Immunological abnormalities in a family with progressive external ophthalmoplegia.

The authors report the muscular and humoral immunological abnormalities found in a family with progressive external ophthalmoplegia (PEO) of the "pure" form. Serum circulating immune complexes as determined by the polyethylen glycol (PEG) test and double radial immunodiffusion (DRID) were positive for IgG in both cases studied and for IgM and Clq for the propositus. In the latter circulating auto-antibodies against smooth muscle were also present. Immunohistochemical studies on striated muscle of the propositus showed positive perivascular IgG and IgM staining and IgG in the sarcolemma basement membrane complex. It is suggested that in this family a genetically inherited abnormal immune response to the muscular blood vessel wall has induced vascular injury and ultimately chronic ischemic muscular damage. This is consistent with the view that PEO is a clinical syndrome, i.e. the expression of various defects affecting primarily or secondarily the energy metabolism of the muscular tissue.