Selective atrophy of the type IIb muscle fibers in rheumatoid arthritis and progressive systemic sclerosis (scleroderma). A biopsy histochemical study.

We have examined biopsy material from the left m. vastus lateralis of eight patients suffering from rheumatoid arthritis and four patients with progressive systemic sclerosis (scleroderma). All were chosen according to the duration and the severity of disease, so that the broadest possible spectrum of signs and symptoms could be considered.