Primary alterations during the development of hidradenitis suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic, inflammatory disease of the apocrine gland-rich (AGR) skin region. The initial steps of disease development are not fully understood, despite intense investigations into immune alterations in lesional HS skin. OBJECTIVES: We aimed to systematically investigate the inflammatory molecules involved in three stages of HS pathogenesis, including healthy AGR, non-lesional HS and lesional HS skin, with the parallel application of multiple mRNA and protein-based methods. METHODS: Immune cell counts (T cells, dendritic cells, macrophages), Th1/Th17-related molecules (IL-12B, TBX21, IFNG, TNFA, IL-17, IL10, IL-23A, TGFB1, RORC, CCL20), keratinocyte-related sensors (TLR2,4), mediators (S100A7, S100A8, S100A9, DEFB4B, LCN2, CAMP, CCL2) and pro-inflammatory molecules (IL1B, IL6, TNFA, IL-23A) were investigated in the three groups by RNASeq, RT-qPCR, immunohistochemistry and immunofluorescence. RESULTS: Epidermal changes were already detectable in non-lesional HS skin; the epidermal occurrence of antimicrobial peptides (AMPs), IL-1ß, TNF-α and IL-23 was highly upregulated compared with healthy AGR skin. In lesional HS epidermis, TNF-α and IL-1ß expression remained at high levels while AMPs and IL-23 increased even more compared with non-lesional skin. In the dermis of non-lesional HS skin, signs of inflammation were barely detectable (vs. AGR), while in the lesional dermis, the number of inflammatory cells and Th1/Th17-related mediators were significantly elevated. CONCLUSIONS: Our findings that non-lesional HS epidermal keratinocytes produce not only AMPs and IL-1ß but also high levels of TNF-α and IL-23 confirm the driver role of keratinocytes in HS pathogenesis and highlight the possible role of keratinocytes in the transformation of non-inflammatory Th17 cells (of healthy AGR skin) into inflammatory cells (of HS) via the production of these mediators. The fact that epidermal TNF-α and IL-23 appear also in non-lesional HS seems to prove these cytokines as excellent therapeutic targets.

The selective sphingosine 1-phosphate receptor modulator BAF312 redirects lymphocyte distribution and has species-specific effects on heart rate.

BACKGROUND AND PURPOSE: BAF312 is a next-generation sphingosine 1-phosphate (S1P) receptor modulator, selective for S1P(1) and S1P(5 ) receptors. S1P(1) receptors are essential for lymphocyte egress from lymph nodes and a drug target in immune-mediated diseases. Here, we have characterized the immunomodulatory potential of BAF312 and the S1P receptor-mediated effects on heart rate using preclinical and human data. EXPERIMENTAL APPROACH: BAF312 was tested in a rat experimental autoimmune encephalomyelitis (EAE) model. Electrophysiological recordings of G-protein-coupled inwardly rectifying potassium (GIRK) channels were carried out in human atrial myocytes. A Phase I multiple-dose trial studied the pharmacokinetics, pharmacodynamics and safety of BAF312 in 48 healthy subjects. KEY RESULTS: BAF312 effectively suppressed EAE in rats by internalizing S1P(1) receptors, rendering them insensitive to the egress signal from lymph nodes. In healthy volunteers, BAF312 caused preferential decreases in CD4(+) T cells, T(naïve) , T(central memory) and B cells within 4-6 h. Cell counts returned to normal ranges within a week after stopping treatment, in line with the elimination half-life of BAF312. Despite sparing S1P(3) receptors (associated with bradycardia in mice), BAF312 induced rapid, transient (day 1 only) bradycardia in humans. BAF312-mediated activation of GIRK channels in human atrial myocytes can fully explain the bradycardia. CONCLUSION AND IMPLICATIONS: This study illustrates species-specific differences in S1P receptor specificity for first-dose cardiac effects. Based on its profound but rapidly reversible inhibition of lymphocyte trafficking, BAF312 may have potential as a treatment for immune-mediated diseases.

Synthesis and glycogen phosphorylase inhibitor activity of functionalized 1,4-benzodioxanes.

