This increase may be related to necrosis, as complement membrane attack complexes have been shown to specifically detect necrotic fibres and endomysial capillaries in muscular dystrophies as in inflammatory myopathies.54, 55 All three antibodies against C4A show positive association with age, but the correlation between the antibodies ranges between 0.39 and 0.77. This evidence concerns the gene C4A and myopathy.