Haptoglobin is an independent marker for disease severity and risk for metabolic complications in hidradenitis suppurativa: A prospective study.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory disease that is highly correlated with obesity. Haptoglobin serum levels have recently been recognized as an important biomarker linking obesity with chronic inflammation. OBJECTIVE: To compare haptoglobin with previously proposed serum biomarkers for the determination of disease severity in HS patients. For this purpose, disease severity of HS patients was determined by a panel of clinical scores as well as several risk factors, such as weight and smoking habits. METHODS: A prospective, diagnostic accuracy study was performed at the International Centre for Hidradenitis suppurativa/Acne inversa Bochum (ICH). The study included a total of 263 patients, including 131 who had a confirmed diagnosis of HS in Hurley I (n = 16), II (n = 56) and III (n = 59) HS, and 132 healthy controls. The main outcome was to identify serological inflammatory markers for HS disease severity [severe (III) vs. moderate/mild (II/I)] as assessed by Hurley classification. RESULTS: The serum levels of acute phase proteins haptoglobin and CRP, as well as the number of neutrophils in peripheral blood, number of monocytes, the systemic immune-inflammation index and the pan-immune-inflammatory value correlated with disease severity according to established clinical scores (mHSS, SAHS, Hurley, DLQI). HS patients had significantly higher haptologlobin levels compared to healthy controls. Logistic regression analysis revealed haptoglobin as the only independent marker predicting severe HS. CONCLUSION: In this prospective study, we discovered that the serum levels of the acute phase protein haptoglobin levels serve as an independent marker of disease severity in HS. While this presents the first study in the context of HS. Thus, the present data not only yield a highly promising serum marker to be further validated.

Comparison of mutation profiles in primary melanomas and corresponding nodal naevi using next-generation sequencing.

BACKGROUND: Nodal naevi (NN) represent aggregates of melanocytes within peripheral lymph nodes. NN are relatively often found in patients with malignant melanoma (MM), and may mimic metastatic disease. AIM: To study mutation profiles in MM and NN to find out whether NN descend from a primary MM. METHODS: Next-generation sequencing was performed on formalin-fixed paraffin-embedded tissue of 26 pairs of primary MM and corresponding NN detected by sentinel lymph node biopsy, and 29 MM-characteristic genes were investigated. RESULTS: In this study, 90% of mutations were detected exclusively in either MM or NN, but not both, in the same patient; the percentage of identical NN and MM mutations in the same individual was only 10%. The most frequently discovered shared mutations were a C>G substitution in the CDKN2A gene and in-frame deletion in ARID1A. Oncogenic driver mutations were frequently observed in MM but only rarely in NN. About three-quarters of mutations in both MM and NN were characterized by C>T or G>A substitutions. The detected rate of ultraviolet (UV)-related C>T base changes was comparably high in both primary MM (35%) and NN (32%). CONCLUSIONS: Based on our data, it seems that NN descend from previously UV-exposed BRAF wildtype cutaneous melanocytes, rather than from primary MM or arrested progenitor cells.

Protein expression of prognostic genes in primary melanoma and benign nevi.

PURPOSE: To evaluate the protein expression characteristics of genes employed in a recently introduced prognostic gene expression assay for patients with cutaneous melanoma (CM). METHODS: We studied 37 patients with CM and 10 with benign (melanocytic) nevi (BN). Immunohistochemistry of primary tumor tissue was performed for eight proteins: COL6A6, DCD, GBP4, KLHL41, KRT9, PIP, SCGB1D2, SCGB2A2. RESULTS: The protein expression of most markers investigated was relatively low (e.g., DCD, KRT9, SCGB1D2) and predominantly cytoplasmatic in melanocytes and keratinocytes. COL6A6, GBP4, and KLHL41 expression was significantly enhanced in CM when compared to BN. DCD protein expression was significantly correlated with COL6A6, GBP4, and KLHL41. GBP4 was positively correlated with KLHL41 and inversely correlated with SCGB2B2. The latter was also inversely correlated with serum S100B levels at time of initial diagnosis. The presence of SCGB1D2 expression was significantly associated with ulceration of the primary tumor. KRT9 protein expression was significantly more likely found in acral lentiginous melanoma. The presence of DCD expression was less likely associated with superficial spreading melanoma subtype but significantly associated with non-progressive disease. The absence of SCGB2A2 expression was significantly more often observed in patients who did not progress to stage III or IV. CONCLUSIONS: The expression levels observed were relatively low but differed in part with those found in BN. Even though we detected some significant correlations between the protein expression levels and clinical parameters (e.g., CM subtype, course of disease), there was no major concordance with the protective or risk-associated functions of the corresponding genes included in a recently introduced prognostic gene expression assay.

