Pulmonary Manifestations of the Idiopathic Inflammatory Myopathies

To review the epidemiology, general clinical aspects and diagnosis, impact on morbidity and mortality, and general treatment approaches for myositis-associated ILD.

The relevant literature was reviewed.

The clinical, radiographic, and histopathological features of interstitial lung disease (ILD) in idiopathic inflammatory myopathies (IIM) are similar to idiopathic ILD. Patients with a known diagnosis of myositis require prompt clinical evaluation including the determination of myositis-associated autoantibodies. Patients possessing autoantibodies associated with ILD or those with any pulmonary symptoms should undergo a pulmonary function test and high-resolution CT (HRCT) scanning of their lungs.

Despite the lack of placebo-controlled trials, systemic glucocorticoids are considered the mainstay of initial treatment of myositis-associated ILD. Glucocorticoid-sparing agents are often concomitantly administered, particularly in patients with severe disease. The first-line conventional immunosuppressive drugs include either mycophenolate mofetil or azathioprine. If these agents fail or if the pulmonary features are severe or rapidly progressive, then more aggressive immunosuppressive or immunomodulatory therapy including cyclophosphamide, tacrolimus or cyclosporine, rituximab, IVIg, or tofacitinib can be considered. Further investigations are required to assess the role of novel therapies in the treatment of myositis-associated ILD.

Revisar la epidemiología, los aspectos clínicos generales, el diagnóstico, el impacto en la morbilidad y la mortalidad y los enfoques generales de tratamiento para la enfermedad pulmonar intersticial (EPI) asociada a miositis.

Se revisó la literatura relevante.

Las características clínicas, radiográficas e histopatológicas de la EPI en las miopatías inflamatorias idiopáticas (MII) son similares a las de la EPI idiopática. Los pacientes con un diagnóstico conocido de miositis requieren una evaluación clínica inmediata que incluya la determinación de autoanticuerpos asociados a la miositis. Los pacientes que poseen autoanticuerpos asociados con EPI o aquellos con cualquier síntoma pulmonar deben someterse a una prueba de función pulmonar y una tomografía computarizada de alta resolución (TCAR) de sus pulmones.

A pesar de la falta de ensayos controlados con placebo, los glucocorticoides sistémicos se consideran el pilar del tratamiento inicial de la EPI asociada a miositis. Los agentes ahorradores de glucocorticoides a menudo se administran de forma concomitante, particularmente en pacientes con enfermedad grave. Los fármacos inmunosupresores convencionales de primera línea incluyen micofenolato mofetilo o azatioprina. Si estos agentes fallan o si las características pulmonares son graves o rápidamente progresivas, se puede considerar una terapia inmunosupresora o inmunomoduladora más agresiva que incluya ciclofosfamida, tacrolimus o ciclosporina, rituximab, IgIV o tofacitinib. Se requieren más investigaciones para evaluar el papel de las nuevas terapias en el tratamiento de la EPI asociada a la miositis.

Pulmonary involvement is doubtless one the most fatal organ manifestations of the autoimmune rheumatic diseases (ARD) and involves the parenchyma, the vessels, the respiratory system itself, but also the muscles and the pleura. Close and regular screening assessments, identification of risk factors, clinical signs associated with the existence of lung disease should alarm the involved physicians treating these patients. The accurate classification is essential, as different treatment options are nowadays available. Pulmonary manifestations of ARD will be analyzed in this review article with special emphasis on interstitial lung disease and pulmonary hypertension.

Antisynthetase syndrome (AS) is a rare autoimmune disease characterized by autoantibodies against aminoacyl-transfer RNA synthetase and clinical features which can include interstitial lung disease (ILD). Current available evidence of treatment is based on expert opinions and case reports. Here, we present a patient with an initial diagnosis of eosinophilic pneumonia, who was later diagnosed with anti-PL7 antisynthetase syndrome with ILD and eosinophilic inflammation. The patient was non-responsive to classic immunosuppressants but responded remarkably well to intravenous immunoglobulin.

A 60-year-old man with no significant medical history presented to the pulmonology clinic with 2 years of progressive weakness and shortness of breath. Showering and other activities of daily living caused him significant fatigue and dyspnea. He had a 20-pack-year smoking history, but no significant history of alcohol or illicit drug use. He did not take any prescribed or over-the-counter medications for chronic medical conditions and had never been on statin therapy. Vital signs were significant for an oxygen saturation of 91% on 4-L nasal cannula. He required up to 6 L of oxygen during a walk test. Physical examination showed mild inspiratory crackles in the lung bases, loud splitting of the second pulmonic valve (P2) with a right parasternal heave, and 2+ pitting edema in the lower extremities. There was muscle weakness, pain, and wasting of the proximal upper and lower extremities, particularly in his legs. He denied any joint pain, and there was no evidence of rash or dysphagia.

Dermatomyositis (DM) is associated with malignancy and interstitial lung disease. Many malignancies associated with DM occur in organs not routinely screened by national guidelines; thus, best screening practices are still debated. Positron emission tomography (PET) has been suggested as a single study alternative to more complex screening panels and may also be valuable in detecting interstitial lung disease progression. Criticisms of PET screening exams have focused on cost and radiation exposure.

To compare the cost of PET and its variants to conventional malignancy screening panels, and to review concerns regarding radiation exposure in PET.

Four variants of PET and PET-CT were included in the study. The conventional screening panel was defined as CT of the abdomen and pelvis without contrast, CT of the thorax without contrast, CEA, CA 19.9, PSA (men), mammography (women), transvaginal ultrasound (women), cytopathology (women), and CA 125 (women). The MarketScan^® Commercial Claims and Encounters database, a collection of private insurance claims data from 53 million Americans, was queried for every instance of each test from 2005 to 2014 and the mean inflation-adjusted cost of each was recorded. The mean total cost to insurance companies and the mean out-of-pocket costs to patients for PET variants were compared to the costs for conventional panels. Additionally, the cost of pulmonary function tests (PFT) from the same period was evaluated.

From 2005–2014, the mean inflation-adjusted costs of PET have trended downward, but the mean cost of PET-CT have trended upward. The mean total cost to insurance companies for PET-CT whole body was $730.70 and $537.62 greater than the cost of conventional panels for men and women, respectively. The out-of-pocket patient costs for PET-CT whole body was $109.82 and $111.33 less than the cost of conventional panels for men and women, respectively. The mean total cost of PFT was $205.02.

The cost of PET-CT whole body was greater than conventional panels for insurance companies, but patient out-of-pocket costs were lower. PET-CT may also have added value in detecting and monitoring interstitial lung disease progression in DM patients. More data are needed on the efficacy of PET-CT in detecting malignancy in DM patients; however, the cost difference is less than expected, suggesting the single scan could be a reasonable alternative to the conventional screening panel in some patients.