Photochemotherapy for systemic sclerosis: effect on clinical and molecular markers

The cutaneous changes seen in systemic sclerosis (SSc) can result in considerable patient morbidity.

We previously reported on the beneficial effect of psoralen ultraviolet A (PUVA) phototherapy in 13 patients with morphoea. We now report the findings of a study in which patients with SSc were treated with PUVA.

Twelve patients with SSc were treated with PUVA phototherapy. The effect on cutaneous disease activity was assessed using the modified Rodnan score, and the effect on serological and immunohistochemical growth factors and adhesion molecules was also measured.

The median Rodnan score at baseline was 24.5 [interquartile range (IQR) 18.5-26.0]. The median number of treatments with PUVA was 24 exposures (IQR 20-26) with a median cumulative exposure of 68.3 J/cm(2) (IQR 28.6-139.8). Of the 12 patients, 11 responded well to phototherapy with a mean change in Rodnan score of 6.58 (36.98%) (P < 0.01, Wilcoxon signed ranks test). After treatment with PUVA there was a significant increase in circulating tumour necrosis factor-alpha levels in 8/12 patients (P = 0.03). In 7/12 patients there was an increase in E-selectin and vascular cell adhesion molecule, although this was not significant.

PUVA treatment is associated with a significant improvement in cutaneous symptoms in patients with SSc as measured by the Rodnan score (P < 0.01). Specific lymphocyte markers, adhesion molecules and cytokines are also affected by this treatment, helping to clarify further the mechanism of action of PUVA treatment and our understanding of the primary pathological process.