An Italian family with inclusion-body myopathy and frontotemporal dementia due to mutation in theVCP gene

Mutations of the valosin-containing protein gene (VCP) are responsible for autosomal-dominant hereditary inclusion-body myopathy associated with frontotemporal dementia and Paget's disease of bone. We identified the p.R155C missense mutation in the VCP gene segregating in an Italian family with three affected siblings, two of whom had a progressive myopathy associated with dementia, whereas one exhibited a progressive myopathy and preclinical signs of Paget's disease of bone. Our study demonstrates that VCP mutations are found in patients of Italian background and may lead to a variable clinical phenotype even within the same kinship.

Inclusion body myopathy and frontotemporal dementia caused by a novel VCP mutation

Hereditary inclusion body myopathy (IBM) with Paget's disease of the bone (PDB) and frontotemporal dementia (FTD) is a rare autosomal dominant disease caused by mutations in the valosin-containing protein (VCP) gene. We report a novel heterozygous VCP gene mutation (R159C) in a 69-year-old Italian patient presenting with slowly progressive muscle weakness of the distal upper and proximal lower limbs since the age of 50 years, 18 years later FTD supervened. No dementia or myopathies were revealed in the family history covering two generations. Degenerative changes and rimmed vacuoles together with VCP- and ubiquitin-positive cytoplasmic and nuclear aggregates were observed at the muscle biopsy. Several elements support the pathogenic role of the R159C VCP gene mutation: the occurrence at the same codon of a different, previously identified pathogenic mutation within a VCP gene mutational hot-spot, the histopathological and biochemical evidence of muscle VCP accumulation and the combined clinical presentation of IBM and FTD. These findings suggest VCP gene investigation even in apparently sporadic cases.

Valosin-containing protein and the pathogenesis of frontotemporal dementia associated with inclusion body myopathy

Frontotemporal dementia with inclusion body myopathy and Paget's disease of bone (IBMPFD) is a rare, autosomal dominant disorder caused by mutations in the gene valosin-containing protein (VCP). The CNS pathology is characterized by a novel pattern of ubiquitin pathology distinct from sporadic and familial frontotemporal lobar degeneration with ubiquitin-positive inclusions without VCP mutations. Yet, the ubiquitin-positive inclusions in IBMPFD also stain for TAR DNA binding protein, a feature that links this rare disease with the pathology associated with the majority of sporadic FTD as well as disease resulting from different genetic alterations. VCP, a member of the AAA-ATPase gene family, associates with a plethora of protein adaptors to perform a variety of cellular processes including Golgi assembly/disassembly and regulation of the ubiquitin-proteasome system. However, the mechanism whereby mutations in VCP lead to CNS, muscle, and bone disease is largely unknown. In this report, we review current literature on IBMPFD, focusing on the pathology of the disease and the biology of VCP with respect to IBMPFD.

Dysphagia in inflammatory myopathy: clinical characteristics, treatment strategies, and outcome in 62 patients

OBJECTIVE

To assess the clinical characteristics, treatment, and outcome of patients with inflammatory myopathy-associated dysphagia.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of all patients with inflammatory myopathy-associated dysphagia seen at the Mayo Clinic in Rochester, Minn, between January 1, 1997, and December 31, 2001.

RESULTS

A total of 783 patients were diagnosed as having inflammatory myopathy during the 5-year study period. Of these, 62 patients (41 women and 21 men; mean age, 68.6 years) had inflammatory myopathy-associated dysphagia: 26 with inclusion body myositis (IBM), 18 with dermatomyositis, 9 with polymyositis, and 9 with overlap syndrome. Dysphagia was a presenting symptom in 13 patients (21%), with the highest incidence in the IBM group. Videofluoroscopic examinations revealed pharyngeal pooling and impaired oropharyngeal and cricopharyngeal function. The benefits of swallowing compensation techniques and exercises were difficult to establish. Interventional procedures were performed in 24 patients (39%) and most frequently (62%) in patients with IBM, with cricopharyngeal myotomy being most beneficial. Patients with IBM had the least symptomatic improvement. Overall, 11 patients died during the median follow-up of 38 months, with respiratory failure due to aspiration pneumonia as the most common cause. Mortality was high in patients who required percutaneous endoscopic gastrostomy (7/11, 64%), and 1- year mortality was highest (31%) in those with dermatomyositis.