A series of novel 1,4-benzodioxanes 11a-e and rac-12a-d carrying thiazolidine-2,4-dione moiety was synthesized and their glycogen phosphorylase inhibitor activity was also evaluated.

C1-inhibitor autoantibodies in SLE.

The presence of anti-C1-inhibitor (anti-C1-INH) autoantibodies is a hallmark of acquired C1-inhibitor deficiency. However, only scarce data are available on their prevalence, diagnostic value, and/or significance in systemic lupus erythematosus (SLE). In a multicentre study, we determined the levels of autoantibodies to C1-inhibitor in sera from 202 patients with SLE and 134 healthy controls. Additional clinical and laboratory parameters, such as organ involvement, as well as anti-C1q, anti-double-stranded DNA antibody, erythrocyte sedimentation rate, C-reactive protein, C3 and C4 serum complement levels have been studied in patients. The level of anti-C1-INH IgG was significantly higher (p = 0.034) in SLE patients, than in the controls. A high anti-C1-INH level of > or =0.4 U/ml (mean of controls + 2 SD) was found in 17% of the patients, but in only 4% of the controls (p = 0.0003). The SLEDAI score was significantly higher (p = 0.048) and the duration of SLE was significantly longer (p = 0.0004) among patients with elevated anti-C1-INH levels compared with patients without this autoantibody (median disease duration 8 vs. 17 years, respectively). Anti-C1-INH level was not correlated with any other laboratory parameter or organ manifestation of the disease. These findings indicate that the anti-C1-INH level is higher in SLE patients than in healthy controls and furthermore, the anti-C1-INH level correlates with the duration and activity of the disease.

Immunological alterations in newly diagnosed primary Sjögren's syndrome characterized by skewed peripheral T-cell subsets and inflammatory cytokines.

OBJECTIVES: To describe how certain peripheral immune parameters reflect the inflammatory alterations in patients with primary Sjögren's syndrome (pSS). We determined lymphocyte subpopulations and their state of activation from peripheral blood, evaluating both soluble serum T-helper (Th)1/Th2-type cytokines and intracytoplasmic cytokines. METHODS: Forty-nine patients with newly diagnosed pSS and 40 healthy individuals, all free from immunomodulant or immunosuppressive medication, were studied. Peripheral blood lymphocyte subgroups were quantified by flow cytometry, soluble cytokines were assessed using enzyme-linked immunosorbent assay (ELISA), and intracellular cytokine levels were measured after phorbol myristate acetate (PMA) stimulation by flow cytometry after staining of intracellular cytokines. RESULTS: Patients with primary SS had higher percentages of activated CD3+/CD69+ T cells than controls. When comparing naïve vs. memory subsets of CD4+ and CD8+ T cells, a shift towards the memory phenotype was observed for both. Natural killer (NK) cell and NK T-cell (NKT) percentages and Th0 and Th1 cell numbers were increased in patients compared to controls. Among circulating cytokines, interferon (IFN)-gamma was high, whereas interleukin (IL)-10 was decreased in SS when compared to controls. CONCLUSIONS: SS, considered as a systemic autoimmune disease, is characterized by a complex interplay of various cytokines and immune cells. The skewed T-cell subsets and cytokine imbalance play important roles in an orchestrated proinflammatory cascade.

Prospective meta-analysis of interleukin 1 gene complex polymorphisms confirms associations with ankylosing spondylitis.

OBJECTIVES: The aim of the current study was to determine the contribution of interleukin (IL)1 gene cluster polymorphisms previously implicated in susceptibility for ankylosing spondylitis (AS) to AS susceptibility in different populations worldwide. METHODS: Nine polymorphisms in the IL1 gene cluster members IL1A (rs2856836, rs17561 and rs1894399), IL1B (rs16944), IL1F10 (rs3811058) and IL1RN (rs419598, the IL1RA VNTR, rs315952 and rs315951) were genotyped in 2675 AS cases and 2592 healthy controls recruited in 12 different centres in 10 countries. Association of variants with AS was tested by Mantel-Haenszel random effects analysis. RESULTS: Strong association was observed with three single nucleotide polymorphisms (SNPs) in the IL1A gene (rs2856836, rs17561, rs1894399, p = 0.0036, 0.000019 and 0.0003, respectively). There was no evidence of significant heterogeneity of effects between centres, and no evidence of non-combinability of findings. The population attributable risk fraction of these variants in Caucasians is estimated at 4-6%. CONCLUSIONS: This study confirms that IL1A is associated with susceptibility to AS. Association of the other IL1 gene complex members could not be excluded in specific populations. Prospective meta-analysis is a useful tool in confirmation studies of genes associated with complex genetic disorders such as AS, providing sufficiently large sample sizes to produce robust findings often not achieved in smaller individual cohorts.

