Yuko Ohnuki

Skeletal Muscle Involvement in Antisynthetase Syndrome

Importance Antisynthetase syndrome, characterized by myositis, interstitial lung disease, skin rash, arthropathy, and Raynaud phenomenon, is a clinical entity based on the presence of aminoacyl transfer RNA synthetase (ARS) antibodies in patients’ serum. However, antisynthetase syndrome is not included in the histological subsets of idiopathic inflammatory myopathies. Objective To elucidate the clinical features of myositis in patients with antisynthetase syndrome. Design, Setting, and Participants In this cohort study, muscle biopsy and blood samples were collected from 460 patients with idiopathic inflammatory myositis from various regional referral centers throughout Japan between October 2010 and December 2014. Data were analyzed in March 2016. Exposures Six different anti-ARS antibodies were detected in serum by RNA immunoprecipitation. Line blot assay and protein immunoprecipitation were also performed. HLA-DRB1 alleles were genotyped. Main Outcomes and Measures The main outcomes were muscle manifestations and histological findings. Predisposing factors, extramuscular symptoms, and follow-up information were also studied. Results Of 460 patients with idiopathic inflammatory myopathies, 51 (11.1%) had anti-ARS antibodies. Of this subset, 31 (61%) were women, with a mean (SD) age at disease onset of 60.2 (16.1) years. Among 6 different anti-ARS antibodies, only 1—the anti-OJ antibody—was not detected by line blot assay but by RNA immunoprecipitation. There were no significant HLA-DRB1 alleles associated with anti-ARS antibodies. All 51 patients presented with muscle limb weakness; 14 (27%) had severe limb weakness, 17 (33%) had neck muscle weakness, 15 (29%) had dysphagia, and 15 (29%) had muscle atrophy. Although patients with anti-OJ antibodies showed severe muscle weakness, the clinical presentations of antisynthetase syndrome were relatively homogeneous. In histology, perifascicular necrosis, the characteristic finding of antisynthetase syndrome, was found in 24 patients (47%). Myositis with anti-ARS antibodies responded to the combination of immunosuppressive therapy with favorable outcomes. Interstitial lung disease, found in 41 patients (80%), was more closely associated with mortality than myositis. Conclusions and Relevance Although clinical presentations of antisynthetase syndrome were relatively homogeneous, anti-OJ antibodies were associated with severe muscle involvement. Antisynthetase syndrome is a clinical and histological subset among idiopathic inflammatory myopathies.

HLA-DRB1 alleles in immune-mediated necrotizing myopathy

Immune-mediated necrotizing myopathy (IMNM), also known as necrotizing autoimmune myopathy, is a histologic entity characterized by marked necrosis in the absence of prominent lymphocytes.1 Risk factors or triggers for IMNM include statin treatment, cancer, and connective tissue disease (CTD).1,2 Although autoantibodies against signal recognition particle (SRP) or 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) are regarded as markers for IMNM, they are not always detected in sera of pathologically defined patients with IMNM. The autoimmune mechanisms of IMNM are not elucidated.

Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome) Complicated by Perforation of the Small Intestine and Cholecystitis

We report a case of eosinophilic granulomatosis with polyangiitis (EGPA; formerly known as Churg-Strauss syndrome) complicated by perforation of the small intestine and necrotizing cholecystitis. A 69-year-old man with a history of bronchial asthma was admitted with mononeuritis multiplex. The laboratory findings included remarkable eosinophilia. He was treated with corticosteroids and his laboratory indices showed improvement; however, his functional deficits remained. His neuropathy gradually improved after the addition of intravenous immunoglobulin (IVIG). He was subsequently treated with oral prednisolone (40 mg/day) as maintenance therapy. Within a month after finishing IVIG, he developed perforation of the small intestine and necrotizing cholecystitis. Intestinal perforation has often been reported as a gastrointestinal complication of EGPA. In contrast, cholecystitis is a rare complication. We report this case because the manifestation of more than one complication is extremely rare. Gastrointestinal symptoms may be a complication of EGPA itself and/or immunosuppressive treatment.

Novel SPG11 Mutations in a Patient with Symptoms Mimicking Multiple Sclerosis

We describe the cases of two sisters with spastic paraplegia 11 (SPG11). The younger sister developed relapsing lesions in the brain white matter with enhancement during the acute phase that mimicked multiple sclerosis (MS). The elevation of myelin basic protein in the cerebrospinal fluid (CSF) suggested demyelination, but a normal IgG index, the absence of oligoclonal bands, and the ineffectiveness of steroid treatment indicate that an autoimmune mechanism may not have been involved. In these affected sisters, we identified novel compound heterozygous mutations in the SPG11 gene. Our cases indicate the possible existence of a broader phenotypic spectrum of SPG11 mutations.

