Immunohistochemical analysis of adhesion molecule expression on muscle biopsy specimens from patients with juvenile dermatomyositis.

OBJECTIVE

To assess expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on muscle biopsy specimens from patients with untreated juvenile dermatomyositis (JDM).

METHODS

Histochemical and immunohistochemical tests for ICAM-1 and VCAM-1 were performed on serial frozen sections from 27 JDM muscle biopsy specimens. ICAM-1 and VCAM-1 expression was analyzed on capillaries, perimysial and endomysial large vessels, and muscle fibers. Expression was assessed and graded semiquantitatively.

RESULTS

Increased ICAM-1 expression was observed on capillaries and perimysial large vessels on semiquantitative analysis, and was statistically more evident than on endomysial large vessels. In all cases, only a few muscle vessels showed expression of VCAM-1. Expression of ICAM-1 and VCAM-1 was observed on few muscle fibers.

CONCLUSION

The observation of ICAM-1 expression on muscle vessels, mainly on capillaries of patients with untreated JDM compared to controls, and VCAM-1 expression to a lesser extent, mostly on muscle vessels surrounded by inflammatory infiltrate, supports the participation of these adhesion molecules in the pathologic mechanism of vascular injury in JDM.