Bcl-2, p53 and c-myc expression in juvenile dermatomyositis

Objective To investigate p53,bcl-2 and c-myc expression in muscle biopsies from child ren affected with juvenile dermatomyositis (JDM) and to verify a possible d ysregulation of programmed cell death in this autoimmune disease. Methods Ten muscle biopsies of children affected with JDM were formalin fixed and p araffin embedded. After haematoxylin and eosin staining, immunohistochemist ry was performed employing monoclonal antibodies anti-p53, anti-bcl-2 and a nti-myc. Two normal muscle biopsies were studied as controls. Results In the biopsies of JDM, two different patterns of myofibers damage were obs erved: the first, with tones characterised by necrosis; and the second with zones where an apoptotic process was dominant. Immunoreactivity for bcl-2 was positive in 8 out of 10 biopsies. P53 and c-myc expression were not pre sent ira any case. No relationship between the degree of bcl-2 immunostaini ng and the disease course or outcome was observed. Conclusions The over-expression of bcl-2 protein in JDM may suggest a dysregulation of apoptosis in myofibers. Further studies are required in order to better und erstand the role of our data in the pathogenetic pathways of the disease.