Role of HLA-DRB1 and PTPN22 genes in susceptibility to juvenile idiopathic arthritis in Hungarian patients.

OBJECTIVE: Juvenile idiopathic arthritis (JIA) is a complex immune-mediated disease characterized by environmental influences along with several predisposing genes in the pathogenesis. The present study was undertaken to investigate the association of polymorphisms in two candidate genes for autoimmunity, human leukocyte antigen (HLA) DRB1 and protein tyrosine phosphatase N22 (PTPN22) with JIA in Hungarian patients. METHODS: A case-control study including 150 Hungarian JIA patients and 200 sex and ethnically matched healthy controls was conducted. Genotyping for HLA-DRB1 and PTPN22 C1858T single nucleotide polymorphism (SNP) (rs2476601) was carried out by group-specific PCR amplification and by real-time PCR allelic discrimination, respectively. RESULTS: In Hungarian patients JIA was associated with HLA-DRB1*01, DRB1*08, DRB1*13 (p=0.048, p=0.002, p=0.019, respectively) with marked differences between the disease subtypes classified according to the ILAR criteria. There was no association of the PTPN22 C1858T SNP with JIA (p=0.66). No correlation was found between the presence of this PTPN22 SNP and HLA-DRB1 alleles. CONCLUSIONS: Our results confirm that certain HLA-DRB1 alleles reported previously as susceptibility factors are strongly associated with JIA in a Hungarian population. However, C1858T polymorphism of PTPN22, another candidate gene of autoimmunity seems to be independent of JIA in Hungarian patients. Our data taken together with various findings in different populations suggest that associations related to PTPN22 seem to be more ethnicity-specific in contrast to the general and less population-dependent role of HLA-DRB1 in JIA.

Association between early onset and organ manifestations of systemic lupus erythematosus (SLE) and a down-regulating promoter polymorphism in the MBL2 gene.

The serum concentration of mannose-binding lectin (MBL) is genetically determined by a series of allelic polymorphisms in the MBL2 gene. Since several polymorphisms of the MBL2 gene have been suggested to be risk locus for systemic lupus erythematosus (SLE), we investigated MBL2 polymorphisms in 315 SLE patients from Hungary and 182 geographically matched healthy controls. Within the group of patients, we found that homozygotes for an MBL2 down-regulating promoter polymorphism at position -221 (YA to XA) (rs7096206) were significantly (p=0.017) younger at diagnosis than the other patients. The frequency of juvenile-onset SLE (

Thrombosis risk in systemic lupus erythematosus: the role of thrombophilic risk factors.

OBJECTIVES: Thromboembolic episodes are frequent manifestations of systemic lupus erythematosus (SLE). Although the presence of anti-phospholipid antibodies (aPL) is known to contribute to thromboembolism (TE), the relative contribution of other TE risk factors is unknown. The aim of this study was to determine the prevalence of TE in a Caucasian SLE population, to identify the risk factors of highest importance, and to assess the clinical value of thrombophilia screening among SLE patients. METHODS: Samples from 105 patients were analysed with a screen including aPL, activated protein C resistance, factor V Leiden (FVL) and prothrombin G20210A mutations; protein C, protein S and antithrombin activity; factor VIII (FVIII) and von Willebrand factor (vWF), and homocysteine (Hcy) levels. RESULTS: The annual incidence of arterial and venous TE events in our SLE population was 5.4 and 12.4 per 1000, respectively. The highest risk of thrombosis was carried by the simultaneous presence of lupus anticoagulant (LA) and anti-cardiolipin (aCL) [relative risk (RR) = 4.03, 95% confidence interval (CI) 2.06-7.86] or anti-beta2-glycoprotein I antibodies (abeta2-GPI) (RR = 5.10, 95% CI 2.58-10.1). Positivity for the individual aPL tests all carried an elevated TE risk. The presence of other risk factors seemed to be of less importance. CONCLUSIONS: In SLE patients, the presence of aPL is a more significant risk factor for the development of thrombosis than the known inherited deficiencies. Based on these data, routine screening for additional hereditary risk factors seems to be unwarranted.

