From the Guidelines
Pleural complications of Rheumatoid Arthritis (RA) include pleural effusions, pleuritis, pneumothorax, and pleural thickening, with pleural effusions being the most common manifestation, occurring in approximately 5-20% of patients with RA, as reported in recent studies 1. The clinical presentation of these complications can vary, with some patients being asymptomatic, while others may experience pleuritic chest pain, dyspnea, or cough.
- Pleural effusions typically contain high protein levels, low glucose concentrations, high lactate dehydrogenase (LDH), and low pH.
- Management of these complications generally focuses on treating the underlying RA with disease-modifying antirheumatic drugs (DMARDs) such as methotrexate, hydroxychloroquine, or biologics like TNF inhibitors.
- For symptomatic pleural effusions, thoracentesis may be necessary for both diagnostic and therapeutic purposes.
- Corticosteroids, such as prednisone 20-40mg daily, tapered over weeks, can help manage acute pleuritis, as suggested by recent guidelines 1. These pleural manifestations occur due to the systemic inflammatory nature of RA, where autoimmune mechanisms trigger inflammation in the pleural space, leading to fluid accumulation and tissue damage.
- It is essential to monitor patients with RA for these complications, especially those with a history of smoking, male gender, disease duration and severity, and high titre of RF or CCP, as they are at higher risk of developing interstitial lung disease (ILD) 1.
- Early identification of progressive pulmonary fibrosis is crucial, and antifibrotic therapies, such as nintedanib, may be beneficial in slowing down disease progression, as recommended by recent guidelines 1.
From the Research
Pleural Complications of Rheumatoid Arthritis (RA)
- Pleural effusions and pulmonary nodules are known complications of RA, although pleural extra-articular manifestations without clinical arthritis are rare 2.
- Pleural effusion is common in middle-aged men with RA and positive rheumatoid factor (RF), and has features of an exudate with a high RF titer 3.
- Underlying lung pathology is common, and generally, rheumatoid pleural effusion (RPE) is small and resolves spontaneously, but symptomatic RPE may require thoracocentesis 3.
- Rarely, RPE has features of a sterile empyematous exudate with high lipids and lactate dehydrogenase, and very low glucose and pH levels, which can eventually lead to fibrothorax and lung restriction 3.
Characteristics of Rheumatoid Pleural Effusion
- The differential cell count of the pleural effusion may suggest empyema, with a tendency for predominant neutrophils to occur consistent with an empyema, and later replacement by lymphocytes 4.
- The effusion is an exudate, characterized by low pH and glucose level, and high lactic dehydrogenase (LDH) and cell count 4.
- Pleural effusion with predominant eosinophilia is rare 4.
Treatment and Management
- Treatment with systemic steroids and intra-pleural steroids are effective in most cases 4.
- Oral, parenteral, and intrapleural corticosteroids, pleurodesis, and decortication have been used for the treatment of sterile RPE 3.
- Infected empyema is treated with drainage and antibiotics 3.
- In some cases, the persistence of the effusion does not result in any respiratory complications, and treatment directed solely at elimination of large rheumatoid pleural effusions may be unrewarding and unnecessary, as long as the underlying lung is normal 5.