NOD2 signalling in hidradenitis suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) is associated with dysregulated immune responses including altered expression of cytokines, chemokines, and antimicrobial peptides and proteins (AMPs). AIMS: To evaluate the expression of nucleotide-binding oligomerization domain-containing (NOD)2 and related factors in HS skin samples and keratinocyte cultures. METHODS: We performed real-time PCR for NOD2, receptor-interacting serine/threonine-protein kinase (RIP)2, cyclic amine resistance locus (CARL), skin-derived antileukoproteinase (SKALP)/elafin, human ß-defensin (hBD)2, LL37, psoriasin and RNAse7 in lesional and nonlesional skin of 19 patients with HS and in keratinocyte cultures [unstimulated, muramyl dipeptide (MDP)-stimulated or Pam2CSK4 (Pam2)-stimulated] from and nonlesional skin. RESULTS: We observed significantly elevated mRNA expression for NOD2 (P < 0.01), hBD2 (P = 0.02), RNase7 (P < 0.001), psoriasin (P < 0.01) and SKALP/elafin (P = 0.02) in lesional compared with nonlesional skin. We found a significant correlation between NOD2 mRNA and hBD2 (r = 46; P = 0.04), psoriasin (r = 0.67; P < 0.01) and SKALP/elafin (r = 0.65; P < 0.01). In unstimulated, Pam2-stimulated and MDP-stimulated normal keratinocytes, NOD2, RIP2, CARL and SKALP/elafin expression significantly (P < 0.05) increased from 6 to 48 h, whereas in unstimulated, Pam2-stimulated and MDP-stimulated HS keratinocytes, RIP2, CARL and SKALP/elafin expression significantly (P < 0.05) declined from 6 to 48 h. mRNA expression of NOD2 (unstimulated, Pam2-stimulated, MDP-stimulated), CARL (unstimulated, Pam2-stimulated, MDP-stimulated) and SKALP/elafin (unstimulated, Pam2-stimulated) at 6 h was significantly increased in HS compared with normal keratinocytes. CONCLUSION: We have shown for the first time that NOD2 signalling is activated in HS and might contribute to the pathogenesis via induction of AMPs and activation of other pathways such as nuclear factor κB signalling.

Increased expression profile of NCSTN, Notch and PI3K/AKT3 in hidradenitis suppurativa.

BACKGROUND: In a small number of kindreds with familial hidradenitis suppurativa (HS) different mutations of NCSTN (nicastrin) have been identified. Blocking of NCSTN leads to impairment of the Notch and PI3K/AKT signalling pathway, which is assumed to play a pathogenic role in HS. However, very limited data are available concerning expression levels of these pathway components in HS skin. OBJECTIVES: To analyse the mRNA and protein expression of NCSTN, Notch1-3, PIK3R3 and AKT3 in HS. METHODS: Skin samples from healthy controls, lesional and perilesional skin of HS patients with and without a positive family history were analysed by quantitative real-time RT-PCR and immunohistochemistry. Univariate statistical analyses were conducted regarding association between expression levels and patient's characteristics. RESULTS: Expression levels of all investigated genes showed significantly higher levels in lesional HS skin compared with healthy controls. Univariate analysis showed no association between a positive family history and mRNA expression levels. Perilesional HS skin of patients with mild disease severity (Hurley I) showed significant higher mRNA expression levels of the investigated pathway components compared to moderate (Hurley II) and severe disease (Hurley III). CONCLUSION: We found no evidence for diminished expression levels of the Notch signalling. In contrast, the NCSTN, Notch and PI3K/AKT signalling components are overexpressed in HS. Future research is needed to investigate a possible pathogenetic role or to reveal a coactivation of these overexpressed components during inflammatory response in HS.

