Rubeosis faciei diabeticorum is not associated with oxidative stress and skin autofluorescence

Abstract Background Rubeosis faciei diabeticorum is a persistent facial erythema in patients with diabetes mellitus. The actual pathogenesis has not been studied. However, it is speculated to be a cutaneous diabetic microangiopathy. Objective Examine the correlation between the severity of facial erythema and the possible causes of microvascular diabetic complications, namely oxidative stress, hyperglycemia, and cutaneous accumulation of advanced glycation end-products . Methods Patients diagnosed with Type 2 diabetes mellitus (n = 32) were enrolled in the study. The facial erythema index was measured using the Mexameter MX18; cutaneous accumulation of advanced glycation end-products was estimated by measuring skin auto fluorescence with the AGE Reader (DiagnOptics Technologies B.V. - Groningen, Netherlands). Glycated haemoglobin, total antioxidant status, and malondialdehyde were measured in blood by TBARS assay. The correlation between the selected variables was assessed by Spearman's rank test; p ≤ 0.05 was considered statistically significant. Results There was a statistically significant correlation between total antioxidant status and the facial erythema index (ρ = 0.398, p = 0.024). Malondialdehyde, skin autofluorescence, glycated haemoglobin, body mass index, duration of diabetes, and age did not demonstrate statistically significant correlation with the facial erythema index. Study limitations This is an observational study. Elevation of total antioxidant status could have been caused by several factors that might have also influenced the development of rubeosis faciei, including hyperbilirubinemia and hyperuricemia. Conclusions The results contradicted expectations. Total antioxidant status correlated positively with facial erythema index; however, there was no correlation with oxidative stress and skin autofluorescence. Further investigations should be conducted to reveal the cause of total antioxidant status elevation in patients with rubeosis faciei.

Local antimicrobial, protease and cytokine defense systems in psoriatic skin.

Background: Psoriasis vulgaris is an infl ammatory skin condition characterized by dramatic biochemical and immunological changes. Aims: The aim of the study was to evaluate antimicrobial response, tissue degeneration reactions and distribution of infl ammatory cytokines in untreated psoriatic skin as well as the correlations between these factors and infl uence on the course of the disease. Methods: We evaluated skin samples obtained from routine punch biopsies in 40 patients with psoriasis vulgaris. All tissue specimens were examined by hematoxylin and eosin staining and immunohistochemistry for human beta defensin 2 (HBD-2), matrix metalloproteinase 2 (MMP-2), tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6) and IL-8. The staining intensity was semi-quantitatively graded. Results: Numerous keratinocytes, fibroblasts and macrophages expressed HBD-2 while the number of MMP-2-positive macrophages, fi broblasts and epitheliocytes varied. TNF-alpha-positive cells varied from a few to numerous in each microscopic fi eld. IL-6-positive cells varied from a few to abundant and IL-8-positive cells from numerous to abundant in each fi eld. Limitations: This study had a rather small patient number. Conclusions: Psoriatic skin shows a strong correlative increase in skin antimicrobial proteins and enzymes mediating tissue degeneration suggesting that the skin maintains compensatory mechanisms during persistent remodeling. While individual notable decrease in antimicrobial proteins was observed in some tissue samples, generally the increased human beta defensin associated with psoriasis is likely to be due to an altered immune status. TNF-alpha, IL-6 and IL-8 are common cytokines expressed in psoriatic skin plaques to maintain the infl ammatory cycle. HBD-2, MMP-2 and TNF-alpha positively correlate with the severity of psoriasis. Meanwhile, the expression of IL-8 signifi cantly decreases with clinically more severe psoriasis, perhaps making these factors candidate prognostic factors for psoriatic inflammation.

The Distribution of Matrix Metalloproteinase-2, Tissue Inhibitor of Metalloproteinase-2 and Tissue Inhibitor of Metalloproteinase-4 in Psoriatic Skin.

Aims: To evaluate the appearance and distribution of matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2) and tissue inhibitor of metalloproteinase-4 (TIMP-4) in lesional skin biopsies of psoriasis patients. Study Design: Observational study. Place and Duration of Study: Institute of Anatomy and Anthropology and Department of Infectology and Dermatology, Rīga Stradiņš University, between September 2013 and June 2014. Methodology: We included 40 patients (31 men, 9 women; age range 18-70 years) with Psoriasis vulgaris, with present characteristic psoriatic eruptions in typical localization sites and no treatment received. Skin samples were obtained using routine punch biopsy method. 10 clinically healthy skin samples obtained during nevus excision procedure were used as control material. All tissue specimens were stained with hematoxylin and eosin and by immunohistochemistry for MMP- 2, TIMP-2 and TIMP-4. The intensity of staining was graded semiquantitatively. Spearman’s rank correlation coefficient was calculated. Results: In psoriasis patients numerous MMP-2-containing keratinocytes were found in epidermis, MMP-2 positive dermal fibroblasts and inflammatory cells varied from few to abundant. Few epidermal cells and moderate to numerous dermal cells contained TIMP-2. Moderate to numerous epidermal and dermal cells contained TIMP-4. Statistically significant strong positive correlation was found between MMP-2 in epidermis and dermis (Spearman’s rank correlation coefficient = .878, P = .000). Statistically significant moderate positive correlation was found between TIMP-2 and TIMP-4 in dermis (Spearman’s rank correlation coefficient = .639, P = .000) and between TIMP-2 in epidermis and dermis (Spearman’s rank correlation coefficient = .564, P = .000). Conclusion: TIMP-4 seems to be most important inhibitor of psoriatic skin degeneration, richly raised by MMP-2. Its moderate correlation with TIMP-2 proves involvement of other tissue inhibitors in the degeneration inhibition and gives evidence about possible patterning between the tissue inhibitors of metalloproteinases.