Clinical and Pathological Analysis of the Common PMD
|School||Hebei Medical University|
|Keywords||Dystrophinopathy dysferlinopathy sarcoglycanopathy Pathology clinical characteristics|
Objective: Progressive muscular dystrophy (PMD) is a group of geneticdiseases which happen at muscle tissue. Their common features are slowmuscle atrophy, the gravis and movement disorders at different degrees. Thecommon types are Duchenne muscular dystrophy (DMD), Becker musculardystrophy (BMD), limb-girdle muscular dystrophy (LGMD), facioscapulohu-meral muscular malnutrition, oculopharyngeal muscular dystrophy, congenitalmuscular dystrophy, Emery-Dreifuss, muscular dystrophy, distal musculardystrophy and myotonic dystrophy.DMD and BMD are the most common types of the progressive musculardystrophy, which are X-linked recessive genetic myopathy caused bydystrophin gene mutations. LGMD is a group of diseases with similar clinicalmanifestations but totally different pathogenesis. The disease is clinicallycharacterized by progressive severe muscles weakness and atrophy ofproximal limb muscles and belt muscle. LGMD can be autosomal dominant(LGMD1type) or recessive (LGMD2type) genetic and can be divided intodifferent subtypes based on gene and protein defects. According to the specificaffected gene, LGMDl can be divided into LGMDlA~LGMDlH, totally8types, and LGMD2can be divided into GMD2A~LGMD2Q, totally17types.The auxiliary examination includes serum CK increasing in variousdegrees, EMG showing typical myogenic damage characteristics and musclepathology. The muscle pathology has broadly similar performance: the size ofthe muscle fibers and muscle fiber necrosis, regeneration, the apparentproliferation of connective tissue.In this study, we use muscle routine histological staining and immun-ohistochemical methods to detect patient muscle dystrophin, dysferlin andsarcoglycan expression, summarize the clinical and pathological features, andidentify the common type of progressive muscular dystrophy. This makes clinical and pathological theoretical basis for future more accurate genotypingdiagnostic and plays an important role in determining the prognosis of thedisease and genetic counseling.Methods: The study is divided into two groups-the experimental groupand the control group. The experimental group has23cases: the clinical andpathological data preserved intact and clinical diagnosis of musculardystrophy patients. I summarized their age of onset, the starting position,location and degree of progressive muscle weakness, muscle atrophy parts,whether associated with clinical and pathological features of thegastrocnemius muscle pseudo-hypertrophy, CK values, the results of the EMG,muscle routine staining results. There are2cases in the control group: theclinical and pathological data preserved intact and clinically diagnosed asmuscle pathology normal.Deep-frozen in liquid nitrogen-precooled isopentanethe frozen muscle the specimens made8um frozen sliced with muscle routinehistological staining,resistant of dystrophin Rod, the anti of dystrophinC-terminal, anti of dystrophin N-terminal anti-dysferlin, anti-α-sarcoglycan,anti-β-sarcoglycan, anti-γ-sarcoglycan, the five kinds of theanti-δ-sarcoglycan protein monoclonal antibodies do immunohistochemicalstaining(IHC).Results:1In the light microscope,23cases of muscle routine case staining musclefibers were angular or round appearance, large and small, partial atrophyobvious nuclear transfer, the gap widened, connective tissue hyperplasia, a lotof degeneration, necrosis and regeneration of muscle fiber degeneration andnecrotic muscle fibers inflammatory cell infiltration,15cases of visiblemuscle fibers split; of NADH, SDH enzyme activity limitations increased orreduce, of which18cases NADH staining visible insect bite-like muscle fibers;12cases of ATP staining two types of muscle fiber distribution normal persons,five cases have the advantage of the type I muscle fibers, six cases of type IImuscle fibers advantage; ORO staining part of the fat composition of musclefibers increased in16cases; PAS stained sections of muscle fiber increased glycogen constituents of the16cases. Muscle pathology staining of thecontrol group, showing the arrangement of muscle fibers within the musclebundle close of similar size, muscle fibers were angular