritic cells by haptens, the signal transduction elements involved in each phenotypic and functional changes that occur in the activation of dendritic cells by haptens remain unknown. Therefore, we examined the role of mitogen-activated protein kinases and nuclear factor-kappaB in the signal transduction of dendritic cells stimulated with two representative haptens, i.e., NiCl2 and 2,4-dinitrochlorobenzene. Human monocyte-derived dendritic cells stimulated with 2,4-dinitrochlorobenzene induced the phosphorylation of p38 and stress-activated protein kinase/c-jun N-terminal kinases, whereas NiCl2 induced that of p44/42 extracellular signal-regulated kinases, p38, and stress-activated protein kinase/c-jun N-terminal kinases. In addition, NiCl2 phosphorylated inhibitor kappaB and activated nuclear factor-kappaB. In contrast, primary irritants, e.g., benzalkonium chloride, or sodium lauryl sulfate, did not activate these signal transduction pathways. By using specific inhibitors for extracellular signal-regulated kinases and p38 pathways, PD98059 and SB203580, respectively, we demonstrated that the augmentation of CD86, HLA-DR, and CD83, and the production of interleukin-8 along with its increased mRNA expression by monocyte-derived dendritic cells stimulated with 2,4-dinitrochlorobenzene, and the augmentation of CD83 and the interleukin-12 p40 production by monocyte-derived dendritic cells stimulated with NiCl2, were suppressed by SB203580, whereas PD98059 suppressed the production of interleukin-1beta and tumor necrosis factor-alpha, together with their increased mRNA expression by monocyte-derived dendritic cells treated with NiCl2. On the other hand, in spite of the activation of nuclear factor-kappaB by monocyte-derived dendritic cells stimulated with NiCl2, nuclear factor-kappaB inhibitor did not significantly affect the phenotypic and functional changes in the activation of monocyte-derived dendritic cells. These data indicate that NiCl2 and 2,4-dinitrochlorobenzene stimulate different signal transduction pathways in monocyte-derived dendritic cells, and subsequently induce different phenotypic and functional changes in them.