Clinical significance of circulating platelet-activating factor acetylhydrolase levels in systemic sclerosis

Platelet-activating factor acetylhydrolase (PAF-AH) has been demonstrated to be one of anti-inflammatory and anti-apoptotic factors, suggesting the potential to be involved in the development of systemic sclerosis (SSc). The aim of this study is to determine serum PAF-AH levels and their clinical associations in patients with SSc. Serum PAF-AH levels were examined by enzyme-linked immunosorbent assay in 57 patients with SSc and 24 healthy individuals. Serum PAF-AH levels were significantly elevated in SSc patients (130.4 ± 69.5 ng/ml) compared with healthy individuals (81.6 ± 34.8 ng/ml; P < 0.001). Among SSc patients, there were no differences in serum PAF-AH levels between those with diffuse cutaneous SSc (135.5 ± 79.3 ng/ml; n = 29) and those with limited cutaneous SSc (125.1 ± 58.6 ng/ml; n = 28). Patients with SSc who had raised PAF-AH levels less often had digital ulcers and arthritis/arthralgias than those with normal PAF-AH levels. The results show that serum PAF-AH levels were increased in patients with SSc and associated with a lower frequency of pitting scars/digital ulcers and arthritis/arthralgias. PAF-AH could be a protective factor against the development of digital ulcers and arthritis/arthralgia in this disease and as such would be a useful serological marker for disease severity.