Combination of thalidomide and cisplatin in an head and neck squamous cell carcinomas model results in an enhanced antiangiogenic activity in vitro and in vivo.

Thalidomide is an immunomodulatory, antiangiogenic drug. Although there is evidence that it might be more effective in combination with chemotherapy the exact mechanism of action is unclear. Therefore, we investigated its effect in combination with metronomically applied cisplatin in a xenotransplant mouse model characteristic for advanced head and neck squamous cell carcinomas, its possible synergistic action in vitro, and which tumor-derived factors might be targeted by thalidomide. Although thalidomide alone was ineffective, a combined treatment with low-dose cisplatin inhibited significant tumor growth, proliferation and angiogenesis in vivo as well as migration and tube formation of endothelial cells in vitro. Noteworthy, the latter effect was enhanced after coapplication of cisplatin in nontoxic doses. An inhibitory effect on tumor cell migration was also observed suggesting a direct antitumor effect. Although thalidomide alone did not influence cell proliferation, it augmented antiproliferative response after cisplatin application emphasizing the idea of a potentiated effect when both drugs are combined. Furthermore, we could show that antiangiogenic effects of thalidomide are related to tumor-cell derived factors including vascular endothelial growth factor, basic fibroblast growth factor, hepatocyte growth factor and Il-8 some known and with, granulocyte colony stimulating growth factor and granulocyte macrophage colony stimulating growth factor, some new target molecules of thalidomide. Altogether, our findings reveal new insights into thalidomide-mediated antitumor and antiangiogenic effects and its interaction with cytostatic drugs.

The analgesic effect of pamidronate is not caused by the elevation of beta endorphin level in Paget's disease--a controlled pilot study.

INTRODUCTION: Although an analgesic effect is an essential component of the mode of action of bisphosphonates, its physiological mechanisms are still unclear. Beta-endorphin release plays an important role in the analgesic effect of both calcitonin and raloxifene. As patients with Paget's disease receive large doses of bisphosphonates within relatively short time periods, we examined whether repeated pamidronate infusion therapy would cause measurable change in beta-endorphin levels MATERIALS & METHODS: Visual analog scale (VAS) scores of pain intensity, beta-endorphin levels, and alkaline phosphatase activity of 11 patients with Paget's disease (7 with the mono- and 4 with the polyostotic form) were determined at baseline, as well as after 3 and 6 infusions (on Days 6 and 12 of treatment, respectively). Eleven untreated patients with Paget's disease (7 with the mono- and 4 with the polyostotic form) served as controls. RESULTS: It was established that in the course of pamidronate infusion therapy BE levels remained constant, whereas the values in serum alkaline phosphatase and pain intensity scores were significantly reduced. CONCLUSIONS: Although high-dose pamidronate therapy does mitigate pain substantially (as demonstrated by the reduction of VAS scores), its analgesic action is probably unrelated to the enhancement of beta-endorphin release.

Lack of genetic association of the Toll-like receptor 4 (TLR4) Asp299Gly and Thr399Ile polymorphisms with spondylarthropathies in a Hungarian population.

OBJECTIVES: Bacteria have long been suggested as aetiological factors in the genetically susceptible host in spondylarthropathies, including ankylosing spondylitis (AS) and reactive arthritis (ReA). Variability of the Toll-like receptor 4 (TLR4) gene has been shown to play a role in the inflammatory response to certain bacterial infections. We investigated whether TLR4 Asp299Gly and Thr399Ile polymorphisms contribute to the genetic background of spondylarthropathies in a cohort of Hungarian patients with AS and ReA. METHODS: DNA was obtained from patients with AS (n=138), ReA (n=91) and ethnically matched healthy controls (n=140). Genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism analysis and the results were confirmed by direct sequencing. RESULTS: No significant differences in allele or genotype frequencies were observed between controls and either the AS patients or the ReA patients. Clinical characteristics of these groups were unrelated to the presence of any of these polymorphisms. CONCLUSIONS: Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms do not contribute to disease susceptibility in either AS or ReA. Functional abnormalities of the TLR4 signalling pathway suggested in spondylarthropathies seem not to be genetically determined by these two common polymorphisms.

