Clinical features of a family with late-onset distal hereditary motor neuropathy harboring p.Pro39Leu variant of HSPB1.

BACKGROUND AND AIMS: Pathogenic variants of HSPB1, the gene encoding the small heat shock protein 27, have been reported to cause autosomal dominant distal hereditary motor neuropathy (dHMN) type II and autosomal dominant Charcot-Marie-Tooth (CMT) disease with minimal sensory involvement (CMT2F). This study aimed to describe the clinical features of patients in a family with late-onset dHMN carrying the Pro39Leu variant of HSPB1. METHODS: Whole-exome sequence analysis identified a heterozygous pathogenic variant (Pro39Leu) of HSPB1 in the proband. The presence of the HSPB1 Pro39Leu variant in two affected individuals was confirmed using direct nucleotide sequence analysis. RESULTS: Both patients exhibited distal muscle weakness with lower extremity predominance and no obvious sensory deficits, leading to a clinical diagnosis of late-onset dHMN. Nerve conduction studies (NCSs) revealed a subclinical complication of sensory disturbance in one of the patients. The clinical and electrophysiological findings of patients with the HSPB1 Pro39Leu variant in this study and previous reports are summarized. INTERPRETATION: This study suggests that the clinical spectrum of patients carrying HSPB1 Pro39Leu variants, especially the disease onset, might be broader than expected, and HSPB1 variants should be considered in patients diagnosed with late-onset dHMN. Furthermore, patients with dHMN may have concomitant sensory deficits that should be evaluated using NCSs.

Lactate promotes survival and hepatocyte differentiation of human induced pluripotent stem cells in a medium without glucose and supplemented with galactose.

Human induced pluripotent stem (iPS) cells initiate hepatocyte differentiation in a medium without glucose and supplemented with galactose, oncostatin M and small molecules [hepatocyte differentiation inducer (HDI)]. To clarify the metabolic differences between iPS cells in HDI and ReproFF (undifferentiated state), a metabolome analysis was performed. iPS cells were cultured in a medium without glucose and supplemented with galactose, as well as 1 mM of calcium lactate, sodium lactate or lactic acid. After 7 days of culture, the cells were subjected to reverse transcription-quantitative PCR analysis. The galactose-1-phosphate concentration was significantly higher in cells cultured in HDI than in those cultured with ReproFF. The lactate concentration in the HDI group was significantly lower than that in the ReproFF group. The expression levels of α-feto protein and albumin were significantly higher in the groups cultured with calcium lactate, sodium lactate and lactic acid as compared with ReproFF. It was suggested that lactate promoted the survival of iPS cells cultured in a medium without glucose and supplemented with galactose. Under these conditions, iPS cells begin to differentiate into a hepatocyte lineage. Lactate may be applied to produce hepatocytes from iPS cells more efficiently.

Predicting the CTG Repeat Size from a Single Spirometry Test Performed at Any Time during the Disease Course of Myotonic Dystrophy Type 1.

Objective In myotonic dystrophy type 1 (DM1), the CTG repeat size in the dystrophia myotonica protein kinase gene has been shown to correlate with disease severity and is a potential predictive marker for respiratory decline. However, genetic testing can be challenging in some clinical situations. We developed a simple formula for estimating the CTG repeat size using a single spirometry test in patients with DM1. Methods In this single-center retrospective study, we reviewed 50 consecutive patients with genetically confirmed DM1 whose follow-up visits were at our hospital. The patients were randomly assigned to training and test analysis subsets. By applying a linear mixed model to the longitudinal spirometry results of the training set, we calculated the fixed effects on the annual respiratory decline. Subsequently, we derived a prediction formula to calculate the repeat size that incorporated %vital capacity (%VC) and the patient's age at the time of the spirometry evaluation; the results were validated by the test set. Results A total of 157 spirometry tests were recorded. The fixed effects on the annual %VC decline were =-0.90. The derived formula [repeat size=-16.8× (age+%VC/0.90) +2663] had a moderate predictive performance with a mean coefficient of determination of 0.41. Conclusion The CTG repeat size in patients with DM1 can be potentially predicted using a simple formula based on a single spirometry test conducted at any time over the disease course. It can be useful as a supportive tool for advance care planning when genetic testing is not available.

Amyotrophic lateral sclerosis with a sudden-onset history.

