Assessment of Interleukin 16 Serum Levels and Skin Expression in Psoriasis Patients in Correlation with Clinical Severity of the Disease

Abstract

Interleukin 16 (IL-16) has been described as a significant cytokine involved in the recruitment of CD4+ cells during inflammation; however, its potential role in psoriasis has not been defined. Our aim was to investigate the IL-16 serum levels and IL-16 mRNA skin expression in psoriasis patients in correlation with disease severity and mRNA skin expression for CD4. Moreover, the IL-16 skin localization was assessed and the -295 T/C IL-16 polymorphism was analyzed. For this exploratory, observational, and cross-sectional study, 97 unrelated patients with chronic plaque type psoriasis and 104 healthy controls were enrolled. IL-16 serum levels were significantly increased in patients compared with controls (P = 0.000022) and positively correlated with Psoriasis Area and Severity Index (r = 0.34, P = 0.0007), Body Surface Area (r = 0.34, P = 0.01) and were significantly higher in individuals with moderate to severe psoriasis (P = 0.0029). There was no significant correlation between IL-16 serum levels and Dermatology Quality of Life Index and no differences in genotype and allele frequencies for -295 T/C IL-16 polymorphism. The expression of IL-16 (mRNA and protein) was elevated in the margin of psoriatic skin while statistically significant increase in IL-16 immunoreactivity, but not in mRNA level, was observed within plaques. Furthermore, the IL-16 mRNA levels within psoriatic lesions positively correlated with the levels of CD4 mRNA, but not with Psoriasis Area and Severity Index. In conclusion, our data revealed an association between circulating IL-16 and severity of psoriasis which indicates that this cytokine could serve as a potential marker of disease activity. However, further investigations are required.

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Is There a Link between Basal Metabolic Rate, Spleen Volume and Hepatic Growth Factor Levels in Patients with Obesity-Related NAFLD?

“…Trying to explain the causal role of IL-16 in predicting BMR by HGF levels, we draw the attention on pathological conditions having overlapping mechanisms with NAFLD. Authors found that IL-16 levels significantly correlate to the disease activity of psoriasis, the duration of which is associated to spleen volume [45,46]. IL-16 might play an important role in the inflammatory process of patients suffering from acute myocardial infarction and correlates with inflammatory cell activation [47].…”

Anti-interleukin and interleukin therapies for psoriasis: current evidence and clinical usefulness

“…This study also showed increased expression of IL-16 mRNA within psoriasis lesions was associated with elevated amount of CD4+ cells. 121 Interleukin-18 IL-18 is one of the cytokines which belong to the IL-1 family. IL-18 expression is increased in keratinocytes from lesional skin, and significantly decreased after treatment.…”

“…This study also showed increased expression of IL-16 mRNA within psoriasis lesions was associated with elevated amount of CD4+ cells. 121…”