Pathophysiologic role of oxidative stress-induced poly(ADP-ribose) polymerase-1 activation: focus on cell death and transcriptional regulation.

PARP-1 is a nuclear enzyme activated by DNA breaks. Activated PARP-1 cleaves NAD into nicotinamide and ADP-ribose and polymerizes the latter covalently coupled to nuclear acceptor proteins. Poly(ADP-ribosyl)ation has been implicated in the regulation of a diverse array of cellular processes ranging from DNA repair, chromatin organization, transcription, replication to protein degradation. On the 'dark side' of poly(ADP-ribosyl)ation, PARP-1 activation has been shown to contribute to tissue injury in shock, diabetes, myocardial or cerebral ischemia reperfusion and various forms of inflammation, as proven by pharmacological studies as well as experiments utilizing PARP-1 knockout animals. To our current knowledge, two mechanisms are responsible for the beneficial effects of PARP inhibitors in inflammatory, neurodegenerative and ischemia-reperfusion-based diseases: (i) inhibition of cell death caused by over-activation of PARP-1; (ii) inhibition of inflammatory signal transduction and production of inflammatory mediators. Here we review the possible regulatory mechanisms (e.g. calcium signaling, metabolism, density-dependent signaling, kinase cascades) of the PARP-1-mediated cell death pathway and discuss recent developments shedding new light on the complex role of PARP-1 in the regulation of the expression of inflammatory mediators.

Abnormal cell-specific expressions of certain protein kinase C isoenzymes in peripheral mononuclear cells of patients with systemic lupus erythematosus: effect of corticosteroid application.

We have studied the expressions of various protein kinase C (PKC) isoenzymes in T cells and monocytes from patients with systemic lupus erythematosus (SLE), in comparison to those of healthy controls and patients with other immunological disorders. As measured by Western blotting, the levels of PKCbeta, delta, eta, epsilon, theta and zeta (but not of PKCalpha) significantly decreased in T cells of SLE patients. In monocytes, however, we observed marked suppressions only in the expressions of PKCdelta, epsilon and zeta but not in the expressions of other PKC isoforms. In vivo corticosteroid application, as well as in vitro steroid treatment of monocytes, elevated the expressions of most isoforms close to normal values; however, the decreased levels of PKCtheta and zeta were not affected by steroid application. These alterations were characteristic to SLE because we could not detect any changes in the PKC levels in mononuclear cells of primary Sjögren's syndrome and mixed connective tissue disease patients. These results suggest that impaired PKC isoenzyme pattern may exist in the T cells and monocytes of SLE patients. Furthermore, the clinically efficient glucocorticoid application in SLE can increase the expression of some members of PKC system.

Vitamin D receptor, oestrogen receptor-alpha and calcium-sensing receptor genotypes, bone mineral density and biochemical markers in Paget's disease of bone.

OBJECTIVES: The significance of genetic polymorphisms in the development of Paget's disease of bone is unclear at present. METHODS: We analysed the BsmI polymorphism of the vitamin D receptor (VDR) gene, the PvuII and XbaI polymorphisms of the oestrogen receptor-alpha (ER alpha) gene, and the A986S polymorphism of the calcium-sensing receptor (CaSR) gene in 69 pagetic patients and 120 healthy subjects. We also examined the relationship of these polymorphisms with lumbar spine and femoral neck BMD as well as with biochemical parameters (serum alkaline phosphatase, osteocalcin and parathyroid hormone) in Paget's disease. RESULTS: The XbaI and PvuII genotype distributions of the ER alpha gene were significantly different between patients with Paget's disease and control subjects (P<0.001). Also, the CaSR A986S genotype frequency was significantly different between pagetic patients and controls (P<0.01). No significant effect of gene polymorphisms on BMD or biochemical parameters of bone turnover was observed. CONCLUSION: Our results suggest that the ER alpha PvuII/XbaI and CaSR A986S polymorphisms may contribute to genetic susceptibility to Paget's disease. However, further studies are required to investigate the underlying pathomechanism and to replicate the associations.

