Soluble tumour necrosis factor-alpha receptor type 1 as a biomarker of response to phototherapy in patients with psoriasis.
Mots clés
Abstrait
The purpose of the study was to analyze the relationship between the serum concentration of soluble tumour necrosis factor-alpha type 1 (sTNF-R1), the severity of plaque-type psoriasis and therapeutic response. We compared sTNF-R1 in 25 patients treated with narrowband ultraviolet B (NB-UVB) radiation and 25 patients treated with systemic photochemotherapy (psoralen plus UVA-PUVA). The pretreatment Psoriasis Area and Severity Index (PASI) score and sTNF-R1 concentration were 16.32+/-5.26 and 1.99+/-0.40 ng ml(-1), respectively, in the group treated with NB-UVB, and 17.22+/-3.48 and 2.07+/-0.31 ng ml(-1), respectively, in the group treated with PUVA. The concentration of sTNF-R1 in healthy controls was 1.49+/-0.34 ng ml(-1) (p<0.05 compared with patients with psoriasis). The pretreatment PASI score correlated with sTNF-R1 in both treatment groups (r=0.46 and r=0.44, p<0.05). NB-UVB and PUVA gave similar therapeutic effects (the PASI score after 20 treatments was 4.42+/-1.67 in the NB-UVB-treated group and 5.55+/-2.10 in PUVA-treated patients); however, the sTNF-R1 concentration at the same time differed significantly: 1.52+/-0.37 ng ml(-1) and 1.98+/-0.39 ng ml(-1) (p<0.001), respectively. Moreover, the decline in sTNF-R1 in both treatment groups was significant only in patients in whom the duration of skin lesions was less than 3 months. The results suggest that the value of serum sTNF-R1 concentration as a marker of response to phototherapy may depend on duration of skin lesions and the treatment method.