Expression of Lefty predicts Merkel cell carcinoma-specific death.

BACKGROUND: Lefty and Nodal are transforming growth factor ß-related proteins, which, beside their role in determination of laterality during embryogenesis, have also been linked with cancer progression. OBJECTIVES: Prompted by the observed significant left-sided laterality of Merkel cell carcinoma (MCC), we addressed whether Lefty and Nodal are expressed in MCC and correlated expression patterns with clinical parameters such as MCC laterality and patient outcome. METHODS: Expression of Lefty and Nodal in primary MCC was assessed in 29 patients by immunohistochemistry. The histology (H-)score was calculated and correlated with clinical parameters. RESULTS: The median (range) H-score of Lefty and Nodal was 17.6 (0-291) and 74.9 (0.7-272), respectively. There was a significant correlation between Lefty expression and Nodal expression (correlation coefficient of 0.60, P = 0.0006). There was no significant correlation between Lefty expression and Nodal expression with either tumour laterality, gender, age, Merkel cell polyomavirus status, disease stage, anatomical localization of primary tumours or disease relapse. On univariate analysis, low Lefty expression and Nodal expression were significantly associated with MCC-specific death (P = 0.010 and P = 0.019, respectively). On univariate analysis, low Lefty expression was the only significant independent predictor for MCC-specific death (P = 0.025) as indicated by an odds ratio of 14 (95% CI: 1.43-137.33). CONCLUSIONS: Lefty and Nodal are frequently expressed in MCC, but not correlated with tumour laterality. Importantly, our data suggest that a low level of Lefty expression in primary MCC is a strong predictor of MCC-specific death.

Frequency of circulating subpopulations of T-regulatory cells in patients with hidradenitis suppurativa.

BACKGROUND: Decreased number of T-regulatory cells (Tregs) and/or their loss of function potentially lead to uncontrolled immune-mediated inflammatory responses. There are only few data available on Tregs in hidradenitis suppurativa (HS) - a disease in which it has been suggested that host immune factors and an overactive immune system of the follicular epithelium play a pathogenetic role. OBJECTIVES: To analyse frequencies of Tregs subpopulations in blood of HS patients in comparison with a healthy control group. MATERIALS & METHODS: Blood samples obtained from HS patients and healthy controls were evaluated by flow cytometry and enzyme-linked immunosorbent assay. RESULTS: The frequency of natural Tregs among CD4+ T lymphocytes were significantly reduced in the HS group compared to the healthy controls. The proportion of activated Tregs, non-suppressive Tregs and proliferating Tregs showed no significant difference when compared to controls. Regarding Tregs frequencies, there was no significant difference between the three Hurley stages. Serum concentrations of IL-10, TGF-ß1 and IL-17A did not show significant differences between the HS and control group. CONCLUSION: The reduction of natural Tregs observed in blood of HS patients could be the result of Tregs homing to sites of inflammatory hot spots in HS skin. Further studies are justified evaluating the role of circulating Tregs during the evolution of HS lesions and as a biomarker for treatment response.

Lysyl oxidase-like-2 mutations and reduced mRNA and protein expression in mid-dermal elastolysis.