Effect of bisphosphonate treatment in patients with Paget's disease of the skull.

OBJECTIVES: Hearing loss has long been known to be a complication of Paget's disease of bone. The aim of this study was to investigate Paget's disease of the temporal bone with special attention to hearing loss. METHODS: Twenty-five patients with skull involvement were treated with either pamidronate or tiludronate. Imaging included radiography, quantitative bone scintigraphy (QBS), single photon emission computed tomography (SPECT) and high-resolution computed tomographic (HRCT) scanning. Audiometric assessment was also performed. RESULTS: Twenty-three of the 25 patients with skull involvement suffered from hearing loss. Bisphosphonate treatment resulted in a decreased serum total alkaline phosphatase (serum tAP) level and QBS ratio, and also seemed to improve the complaints of the patients. HRCT demonstrated involvement of the middle ear ossicles (n = 7), involvement of the petrous pyramids (n = 14), demineralization of the otic capsule (n = 10), porosis pericochlearis (n = 8), narrowing of the external auditory meatus (n = 12), mastoid process thickening (n = 5) and stapedial footplate thickening (n = 4). The audiometric examination did not show any significant changes 1 yr after bisphosphonate treatment. CONCLUSIONS: HRCT imaging is a well suited tool for demonstrating the complication of Paget's disease. QBS and measurement of serum tAP level may also be regarded as useful techniques for monitoring treatment. However, hearing may remain impaired in spite of the improved scintigraphy and laboratory parameters, therefore, audiometric assessment is also important in pagetic patients with skull involvement.

Prevalence of obesity in an elderly Hungarian population.

BACKGROUND: There are few cross-sectional population-based studies on obesity in Hungary. Aim of this study was to characterize the prevalence, associated diseases and metabolic laboratory parameters for obesity in men and women in Budapest, Hungary. METHODS: A random sample of 641 persons (307 males and 334 females) aged 50 years and over were recruited from a population register in Budapest. Subjects were interviewed, had height and weight measured in standard fashion. Those who were obese (BMI > 30.0 kg/m2) were matched individually with non-obese subjects. Altogether 101 pairs (48 women and 53 men pairs) were taking part and these subjects had blood taken for amount of serum glucose, lipids and uric acid. RESULTS: The mean age of men and women was 65.0 (SD = 9.1) years and 64.6 (SD = 8.9) years, respectively. The prevalence of obesity was 18.1% in men and 15.4% in women (p < 0.05). In both sexes the mean body mass index was higher at age of 50-64 years than at older ages [in men 27.2 (SD = 3.7) kg/m2 vs. 26.7 (SD = 3.3) kg/ m2, p = 0.286 and in women 26.7 (SD = 4.2) kg/m2 vs. 25.4 (SD = 4.0) kg/m2, p = 0.005]. Body mass index was higher in men than in women at all ages. In the case-control study the mean age of obese and non-obese individuals were 63.1 (SD = 7.8) years and 63.2 (SD = 7.9) years, respectively. Obesity was significantly associated with a history of diabetes mellitus (18 vs. 7%, p < 0.05) and hypertension (48 vs. 28%, p < 0.05). Compared to the non-obese, those who were obese had a higher level of serum uric acid (311 +/- 102 vs. 280 +/- 96 micromol/l, p < 0.05) and triglyceride (2.67 +/- 1.95 vs. 1.86 +/- 0.95 mmol/l, p < 0.05). CONCLUSION: The high prevalence of obesity both in elderly men and women and its strong association with chronic diseases causes economical and social burden for Hungary. Strategies and programs for weight maintenance as well as weight reduction must become a higher public health priority.

Termination of disease-modifying antirheumatic drugs in rheumatoid arthritis and in psoriatic arthritis. A comparative study of 270 cases.