CONCLUSION

Dysphagia is a serious and at times presenting problem in patients with inflammatory myopathy. It occurs most frequently and appears to be most refractory in patients with IBM. The mortality rate was high in patients who required percutaneous endoscopic gastrostomy, and the 1-year mortality rate was the highest in patients with dermatomyositis.

Celiac disease and antibodies associated with celiac disease in patients with inflammatory myopathy

Celiac disease is usually associated with autoimmune disorders and has occasionally been reported in patients with inflammatory myopathies. Our aim was to determine the presence of celiac disease and antibodies associated with celiac disease in patients with inflammatory myopathies and to investigate their relationship. Serum antigliadin, anti-tissue transglutaminase, and antiendomysial antibodies were determined in 51 patients with inflammatory myopathies. HLA-DQ2 and -DQ8 alleles were studied to assess their complementary diagnostic value. Jejunal biopsy was performed in patients with moderate to high levels of antigliadin antibodies. Patients with jejunal histology consistent with celiac disease initiated a gluten-free diet. Seventeen patients (31%) were positive for antigliadin antibodies, which were significantly more frequent in patients with inclusion-body myositis than dermatomyositis (P < 0.001). Positive status to HLA-DQ2 and/or -DQ8 did not differ between antigliadin-positive (75% and 12.5%) or -negative (60% and 15%) patients. Three of five jejunal biopsies were diagnostic for celiac disease with histological normalization after a gluten-free diet. Thus, celiac disease is more prevalent in patients with inflammatory myopathies than in the general population. Positive status to HLA-DQ2 allele, which is known to be more frequent in patients with inflammatory myopathies, could explain the high prevalence of antigliadin antibodies in this population. The diagnostic value of HLA-DQ2 or -DQ8 haplotypes to detect celiac disease in patients with inflammatory myopathy is limited.

[Renal involvement by AA amyloidosis in inclusion body myositis]

Inclusion body myositis is currently considered a variant of adult inflammatory myopathies. Clinical course is insidious and besides typical proximal muscles disorder, extension to distal ones is found in up to 95% of cases. Mean survival ranges from 3 to 5 years. Infections are the first death cause, secondary to existing disability a few years after diagnosis. Chronic rheumatic diseases related amyloidosis has became the most frequent kind of reactive amyloidosis or AA amyloidosis. Clinical manifestations of AA amyloidosis mainly affect the kidney. We present the case of a woman with Inclusion body myositis and renal involvement by AA amyloidosis. In our review of literature we haven t found any article relating AA amyloidosis with idiopathic inflammatory myopathies of the adult, what would turn this case into the first ever reported. We can probably find the reason in the bad prognosis of this entity. So we propose making a renal biopsy to all those patients with a long lasting rheumatologic disease and unexpected impaired renal function.

Pediatric macrophagic myofasciitis associated with motor delay

BACKGROUND

Macrophagic myofasciitis (MMF) is a rare inflammatory myopathy characterized by accumulation of perifascicular macrophages without muscle fiber necrosis. Few sporadic pediatric cases have been described, and MMF is recognized as a possible reaction to intramuscular injections of aluminum-containing vaccines. The association of MMF and motor delay is unclear in the pediatric population. We report the clinical evaluation and follow-up of 4 young children with MMF and review of 4 cases previously reported of sporadic, pediatric MMF to better determine the possible association of sporadic MMF in children presenting with motor delay.

PATIENTS AND METHODS

Described our 4 case reports in which we observed children presenting for evaluation of motor delay with unrevealing clinical and laboratory evaluations for common causes of motor delay and histopathological evaluations consistent with macrophagic myofasciitis. Muscle data was obtained by quadriceps muscle biopsy.