appearance, nodegeneration, necrosis and phagocytosis, increased nuclear-free transfer, noabnormal staining NADH-TR and SDH staining. NSE staining, ORO stainingand PAS staining were normal the basic ATPase staining two types of musclefibers arranged in a mosaic.2Altogether10dystrophin,9dysferlin and11α-sarcoglycan can deficiencywere found in the group by IHC.there were4absence,6defect indystrophinN/C/R staining,1absence and8defect in dysferlin staining,1absence and10defect in α-sarcoglycan.10β-sarcoglycan,9γ-sarcoglycan and9δ-sarcoglycan are defected in the group by IHC. IHC staining of thespecimen muscle fiber membrane had no control group weakened andmissing.3The clinical characteristics of progressive muscular dystrophy sufferers3.1DystrophinopathyDystrophinopathy is a group of diseases with clinical manifestation.Experimental group has10cases which meet dystrophinopathy diagnosis,including4DMD cases and6BMD cases. It contains10male cases and thereis a family patient history. The patients’ creatine kinase levels are increased.DMD patients are insidious onset in childhood, generally with performance ofproximal weakness of the lower limbs, duck step-by-step, easy to fall, andunilateral limb weakness. The disease has a rapid progress. BMD patients areusually onset at adolescent, which has similar symptoms with DMD: muscleweakness lighter than DMD, maybe associated with dilatationcardiomyopathy, the progress of the disease is relatively moderate, theelectromyography icon myogenic.Muscle biopsy histologic examinationshowed myogenic damage, visible to varying degrees of muscle fiber atrophy,degeneration, necrosis, muscle split muscle fibers interstitial widened invasivefat cells, connective tissue proliferation, nuclear transfer increases, deeplystained, some visible worm-eaten phenomenon. 3.2sarcoglycanopathyCase6is a male of22years old. The symptoms are progressive increaseproximal limb weakness14years, duck step, no muscle atrophygastrocnemius muscle hypertrophy, no sensory disturbances and pyramidaltract signs, no positive family history. His serum CK levels4491U/L, andECG showed a short PR interval. Muscle biopsy histological examinationshowed the muscle part of regional fat, muscle fibers arranged looser, largeand small, rounded appearance majority is shrinking, occasionallydegeneration, necrosis and phagocytosis, occasional muscle split muscleregeneration and nuclear transfer. Immunohistochemical staining showed thecomplete absence of α-sarcoglycan, β/γ/δ-sarcoglycan staining is incomplete,dystrophin R/N staining are weakened. The dysferlin staining is weakensd onmembrane, and deepen in the cytoplasmic.According to the IHC staining,case6is sarcoglycanopathy. In combination with muscle routine case andimmunohistochemical staining, clinical and pathological diagnosis areLGMD2D.3.3DysferlinopathyCase21is a female of38years old.14years ago, the first performancewas the weakness of distal right lower limbs. With the progress of thedisease,the weakness have appeared in the proximal of the upper limbs andthe left distal lower extremity.CK is4095.7U/L. Myogenic electromyographyicon showed myogenic muscle fiber atrophy. Muscle biopsy histologicalexamination showed myogenic muscle fiber atrophy, degeneration andnecrosis, visible nuclear shift and muscle splitting, the muscle bundle clothingand muscle underwear connective tissue hyperplasia, muscle fibers visiblesmall focal or scattered distribution of inflammatory cell infiltration.Comparing with normal skeletal muscle specimens, immunohistochemicalstaining visible dysferlin missing, dystrophin and sarcoglycan staining showedcomplete. Combined with clinical and pathological,the diagnosis isdysferlinopathy. Conclusions:1. Dystrophinopathy is the most type in PMD.2. Protein is more accurate diagnosis than the clinical diagnosis.3. BMD patients’condition is relatively light with different clinicalmanifestations and many similar features with LGMD. Muscle pathologymanifested as changes of varying degrees of muscular dystrophy, non-specific.It is difficult to make the identification of sporadic cases with LGMD needfurther line IHC detection.4. Dysferlinopathy is usually misdiagnosed as polymyositis.It should bediagnosised by IHC.5. Muscle cell membrane dystrophin or sarcoglycan protein deficienciesare possible to cause secondary missing each other.