Anti-PD-1 antibody monotherapy versus anti-PD-1 plus anti-CTLA-4 combination therapy as first-line immunotherapy in unresectable or metastatic mucosal melanoma: a retrospective, multicenter study of 329 Japanese cases (JMAC study).

BACKGROUND: Anti-programmed cell death protein 1 (PD-1) antibody monotherapy (PD1) has led to favorable responses in advanced non-acral cutaneous melanoma among Caucasian populations; however, recent studies suggest that this therapy has limited efficacy in mucosal melanoma (MCM). Thus, advanced MCM patients are candidates for PD1 plus anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) combination therapy (PD1 + CTLA4). Data on the efficacy of immunotherapy in MCM, however, are limited. We aimed to compare the efficacies of PD1 and PD1 + CTLA4 in Japanese advanced MCM patients. PATIENTS AND METHODS: We retrospectively assessed advanced MCM patients treated with PD1 or PD1 + CTLA4 at 24 Japanese institutions. Patient baseline characteristics, clinical responses (RECIST), progression-free survival (PFS), and overall survival (OS) were estimated using Kaplan-Meier analysis, and toxicity was assessed to estimate the efficacy and safety of PD1 and PD1 + CTLA4. RESULTS: Altogether, 329 patients with advanced MCM were included in this study. PD1 and PD1 + CTLA4 were used in 263 and 66 patients, respectively. Baseline characteristics were similar between both treatment groups, except for age (median age 71 versus 65 years; P < 0.001). No significant differences were observed between the PD1 and PD1 + CTLA4 groups with respect to objective response rate (26% versus 29%; P = 0.26) or PFS and OS (median PFS 5.9 months versus 6.8 months; P = 0.55, median OS 20.4 months versus 20.1 months; P = 0.55). Cox multivariate survival analysis revealed that PD1 + CTLA4 did not prolong PFS and OS (PFS: hazard ratio 0.83, 95% confidence interval 0.58-1.19, P = 0.30; OS: HR 0.89, 95% confidence interval 0.57-1.38, P = 0.59). The rate of ≥grade 3 immune-related adverse events was higher in the PD1 + CTLA4 group than in the PD1 group (53% versus 17%; P < 0.001). CONCLUSIONS: First-line PD1 + CTLA4 demonstrated comparable clinical efficacy to PD1 in Japanese MCM patients, but with a higher rate of immune-related adverse events.

Epitope analysis of antidesmoglein 1 autoantibodies from patients with pemphigus foliaceus across different activity stages.

BACKGROUND: Pemphigus foliaceus (PF) and pemphigus vulgaris (PV) are closely related, but clinically distinct, autoimmune blistering diseases caused by autoantibodies against desmoglein (Dsg)1 and Dsg3, respectively. Using ethylenediaminetetraacetic acid (EDTA)-treated Dsg3 enzyme-linked immunosorbent assay (ELISA) we have shown that the proportion of anti-Dsg3 antibodies against calcium-dependent epitopes decreased upon shifting to the inactive phase in patients with PV. OBJECTIVES: To analyse the epitope profiles of anti-Dsg1 antibodies across the different activity stages of PF. METHODS: We evaluated five patients with PF who retained high serum levels of anti-Dsg1 antibodies in the inactive phase. Sera were obtained in both the active and inactive phases, and were analysed by EDTA-treated and exfoliative toxin-treated ELISAs. To map the epitopes of anti-Dsg1 antibodies, immunoprecipitation-immunoblotting was performed using a set of Dsg1/Dsg2 domain-swapped molecules. RESULTS: Anti-Dsg1 antibodies against the calcium-dependent epitopes of Dsg1 were the predominant antibodies in both the active and inactive phases. The proportion of anti-Dsg1 antibodies against the calcium-dependent epitopes did not change upon shifting to the inactive phase. The results of immunoprecipitation-immunoblotting showed that most of the anti-Dsg1 antibodies bound to the extracellular domains (EC)1-2 of Dsg1. CONCLUSIONS: In patients with PF, the calcium-dependent epitopes on EC1 and EC2 of Dsg1 contained definitively pathogenic and nonpathogenic epitopes. The disease activity might be differentially controlled by the antibodies between PF and PV depending on the presence or absence of the nonpathogenic epitope.

