Other treatments for MG include intravenous immunoglobulin and plasma exchange, and these modalities can be considered depending on the patient’s clinical course. In JI-101 conclusion, we report the case of a patient who developed MG 8 years after the onset of ASS\ILD. ILD alone, it is well known that careful attention should be paid to the development of myositis during follow\up. Here, we report a 56\year\old woman whose ILD with anti\EJ antibody had been treated, but 8 years after the onset of ILD, myasthenia gravis (MG) developed. MG is an autoimmune disorder characterized by weakness and skeletal muscle fatigue, and it is sometimes associated with other autoimmune disorders. However, only two cases of polymyositis (PM) with positive antisynthetase antibody\positive PM overlapping JI-101 MG have been reported 3, 4. Both had anti\Jo\1 antibody, and there have been no reports of patients with antisynthetase antibody other than anti\Jo\1 antibody who had overlapping MG. Our case suggests that not only myositis but also overlapping of MG should be considered when antisynthetase antibody\positive ILD patients develop muscle symptoms during their follow\up. Case Report A 56\year\old woman with no past history or family history of note developed dyspnea on effort in November 2007 without muscle pain or arthralgia and presented to a local physician. Heliotrope rush and Gottron’s papules were not found. Serum muscle enzymes were within normal range, and she was unfavorable for anti\Jo\1 antibody, anti\Scl\70 antibody, anti\dsDNA antibody, anti\SS\A/Ro antibody, anti\SS\B/La antibody, anti\RNP antibody, and antinuclear cytoplasmic antibodies. Chest X\ray showed reticular shadows and ground\glass opacities (GGOs) in both lung fields, and her serum KL\6 was elevated to 1460 U/mL. She was diagnosed as having idiopathic interstitial pneumonia, and prednisolone (PSL) 30 mg/day was started. As a result, her conditions improved, as shown by JI-101 chest X\rays, and the dose of PSL was tapered; however, she developed dyspnea and dry cough when the daily dose of PSL was tapered to 10 mg/day. Another chest X\ray showed the development of new GGOs in both lung fields, and she was referred to Saitama Cardiovascular and Respiratory Center for further evaluation in August 2008. On presentation, auscultation detected fine Rabbit polyclonal to PLEKHG3 crackles in both chest fields. She did not have any muscle weakness. Mechanic’s hands were found, but heliotrope rush and Gottron’s papules, which are characteristic of PM/dermatomyositis (DM), were not found. Arterial blood gas analysis showed a pH of 7.46, PaCO2 of 39.2 Torr, and PaO2 of 78.5 Torr under ambient air, and her serum KL\6 was 1982 U/mL. Serum antinuclear antibody was 160 titers (speckled pattern), and she was unfavorable for anti\Jo\1 antibody, anti\dsDNA antibody, anti\SS\A/Ro antibody, anti\SS\B/La antibody, anti\RNP antibody, anti\Scl\70 antibody, and anti\CCP antibody. Chest X\ray showed reticular shadows in both lung fields, and chest computed tomography showed GGOs and reticular shadows predominantly in the lower lobes (Fig. ?(Fig.1A1A and B). Bronchoalveolar lavage fluid showed 48.6% macrophages, 39.3% lymphocytes, 5.6% neutrophils, and 6.5% eosinophils, but the specimen obtained via transbronchial lung biopsy was inadequate for evaluation. We suspected her of having ASS, and serum antisynthetase antibodies other than anti\Jo\1 antibody were investigated by an immunoprecipitation method as reported elsewhere 1, and the result was positive for anti\EJ antibody. Electromyographic findings were normal, but repetitive low\frequency stimulation was not performed. Diagnostic criteria of PM/DM 5 were not satisfied. We diagnosed her as having ASS\ILD and increased her PSL dose to 50 mg/day, which improved the lung opacities (Fig. ?(Fig.1C).1C). The PSL was gradually tapered, but new lung opacities developed in July 2010 when the PSL dose was at 9 mg/day (Fig. ?(Fig.1D).1D). We began cyclosporin A 150 mg/day and increased the PSL to 15 mg/day. The lung opacities improved again (Fig. ?(Fig.1E),1E), but new lesions developed in January 2013 when the PSL was at 5 mg/day (Fig. ?(Fig.1F).1F). The PSL was increased to 15 mg/day, and the cyclosporin A was changed to azathioprine, which was later stopped because of drug\induced liver damage. Tacrolimus 2 mg/day was then introduced, and the PSL was increased to 30 mg/day, which improved the lung opacities, after which the PSL was again gradually tapered. From November 2015, the PSL was tapered from 20 to 17.5 mg/day, but then bilateral ptosis and diurnal variation in muscle weakness (morning\time improvement and evening\time worsening) developed in her proximal lower limbs in December 2015. She did not complain of muscle pain or dyspnea, but manual muscle testing showed muscle weakness (4/5) in her quadriceps. Findings of mechanic’s hands; results of pulmonary function testing including vital capacity, forced expiratory volume in 1 sec, total lung capacity, and residual volume; and results of arterial blood gas analysis indicated no deterioration. Serum muscle enzymes including creatine kinase, aldolase, and myoglobin were not elevated. Her blood concentration of tacrolimus was low in January 2016 (2.9 ng/mL)..