Interleukin-21 receptor signalling is not critically required for imiquimod-induced psoriasiform dermatitis in mice.

Psoriasis is largely mediated by interleukin (IL)-23/T helper (Th) 17 axis, and IL-21 is a pleiotropic cytokine expressed by Th17 cells. Despite previously reported possible pathogenic roles of IL-21 in human psoriasis, we found that IL-21 receptor (IL-21R) signalling was not crucial for imiquimod-induced psoriatic inflammation, using IL-21R-/- mice. The severity of imiquimod-induced psoriatic manifestation and pro-inflammatory Th17 cytokine levels, IL-17A-producing γδ T cells and CD4+ T cells, and in vitro IL-17A production by γδ T cells after IL-23 stimulation was comparable between wild-type and IL-21R-/- mice. Collectively, IL-21R signalling was not critically involved in IMQ-induced psoriatic inflammation despite an increased IL-21 expression in the IMQ-treated mouse skin. Our data may represent the significant differences between human psoriasis and murine psoriasis model, and further studies using other models will be required to elucidate the role of IL-21 in psoriasis pathogenesis.

Deconvolution of spectral power distribution of high-power laser diode arrays.

A novel method is proposed to predict the spectral power distributions (SPDs) of individual emitters in a high-power laser diode (LD) array. The proposed method deconvolutes the SPD of an LD array by taking into account the thermal cross-talk effect as well as the current competition effect. A complete analytical expression to deconvolute the SPD of an LD array is described. The expression contains four key parameters that are to be measured experimentally: (1) the normalized SPD of the central emitter, (2) the temperature coefficient of wavelength, (3) the current competition constant, and (4) the maximum power of the center emitter. The method is implemented with a commercial water-cooled high-power LD array. The SPD of the LD array predicted from the SPDs of individual emitters are compared with the experimentally measured SPD of the LD array. The results show excellent agreement in both shape and magnitude, which corroborates the validity of the proposed method.

Method for predicting junction temperature distribution in a high-power laser diode bar.

A hybrid experimental/numerical method is proposed for predicting the junction temperature distribution in a high-power laser diode (LD) bar with multiple emitters. A commercial water-cooled LD bar with multiple emitters is used to illustrate and validate the proposed method. A unique experimental setup is developed and implemented first to measure the average junction temperatures of the LD bar emitters. After measuring the heat dissipation of the LD bar, the effective heat transfer coefficient of the cooling system is determined inversely from the numerical simulation using the measured average junction temperature and the heat dissipation. The characterized heat dissipation and effective heat transfer coefficient are used to predict the junction temperature distribution over the LD bar numerically under high operating currents. The results are presented in conjunction with the wall-plug efficiency and the center wavelength shift.

Decreased PD-1 positive blood follicular helper T cells in patients with psoriasis.

Follicular helper T (Tfh) cells are recently characterized subset of helper T cells, which are initially found in the germinal centers of B cell follicles. The major role of Tfh cells is helping B cell activation and antibody production during humoral immunity. Recently, blood Tfh cells were shown to be associated with autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, bullous pemphigoid and psoriasis. There is only one study which investigated Tfh cells in psoriasis patients. Therefore, in this study, we evaluated and analyzed blood Tfh cells in Korean patients with psoriasis. A total of 28 psoriasis patients and 16 healthy controls were enrolled. The frequency and absolute number of CXCR5(+)PD-1(+) Tfh cells were decreased in patients with psoriasis compared to healthy controls. CD4(+)CXCR5(+) T cells and CXCR5(+)ICOS(+) Tfh cells did not show differences. The frequency and absolute number of CXCR5(+)PD-1(+) Tfh cells in psoriasis patients negatively correlated with erythrocyte sedimentation rate and positively correlated with disease duration. The absolute number of CXCR5(+)ICOS(+) Tfh cells also showed positive correlation with disease duration. However, the subpopulations of Tfh cells did not correlate with Psoriasis Area and Severity Index. Serum interleukin-21 level was significantly increased in psoriasis patients compared to healthy controls, however, its level did not correlate with clinical and experimental parameters of psoriasis patients. These findings suggest the decreased function of Tfh cells in psoriasis, which could result in attenuated B cell immune responses in the pathogenesis of psoriasis. However, further investigations are necessary to confirm the function of Tfh cells in psoriasis vulgaris.

