[Expression and distribution of type I, III and V collagens in skin lesions from patients with systemic sclerosis]

To investigate the expressionand distribution of collagen I, III, and V (Col I, III, and V) in skin lesions of systemic sclerosis patients (SSc).

Skin lesions were collected from 36 patients with SSc (mild fibrosis 9 patients, moderate 14, and severe 13). The expression and distribution of alpha1 chain of collagen type I, III and V [alpha1 (I), alpha1 (III) and alpha1 (IV)] in skin lesions were detected with immunohistochemical SP method, while 6 normal skin tissues were used as controls.

All the three types of collagens were observed with diffuse distribution in dermis of SSc skin lesions. The deep staining alpha1 (I) and alpha1 (III) clumps and bands were seen in reticular layer, while alpha1 (V) was more homogeneously andcommonly around small vessels and appendages. The expression of alpha (I), and alpha1 (III), and alpha1 (V) appeared to gradually increase in dermis and the area around small vessels, appendages with the increase of fibrosis severity (P < 0.05). The level of alpha1 (V) was obviously elevated at early stage, and persisted in whole fibrotic process, while al (I) and alpha1 (III) increased apparently later in middle and late stages.

alpha1 (V) began to deposit prior to alpha1 (I) and alpha1 (III) at early stage in SSc and persisted in whole fibrotic process. The changes of alpha1 (V) contents started in dermal tissues around small vessels and appendages, which may involve in the development of vasculitis in SSc.