102 rheumatoid arthritis (RA) and 104 psoriatic arthritis (PsA) patients' records were analysed according to a standardised protocol. Using Cox regression, life-table analysis and log rank test, the effectiveness and toxicity of, and duration of disease modifying antirheumatic drug (DMARD) treatment were compared in RA and PsA. RA patients were treated with gold sodium thiomalate (GST), methotrexate (MTX) and sulphasalazine (SSZ) for a median duration of 35, 72 and 12 months respectively, whereas PsA patients were treated for 12, 12 and 17 months. The differences for GST and MTX were statistically significant (p=0.0043 and 0.0447). Drug toxicity was more frequently seen among patients with PsA (p=0.0023). No difference in efficacy could be proved. Results suggest that there is a significant difference between RA and PsA patients in terms of toxicity of these agents. Therefore, separate treatment strategies are needed, and earlier results with RA may not be directly applicable to PsA.

Partial protection by poly(ADP-ribose) polymerase inhibitors from nitroxyl-induced cytotoxity in thymocytes.

Nitroxyl (NO(-)/HNO), has been proposed to be one of the NO(*)-derived cytotoxic species. Although the biological effect of nitroxyl is largely unknown, it has been reported to cause DNA breakage and cytotoxicity. We have therefore investigated whether NO(-)/HNO-induced DNA single-strand breakage activates the nuclear nick sensor enzyme poly(ADP-ribose) polymerase (PARP) and whether PARP activation affects the mode of NO(-)/HNO- induced cell death. NO(-)/HNO generated from Angeli's salt (AS, sodium trioxodinitrate) (0-300 microM) induced DNA single-strand breakage, PARP activation, and a concentration-dependent cytotoxicity in murine thymocytes. AS-induced cell death was also accompanied by decreased mitochondrial membrane potential and increased secondary superoxide production. The cytotoxicity of AS, as measured by propidium iodide uptake, was abolished by electron acceptors potassium ferricyanide, TEMPOL, the intracellular calcium chelator BAPTA-AM, and by PARP inhibitors 3-aminobenzamide (3-AB) and PJ-34. The cytoprotective effect of 3-AB was paralleled by increased output of AS-induced apoptotic parameters such as phosphatidylserine exposure, caspase activation, and DNA fragmentation. No significant increase in tyrosine nitration could be observed in AS-treated thymocytes as opposed to peroxynitrite-treated cells, indicating that tyrosine nitration is not likely to contribute to NO(-)/HNO-induced cytotoxicity. Our results demonstrate that NO(-)/HNO-induced PARP activation shifts the default apoptotic cell death toward necrosis in thymocytes. However, as total PARP inhibition resulted only in 30% cytoprotection, PARP-independent mechanisms dominate NO(-)/HNO-induced cytotoxicity in thymocytes.

The effect of heat-inactivated Helicobacter pylori on the blastogenic response of peripheral blood mononuclear cells of patients with chronic urticaria.

BACKGROUND: Helicobacter pylori, the most important etiologic factor of gastritis and peptic ulcer, has recently been associated with several extradigestive diseases. Previous studies reported conflicting results on H. pylori eradication in chronic urticaria, in that some studies showed a benefit, while others found no effect. METHODS: Peripheral blood mononuclear cells of 24 chronic urticaria patients (13 seropositive/11 seronegative for H. pylori) and 18 healthy controls (9 seropositive/9 seronegative) were stimulated with whole heat-inactivated H. pylori (8 x 10(5), 8 x 10(6 )and 8 x 10(7) bacteria/well), phytohemagglutinin (2 microg/ml) and pokeweed mitogen (5 microg/ml). The proliferative response was determined by (3)H-thymidine incorporation. Helicobacter-specific IgG antibody response was determined by ELISA. RESULTS: There were significantly higher proliferative responses to various concentrations of whole heat-inactivated H. pylori antigen in 6- to 7-day cultures of peripheral blood mononuclear cells of chronic urticaria patients compared to healthy controls. We found a tendency to exhibit a higher proliferative response to either Helicobacter antigens or mitogens in seropositive compared to seronegative patients. CONCLUSION: Our results support the hypothesis that there is an increased lymphocyte reactivity in chronic urticaria, perhaps further enhanced by the presence of H. pylori which, therefore, may be involved as a trigger in the pathogenesis of chronic urticaria.