Distribution of cell adhesion molecules in skeletal muscle from patients with systemic lupus erythematosus.

OBJECTIVE

To investigate the pathophysiology of perivascular mononuclear cell infiltrates observed in skeletal muscle from patients with systemic lupus erythematosus (SLE).

METHODS

Immunocytochemical techniques were used to examine frozen 5 microns sections from the quadriceps needle muscle biopsy specimens of 14 patients with SLE (including seven with infiltrates) for the expression of the cytokine inducible adhesion molecules intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin.

RESULTS

Vessels in 6/7 SLE biopsy specimens with perivascular infiltrates expressed VCAM-1 at a density of > 2 vessels/mm2 in contrast with 0/7 SLE biopsy specimens without infiltrates and 1/6 control specimens. In contrast, E-selectin expression was increased ( > 0.3 positive vessels/mm2) in SLE biopsy specimens compared with control tissue regardless of the presence of perivascular infiltration. VCAM-1 and ICAM-1 were also noted on extravascular cells in the infiltrates, being particularly prominent on the intermuscle fibre dendritic processes of CD68+ HLA-DR+ cells.

CONCLUSION

Expression of these cytokine inducible adhesion molecules may be important in the migration of mononuclear cells into skeletal muscle and may be involved in intercellular interactions within the tissue.