RESULTS

Clinical presentations were similar in all children and were characterized by motor delay, hypotonia, and failure to thrive with an unrevealing evaluation for central nervous system disease, congenital, and mitochondrial myopathies.

CONCLUSIONS

Our cases and those previously reported in the literature demonstrate MMF should be considered in the evaluation of children with failure to thrive, hypotonia, and muscle weakness, as clinical outcome appears to be favorable.

Inclusion body myopathy-associated mutations in p97/VCP impair endoplasmic reticulum-associated degradation

Mutations in the AAA+ protein (ATPase associated with a variety of cellular activities) p97/VCP (valosin-containing protein) cause a dominantly inherited syndrome of inclusion body myopathy with Paget's disease of the bone and fronto-temporal dementia (IBMPFD). p97/VCP is a ubiquitously expressed protein that participates in a number of cellular processes including endoplasmic reticulum-associated degradation (ERAD). p97/VCP aids in the extraction of ubiquitinated proteins from the endoplasmic reticulum (ER) and facilitates their delivery to the proteasome. This study focuses on the effects of disease-associated p97/VCP mutations on this pathway. We show that p97/VCP containing the most prevalent IBMPFD-associated mutation, R155H, has normal ATPase activity and hexameric structure. However, when expressed in cultured cells, both this and a second IBMPFD-associated p97/VCP mutant increase the overall level of ubiquitin-conjugated proteins and specifically impair degradation of mutant DeltaF508-CFTR handled by the ERAD pathway. These effects are similar to those previously described for an ATPase deficient p97/VCP mutant and suggest that IBMPFD mutations impair p97/VCP cellular function. In a subset of cells, IBMPFD mutations also promote formation of aggregates that contain p97/VCP, ubiquitin conjugates and ER-resident proteins. Undegraded mutant DeltaF508-CFTR also accumulates in these aggregates. We conclude that IBMPFD mutations in p97/VCP disrupt ERAD and that this may contribute to the pathogenesis of IBMPFD.

Inclusion body myopathy and Paget disease is linked to a novel mutation in the VCP gene

Mutations in the valosin-containing protein (VCP) on chromosome 9p13-p12 were recently found to be associated with hereditary inclusion body myopathy, Paget disease of the bone, and frontotemporal dementia (IBMPFD). We identified a novel missense mutation in the VCP gene (R159H; 688G>A) segregating with this disease in an Austrian family of four affected siblings, who exhibited progressive proximal myopathy and Paget disease of the bone but without clinical signs of dementia.

PM-Scl-Antikörper positive systemische Sklerodermie assoziiert mit Einschlusskörper-Myositis

We describe a 72- year-old patient with a ten year history of anti-PM-Scl positive systemic sclerosis associated with inclusion-body myositis. While the association of dermatomyositis and polymyositis with anti-PM-Scl positive systemic sclerosis is frequently reported, inclusion-body myositis was, to the best of our knowledge, only previously described once in association with anti-PM-Scl-positive systemic sclerosis. The distinction between inclusion-body myositis and other forms of inflammatory myopathy, like the histopathologically well distinguishable polymyositis or dermatomyositis, is relevant because of the poor response of inclusion- body myositis to immunosuppressive treatment. Our case underlines that in patients with anti-PM-Scl-positive systemic sclerosis and treatment resistant progressive myopathy the diagnosis of inclusion body myositis should be considered.

IBM-type inclusions in a patient with slow-channel syndrome caused by a mutation in the AChR epsilon subunit

We report a patient with a slow-channel congenital myasthenic syndrome who carries a novel slow-channel mutation in the epsilon subunit of the acetylcholine receptor and has tubulofilamentous inclusion bodies, in skeletal muscle of the type observed in hereditary and sporadic inclusion body myositis. Ultrastructural analysis of a muscle specimen obtained at the age of 9 years showed an endplate myopathy typical of the slow-channel syndrome. Twenty years later, a second muscle specimen again showed the endplate myopathy as well numerous nuclear and cytoplasmic tubulofilamentous inclusion bodies. Molecular genetic studies revealed a novel valine to phenylalanine mutation (epsilonV259F) in the M2 domain of the acetylcholine receptor. Coexistence of the slow-channel syndrome with a feature of IBM has not been observed before.

