Estimation of tissue and serum lipocalin-2 in psoriasis vulgaris and its relation to metabolic syndrome

Abstract

Adipose tissue is now considered an endocrine organ secreting different cytokines known as adipocytokines. Lipocalin-2 has been recently identified as an adipokine present in the circulation, it is related to insulin resistance, obesity, atherosclerotic diseases and type 2 diabetes. Lipocalin-2 and psoriasis are assumed to be closely associated with the metabolic syndrome. The aim of the present study is to estimate the level of lipocalin-2 in the serum and tissue of psoriatic patients and to correlate these levels with markers of metabolic syndrome, CRP and disease severity. This study was done on 30 patients of psoriasis and 30 healthy controls. All patients and controls were subjected to clinical examination. Serum, tissue levels of lipocalin-2 and C-reactive protein (CRP) were measured by enzyme linked immunosorbent assay technique. Metabolic syndrome parameters including anthropometric measures, lipid profiles, blood sugar and blood pressure were studied. Patients with psoriasis showed significant association with metabolic syndrome parameters than controls. Tissue lipocalin-2 was significantly higher than serum levels in psoriasis patients. A significant difference was detected in tissue levels of lipocalin-2 and not in the serum between patients and controls. Both tissue and serum lipocalin-2 correlated with CRP. Although there was a correlation between tissue and serum levels of lipocalin-2 in patients, there was no correlation between both of them with metabolic syndrome and related disorders. Our results revealed that patients with psoriasis are at increased risk of metabolic and cardiovascular complications, tissue lipocalin-2 is more specific to psoriasis than serum lipocalin-2. Lipocalin-2 has no role in determining severity of the disease. Neither tissue nor serum lipocalin-2 conveys cardiovascular risk in psoriasis patients.

Effect of psoriasis activity and topical treatment on serum lipocalin-2 levels

“…Our findings are in contrary to the study of Kamata et al who found significant negative correlation with LDL-C in psoriatic patients (20). El-Hadidi et al has shown no associations between lipocalin-2 levels and all lipid parameters including LDL-C, HDL-C (high-density lipoprotein-cholesterol), TG (triglycerides) and cholesterol (13). On the other hand, Jang et al and Wang et al found a significant positive correlation between LCN2 concentrations and BMI or hipertriglycerydemia, but in patients with metabolic syndrome (23,24).…”

“…As for the correlation between adipocyte-secreted lipocalin-2 and indicators for obesity and metabolic syndrome, we found no significance between LCN2 serum levels and BMI in patients with psoriasis. Our findings were the same as in papers of Kamata et al and Ataseven et al but in contrary to the study of El-Hadidi et al (13,20,24). Stejskal et al also did not report any correlation between lipocalin-2 and BMI in subject with metabolic syndrome (22).…”

“…These three studies' results as well as ours have shown elevated concentrations of lipocalin-2 compared to controls. However, El-Hadidi et al did not observe any statistical difference in serum LCN2 levels between study group and controls (13). They noted significantly higher tissue lipocalin-2 levels emphasizing its higher specificity to psoriasis than serum LCN2 levels.…”

“…Lipocalin-2 (LCN2), also known as neutrophil gelatinase-associated lipocalin (NGAL), is a 25 kDa protein built of 178 amino acids and was isolated from human neutrofils in the early 90's (12). It is expressed in liver, lungs, kidneys, stomach, colon and adipocytes, macrophages or epithelial cells (13,14). LCN2 plays a key role in the innate immune response by its bacteriostatic effect through binding to iron-laden bacterial siderophores and thereby inhibiting their proliferation (15).…”

Altered Systemic Adipokines in Patients with Chronic Urticaria

“…Psoriasis itself might act as an inflammatory stimulus to induce LCN2 production in neutrophils [28] . Also, histamine was found to upregulate the expression of LCN2 in a human breast cancer cell line [29] .…”