Figure 2
From: Skeletal muscle pathology of infantile Pompe disease during long-term enzyme replacement therapy
Analysis of quadriceps muscle biopsy from Patient 1 prior to and following 12 and 96 months of ERT. (A) Epon-embedded PAS/Richardson’s-stained section shows mild to extensive vacuolation in many fibers (magnification 25×). (B) At a higher magnification (200×), it is evident that nearly all fibers are at least mildly affected. (C, D) After 12 months of ERT (age 13.1 months), no effaced fibers are seen, and there is much less glycogen overall (100× and 200×, respectively). (E, F) After 96 months of ERT (age 97.1 months), there is only subtle microvacuolar damage in occasional fibers and no evident glycogen accumulation (100× and 630×, respectively). (G, H) H&E-stained paraffin and PAS-D sections (25× and 630×, respectively) show little interstitial stroma in otherwise normal-looking fibers. (I, top and bottom) LAMP2/LC3 staining (lysosomes: green; autophagosomes: red) demonstrates mostly intact muscle fibers (for example, top); autophagic pathology can be seen in ~2% of fibers (bottom; arrowheads). Bar: 10 μm.