BACKGROUND: Mid-dermal elastolysis (MDE) is a rare skin condition, characterized by selective loss of elastic fibres in the mid dermis. The pathogenesis of MDE is still unclear. AIM: To investigate expression of lysyl oxidase-like 2 (LOXL2) in a reasonable sample of patients with MDE and to search for mutations in LOXL2. METHODS: We investigated archived lesional tissue of 13 patients with MDE and skin tissue samples of 10 sex- and age-matched healthy controls (HCs). Gene and protein expression of LOXL2 was investigated using real-time reverse-transcription PCR and immunohistochemistry. Mutation analysis was performed using the Sanger method. RESULTS: We observed decreased LOXL2 mRNA expression in lesional skin of patients with MDE (0.48 ± 0.16) compared with healthy skin of the same patients (1.5 ± 0.51) and normal skin of HCs (1.9 ± 0.13). Compared with healthy patient skin (epidermis 2.38 ± 1.6, dermis 1.2 ± 1), LOXL2 protein expression in lesional patient skin (epidermis 1.1 ± 0.7, dermis 0.3 ± 0.45) was significantly decreased (P < 0.04 and P = 0.02, respectively). Mutation analysis of the entire LOXL2 gene could be performed for five patients, all of whom were found to have at least one mutation in the LOXL2 gene. Three of these had a mutation in the promoter region (c.967 G>C, c.1022 C>T, and c.1025 G>A, respectively), and one of them also had a mutation in the splice region of intron 11/exon 12 (IVS11-1 G>A). Of the remaining two patients, one had a mutation in exon 3 (T1391), and the other had a mutation in exon 11 (C663Y). CONCLUSIONS: Our present data suggest that decreased elastin renewal due to LOXL2 mutations and consecutive reduced LOXL2 expression contribute to the pathogenesis of MDE.

Interleukin-36 in hidradenitis suppurativa: evidence for a distinctive proinflammatory role and a key factor in the development of an inflammatory loop.

BACKGROUND: Possible regulatory involvement of the interleukin (IL)-36 family in inflammatory diseases has been suggested. OBJECTIVES: To analyse the expression of IL-36α, IL-36ß, IL-36γ and the antagonistic cytokines IL-36 receptor agonist (IL-36Ra), IL-37 and IL-38 in the skin of patients with hidradenitis suppurativa (HS). METHODS: Skin samples from lesional and corresponding perilesional HS skin, and from healthy controls were included in this study and analysed by quantitative real-time reverse-transcriptase polymerase chain reaction (PCR). To evaluate the PCR results of IL-36α, IL-36ß and IL-36γ, a subset of skin samples was studied by immunohistochemistry. RESULTS: Expression levels of IL-36α, IL-36ß, IL-36γ and IL-36Ra were all significantly higher in lesional HS skin than in healthy controls. IL-37 and IL-38 levels were significantly higher in perilesional HS skin than in healthy controls and were decreased in lesional HS skin. Limitations of the study are its descriptive nature and the small sample size. CONCLUSIONS: Our results showed a possible involvement of IL-36 cytokines in the inflammatory network of HS and a dysbalance between the agonistic and antagonistic cytokines in HS skin.

The microRNA effector RNA-induced silencing complex in hidradenitis suppurativa: a significant dysregulation within active inflammatory lesions.

Recently, we could show that the expression levels of the key regulators of the microRNA (miRNA) maturation and transport were dysregulated in inflamed hidradenitis suppurativa (HS) tissue (Heyam et al. in Wiley Interdiscip Rev RNA 6:271-289, 2015). The RNA-induced silencing complex (RISC) is the central element of the miRNA pathway and regulates miRNA formation and function. We investigated the expression of the RISC components, namely transactivation-responsive RNA-binding protein-1 (TRBP1), TRBP2, protein activator (PACT) of the interferon-induced protein kinase R, Argonaute RISC Catalytic Component-1 (AGO1) and Component-2 (AGO2), metadherin, and staphylococcal nuclease and Tudor domain-containing-1 (SND1) in inflamed HS tissue compared to healthy and psoriatic controls by real-time reverse transcription polymerase chain reaction. Expression levels of all investigated components were significantly lower in lesional HS skin (n = 18) compared to healthy controls (n = 10). TRBP1, PACT, AGO1, AGO2, and SND1 expression levels were significantly down-regulated in lesional HS skin compared to healthy-appearing perilesional skin (n = 7). TRBP2 and SND1 expression levels were significantly lower in healthy-appearing perilesional skin compared to healthy controls. In lesional HS skin, expression levels of PACT, AGO1, and AGO2 were significantly lower compared to psoriatic skin (n = 10). In summary, our data showed that all investigated components of RISC are dysregulated in the skin of HS patients, providing support for the hypothesis that miRNAs may have a pathological role in the inflammatory pathogenesis of HS.