OBJECTIVE: We report on two patients with amyotrophic lateral sclerosis (ALS) complaining of sudden-onset difficulty in finger elevation. CASE REPORT: A 65-year-old man (the first patient) and a 66-year-old man (the second patient) suddenly became aware of difficulty in finger elevation of one hand. They were not aware of any other symptoms prior to the onset. In the first patient, cerebral infarction at the precentral gyrus was initially suspected. In the second patient, cervical spondylosis was initially suspected, and cervical spine surgery was planned. However, needle EMG revealed widespread neurogenic changes and abundant fasciculation potentials for both patients. Widespread weakness emerged in time and relentlessly progressed, and finally the diagnosis of ALS was made. In both cases, notable weakness in the extensor digitorum (ED) muscle with relatively mild weakness in the other muscles in the affected limb was a characteristic finding. Loss of one motor unit in ED that has already enlarged due to reinnervation must have caused sudden awareness of the weakness. SIGNIFICANCE: Clinicians should recognize the presence of ALS patients with a sudden-onset history because the risk of initial misdiagnosis is high for such patients.

Study of Duchenne muscular dystrophy long-term survivors aged 40 years and older living in specialized institutions in Japan.

The national muscular dystrophy wards database of Japan lists 118 long-term Duchenne muscular dystrophy (DMD) patients who were at least 40 years old as of October 1, 2013. To elucidate the clinical features of DMD patients aged 40 years and older, we obtained gene analysis and muscle biopsy findings, as well as medical condition information. Ninety-four of the registered patients consented to participate, of whom 55 meeting genetic or biochemical criteria confirming DMD were analyzed. The mean age at the time of the study was 43.6 ± 3.0 years, while at the time of independent ambulation loss it was 10.6 ± 1.5 years and at mechanical ventilation introduction it was 24.1 ± 5.5 years. All were receiving continuous ventilation support, 27 with non-invasive positive pressure ventilation and 28 with tracheal intermittent positive pressure ventilation. Thirty-eight were receiving ß-blockers or a renin-angiotensin system inhibitor, while 9 were free from those agents. Forty had maintained oral nutrition. The 55 analyzed patients had survived into their 40s by receiving multidisciplinary intervention. Our findings emphasize the need of future studies to investigate disease modifiers and the mechanism of long-term survival. In addition, establishment of a worldwide care standard with focus on quality of life for adult males with DMD is important.

Anti-TIF1-γ antibody and cancer-associated myositis: A clinicohistopathologic study.

OBJECTIVE: We aimed to analyze the clinical and histopathologic features of cancer-associated myositis (CAM) in relation to anti-transcriptional intermediary factor 1 γ antibody (anti-TIF1-γ-Ab), a marker of cancer association. METHODS: We retrospectively studied 349 patients with idiopathic inflammatory myopathies (IIMs), including 284 patients with pretreatment biopsy samples available. For the classification of IIMs, the European Neuromuscular Center criteria were applied. Patients with CAM with (anti-TIF1-γ-Ab[+] CAM) and without anti-TIF1-γ-Ab (anti-TIF1-γ-Ab[-] CAM) were compared with patients with IIM without cancers within and beyond 3 years of myositis diagnosis. RESULTS: Cancer was detected in 75 patients, of whom 36 (48%) were positive for anti-TIF1-γ-Ab. In anti-TIF1-γ-Ab(+) patients with CAM, cancers were detected within 1 year of myositis diagnosis in 35 (97%) and before 1 year of myositis diagnosis in 1. All the anti-TIF1-γ-Ab(+) patients with CAM satisfied the dermatomyositis (DM) criteria, including 2 possible DM sine dermatitis cases, and were characterized histologically by the presence of perifascicular atrophy, vacuolated fibers (VFs), and dense C5b-9 deposits on capillaries (dC5b-9). In contrast, 39 anti-TIF1-γ-Ab(-) patients with CAM were classified into various subgroups, and characterized by a higher frequency of necrotizing autoimmune myopathy (NAM). Notably, all 7 patients with CAM classified into the NAM subgroup were anti-TIF1-γ-Ab(-) and exhibited no dC5b-9 or VFs. CONCLUSIONS: CAM includes clinicohistopathologically heterogeneous disease entities. Among CAM entities, anti-TIF1-γ-Ab(+) CAM has characteristically shown a close temporal association with cancer detection and the histopathologic findings of dC5b-9 and VFs, and CAM with NAM is a subset of anti-TIF1-γ-Ab(-) CAM.

[The painful multiple mononeuropathy of acute onset in the left arm which was diagnosed as leprous neuropathy].