Assessments of neutrophil to lymphocyte ratio and platelet to lymphocyte ratio in Korean patients with psoriasis vulgaris and psoriatic arthritis.

The objective of this retrospective study is to assess neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) as inflammatory markers in patients with psoriasis and psoriatic arthritis (PsA). A hundred and eleven psoriasis patients and 25 PsA patients were compared with 94 healthy controls. Demographic, clinical and laboratory information were collected and analyzed. NLR and PLR were calculated. White blood cell (WBC), neutrophils, eosinophils and NLR were increased in psoriasis patients compared with controls. WBC, neutrophils, NLR, monocytes, platelets and PLR were increased in PsA patients compared with both controls and psoriasis patients. Erythrocyte sedimentation rate (ESR) and C-reactive protein were significantly higher in PsA patients compared with psoriasis patients. Among psoriasis patients, Psoriasis Area and Severity Index (PASI) score correlated positively with platelets, NLR and PLR. These parameters were all significantly higher in moderate to severe psoriasis patients (PASI ≥ 10) compared with mild patients (PASI < 10). Elevated platelets, NLR and PLR were significantly associated with the increased PASI scores in multivariate analysis. NLR, PLR and ESR were statistically significant predictors for the presence of PsA in psoriasis patients. NLR was the strongest predictor (odds ratio = 3.351, P = 0.005). In conclusion, elevated NLR and PLR were significantly associated with psoriasis and PsA. Both NLR and PLR were strong predictors for the presence of PsA among psoriasis patients.

A Retrospective Study of Methylprednisolone Mini-Pulse Therapy Combined with Narrow-Band UVB in Non-Segmental Vitiligo.

BACKGROUND: Systemic corticosteroids have been used to arrest the progression of vitiligo. However, side effects have been a constant issue. OBJECTIVE: We evaluated the clinical efficacy and side effect of oral methylprednisolone (MPD) mini-pulse therapy combined with narrow-band UVB (NBUVB) for adults with non-segmental vitiligo retrospectively. METHODS: 32 patients with extensive and/or spreading vitiligo received 0.5 mg/kg MPD on 2 consecutive days per week with NBUVB therapy for at least 3 months. RESULTS: All of the 32 patients (100%) showed progression arrest within 12 weeks. Nineteen out of 32 patients (59.4%) presented repigmentation on more than 25% of lesions. Thirteen patients (40.6%) achieved satisfactory repigmentation in more than 50% of lesions. Only 2 patients discontinued the medication due to gastrointestinal trouble. CONCLUSION: Oral MPD mini-pulse therapy combined with NBUVB appears effective in arresting vitiligo progression and rapidly inducing repigmentation with minimal side effects.

Eczematous dermatitis due to subcutaneous teriparatide injection.

Teriparatide, or recombinant human parathyroid hormone, is approved for the treatment of osteoporosis. Possible cutaneous adverse events of teriparatide are urticaria, injection site pain, swelling, bruising, and pruritus. However, there have been no reports of widespread eczematous reactions caused by teriparatide. A 47-year-old male was recently diagnosed with osteogenesis imperfecta and prior to teeth extractions, he was subcutaneously injected with teriparatide. The patient developed multiple pruritic erythematous papules and plaques on his abdomen, around the site of the injection. A skin biopsy was done, which showed mild spongiosis and superficial perivenular lymphocytic infiltration with a few eosinophils. Drug-related eczematous changes were most likely suspected and in addition to the discontinuation of the injection, topical steroid was prescribed, in which dramatic improvements were observed. We report the eczematous hypersensitivity reaction caused by teriparatide, which is an adverse reaction that has not been reported before.

Cutaneous Serratia marcescens infections in Korea: A retrospective analysis of 13 patients.