T regulatory cells and other lymphocyte subsets in patients with bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is the most common autoimmune blistering disease, and is associated with autoantibodies to the hemidesmosomal BP autoantigens BPAG1 and BPAG2. AIM: We aimed to investigate the significance of T regulatory cells and other lymphocyte subsets in patients with BP. METHODS: In total, 31 inpatients with BP were treated with systemic prednisolone in a tapered dose regimen, while 28 healthy individuals matched for age and sex served as the healthy control (HC) group., Blood samples were taken at baseline and after treatment, and levels of inducer/helper and suppressor/cytotoxic T lymphocytes, B lymphocytes, natural killer cells, CD4+CD25++CD127- cells were assessed by flow cytometry, while CD4, CD8, and FOXP3 positivity were assessed by immunohistochemistry, and FOXP3 mRNA was assessed by reverse transcription (RT)-PCR. RESULTS: Flow cytometry showed that numbers of CD8+ and CD4+CD25++CD127- cells were significantly increased, while the number of CD4+ cells and the CD4/CD8 ratio were significantly decreased at baseline and after therapy in patients with BP compared with HCs. Immunohistology revealed that CD4+, CD8+ and FOXP3+ cells were significantly increased at baseline and post-treatment in patients with BP compared with HCs. FOXP3 mRNA levels were significantly increased in the blood of patients with BP compared with HCs. CONCLUSION: These results indicate that increased numbers of CD8+, CD4+CD25++CD127- cells and FOXP3+ cells may play a pathogenetic role during the course of BP.

Expression of miRNA-155, miRNA-223, miRNA-31, miRNA-21, miRNA-125b, and miRNA-146a in the Inflammatory Pathway of Hidradenitis Suppurativa.

Hidradenitis suppurativa (HS) has been associated with marked inflammatory perturbation. The mechanisms regulating the inflammatory network remain elusive. microRNAs (miRNAs) have been described as gene regulators of inflammation. We evaluated the messenger RNA (mRNA) expression levels of six selected inflammation-related miRNAs in lesional and perilesional skin samples of HS patients and in healthy controls. Samples of 15 HS patients and 10 healthy controls were included in this prospective study. Expression levels of the miRNAs miRNA-155-5p, miRNA-223-5p, miRNA-31-5p, miRNA-21-5p, miRNA-125b-5p, and miRNA-146a-5p were studied by quantitative real-time reverse transcription polymerase chain reaction. We observed a significant overexpression of miRNA-155-5p, miRNA-223-5p, miRNA-31-5p, miRNA-21-5p, and miRNA-146a-5p in lesional HS skin compared to healthy controls. Expression of these miRNAs was also significantly increased in lesional HS skin when compared to perilesional skin. Only miRNA-155-5p showed an increased expression in perilesional skin compared to healthy controls. In contrast, miRNA-125b-5p had a significantly lower expression in lesional HS skin compared to perilesional skin. We found that the studied inflammation-related miRNAs were significantly dysregulated in lesional HS skin and may have regulatory roles in the inflammatory process of HS. Given their predicted targets and functions, our findings point to these miRNAs as potential disease biomarkers, and manipulation might be used therapeutically to target the inflammatory pathway in HS.

Cyclooxygenase 2 expression and apoptosis in normal and psoriatic epidermis models exposed to salt water soaks and narrowband ultraviolet B radiation.

