Serum level of adiponectin increases and those of leptin and resistin decrease following the treatment of psoriasis

Dear Editor, Serum level of adiponectin is increased in rheumatoid arthritis (RA) and inflammatory bowel disease during infliximab treatment. In the present study, we examined the serum levels of adipokines during various treatments of psoriasis. Psoriatic severity was determined by Psoriasis Area and Severity Index (PASI) score. A total of 37 plaque-type psoriasis patients, including 25 men and 12 women aged 35–71 years (mean age, 46.3), with PASI scores ranging 12.3–22.3 (mean 14.5) and body surface area of 9–45 (mean, 14.3) were enrolled. The patients were treated with infliximab, adalimumab, ustekinumab and narrowband ultraviolet B (NB-UVB) irradiation in addition to topical glucocorticoids or active vitamin D3 treatment. Signed informed consent was taken from all the patients and controls according to the guideline of the Asahikawa Medical School Ethics Committee. Serum levels of adiponectin, leptin and resistin were measured by enzymelinked immunosorbent assay kits (R&D System, Oxon, UK). The serum levels of cytokines were presented as an arithmetic mean standard deviation. Mann–Whitney U-test was used for statistical analysis. A total of 37 psoriatic patients were treated with infliximab (seven cases), adalimumab (10 cases), ustekinumab (seven cases) and NB-UVB (13 cases). All treatments significantly decreased PASI scores (Table 1). There was no significant difference in patients’ body mass index between before (26.2 2.5) and after the treatments (26.3 3.3). At 12 weeks, serum levels of adiponectin, leptin and resistin were not significantly different compared with the pretreatment levels. At 24 week, however, serum levels of adiponectin were significantly increased in all the treatment groups (Table 1). In contrast, serum levels of leptin and resistin were significantly decreased in the treatment groups at 24 weeks (Table 1). There was no significant difference in serum levels of adiponectin, leptin and resistin among the psoriasis treatments groups at 0, 12 and 24 weeks (Table 1). Although serum levels of adiponectin and leptin were not affected at 12 weeks, significant improvements were observed at 24 weeks. Shibata et al. showed increased serum levels of adiponectin in psoriatic patients at 8 weeks following antitumor necrosis factor (TNF)-a treatment. In their study, the patients responded well to the treatment and the PASI clearance rate at 8 weeks was 72%. In contrast, the PASI clearance rate of our patients at 12 weeks was 53% and that at 24 weeks was 74%, which is close to the value of Shibata et al. at 8 weeks. In contrast, Peters et al. showed lack of the effect of onercept, an antibody against human soluble p55 TNF receptor on the serum levels of adiponectin in psoriatic arthritis patients despite the significant improvement of 28-item Disease Activity Index score. The difference in the treatment target and clinical type of psoriasis may explain the difference in adiponectin serum levels. The present study demonstrated that serum levels of adipokines alter during ustekinumab and NB-UVB irradiation treatments. Previously, we reported that serum levels of adiponectin are inversely related with serum TNF-a levels in psoriatic patients, which is compatible with the present results. Because adiponectin does not directly bind with anti-