Step-up versus primary intensive approach to the treatment of interstitial pneumonia associated with dermatomyositis/polymyositis: a retrospective study

Corticosteroids (CS) are the standard initial treatment for interstitial pneumonia (IP) associated with dermatomyositis (DM)/polymyositis (PM). However, many patients fail to respond and have significantly high mortality even if immunosuppressive drugs (ISDs) are subsequently added, while a more intensive initial approach using ISDs is suggested to improve their survival. We conducted a retrospective study to examine the association between initial therapeutic approaches and clinical outcomes of active IP in DM/PM patients. We reviewed medical records of 34 consecutive DM/PM patients who had active IP defined by the presence of pulmonary function abnormality or active symptoms, and compared clinical outcome between those patients to whom ISDs were added if CS alone did not result in a favorable response (a step-up approach) and those who were started on ISDs simultaneously with CS (a primary intensive approach). Clinical endpoints were death, pulmonary death, and progression or improvement of pulmonary function. The step-up approach was used in 20 patients, to 11 of whom ISDs were eventually added after a median of 2.0 weeks, while the primary intensive approach was used in 14 patients. The primary intensive approach group had significantly better survival than the step-up approach group (P = 0.030 by the log-rank test). These two groups did not differ significantly in demographic characteristics and baseline clinical and laboratory features. Intensive approach by starting ISDs simultaneously with CS in the initial treatment for active IP in DM/PM patients was associated with better survival, emphasizing the impact of initial treatment on their survival. Prospective clinical investigation of this approach is now needed, but the limited clinical utility of CS as an initial treatment might ethically challenge clinical-trial designing.     

A case of polymyositis complicated with myasthenic crisis

We report a 62-year-old woman who suffered from polymyositis (PM) complicated with myasthenic crisis. Electromyography and muscle biopsy indicated a diagnosis of PM; however, respiratory failure due to respiratory muscle weakness was seen in spite of a normal serum creatine kinase (CK) level. The positive anti-acetylcholine receptor antibody led us to the diagnosis of myasthenic crisis. PM with respiratory muscle weakness is rare. We suggest that the possibility of other neurological disorder complications should be considered when PM patients have respiratory muscle weakness out of proportion to the serum CK level.     

Hypernatremic myopathy caused by a hypothalamic mixed germ cell tumor mimicking polymyositis

Hypernatremic myopathy was rarely reported in the literature and its clinical features have never been well-described. We present a 22-year-old man who had adipsic hypernatremia manifested with progressive proximal muscle weakness and remarkably high creatine kinase level that has never been reported in the cases of hypernatremic myopathy. His initial presentations were similar to that of polymyositis without the evidence of central nervous system dysfunction and hypopituitarism. The serum level of sodium at the beginning of myopathy is the lowest known in the literature. All the clinical presentations in this patient resulted from a hypothalamic mixed germ cell tumor with sub-acute intra-tumoral hemorrhage.     

Pregnancy outcome in idiopathic inflammatory myopathy

The aim of our study was to assess the prevalence and outcome of pregnancy in idiopathic inflammatory myopathy patients who became pregnant after the onset of the disease. Female idiopathic inflammatory myopathy patients (173) were included in our study. The patients’ charts and clinical data were retrospectively analyzed. One hundred and four female idiopathic inflammatory myopathy patients had 186 pregnancies, but only nine of these patients (4 polymyositis-PM, 5 dermatomyositis-DM) became pregnant after the onset of the disease. Nine patients with pregnancies after the disease onset had 14 gravidities. Six pregnancies resulted in normal deliveries, two ended in prematurity, six ended in abortions (two induced abortions). Regarding the four patients (3 PM, 1 DM) with active disease at the time of pregnancy, two pregnancies ended in prematurity, four ended in spontaneous abortion and one healthy baby delivered. The other five patients (2 PM, 3 DM) with the disease in remission had uneventful pregnancies and healthy babies were delivered. Treatment was not required during pregnancy in case of two dermatomyositis patients with long lasting remission. New onset dermatomyositis developed in one patient in her pregnancy’s third trimester. The mean weight of newborns in the active myositis cases was 2,193 (1,680–2,700) g; while in patients with remission was 3,167 (2,800–3,800) g. The active maternal disease in idiopathic inflammatory myopathy (IIM) might result intrauterin retardation and death. Disease activity in active and new-onset cases could be controlled by increasing the dose of corticosteroid.     