BACKGROUND: Combined treatment using salt water baths and artificial ultraviolet (UV) radiation (balneophototherapy, BPT) is a common therapeutic option for conditions such as psoriasis. However, it remains unknown whether pre-treatment with salt water soaks alter inflammatory and/or carcinogenic effects of UVB phototherapy. OBJECTIVES: We aimed to investigate the impact of BPT on COX-2 gene expression and apoptosis in normal and psoriatic keratinocytes. METHODS: Normal epidermis models (NEM) and psoriatic epidermis models (PEM) were treated using different salt water soaks (3% NaCl, 30% NaCl, 30% Dead Sea salt; DSS) and subsequent narrowband ultraviolet B (NB-UVB) for three consecutive days. RT-PCR was performed for cyclooxygenase 2 (COX-2), survivin, and caspase-3. RESULTS: Compared with untreated controls COX-2 mRNA was significantly increased in NB-UVB irradiated NEM and PEM. NB-UVB-exposed and non-exposed 30% NaCl and 30% DSS-treated NEM and PEM (except for NB-UVB-exposed and non-irradiated 30% DSS) showed significantly higher COX-2 mRNA when compared with controls and 3% NaCl. In NB-UVB-exposed 30% NaCl and 30% DSS-treated NEM and PEM survivin mRNA was significantly decreased when compared with controls and 3% NaCl. Compared with NB-UVB-exposed controls mRNA of caspase-3 was significantly increased in NB-UVB-exposed 30% NaCl and 30% DSS-treated PEM. CONCLUSION: Although BPT using high-concentrated salt water solutions is associated with increased epidermal COX-2 mRNA expression, apoptosis of keratinocytes is enhanced possibly due to the down-regulation of survivin mRNA expression. If confirmed in larger studies these observations have important implications for BPT efficacy as well as safety, particularly with regard to the risk of early carcinogenesis.

Expression of human ß-defensin-2 in psoriatic epidermis models treated with balneophototherapy.

BACKGROUND: The molecular mechanisms of action of salt water soaks combined with ultraviolet (UV) irradiation--balneophototherapy (BPT)--are unknown. OBJECTIVES: We aimed to investigate the effect of BPT on the expression of human ß-defensin-2 (hBD2) using a psoriatic epidermis model (PEM). METHODS: Using real-time RT-PCR and ELISA, we studied the expression patterns of hBD2 in PEM which were treated over three consecutive days with differently concentrated salt water solutions [(3% NaCl; 30% NaCl, 30% Dead Sea salt (DSS)] and consecutive narrowband UVB exposure. RESULTS: mRNA of hBD2 was significantly reduced in irradiated 3% NaCl, 30% NaCl and 30% DSS soaked PEM when compared with non-irradiated PEM. ELISA for hBD2 revealed significantly reduced protein expression in irradiated 3% NaCl, 30% NaCl and 30% DSS soaked PEM when compared with non-irradiated PEM. Compared with irradiated controls and 3% NaCl soaked and irradiated PEM, BPT using 30% NaCl and 30% DSS revealed significantly decreased hBD2 protein levels. CONCLUSIONS: Both mono-treatment with salt water soaks and BPT of PEM result in altered expression of hBD2, whereas the effects observed are most prominent after BPT. hBD2 gene and protein expression is predominantly down-regulated following BPT indicating that this combined phototherapeutic regimen is superior to mono-UVB or salt water soaks alone with respect to normalization of hBD2 expression in psoriatic epidermis.

Altered global methylation and hydroxymethylation status in vulvar lichen sclerosus: further support for epigenetic mechanisms.

BACKGROUND: Epigenetics refers to functionally relevant changes in the genome other than those of DNA sequence that can lead to changes in gene expression or cellular phenotype. There is evidence that epigenetics is relevant in the pathogenesis of autoimmune diseases such as vulvar lichen sclerosus (VLS), as well as in cancer, including cutaneous squamous cell carcinoma, which is frequently associated with VLS. OBJECTIVES: To study the global methylation and hydroxymethylation status in healthy controls and VLS lesions before and after long-term ultraviolet (UV)A1 treatment. METHODS: We studied 12 controls and 10 patients with VLS who were treated with medium-dose UVA1 four times weekly for 3 months. Immunohistochemistry and mutation analyses (polymerase chain reaction) were performed for 5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC), isocitrate dehydrogenases (IDHs) and the ten-eleven translocation (TET)2 enzyme. RESULTS: After 3 months of treatment, 5mC was significantly increased in VLS compared with baseline and controls. However, compared with controls 5hmC levels were significantly reduced in baseline VLS, but normalized after UVA1 treatment. Compared with controls, IDH1 expression was significantly higher in both treated and baseline VLS. By contrast, IDH2 levels were significantly reduced in baseline VLS compared with controls and UVA1-treated VLS. However, gene sequencing of the IDH1, IDH2 and TET2 genes did not reveal evidence of mutations. CONCLUSIONS: VLS is associated with altered expression of IDH enzymes and aberrant hydroxymethylation, indicating an epigenetic background for the pathogenesis of VLS. UVA1 phototherapy may cause normalization of 5hmC patterns, but also global DNA hypermethylation in VLS lesions, raising concerns with respect to an increased risk of photocarcinogenesis.

