Figure 6.

Muscle biopsy changes following follistatin gene therapy. (a) Pretreatment biopsy from Patient 05; (b) Posttreatment biopsy from Patient 05; (c) Pretreatment biopsy from Patient 06; (d) Posttreatment biopsy from Patient 06. The posttreatment biopsies show reduced fibrosis and a decrease in central nucleation. The number of small muscle fibers is markedly reduced and fewer split fibers are seen. Fiber size analyses showed a shift toward larger mean fiber diameter populations: Patient 05, prebiopsy 40.14 ± 2.10 µm (n = 323 fibers) versus postbiopsy 59.33 ± 1.54 µm (n = 292 fibers); P < 0.0001; Patient 06, pre 47.48 ± 2.00 µm (n = 245 fibers) versus post 63.74 ± 2.45 µm (n = 277) P < 0.0001.