A 31-year-old man from Myanmar with leprous neuropathy was reported. The progress of the disease was subacute but the painful symptom at the time of the onset was acute. Multiple mononeuropathy was diagnosed by the biopsy findings of the left superficial radial nerve. He was admitted to our hospital with the complaint of the weakness of his left hand and fingers which were very painful and got worse in several weeks. Motor palsy was observed in his left ulnar, median, and radial nerves, and there was the hypesthesia or anesthesia in his left hand, forearm and the medial side of his left upper arm. On nerve conduction studies, the amplitudes of CMAP and SNAP severely diminished or not detected. The pattern was compatible with multiple mononeuropathy. The biopsy of the left superficial radial nerve was performed. The pathological findings were the destruction of nerve fascicles, replacement of nerve fibers with inflammatory cells, and Mycobacterium leprae was found with the specific stain. These findings confirmed the diagnosis of the leprous neuropathy. Leprous neuropathy is one of the commonest causes of infectious neuropathy in the world, especially in Southeast Asia. These days many foreign workers from that area are staying in Japan, and the chances to see the disease are increasing. We have to recognize leprous neuropathy as a candidate for the multiple mononeuropathy of acute onset with painful dysesthesia similar to vascular neuropathy.

[A case with myositis as a manifestation of chronic graft-versus-host-disease (GVHD) with severe muscle swelling developed after aggressive muscular exercise].

We report a 21-year-old-man, with myositis as a manifestation of chronic graft-versus-host-disease (GVHD). He was diagnosed as having acute myelogenous leukemia at the age of 18 years, and had bone marrow transplantation (BMT) two years after the onset of the disease. Cutaneous manifestation of acute GVHD appeared on the twelfth day following BMT, which responded to prednisolone. Thereafter, GVHD has been well-controlled except for mild liver dysfunction which was thought to be a sign of chronic GVHD. Eleven months after BMT, he enjoyed snowboarding for two days from morning till night. Two days later, he experienced muscle swelling with pain and fever, which gradually worsened for which he was admitted to our hospital. Neurological examination revealed severe proximal and distal muscle swelling with fever and tenderness in all extremities. Mild, symmetrical, proximal weakness was observed in all four limbs. Severity of muscle swelling and its generalized nature restricted the movements of shoulder-, elbow- and ankle-joints and he was unable to walk. Laboratory investigations revealed creatine kinase (CK) of 7,860 IU/L, C-reactive protein (CRP) of 21.5 mg/dL and raised biliary enzymes. MRI generated high intensity signals from the swollen muscles. Muscle biopsy examination of involved areas showed severe interstitial edema and mononuclear cells infiltration. Macrophages were scattered through out the perimysium and endomysium. On the other hand, T cells and B cells were localized to the endomysium. Although a lot of CD8 positive T cells were seen adjacent to non-necrotic fibers, none of them was obviously invading the non-necrotic fibers. Perifascicular atrophy was not seen. Symptoms gradually worsened over two weeks or so when prednisolone was started to which he responded rapidly. While tapering steroids, the symptoms relapsed on resuming aggressive exercise. Resumption of the treatment regime promptly controlled the symptoms. The cause of myositis as a manifestation of chronic GVHD is unclear. T-cell or B-cell dysfunction, collagen-vascular-like processes, viral infection and direct damage by radiation or chemotherapy have been supposed to involve in the disease process. Our case suggests that aggressive muscular exercise could play as a initiator of myositis as a manifestation of chronic GVHD.

[A case of chronic inflammatory demyelinating polyneuropathy presenting with acute pain and SIADH followed by weakness of all four limbs 2 month after the first symptoms].

We report a 73-year-old man who presented symptoms of low back pain and SIADH followed by weakness of all four limbs and sensory disturbance of the lower legs 2 month after the first symptoms. He was referred to our department because of the evolution of weakness. Neurological examination on admission revealed weakness of the arms and legs, areflexia, and hypoesthesia of the lower legs. The straight leg raising test induced prominent radiating pain bilaterally. The level of sodium was 114 mEq/l, the plasma osmolality was 239 mOsm/kg, and the level of plasma antidiuretic hormone was 3.45 pg/ml. Other blood chemical values were unremarkable. The urine osmolality was 527 mOsm/kg. T1-weighted MR image with gadolinium showed thickening and enhancement of the nerve root. Nerve conduction study revealed compromised conduction with demyelinating features, and somatosensory evoked potential study could not show any potentials. He was diagnosed as having CIDP complicating with SIADH. An association between SIADH and AIDP has been much reported previously. To our knowledge, however, there has been no report of SIADH complicating with CIDP.

Roles of mast cells in the pathogenesis of inflammatory myopathy.

