Serum and tissue angiotensin-converting enzyme in patients with alopecia areata.

BACKGROUND: Alopecia areata is an immune-dependent disorder characterized by the interaction of T-lymphocytes with follicular antigens. Recent studies have shown the existence of a local renin-angiotensin system in the skin, where angiotensin-converting enzyme (ACE) plays a role in autoimmunity and inflammation. AIM: The objective of this study was to evaluate serum and tissue ACE activity in patients with alopecia areata. METHODS: This case-control study was conducted on patients with alopecia areata and healthy controls. Serum and tissue ACE activity were assessed and compared between the two groups. RESULTS: Twenty-five alopecia areata patients (60% male, mean age 32.1 ± 9.9 years) and 24 controls (50% male, mean age 37.4 ± 8.8 years) were included. Mean serum ACE activity was 52.1 ± 9 U/L in cases and 55.3 ± 14.7 U/L in controls (P = 0.37). Tissue ACE activity was significantly lower in cases in all parts of the skin i.e. epidermis (P = 0.016), follicular epithelium (P = 0.004), and endothelium (P = 0.037). Among cases, serum ACE activity was significantly higher in patients with more severe disease (P = 0.030), nonpatchy alopecia areata (alopecia universalis; ophiasis, patchy and ophiasis, diffuse) (P = 0.029), and with nail involvement (P = 0.027). LIMITATIONS: The sample size was too small to draw definite conclusions. Further, most of the patients had only mild or moderate alopecia areata. CONCLUSION: Unlike in some other inflammatory diseases, the tissue level of ACE seems to be significantly lower in alopecia areata compared to normal controls. Serum ACE was significantly higher in patients with more severe disease.

Is there a correlation of serum and tissue T helper-1 and -2 cytokine profiles with psoriasis activity and severity? A cross-sectional study.

BACKGROUND: Previous studies correlating Th1 and Th2 cytokine profiles with psoriasis activity provided inconsistent results. Correlation of tissue cytokine levels with psoriasis severity has not been studied till now. OBJECTIVE: To compare serum and tissue Th1 and Th2 cytokine profiles of patients with active and stable psoriasis as well as healthy controls, and to correlate them with psoriasis severity. METHODOLOGY: This was a cross-sectional study involving adult patients with 'active' psoriasis (untreated progressive chronic plaque psoriasis, guttate psoriasis, and erythrodermic psoriasis), 'stable' psoriasis (stable plaque psoriasis or those with completely resolved lesions) and healthy subjects with non-inflammatory skin lesions as controls. Mean levels of Th1 and Th2 cytokines in serum [interleukin 2 (IL-2), interferon-gamma (IFN-γ), IL-4, IL-10] and tissue mRNA expression (IFN-γ, IL-4) were compared among these three groups. RESULTS: There were 30 patients each in active and stable psoriasis groups, and 15 in the control group. Mean serum IL-2, IFN-γ, and IL-10 levels of patients with psoriasis patients were significantly higher than the controls (P < 0.001 for both active and stable psoriasis), whereas mean serum IL-4 level of patients was significantly lower than the controls (P < 0.001). However, there was no statistically significant difference of serum cytokine levels between active and stable psoriasis groups. Mean quantitative tissue mRNA expression of IFN-γ and IL-4 of patients with active and stable psoriasis were significantly lower than the controls (P < 0.001 and <0.01, respectively), but were not significantly different between active and stable psoriasis groups. Serum and tissue cytokines showed weak correlation with psoriasis area and severity index. LIMITATIONS: Small sample size and heterogenous nature of patients with psoriasis in terms of disease activity, morphology and treatment are limitations of this study. CONCLUSIONS: There is no significant change in the serum or tissue levels of Th1 and Th2 cytokines with activity or severity of psoriasis.

Chiral inversion of drugs: coincidence or principle?

2-arylpropionic acid derivatives are probably the most frequently cited drugs exhibiting the phenomenon that is best known as chiral inversion. One enantiomer of drug is converted into its antipode either in the presence of a solvent or more often in inner environment of an organism. Mechanistic studies of the metabolic chiral inversion were carried out for several drugs from NSAIDs, and a model of this inversion was suggested and subsequently confirmed. The chiral inversion of NSAIDs has been intensively studied in the context of the pharmacological and toxicological consequences. However, the group of NSAIDs is not the sole group of drugs in which the inversion phenomenon can be observed. There exist several other drugs that also display chiral inversion of one or even both of their enantiomers. These drugs belong to different pharmacotherapeutic groups as monoamine oxidase inhibitors, antiepileptic drugs, drugs used in the treatment of hyperlipoproteinemia or drugs that are effective in the treatment of leprosy. Moreover, some chiral or prochiral drugs are metabolized to give chiral metabolites that undergo chiral inversion too, which can have direct impact on pharmacological properties or toxicity of the drug. As the process of chiral inversion is affected by several factors, so the intensity of chiral inversion of individual substances and at different conditions can differ considerably. Interspecies differences and types of tissue are reported to be the main factors that were recognized to play the key role in the process of chiral inversion. Some of more recent studies have revealed that several other factors, such as the route of administration or interaction with other xenobiotics, can influence the enantiomeric conversion, too. Chiral inversion does not seem to be a phenomenon connected with only several drugs from some unique group of 2-arylpropionic acid derivatives: it is also observed in drugs with rather different chemical structures and is much more frequent than it can be realized.