Serratia marcescens is a Gram-negative bacillus belonging to the Enterobacteriaceae family. Because of increasing reports of antimicrobial resistance, this bacterium has received considerable attention and has emerged as an important pathogen. In order to reveal clinical and microbiological characteristics of S. marcescens cutaneous infection and to suggest appropriate antibiotic treatment, we retrospectively analyzed 17 strains isolated from wound swabs of Korean patients between November 2005 and March 2014. A total of 13 patients (five men and eight women) were included in our study, with a mean age of 46.3 years (range, 21-82). Based on medical history, seven patients were classified as immunocompromised. Prior predisposing factors for infections were noted in 12 patients, including pre-existing leg ulcers or dermatitis (5/13), preceding cancer surgeries (2/13), plastic surgeries and filler injection (2/13), traumas (2/13) and medical procedures following cutaneous abscess (1/13). Cutaneous infections showed various clinical presentations, including spontaneous dermal abscess, fingernail change, painful nodules and papular erosions. We found that third- and fourth-generation cephalosporins, gentamicin, levofloxacin and meropenem appeared active against all 17 strains in vitro. Clinically, all patients treated with empirical first-generation cephalosporin showed treatment resistance, and oral quinolone monotherapy was the most preferred antibiotic regimen without treatment failure, with an average treatment duration of 25 days (range, 14-42). This study demonstrates the various clinical presentations and treatment responses for cutaneous S. marcescens infection. Moreover, we suggest that initial antibiotic coverage should be broad enough to account for multidrug resistance in this rare pathogen.

Clinical features of psoriatic arthritis in Korean patients with psoriasis: a cross-sectional observational study of 196 patients with psoriasis using psoriatic arthritis screening questionnaires.

The prevalence and clinical features of psoriatic arthritis (PsA) in psoriasis patients vary widely in different countries, and studies on Korean population are rarely reported. The aim of this study was to investigate the clinical features of PsA in a Korean population of patients with psoriasis by using psoriatic arthritis screening questionnaires. A cross-sectional observational study was conducted, and consecutive psoriatic patients were evaluated for PsA by using two kinds of psoriatic arthritis screening questionnaires: Psoriatic Arthritis Screening and Evaluation tool (PASE) and Psoriasis Epidemiology Screening Tool (PEST). Psoriatic patients with higher score in screening questionnaires were referred to rheumatologist for confirmative diagnosis of PsA. Among 196 psoriasis patients screened by PASE and PEST, total prevalence of PsA was 11.2 % (n = 22/196) with 59.1 % of the cases being newly diagnosed. Compared with patients without PsA, patients with PsA had more extensive psoriasis, higher frequency of pustular and inverse type of psoriasis, and lower frequency of plaque type of psoriasis. Spondylitis was the most common manifestation pattern, followed by polyarthritis, oligoarthritis, predominant distal interphalangeal arthritis, and arthritis mutilans. Our findings are consistent with a low prevalence of PsA among patients with psoriasis in Asia. We also confirm a spondylitis as the most common pattern of PsA in Korea. PsA screening questionnaires can be a simple and useful tool to screen PsA in patients with psoriasis.

Programmed death-ligand 1, 2 expressions are decreased in the psoriatic epidermis.

Psoriatic keratinocytes are one of the key components that amplify and maintain chronic inflammation. We hypothesized that lack of proper regulatory functions of keratinocytes can be responsible for chronic inflammation in psoriasis. Programmed death-ligands (PD-L) 1, 2 are expressed on keratinocytes, and expressions by nonlymphoid cells are important for mediating peripheral T cell tolerance. In our study, we investigated whether PD-L1, 2 expressions are altered in keratinocytes of psoriatic epidermis compared to normal epidermis. Epidermis was separated and analyzed for PD-L1, 2 expressions in mRNA and protein levels. Immunohistochemical stainings were done in skin biopsy samples from psoriasis, normal skin, allergic contact dermatitis (ACD), pityriasis rosea (PR) and lichen planus (LP). Expressions of PD-L1, 2 mRNA levels were significantly decreased in psoriatic epidermis compared to normal epidermis. In protein levels, PD-L1 expression was significantly decreased in psoriatic epidermis. However, PD-L2 expression was not detected in both normal and psoriatic epidermis. Immunohistochemical stainings revealed significantly less PD-L1 expression in psoriatic epidermis compared to normal epidermis. Even compared to other cutaneous inflammatory diseases, psoriatic epidermis showed less expression than ACD, PR and LP. PD-L2 expression was minimally detected in normal epidermis and not in psoriatic epidermis, but its expression was increased in ACD, PR and LP. In conclusion, we demonstrated that PD-L1, 2 are decreased in psoriatic epidermis in mRNA and protein levels. In addition, we showed that their expression was significantly lower than other inflammatory skin diseases. We suggest that decreased expression of PD-L1, 2 on psoriatic epidermis can contribute to its chronic unregulated inflammatory characteristics.

