An analysis of clinical features and pathology in 40 patients with dysferlinopathy

Abstract

Objective To analyze retrospectively the clinical manifestations，features of the biopsy of skeletal muscle with histochemistry and immunohistochemistry staining of 40 patients with dysferlinopathy and investigate its clinical，pathological diagnostic value. Methods The clinical data，features of the biopsy of skeletal muscle with histochemistry，immunohistochemistry staining of 40 patients with dysferlinopathy were analyzed. Results Chronic progressive weakness and wasting were the general clinical manifestations.In our study，it was divided into three phenotypes according to the involved muscles of dysferlinopathy: 27 cases with proximal muscle (LGMD2B)，12 cases with the gastrocenemius (MM)，1 case with the tibialis anterior muscle (DMAT).The serum creatine kinase levels all had a rise in different degree (134-19 795 U/L).All the patients showed myogenic lesions in electrophysiologic study.12 patients underwent skeletal muscle MRI.Proximal muscle was involved in 4 cases; gastrocnemius muscle was mainly involved in 7 cases; and anterior tibial muscle initially was involved in 1 case.All 40 cases showed active muscle fiber degeneration，necrosis and regeneration on muscle pathology.Connective tissues were proliferated and inflammatory cells infiltrated in endomysium，perimysium and perivascular sites of 16 patients.Immunohistochemical staining with anti-dysferlin monoclonal antibody identified the deficiency of dysferlin in the sarcolemma of 30 cases with dysferlinopathy，and dysferlin was severely reduced in 10 cases. Conclusion Progressive weakness and wasting of skeletal muscle are the clinical manifestations of dysferlinopathy.The early involved muscles determine the clinical phenotype of dysferlinopathy.High serum creatine kinase levels show that dysferlinopathy is a membrane protein null disease.Muscle MRI of lower limbs may reflect the involved muscles，which is essential for clinical phenotypes and selecting muscle biopsy.The pathological characters of dysferlinopathy are changes of muscular dystrophy.Inflammatory cellular infiltration is relatively common in biopsied muscles of many dysferlinopathy patients，and dysferlinopathy needs to be differentiated from inflammatory myopathies.The deficiency or severely decreased dysferlin on the sarcolemma in immunohistochemical staining with anti-dysferlin monoclonal antibody is an important information for diagnosing dysferlinoapthy. Key words: Muscular dystrophies，limb-girdle; Membrane proteins; Muscle proteins; Biopsy; Muscle，skeletal; Immunohistochemistry