Granulysin-producing cytotoxic T cells in the mucocutaneous lesions of Behçet disease: a distinct inflammatory response from erythema nodosum.

BACKGROUND: Cytotoxic T lymphocytes (CTLs) have been recognized as an important effector cell in Behçet disease (BD). Granulysin is a cytolytic granule protein expressed by CTLs and natural killer cells. AIM: To evaluate the involvement of granulysin-producing T cells in the pathogenesis of BD. METHODS: Using immunohistochemistry, lymphocyte subsets expressing granulysin were investigated in mucocutaneous lesions of BD. Serum granulysin levels were assayed by ELISA. RESULTS: Granulysin-positive cells were seen in specimens from oral ulcers, genital ulcers and acne-like eruptions, but not erythema nodosum-like lesions. Both CD4+ and CD8+ T cells expressed granulysin. Serum granulysin levels did not correlate with disease activity in BD. CONCLUSION: Immune reactions mediated by granulysin-positive CTLs may play an important role in the pathogenesis of acne-like eruptions, oral ulcers and genital ulcers in BD.

Acne-associated syndromes: models for better understanding of acne pathogenesis.

Acne, one of the most common skin disorders, is also a cardinal component of many systemic diseases or syndromes. Their association illustrates the nature of these diseases and is indicative of the pathogenesis of acne. Congenital adrenal hyperplasia (CAH) and seborrhoea-acne-hirsutism-androgenetic alopecia (SAHA) syndrome highlight the role of androgen steroids, while polycystic ovary (PCO) and hyperandrogenism-insulin resistance-acanthosis nigricans (HAIR-AN) syndromes indicate insulin resistance in acne. Apert syndrome with increased fibroblast growth factor receptor 2 (FGFR2) signalling results in follicular hyperkeratinization and sebaceous gland hypertrophy in acne. Synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) and pyogenic arthritis-pyoderma gangrenosum-acne (PAPA) syndromes highlight the attributes of inflammation to acne formation. Advances in the understanding of the manifestation and molecular mechanisms of these syndromes will help to clarify acne pathogenesis and develop novel therapeutic modalities.

Infectious complications and managements for surgical site infections in genital Paget's disease.

BACKGROUND: Extramammary Paget's disease is an intra-epidermal carcinoma that occurs preferentially in genital areas. Patients with genital Paget's disease (GPD) sometimes develop severe post-surgical infections because of this anatomical disadvantage. OBJECTIVE: To study perioperative micro-organisms and surgical site infection (SSI) in GPD. METHODS: We examined micro-organisms isolated from preoperative lesions, necrotic sites and infected wounds in 60 adult patients with GPD who underwent surgery at our hospital between November 1990 and December 2005. Based on the obtained microbiological data, we assessed the incidence, risk factors and treatment of SSI. RESULTS: The colonized organisms found in preoperative GPD were Enterobacteriaceae (27.6%), methicillin-sensitive Staphylococcus aureus (MSSA) (22.4%) and coagulase-negative staphylococci (CNS) (15.5%), among others. In the postoperative necrotic sites, the frequency of MSSA isolation was reduced to 9.4%, while Pseudomonas aeruginosa and methicillin-resistant S. aureus (MRSA) both increased in frequency from 3.4% and 0% upon preoperative examination to 18.8% and 9.4%, respectively. The incidence of SSI was 15%. In 7 of 9 SSIs, MRSA and/or P. aeruginosa were isolated. CONCLUSION: We have successfully identified a number of perioperative micro-organisms in GPD. The present observations may be extremely useful in choosing appropriate antimicrobial agents for use in the surgical treatment of GPD.

Distribution of the exfoliative toxin D gene in clinical Staphylococcus aureus isolates in France.