Steroid-responsive subacute polymyositis in an adult following respiratory syncytial virus infection

The role of viral infections in the aetiopathogenesis of polymyositis remains speculative. We report a case of profound subacute polymyositis with incipient ventilatory failure following serologically confirmed infection by respiratory syncytial virus (RSV), with a dramatic and sustained response to pulse corticosteroid therapy. We suggest a possible autoimmune mechanism to account for this sequence of events.     

Clinical interpretation of antinuclear antibody tests in systemic rheumatic diseases

Autoantibody tests have been used extensively in diagnosis and follow-up of patients in rheumatology clinics. Immunofluorescent antinuclear antibody test using HEp-2 cells is still considered the gold standard for screening of autoantibodies, and most of specific autoantibodies are currently tested by ELISA as a next step. Among the many autoantibody specificities described, some have been established as clinically useful diagnostic markers and are included in the classification criteria of diseases. Despite a long history of routine tests and attempts to standardize such assays, there are still limitations and problems that clinicians need to be aware of. Clinicians should be able to use autoantibody tests more efficiently and effectively with a basic knowledge on the significance of and potential problems in autoantibody tests.     

Clinical and histopathological features of myopathies in Japanese patients with anti-SRP autoantibodies

To elucidate the clinical and histopathological features associated with autoantibodies to the signal recognition particle (SRP), we have studied 23 Japanese patients with this specificity among 3,500 patients with polymyositis/dermatomyositis and other connective tissue diseases. Anti-SRP antibodies were determined based on analysis of RNA and protein components by immunoprecipitation assays. The pathological analysis was performed by using special stainings including alkaline phosphatase, myosin ATPase, and modified Gomori trichrome stainings. Twenty-one (92%) of these 23 patients had myositis, 8 of whom (38%) required cytotoxic agents or intravenous immunoglobulin therapy in addition to corticosteroid therapy. Four patients (16%) had rheumatoid arthritis, two of whom had no features of myositis. Muscle biopsy specimens of 11 patients were examined histologically in detail. All 11 had muscle fiber necrosis and/or regeneration, but only one had infiltration of inflammatory cells. Six of the 11 (55%) patients showed type I fiber predominance by ATPase staining, while eight control myositis patients without anti-SRP antibodies did not. There was no correlation of other neurogenic features in histology with the presence of anti-SRP antibodies. These studies suggest that anti-SRP autoantibodies are most likely to be related to myopathies that are resistant to corticosteroid therapy and without inflammation histopathologically. An erratum to this article can be found at     

Polymyositis-like syndrome caused by hypothyroidism, presenting as camptocormia

Polymyositis-like syndrome characterized by proximal muscle weakness and elevation of muscle enzymes may be a presenting manifestation of hypothyroidism. Camptocormia, which can be caused by myopathy of the paraspinal muscles, is an involuntary truncal flexion of the thoracolumbar spine while standing or walking. Among various neuromuscular disorders, hypothyroidism has not been reported in the literature as a cause of camptocormia. This is the first report of polymyositis-like syndrome with camptocormia caused by hypothyroidism.     

以肾脏损害为主要表现的多发性肌炎与皮肌炎四例临床分析

目的 探讨以肾脏损害为主要表现的多发性肌炎(PM)与皮肌炎(DM)的诊断和临床特点.方法 回顾性分析4例肾脏损害合并PM与DM患者的临床资料,并结合文献复习其临床特点和诊治进展.结果 4例患者均为女性,中位年龄数为55岁,肾脏表现分别为局灶节段硬化性肾小球肾炎、肾小球轻微病变、Ⅰ型肾小管酸中毒和慢性肾衰竭.其中1例合并膀胱肿瘤,同时出现肾衰竭.另3例肾脏病变轻微,临床表现为微量白蛋白尿或少量蛋白尿,肾功能正常.上述肾脏损害在PM/DM中均不常见.结论 PM和DM的诊断应结合临床资料、肌酶水平和肌电图检查,有条件者应行肌肉活检以确诊,同时应排除可能的恶性疾病.该病肾脏损害少见,常见的病理类型为系膜增生性肾小球肾炎,治疗可用糖皮质激素、免疫抑制剂等,也可试用免疫球蛋白或甲泼尼龙冲击治疗.