Positive troponin T without cardiac involvement in inclusion body myositis

Cardiac troponin T (cTnT) is considered as a specific marker for acute myocardial infarction. Here, we present a case with elevated cTnT, determined by a third-generation assay, without signs of a myocardial lesion. Routine investigation of a 66-year-old female patient with indolent B-cell lymphoma revealed increased serum levels of creatine kinase (CK), MB fraction of CK (CK-MB), and cTnT, although she did not complain of cardiac symptoms. Electrocardiographic monitoring, echocardiography, magnetic resonance computed angiography, and percutaneous coronary angiography excluded myocardial damage. However, the close follow-up showed a steady increase of CK-MB and cTnT levels and gradual development of weakness in both thighs. A biopsy of the right quadriceps muscle led to the diagnosis of inclusion body myositis. In contrast to cTnT, cardiac troponin I could not be detected retrospectively in any of her serum samples. These results demonstrate for the first time that cTnT is elevated in patients with inclusion body myositis.

Use of a cell-free system to determine UDP-N-acetylglucosamine 2-epimerase and N-acetylmannosamine kinase activities in human hereditary inclusion body myopathy

Hereditary inclusion body myopathy (HIBM) is an autosomal recessive neuromuscular disorder associated with mutations in uridine diphosphate (UDP)-N-acetylglucosamine (GlcNAc) 2-epimerase (GNE)/N-acetylmannosamine (ManNAc) kinase (MNK), the bifunctional and rate-limiting enzyme of sialic acid biosynthesis. We developed individual GNE and MNK enzymatic assays and determined reduced activities in cultured fibroblasts of patients, with HIBM harboring missense mutations in either or both the GNE and MNK enzymatic domains. To assess the effects of individual mutations on enzyme activity, normal and mutated GNE/MNK enzymatic domains were synthesized in a cell-free in vitro transcription-translation system and subjected to the GNE and MNK enzymatic assays. This cell-free system was validated for both GNE and MNK activities, and it revealed that mutations in one enzymatic domain (in GNE, G135V, V216A, and R246W; in MNK, A631V, M712T) affected not only that domain's enzyme activity, but also the activity of the other domain. Moreover, studies of the residual enzyme activity associated with specific mutations revealed a discrepancy between the fibroblasts and the cell-free systems. Fibroblasts exhibited higher residual activities of both GNE and MNK than the cell-free system. These findings add complexity to the tightly regulated system of sialic acid biosynthesis. This cell-free approach can be applied to other glycosylation pathway enzymes that are difficult to evaluate in whole cells because their substrate specificities overlap with those of ancillary enzymes.

Reversible inflammatory and vacuolar myopathy with vitamin E deficiency in celiac disease

We report a patient with late-onset celiac disease and neurological manifestations including myopathy, polyneuropathy, and ataxia. Laboratory investigations showed anti-gliadin antibodies and severe vitamin E deficiency. Muscle biopsy revealed inflammatory infiltrates and rimmed vacuoles, similar to those found in inclusion-body myositis. A gluten-free diet and vitamin E supplementation reversed both the clinical neurological manifestations and the abnormalities in the muscle biopsy. Anti-gliadin antibodies were no longer present. This case illustrates the spectrum of neurological complications of celiac disease and documents the occurrence of reversible pathology resembling inclusion-body myopathy in the muscle.

Steroid-responsive inclusion body myositis associated with endometrial cancer

Inclusion body myositis (IBM) is an uncommon chronic inflammatory myopathy. Although the association between other myopathies and cancer has been well established, the relationship between IBM and neoplasia is not completely understood. Unlike polymyositis (PM) or dermatomyositis (DM), IBM rarely responds to immunosuppressive treatment and the response is seldom long-lasting. We describe a case of IBM associated with endometrial carcinoma that also demonstrated a unique response to steroids alone which persisted despite cancer relapse. The factors that are associated with a response of IBM to steroids are discussed. An atypical, steroid-responsive form of the disease is delineated.