Exfoliative toxin D (ETD) was identified recently as a new exfoliative toxin serotype. Like other exfoliative toxins, ETD induces intra-epidermal cleavage through the granular layer of the epidermis of neonatal mice. The distribution of ETD production was investigated in Staphylococcus aureus isolates from infected and colonised patients in France. The etd gene was found in 55 (10.5%) of 522 isolates tested. Isolates responsible for bullous impetigo and generalised staphylococcal scalded skin syndrome did not harbour etd, but etd was significantly more frequent in isolates causing cutaneous abscesses and furuncles. Most etd- and Panton-Valentine leukocidin-positive strains belonged to the clone of community-acquired methicillin-resistant S. aureus spreading currently throughout France.

Involvement of granulysin-producing T cells in the development of superficial microbial folliculitis.

BACKGROUND: Granulysin is a recently identified antimicrobial protein expressed on cytotoxic T cells, natural killer (NK) cells and NKT cells. It has been shown that granulysin contributes to the defence mechanisms against mycobacterial infection. Superficial microbial folliculitis is a common skin disease. In a previous report, we showed that, as a first line of defence, alpha-defensin, a human neutrophil peptide, and beta-defensin (human beta-defensin-2) were expressed in infiltrating neutrophils and in lesional epidermal keratinocytes, respectively, in superficial folliculitis. As we also observed many infiltrating lymphocytes in lesional dermis, we hypothesized that infiltrating lymphocytes may possess antimicrobial substances, such as granulysin, and play a role in the defence mechanism as a second line of defence. OBJECTIVES: Seven specimens of superficial microbial folliculitis diagnosed clinically and histologically were examined by means of immunohistochemistry. To identify the phenotype of cells expressing granulysin, confocal laser microscopic examination was performed. RESULTS: A dense lymphoid cell infiltrate was observed in pustules, in the perivascular regions. A large number of these lymphoid cells were positive for granulysin. Phenotypically, cells consisted of CD3+ T cells, CD8+ T cells and UCHL-1+ T cells. CD20+ cells and CD56+ cells were not observed. Microscopic examination with a confocal laser showed that the lymphocytes producing granulysin were CD3+ and CD4+ T cells but not CD8+ T cells. CONCLUSIONS: We showed that many granulysin-bearing T cells infiltrated affected follicles and perilesional dermis in superficial microbial folliculitis. However, few granulysin-positive lymphoid cells were observed in sterile pustular lesions. Our observations indicated that adaptive immunity such as granulysin, a lymphocyte-produced antimicrobial protein, may play an important role in the cutaneous defence mechanism.

Confocal laser scanning microscopic observation of glycocalyx production by Staphylococcus aureus in skin lesions of bullous impetigo, atopic dermatitis and pemphigus foliaceus.

BACKGROUND: Glycocalyx collapses during dehydration to produce electron-dense accretions. Confocal laser scanning microscopy (CLSM) may be used to visualize fully hydrated microbial biofilms. OBJECTIVES: Using CLSM, to analyse glycocalyx production by Staphylococcus aureus cells in skin lesions of bullous impetigo, atopic dermatitis and pemphigus foliaceus. A second objective was to compare numbers of S. aureus cells in tissue sections prepared by different methods for routine light microscopy. METHODS: S. aureus cells in skin lesions of impetigo, atopic dermatitis and pemphigus were stained with safranin, and positive staining with fluorescein isothiocyanate-conjugated concanavalin A was considered to indicate the presence of glycocalyx. RESULTS: All S. aureus cells tested in skin lesions of impetigo, atopic dermatitis and pemphigus were covered with glycocalyx and formed microcolonies. The numbers of S. aureus cells in a routine light microscopy section were significantly lower than those in a frozen section that had not been dehydrated with ethanol. CONCLUSIONS: S. aureus cells generally produce glycocalyx in skin lesions of bullous impetigo, atopic dermatitis and pemphigus foliaceus, which accounts for the difficulty of removing S. aureus cells from these skin lesions. The glycocalyx may collapse during dehydration and most of the S. aureus cells may be carried away during preparation of routine light microscope sections.

