Serum Levels of Interleukin-6 in Patients with Cutaneous Polyarteritis Nodosa

Abstract

ulcerations. Cutaneous nodules (100.0%) were the most common skin manifestations and were observed in all of our patients with CPN. Forty (88.9%) of the patients with CPN had livedo racemosa, and 33 (73.3%) had purpuric lesions on their lower extremities. Twenty-seven (60.0%) of the patients with CPN were positive for serum CRP, and LAC activity was observed in 27 of them (60.0%). Nineteen (42.2%) of the patients with CPN had elevated serum IL-6 levels and 29 (66.4%) had elevated serum IL-8 levels, while only 4 (8.9%) had elevated serum TNF-α levels. Seven (15.6%) were positive for serum IgG anti-PS/PT antibody, 33 (73.3%) for IgM anti-PS/ PT antibody, and 6 (13.3%) for IgG aCL antibody. DIF studies were performed on skin biopsy samples from 29 of the patients with CPN, and revealed complement 3 expression within affected vessels of the lesions in 21 (72.4%) of them. In addition, 18 (62.1%) of those 29 patients with CPN showed IgM deposition within affected vessels. Thirty-four (75.6%) of the patients with CPN were treated with warfarin, and prednisolone therapy was administered to 27 (60.0%) of them. We divided the 45 patients with CPN into two groups; the elevated IL-6 group and the normal IL-6 group (Table I). The number of men in the elevated IL-6 group was significantly higher than in the normal IL-6 group. Patients with elevated IL-6 had a significantly higher frequency of arthralgia compared with patients without elevated IL-6. Skin ulcerations were also significantly more prevalent among patients with elevated IL-6 compared with patients without elevated IL-6. Elevated IL-6 patients had significantly higher CRP serum levels than normal IL-6 patients. LAC in the elevated IL-6 group was significantly more prevalent than in the normal IL-6 group. Serum IgG anti-PS/PT antibody levels differed significantly between the elevated IL-6 group and the normal IL-6 group. Similarly, serum IgG aCL antibody levels were significantly higher in the elevated IL-6 group compared with the normal IL-6 group. In contrast, IgM anti-PS/PT antibody levels in patients with CPN with elevated IL-6 were significantly lower than in normal IL-6 level patients with CPN. The selected prevalence of prednisolone in the elevated IL-6 group was significantly higher than in the normal IL-6 level group.