Preventive Effect of Human Acellular Dermal Matrix on Post-thyroidectomy Scars and Adhesions: A Randomized, Double-Blinded, Controlled Trial.

BACKGROUND: Acellular dermal matrix (ADM) has been used for antiadhesion formation along with wound healing in various surgical fields. OBJECTIVE: The aim is to assess the efficacy of ADM implantation in the prevention of postoperative scars and adhesions after conventional, open, total thyroidectomy. MATERIALS AND METHODS: Forty-four patients with papillary thyroid carcinoma undergoing thyroidectomy were randomly assigned to the study (ADM implantation) or control group (without ADM). Global photographic assessment, Vancouver scar scale (VSS), objective scar assessment, and swallowing impairment index were assessed at baseline, immediately after surgery, and at 1 and 2 months after surgery. RESULTS: Nineteen control and 20 study group participants completed the study. The mean VSS score of the study group was significantly lower than the controls at both 1 month (3.06 ± 1.25 vs 4.41 ± 1.54, respectively) and 2 months (2.76 ± 1.56 vs 4.35 ± 1.58, respectively) after surgery. Scar quality measures (mean melanin and erythema indexes) were significantly lower in the study group compared with controls. Study group participants had significantly lower swallowing impairment scores than controls. The mean postoperative hospitalization of both groups was not significantly different. CONCLUSION: Acellular dermal matrix-assisted implants appear to improve post-thyroidectomy scar and swallowing impairments without delays in operation time.

Increased large unstained cells value in varicella patients: A valuable parameter to aid rapid diagnosis of varicella infection.

Varicella is a highly contagious infection caused by varicella zoster virus. Sometimes it is difficult to differentiate between other viral infections such as Kaposi's varicelliform eruption (KVE) and disseminated herpes zoster (HZ). The large unstained cells (LUC) value is a differential count parameter reported by routing hematology analysis. LUC have been studied previously, but never been reported in the context of varicella or in dermatological published work. The aim of this study was to compare the LUC values in varicella patients with that in KVE and disseminated HZ patients. Sixty-nine varicella patients, 30 KVE patients and 11 disseminated HZ patients were included in this retrospective study. All data were analyzed using SPSS version 17.0 or GraphPad Prism version 5.0. The mean percentage of LUC (%LUC) in varicella patients was higher than the upper limit of normal reference range and it was increased compared to %LUC of both KVE (P < 0.0001) and disseminated HZ (P = 0.0051) patients. %LUC of varicella patients significantly decreased with clinical improvements (P = 0.0017). %LUC was significantly increased in varicella patients and corresponded with clinical improvements. Patients with %LUC of 3.55 or more favor the diagnosis of varicella over both KVE and disseminated HZ with 71.01% sensitivity and 84.44% specificity. We suggest that %LUC can assist in making a precise diagnosis of varicella in confusing cases.

Mean platelet volume is elevated in patients with psoriasis vulgaris.

PURPOSE: This retrospective study was done to investigate the mean platelet volume (MPV) level in patients with psoriasis vulgaris and its relationship with disease severity. MATERIALS AND METHODS: We undertook a cross-sectional study on 176 patients and 101 healthy controls to examine the association between MPV and psoriasis. Various clinical and laboratory parameters were analyzed and compared. RESULTS: Platelet distribution width and MPV were significantly higher in patients with psoriasis than controls. In addition, there was positive correlation between Psoriasis Area Severity Index (PASI) and MPV. When psoriasis patients were grouped into mild psoriasis (PASI<10) and moderate to severe psoriasis (PASI≥10), the MPV of the latter group was significantly elevated. Nevertheless, patients with higher MPV level (MPV≥10.4 fL) did not show higher PASI than lower MPV level (MPV<10.4 fL). MPV levels significantly decreased after improvements of psoriasis with various treatments. The variations of MPV and PASI also showed significant correlation. CONCLUSION: We have shown that MPV is increased in psoriasis patients and correlates with disease severity. Therefore, MPV levels may be considered as a marker of disease severity of psoriasis.