Factors affecting the concentration of soluble tumour necrosis factor-α receptor type I in the blood serum of patients with localized scleroderma

Introduction
The aim of the study was to assess of sTNFαR1 concentration in the serum of patients with localized scleroderma (in comparison with a control group).

Material and methods
This was a prospective study. The patients with localized scleroderma were divided into two groups: 21 persons treated with PUVA therapy and 20 persons treated with procaine penicillin. In the case of the patients treated with intramuscularly administered procaine penicillin (dose: 2,400,000 IU/day), achievement of a total dose of at least 30 million IU/day was considered as the end of the therapy. In the group of patients treated with photochemotherapy, the single initial dose during a PUVA session was 0.5 J/cm2 and it was increased by 0.5 J/cm2 every other day to reach the maximum value of 10 J/cm2 , depending on the clinical condition. The study involved three sessions a week.

Results
sTNFαR1 concentration in the serum of patients with localized scleroderma was significantly higher in comparison with the control group and correlated with the skin damage index. The difference in the determined particle level was higher in the group of patients undergoing photochemotherapy (median: 106.25 ng/ml) than in the group taking penicillin (median: 81.50 ng/ml). Patients treated with PUVA sessions demonstrated a greater decrease in sTNFαR1 concentration and an improvement of the clinical condition after therapy completion.

Conclusions
The obtained results suggest a potential role of sTNFαR1 in the pathogenesis of localized scleroderma