Confocal laser scanning microscopic observation of glycocalyx production by Staphylococcus aureus in mouse skin: does S. aureus generally produce a biofilm on damaged skin?

BACKGROUND: Bacteria that adhere to damaged tissues encase themselves in a hydrated matrix of polysaccharides, forming a slimy layer known as a biofilm. This is the first report of detection of glycocalyx production by Staphylococcus aureus using confocal laser scanning microscopy (CLSM) on damaged skin tissues. OBJECTIVES: To analyse glycocalyx production by S. aureus cells on damaged skin tissues and the influence of polymorphonuclear leucocytes (PMNs) and various antimicrobial agents on its production using CLSM in cyclophosphamide (Cy)-treated (neutropenic) or non-Cy-treated (normal) mice. METHODS: S. aureus cells were inoculated on damaged skin tissues in neutropenic or normal mice with or without topical application of antimicrobial agents. S. aureus cells were stained with safranine, and positive staining with fluorescein isothiocyanate-conjugated concanavalin A was considered to indicate the presence of glycocalyx. RESULTS: All S. aureus cells tested on damaged skin tissues formed microcolonies encircled by glycocalyx. The colony counts of S. aureus cells on croton oil dermatitis in normal mice treated with 2% fusidic acid ointment were about 100 times lower than those in neutropenic mice (control). CONCLUSIONS: As S. aureus cells can generally produce a biofilm on damaged skin tissues, antimicrobial agents may not eradicate S. aureus cells without the help of PMNs. S. aureus glycocalyx may play a crucial role in colonization and adherence to damaged skin tissues.

Amicrobial pustular dermatosis in two patients with immunological abnormalities.

We report two patients with severe amicrobial pustular dermatosis with immunological abnormalities: a 63-year-old woman with a 30-year-history of discoid lupus erythematosus and sicca syndrome, and a 35-year-old woman with high levels of gamma-globulinemia and positive antinuclear antibodies. Both patients presented with crusty and eroded erythematous plaques studded with aseptic pustules on the back, face, and scalp. Histological examination showed acanthosis, neutrophilic exocytosis to the epidermis, and neutrophilic and lymphocytic infiltration with nuclear dust in the dermis. These patients were diagnosed as having "amicrobial pustulosis associated with autoimmune diseases". The eruptions improved with combination treatment of oral prednisolone with cyclosporin A or diaminodiphenylsulphone. Although the pathogenesis remains unclear, amicrobial pustular dermatosis might be one of the cutaneous complications in autoimmune diseases.

Koebner phenomenon on skin graft donor site in cutaneous angiosarcoma.

An 81-year-old woman developed a necrotic plaque and a surrounding purple-red, irregularly shaped macule on her scalp. The diagnosis of angiosarcoma was confirmed histologically. A wide surgical excision was made followed by a split-thickness skin graft from her right buttock. Nine months later, she noticed a dark purple-red lesion on the donor site which grew rapidly into a large mass. Histological examination revealed irregular clefts and vascular channels lined by atypical endothelial cells. Lung metastasis and pneumothorax were also noted. The secondary tumor appeared to represent Koebner phenomenon in a patient with angiosarcoma of the scalp.

Antibacterial action of several tannins against Staphylococcus aureus.

We examined the antibacterial action of several tannins on plasma coagulation by Staphylococcus aureus and the effect of conventional chemotherapy combined with tannic acid below the MIC. Coagulation was inhibited in plasma containing tannic acid (100 mg/L), gallic acid (5000 mg/L), ellagic acid (5000 mg/L), (-)-epicatechin (1500 mg/L), (-)-epicatechin gallate (500 mg/L) or (-)-epigallocatechin gallate (200 mg/L) after incubation for 24 h. All tannins inhibited coagulation at a concentration below the MIC. The MICs of oxacillin and cefdinir for S. aureus were reduced to < or = 0.06 mg/L in Mueller-Hinton agar plates with tannic acid (100 mg/L) at a concentration below the MIC. The antistaphylococcal activity of tannic acid was reduced in plates with 10% rabbit blood, but not in those with 10% rabbit plasma. Membranous structures formed in a culture medium containing equal proportions of plasma and tryptic soy broth after incubation for 24 h. The colony counts of S. aureus in membranous structures in the medium containing oxacillin (40 mg/L) and tannic acid (100 mg/L) were c. 10-fold lower than those in medium containing oxacillin (40 mg/L) alone (P < 0.01). Tannic acid merits further investigation as a possible adjuvant agent against S. aureus skin infections treated with beta-lactam antibiotics.