Exome and copy number variation analyses of Mayer–Rokitansky–Küster– Hauser syndrome

Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome is characterized by congenital absence of the vagina and uterus. We conducted genome-wide SNP analyses and exome sequencing to detect the causes of MRKH syndrome. We identified de novo variants of MYCBP2, NAV3, and PTPN3 in three families and a variant of MYCBP2 in a sporadic case. Here, we demonstrated the partial genetic makeup of Japanese MRKH syndrome.

Reference Grade Characterization of Polymorphisms in Full-Length HLA Class I and II Genes With Short-Read Sequencing on the ION PGM System and Long-Reads Generated by Single Molecule, Real-Time Sequencing on the PacBio Platform

Although NGS technologies fuel advances in high-throughput HLA genotyping methods for identification and classification of HLA genes to assist with precision medicine efforts in disease and transplantation, the efficiency of these methods are impeded by the absence of adequately-characterized high-frequency HLA allele reference sequence databases for the highly polymorphic HLA gene system. Here, we report on producing a comprehensive collection of full-length HLA allele sequences for eight classical HLA loci found in the Japanese population. We augmented the second-generation short read data generated by the Ion Torrent technology with long amplicon spanning consensus reads delivered by the third-generation SMRT sequencing method to create reference grade high-quality sequences of HLA class I and II gene alleles resolved at the genomic coding and non-coding level. Forty-six DNAs were obtained from a reference set used previously to establish the HLA allele frequency data in Japanese subjects. The samples included alleles with a collective allele frequency in the Japanese population of more than 99.2%. The HLA loci were independently amplified by long-range PCR using previously designed HLA-locus specific primers and subsequently sequenced using SMRT and Ion PGM sequencers. The mapped long and short-reads were used to produce a reference library of consensus HLA allelic sequences with the help of the reference-aware software tool LAA for SMRT Sequencing. A total of 253 distinct alleles were determined for 46 healthy subjects. Of them, 137 were novel alleles: 101 SNVs and/or indels and 36 extended alleles at a partial or full-length level. Comparing the HLA sequences from the perspective of nucleotide diversity revealed that HLA-DRB1 was the most divergent among the eight HLA genes, and that the HLA-DPB1 gene sequences diverged into two distinct groups, DP2 and DP5, with evidence of independent polymorphisms generated in exon 2. We also identified two specific intronic variations in HLA-DRB1 that might be involved in rheumatoid arthritis. In conclusion, full-length HLA allele sequencing by third-generation and second-generation technologies has provided polymorphic gene reference sequences at a genomic allelic resolution including allelic variations assigned up to the field-4 level for a stronger foundation in precision medicine and HLA-related disease and transplantation studies.

Dual Therapy with Aspirin and Cilostazol May Improve Platelet Aggregation in Noncardioembolic Stroke Patients: A Pilot Study

Objective Some previous studies have found clinical benefit of dual antiplatelet therapy with aspirin and cilostazol for prevention of secondary stroke, but the physiological mechanism involved remains unknown. We aimed to clarify the effects of aspirin/cilostazol therapy on the platelet and endothelial functions of patients with acute noncardioembolic ischemic stroke, in comparison to patients who were treated with aspirin alone. Methods The present randomized prospective pilot study enrolled 24 patients within a week after the onset of noncardioembolic ischemic stroke. The patients were randomly allocated to receive aspirin (100 mg/day) (A group; 11 patients) or cilostazol (200 mg/day) plus aspirin (100 mg/day) (CA group; 13 patients). We measured platelet aggregation, platelet activation, and the thrombomodulin (TM), highly sensitive C-reactive protein (hs-CRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and von Willebrand (vWF) antigen levels and vWF activity over a 4-week period after enrollment. Results There was no significant difference in the platelet functions of the A and CA groups. However, the platelet aggregation induced by adenosine diphosphate (ADP) was decreased at 2 and 4 weeks (p<0.05) after treatment in comparison to the pre-treatment values in the CA group, but not in the A group. Platelet activation, and the hs-CRP, TM, ICAM-1, VCAM-1 and vWF values did not significantly decrease after treatment in either group. Conclusion Although there were no significant differences in platelet aggregation, platelet activation or the endothelial biomarker levels of the A and CA groups, dual therapy with aspirin and cilostazol inhibited platelet aggregation in comparison to the pre-treatment values, similarly to patients who received aspirin alone. This may suggest the clinical usefulness of dual therapy with aspirin and cilostazol in the treatment of patients with noncardioembolic ischemic stroke.

Inflammatory myopathies and human leukocyte antigen

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of subacute, chronic or acute systemic immune‐mediated diseases of the skeletal muscles. Recently, research has shown the utility of adding new classifications of myopathies, mainly based on their pathology and the presence of specific autoantibodies. In addition, developments in genetics have helped reveal the genetic background of IIM. The human leukocyte antigen genomic region has been consistently shown to be the strongest genetic risk factor for IIM. The present review summarizes the previous and current literature on human leukocyte antigen analysis of IIM, as well as future directions for research.