Is there still a place for neutrophil gelatinase-associated lipocalin to serve as a biomarker in psoriasis?

INTRODUCTION: Neutrophil gelatinase-associated lipocalin (NGAL) is believed to be involved in the pathogenesis of psoriasis, and its serum level was previously found to decline after administration of biologics, UV, and cyclosporine therapy. AIM: To investigate whether NGAL may serve as a biomarker of disease activity in psoriasis vulgaris. MATERIAL AND METHODS: To measure the level of NGAL in serum, 36 patients with psoriasis vulgaris and 33 healthy controls were enrolled. Measurements were correlated to patients' and disease characteristics, including the Psoriasis Activity and Severity Index (PASI), Body Surface Area (BSA), itch and its intensity measured with the Peak Pruritus Numerical Rating Scale (PP-NRS), and involvement of special regions (scalp, genitals, hands, nails). RESULTS: A significantly higher level of NGAL in serum was found in patients with psoriasis than in healthy controls. It showed a moderate correlation with PASI but none with BSA. The genital involvement was associated with significantly greater serum level of NGAL. Itch corresponded to higher concentration of NGAL, and PP-NRS corelated moderately with the level of circulating NGAL. CONCLUSIONS: An elevated level of circulating NGAL indicates its participation in the pathogenesis of psoriasis and the development of the itch. The serum level of NGAL does not allow for the evaluation of disease severity because it shows only moderate correlation with PASI. Determination of the circulating NGAL level may help to identify patients with greater risk for involvement of the genital region.