Inclusion body myositis in connective tissue disorders: case report and review of the literature

We report a patient with systemic lupus erythematosus (SLE) and secondary Sjögren's syndrome (SS) who developed inclusion body myositis (IBM) which, contrary to the typical presentation of this disorder, was symmetrical in nature although the diagnosis was only made after electron microscopy was performed. Therapy with increased doses of methotrexate proved to be beneficial, with the patient having full recovery after 8 months of therapy. It appears that a subset of IBM may be related to autoimmune disorders, an issue that was disputed in the past, and these patients may have a better prognosis than typical IBM patients. This is the first case report of IBM in a patient who had the dual diagnosis of SLE and SS.

Coexistence of X-linked recessive Emery-Dreifuss muscular dystrophy with inclusion body myositis-like morphology

We reported three cases (two familial and one sporadic) of X-linked Emery-Dreifuss muscular dystrophy (EDMD), genetically documented. Two patients demonstrated a typical inclusion body myositis (IBM)-like morphology. The third patient had only minor changes. Patients had elbow and ankle contractures, progressive wasting of humeroperoneal muscles and cardiac failure (pacemaker implantation in all). There was a mutation within the Xq28 gene and complete absence of emerin in the nuclear membrane. Mononuclear cell infiltrations, rimmed vacuoles, amyloid deposits, as well as cytoplasmic and nuclear tubulofilamentous muscle inclusions were most unusual findings. Coexistence of IBM-like morphology and X-linked recessive EDMD might indicate that pathological features of IBM are nonspecific and may be present in other neuromuscular disorders.

Injection of Botulinum Toxin a to Upper Esophageal Sphincter for Oropharyngeal Dysphagia in Two Patients with Inclusion Body Myositis

Inclusion body myositis (IBM) is a progressive degenerative skeletal muscle disease leading to weakening and atrophy of both proximal and distal muscles. Dysphagia is reported in up to 86% of IBM patients. Surgical cricopharyngeal myotomy may be effective for cricopharyngeal dysphagia and there is one published report that botulinum toxin A, injected into the cricopharyngeus muscle using a hypopharyngoscope under general anesthesia, relieved IBM-associated dysphagia. This report presents the first documentation of botulinum toxin A injection into the upper esophageal sphincter using a flexible esophagogastroduodenoscope under conscious sedation, to reduce upper esophageal sphincter pressure and successfully alleviate oropharyngeal dysphagia in two IBM patients.

Creutzfeldt-Jakob disease and inclusion body myositis: Abundant disease-associated prion protein in muscle

Pathologicalprion protein (PrP(Sc)) is the hallmark of prion diseases affecting primarily the central nervous system. Using immunohistochemistry, paraffin-embedded tissue blot, and Western blot, we demonstrated abundant PrP(Sc) in the muscle of a patient with sporadic Creutzfeldt-Jakob disease and inclusion body myositis. Extraneural PrP(C)-PrP(Sc) conversion in Creutzfeldt-Jakob disease appears to become prominent when PrP(C) is abundantly available as substrate, as in inclusion body myositis muscle.

Clinical and genetic heterogeneity in chromosome 9p associated hereditary inclusion body myopathy: exclusion of GNE and three other candidate genes

We have previously reported a new autosomal dominant inclusion body myopathy clinically resembling limb girdle muscular dystrophy, associated with Paget disease of bone in the majority and frontotemporal dementia in a third of individuals. The critical locus for this unique disorder now termed IBMPFD is 9 p21.1-p12, spans 5.5 Mb and contains the gene responsible for the recessive quadriceps-sparing inclusion body myopathy (IBM2). Mutation analysis of the GNE gene associated with IBM2 in affected individuals from four IBMPFD families did not identify any mutations, indicating that the two disorders are not allelic. Expression studies indicate that GNE has a tissue-specific splice pattern, with four splice variants. Mutation analysis in three other candidate genes (beta-tropomyosin, NDUFB6 and SMU1) did not identify any mutations.