Circulating levels of soluble CD30 are increased in patients with systemic sclerosis (SSc) and correlate with serological and clinical features of the disease.

Activated Th2 lymphocytes express the surface molecule CD30 and release a soluble form of the same molecule which can be detected both in vivo and in vitro. In the present study, high levels of soluble CD30 were found in the peripheral blood of patients with SSc, and a significant correlation with skin score and erythrocyte sedimentation rate (ESR) was detected. Furthermore, we observed a higher spontaneous release of soluble CD30 in the supernatants of unstimulated cultures of peripheral blood mononuclear cells from our patients compared with healthy controls. Taken together, these data suggest a possible involvement of Th2 cells in the immunopathogenesis of SSc, and the dosage of CD30 soluble in the peripheral blood may be helpful in following the outcome of the disease.