A combination of roxithromycin and imipenem as an antimicrobial strategy against biofilms formed by Staphylococcus aureus.

We examined the effects of a combination of roxithromycin and imipenem on a biofilm model of Staphylococcus aureus. Treatment with roxithromycin alone and imipenem alone did not decrease the number of viable bacterial cells compared with the control. However, a combination treatment of roxithromycin and imipenem significantly decreased the number of viable bacterial cells on day 8 after inoculation in the in vivo model (P < 0.01). On days 5 and 8 after inoculation, numerous polymorphonuclear leucocytes and macrophages invaded the bacterial clusters in the roxithromycin- and roxithromycin/imipenem-treated groups, but did not invade the control or imipenem-treated groups. The present study indicated that a combination of roxithromycin and imipenem is a potentially effective treatment for S. aureus biofilm-associated skin infections as it can induce the invasion of polymorphonuclear leucocytes into the biofilm.

Antimicrobial effects of acidic hot-spring water on Staphylococcus aureus strains isolated from atopic dermatitis patients.

The present study examined the antimicrobial effects of acidic hot-spring water on Staphylococcus aureus strains isolated from atopic dermatitis (AD) patients. Plasma coagulation by S. aureus cells was not detected in plasma containing acidic hot-spring water (60%, pH 5.4) or hydrochloric acid (pH 5.0) after incubation for 24 h. S. aureus cells did not grow in Mueller-Hinton broth with acidic hot-spring water (50%, pH 4.4) after 24 h incubation. The colony counts of S. aureus cells in tryptic soy broth containing acidic hot-spring water (60%, pH 3.9) were over ten times lower than those in tryptic soy broth alone after incubation for 24 h (P<0.01). A membranous structure (an immature biofilm) was formed on the coverslips of tissue culture dishes by S. aureus cells in plasma after incubation for 24 h, although the colony counts of S. aureus cells in the immature biofilms in plasma containing acidic hot-spring water (60%, pH 5.4) were about eight times lower than those in plasma alone after incubation for 24 h (P<0.01). The colony counts of S. aureus cells that attached on coverslips in plasma containing acidic hot-spring water (60%, pH 5.4) or hydrochloric acid (pH 5.4) were over 1000 times lower than those in plasma alone after incubation for 24 h. These results suggest that 50% acidic hot-spring water has a bacteriostatic effect, 60% acidic hot-spring water has a moderate bactericidal effect against floating S. aureus cells and those cells in a biofilm, and, 60% acidic hot-spring water has an inhibitory effect on plasma coagulation and attachment of S. aureus cells. Furthermore, our present results suggest that a small amount of some ions in hot-spring water such as manganese and iodide ions are very important for a bactericidal activity of hot-spring water as well as the low pH condition.

The production of superantigenic exotoxins by coagulase-negative staphylococci isolated from human skin lesions.

We examined the production of superantigenic exotoxins in 136 coagulase-negative staphylococci isolated from various skin lesions in humans using a reversed passive latex agglutination test (Denka Seiken). As a control we examined the same in 50 Staphylococcus aureus strains isolated from non-infective skin ulcers in humans. Of the 136 strains of coagulase negative-staphylococci, 9 (6.6%) produced one or more identifiable exotoxins. In contrast, 21 (42%) out of the 50 S. aureus strains produced one or more identifiable exotoxins (P<0.01).