Tissue lipocalin-2 in psoriasis: is it a marker of metabolic disturbance or a possible marker of therapeutic efficacy after narrow band ultraviolet B? 
Lipocalin-2 (LCN2) is an adipokine related to insulin resistance and metabolic syndrome (MetS) in addition to its role in innate immunity and apoptosis.  To estimate LCN2 tissue levels (lesional and non-lesional) in psoriasis.  To assess the metabolic status of patients and to detect any possible associations between LCN2 and MetS. To evaluate the effect of narrow-band ultraviolet B (NBUVB) on tissue LCN2 in psoriasis.  This case-control study was conducted on 25 psoriatic patients and 25 healthy controls.  Dyslipidemia and MetS have been evaluated.  Tissue LCN2 was estimated using ELISA technique before and after treatment with NBUVB.  Tissue LCN2 was significantly higher in psoriasis, with no significant difference as regards dyslipidemia or metabolic disturbance in these patients.  Both lesional and non-lesional LCN2 and PASI score dropped significantly after NBUVB.  No significant correlations have been detected between tissue LCN2 and disease extent or PASI score.  Significant positive correlations were detected regarding tissue LCN2 levels between lesional and non-lesional samples before and after treatment.  Psoriatic patients were at higher risk of metabolic disorders.  LCN2 was not related to metabolic disturbances in our patients.  NBUVB might exert its therapeutic effect in psoriasis through reduction of tissue LCN2.