Expression of toll-like receptor 2 on peripheral blood monocytes of patients with inflammatory and noninflammatory acne vulgaris

The pathogenesis of acne vulgaris is multifactorial and entails the interplay of hormonal, microbial and immunological events. The bacterium Propionibacterium acnes is involved in the induction of comedogenesis and maintenance of the inflammatory phase of acne. Toll-like Receptor 2 (TLR2) expressed on mononuclear inflammatory cells and possibly on keratinocytes and sebocytes is thought to be of vital importance in mediating P. acnes-induced inflammatory response in acne vulgaris. This work aimed to study the degree of expression of TLR2 on peripheral blood monocytes (PBM) from patients with non-inflammatory and inflammatory acne and to investigate the influence of systemic isotretinoin therapy on TLR2 expression. Sixteen patients with predominantly non-inflammatory acne, 16 patients with predominantly inflammatory acne and 16 age and sex matched healthy subjects were involved in this study. Cell surface expression of CD14 and TLR2 were determined by cell surface staining and flowcytometry. TLR2 expression was analyzed for 12 patients with severe and/or scaring inflammatory acne after oral isotretinoin therapy for two months. The mean fluorescence intensity (MFI) of TLR2 on PBM reported a statistically significant difference between patients with non-inflammatory acne, patients with inflammatory acne and control subjects. MFI of TLR was significantly lower for patients with inflammatory acne after systemic isotretinoin therapy. Data obtained suggest that TLR2 expression on PBM is an important event in acne pathogenesis and targeting this molecule might be a useful therapeutic goal in the future.

Diminished CD4+CD25+ T-lymphocytes in peripheral blood of patients with systemic lupus erythematosus

The exact aetio-pathogenesis of systemic lupus erythematosus (SLE) is still speculative, where dysregulation or depletion of CD4+CD25+ T lymphocytes is among the supposed mechanisms. In this study, we thought to investigate patients with SLE for percentages of CD4+CD25+ T cells in their peripheral blood and to correlate this with their disease activity scores. Twenty-five patients with SLE who fulfilled, at least, four of the revised Criteria of the American College of Rheumatology (ACR) and twenty healthy volunteers participated in this study. Activity of SLE was assessed by SLE disease activity index (SLEDAI) score. Percentages of CD4+CD25+ T-cells were determined by a flowcytometric technique, while recently activated T-cells were analysed by assaying the expression of the T-cell activation marker, CD69. A statistically significant (p = 0.003) reduction of percentage of CD4+CD25+ T cells was observed among patients (mean 7.16+/-4.53 %) when compared with control subjects (mean 11.36+/-4.50 %), while a non-significant (p = 0.475) low expression of CD69 on CD4+ T cells was observed between patients (mean 0.32+/-0.28 %) and control subjects (mean 0.32+/-0.38 %). In addition, no correlation could be detected between percentages of CD4+CD25+ T cells and SLEDAI scores among SLE patients (p=0.079). In conclusion, this study adds some evidence for the role of CD4+CD25+ T cells in the pathogenesis of SLE that may have some future therapeutic applications.

Increased circulating FcepsilonRII-bearing B-lymphocytes and serum levels of IL-4 in non-autoreactive chronic idiopathic urticaria

The exact pathophysiology of chronic idiopathic urticaria (CIU) is not well understood. The concept of autoreactivity has evolved to explain the disease in up to 50% of cases, while the search for other mechanisms is still needed to explain the disease, at least among the remaining subpopulation of non-autoreactive CIU. Therefore, we thought to investigate some aspects of the IgE-dependent, lymphocyte-mediated late-phase response (LPR) of anaphylaxis. We searched for percentages of FcepsilonRII-bearing (CD23+) B and T lymphocytes and correlated this with total IgE serum levels, IL-4 serum levels and the disease severity scores. Twenty-five patients with non-autoreactive CIU and ten healthy control subjects participated in this study. CD23+ B- and T-cells were assessed by flow cytometry, total IgE serum levels were estimated by enzyme linked fluorescent assay (ELFA), IL-4 serum levels were estimated by Enzyme Amplified Sensitivity Immunoassay (EASIA), while disease severity was determined by a daily self-assessment urticaria activity and itching score. Our results showed that the mean values for percentages of CD23+ B-cells (6.7 +/- 2.3%), total IgE serum levels (139.6 +/- 103.9 microg/dl) and IL-4 serum levels (18.3 +/- 14.7 ng/ml) for patients were statistically significant (p = 0.002, 0.013 and 0.008, respectively), when compared with the corresponding values for controls (4.0 +/- 1.7%, 51.5 +/- 25.1 microg/dl, and 5.1 +/- 4.1 ng/ml, respectively), while the difference between the mean percentage of CD23+ T-cells for patients (2.8 +/- 2%) and that for controls (2.1 +/- 0.6%) was non-significant (p = 0.267). Strong positive correlations were detected between percentages of CD23+ B-cells and severity scores (r = 0.678, p = 0.0001), total IgE serum levels (r = 0.756, p = 0.0001) and IL-4 serum levels (r = 0.709, p = 0.0001), while no correlation was detected between CD23+ B-cells and CD23+ T-cells (r= 0.188, p= 0.368). It is concluded, that CD23+ B-cells, regulated by IL-4, may contribute in the pathogenesis of non-autoreactive CIU, by producing high levels of IgE and possibly lymphokines, while CD23+ T-cells may be involved in early antigen recognition. This may have a future therapeutic ramification in this distinct subset of CIU by targeting low-affinity IgE receptors.

Induction of lipocortin 1 by topical steroid in rat skin

Western blotting and densitometric analysis of extracts obtained from EDTA extraction of skin segments showed greater extracellular Lipocortin 1 (LC1) in skin sites from steroid-treated animals compared to that seen in matched vehicle treated animals. Extracellular LC1 was maximal 3 hr after steroid, less was found in skin after 6 hr and levels had returned to basal at 18 hr. Pre-treatment of rats with the glucocorticoid receptor antagonist RU38486 (20 mg/kg) prevented the steroid induction of extracellular LC1 at both the 3 and 6 hr time-points. Systemic treatment of rats with betamethasone sodium phosphate (0.1-1 mg/kg) showed that the induction of LC1 on the cell surface was both time- and dose-dependent. Oedema in rat skin caused by 5-hydroxytryptamine (5-HT), platelet activating factor (PAF) and zymosan activated serum (ZAS) was assessed using 125I-labelled human serum albumin. Following a 3 hr topical treatment with betamethasone-17-valerate the inflammatory activities of all of the tested stimuli were significantly attenuated demonstrating that at this time-point the topical steroid was biologically active. Topical steroid treatment of the skin resulted in a translocation of LC1 to the cell surface, which was maximal after a 3 hr period and was also temporally associated with the anti-inflammatory effect of these agents.