INTRODUCTION: In addition to the pivotal roles of mast cells in allergic diseases, recent data suggest that mast cells play crucial roles in a variety of autoimmune responses. However, their roles in the pathogenesis of autoimmune skeletal muscle diseases have not been clarified despite their distribution in skeletal muscle. Therefore, the objective of this study is to determine the roles of mast cells in the development of autoimmune skeletal muscle diseases. METHODS: The number of mast cells in the affected muscle was examined in patients with dermatomyositis (DM) or polymyositis (PM). The susceptibility of mast cell-deficient WBB6F1-Kit(W)/Kit(Wv) mice (W/W(v) mice) to a murine model of polymyositis, C protein-induced myositis (CIM), was compared with that of wild-type (WT) mice. The effect of mast cell reconstitution with bone marrow-derived mast cells (BMMCs) on the susceptibility of W/W(v) mice to CIM was also evaluated. RESULTS: The number of mast cells in the affected muscle increased in patients with PM as compared with patients with DM. W/W(v) mice exhibited significantly reduced disease incidence and histological scores of CIM as compared with WT mice. The number of CD8⁺ T cells and macrophages in the skeletal muscles of CIM decreased in W/W(v) mice compared with WT mice. Engraftment of BMMCs restored the incidence and histological scores of CIM in W/W(v) mice. Vascular permeability in the skeletal muscle was elevated in WT mice but not in W/W(v) mice upon CIM induction. CONCLUSION: Mast cells are involved in the pathogenesis of inflammatory myopathy.

Prognostic impact of left ventricular noncompaction in patients with Duchenne/Becker muscular dystrophy--prospective multicenter cohort study.

BACKGROUND: The reported prevalence of left ventricular noncompaction (LVNC) varies widely and its prognostic impact remains controversial. We sought to clarify the prevalence and prognostic impact of LVNC in patients with Duchenne/Becker muscular dystrophy (DMD/BMD). METHODS: We evaluated the presence of LNVC in patients with DMD/BMD aged 4-64 years old at the study entry (from July 2007 to December 2008) and prospectively followed-up their subsequent courses (n=186). The study endpoint was all-cause death and the presence of LVNC was blinded until the end of the study (median follow-up: 46 months; interquartile range: 41-48 months). RESULTS: There were no significant differences in baseline characteristics between patients with LVNC (n=35) and control patients without LVNC (n=151), with the exception of LV function. Patients with LVNC showed, in comparison with patients without LVNC, a significant negative correlation between age and LVEF (R=-0.7 vs. R=-0.4) at baseline; and showed a significantly greater decrease in absolute LVEF (-8.6 ± 4.6 vs. -4.3 ± 4.5, p<0.001) during the follow-up. A worse prognosis was observed in patients with LVNC (13/35 died) than in patients without LVNC (22/151 died, Log-rank p<0.001). Multivariate Cox analysis revealed that LVNC is an independent prognostic factor (relative hazard 2.67 [95% CI: 1.19-5.96]). CONCLUSION: LVNC was prevalent in patients with DMD/BMD. The presence of LVNC is significantly associated with a rapid deterioration in LV function and higher mortality. Neurologists and cardiologists should pay more careful attention to the presence of LVNC.

Efficacy and tolerance of gastrostomy feeding in Japanese muscular dystrophy patients.

Although muscular dystrophy patients often have feeding difficulty and need long-term enteral nutrition, only a few reports have described gastrostomy feeding in these patients. This study was designed to evaluate the efficacy and tolerance of gastrostomy feeding in patients with muscular dystrophy. We performed a retrospective, multicenter study on 144 patients with muscular dystrophy who received gastrostomy feeding between 2007 and 2009 in 25 neuromuscular centers in Japan. There were 77 Duchenne muscular dystrophy (median age at gastrostomy placement 26 years, range 13-47 years), 40 myotonic dystrophy (median age 54.5 years, range 13-70 years), 11 Fukuyama congenital muscular dystrophy (median age 22 years, range 13-29 years), 5 limb girdle muscular dystrophy (median age 62 years, range 43-78 years), and 5 facioscapulohumeral muscular dystrophy (median age 52 years, range 28-67 years) patients. Many benefits including amelioration of malnutrition, swallowing difficulty and respiratory status were observed after the introduction of gastrostomy feeding. Especially in patients with Duchenne muscular dystrophy, mean body weight significantly increased after gastrostomy placement. Although most complications, which are commonly observed in other populations, were tolerable, respiratory failure and peritonitis were important concerns. These findings suggest that gastrostomy placement at an appropriate time is advisable in patients with muscular dystrophy.