Glutathione-S-transferase T1 genotyping and phenotyping in psoriasis patients receiving treatment with oral fumaric acid esters.

BACKGROUND: Glutathione S-transferases (GSTs) are involved in detoxification of xenobiotics such as fumaric acid esters (FAE). OBJECTIVES: To perform GSTT1 geno- and phenotyping in psoriasis patients treated with FAE to find out whether the responder status and/or occurrence of side-effects are associated with allelic variants and enzymatic activity of GSTT1. METHODS: We treated 106 psoriasis patients with FAE. GSTT1 genotyping was performed using PCR, phenotyping was carried out by means of a validated high performance liquid chromatography assay at baseline and under treatment. RESULTS: The distribution of GSTT1 genotypes was as follows: 31% *A/*A; 49% *A/*0; 20% *0/*0. GSTT1 phenotypes as expressed in enzyme activity significantly differed between conjugators classes. (P < 0.001). GSTT1 activity under treatment was significantly (P = 0.0001) increased when compared with baseline. There were no significant associations between the aforementioned GSTT1 pheno- and genotypes and clinical parameters such as psoriasis area and severity index (PASI)50, adverse effects and FAE dosage (P > 0.05), except for the frequent occurrence of reduction (>50%) of circulating lymphocytes in patients with *0/*0 GSTT1 status (P = 0.036; odds ratio: 6, 95% CI: 1.1-32). CONCLUSION: GSTT1 geno- and phenotypes significantly correlate in psoriasis patients and do not substantially differ from healthy controls. Response to FAE does likely not depend on GSTT1. However, *0/*0 GSTT1 status is a predictor for the occurrence of marked reduction of lymphocyte counts under FAE therapy. Notably, FAE seem to enhance GSTT1 enzyme activity in high and low conjugators.

T regulatory cells and related immunoregulatory factors in polymorphic light eruption following ultraviolet A1 challenge.

BACKGROUND: Polymorphic light eruption (PLE) is considered to be an autoimmune-mediated skin condition in which the normal ultraviolet (UV)-induced local immunosuppression appears to be absent, leading to recognition of photoinduced autoantigens and subsequent inflammation. OBJECTIVES: To investigate T regulatory cells (Tregs) and related immunoregulatory factors in PLE lesions and controls. METHODS: Skin biopsies were performed in 13 patients with UVA1-challenged PLE, 12 female patients with chronic discoid lupus erythematosus (CDLE) and 11 healthy controls who had exposure to UVA1. Immunohistochemistry and four-colour immunofluorescence studies were performed. RESULTS: Patients with CDLE and UVA1-exposed controls showed significantly decreased epidermal immunoreactivity for CD1a compared with patients with PLE (P = 0·0001). Four-colour immunofluorescence revealed a median percentage of CD4+CD25+FOXP3+ Tregs of 7·6% (range 3·7-13·6%) in PLE, a median of 11·7% (range 9·5-13·9%) in CDLE and a median of 3·4% (range 0-6·8%) in controls. Compared with UVA1-exposed controls, PLE and CDLE lesions showed significantly decreased transforming growth factor (TGF)-ß1 immunoreactivity in the epidermis (P = 0·0003). In PLE lesions, we observed significantly decreased interleukin (IL)-10 expression compared with CDLE (P = 0·022). In the dermis, receptor activator of nuclear factor-κB ligand (RANKL) expression was increased in UVA1-exposed controls compared with PLE and CDLE (P = 0·018). CONCLUSIONS: Similar to CDLE lesions, UVA1-challenged PLE lesions display an altered immunoregulatory network, as indicated by decreased epidermal or dermal expression of TGF-ß1, IL-10 and RANKL, and a relatively low number of Tregs, particularly when compared with other inflammatory skin conditions reported in the literature.