Rheumatoid lung

Epidemiology

RA affects 0.5-1% of the population. Women 2:1 men .

Pathophysiology

Rheumatoid arthritis (RA) is a systemic autoimmune disease of which we don't know the cause. There are genetic and environmental factors. 

Clinical findings

Joint disease

Symmetrical swelling, pain, and stiffness, with the small joints of the hands, feet, wrist, and ankles most commonly affected in early disease.  Destructive joint changes may appear early in the disease course, with nearly half of patients diagnosed with RA showing radiographic evidence of bone erosions within the first year of disease in some reports.

 Extra-articular manifestations

Extra-articular (outside the joint) manifestations are frequently observed in RA and include inflammatory involvement of the 

• skin
• hear
• lungs
• eyes

PLEURAL DISEASE

 Pleural disease is common in patients with rheumatoid arthritis (RA), but it is usually subclinical. As an example, autopsy studies identified pleural disease in 38 to 73 percent of patients with RA, but only 5 to 21 percent of those affected had complained of pleurisy, and just over 5 percent had radiologic evidence of a pleural effusion. Pleural disease is most common in patients with longstanding RA but can precede joint disease. In addition, it is more common in men and coexists with rheumatoid nodules and interstitial lung disease (ILD) in up to 30 percent of patients.[1]

 Types of pleural disease

RA-associated pleural abnormalities include the following: [1]

• Exudative “rheumatoid” effusion 
• Cholesterol (chyliform) effusion 
• Nonexpandable lung due to pleural inflammation or fibrous peel 
• Drug-induced pleuritis (eg, methotrexate, infliximab) 
• Empyema and pyopneumothorax 
• Bronchopleural fistula 
• Pneumothorax or hemopneumothorax

Testing

Biopsy 

In a patient with a persistent, sterile exudative effusion, but without the classic cytologic finding of rheumatoid pleuritis, chemistries of cholesterol effusion, or pleural pressure characteristics of nonexpandable lung, a pleural biopsy may be helpful in excluding other disorders, such as tuberculosis or malignancy, or securing a diagnosis of rheumatoid pleuritis. Pleural tissue can be obtained percutaneously or during video-assisted thoracoscopy. [1]

Treatment of rheumatoid pleural effusion

Rheumatoid pleuritis and pleural effusions usually do not require specific treatment as they commonly resolve spontaneously or with treatment of RA joint disease, over 1 to 36 months (mean 14 months), although larger effusions are more likely to be symptomatic and require treatment. It is not known whether anti-inflammatory treatment of larger rheumatoid effusions will decrease the likelihood of long-term sequelae such as a trapped lung (fibrothorax). When rheumatoid pleuritis is symptomatic and does not resolve spontaneously, utilize one or more of the following therapies, starting with the least toxic: 

Nonsteroidal anti-inflammatory drugs 

When treatment is needed because of pleuritic chest pain or the size of the effusion, the initial choice is an nonsteroidal anti-inflammatory drug (NSAID); improvement is generally seen within a week. [1]

Glucocorticoids (oral or intrapleural) 

For symptomatic rheumatoid effusions refractory to NSAIDs, after excluding infection, we use a moderate dose of oral glucocorticoids (eg, 10 to 20 mg of prednisolone daily) based upon case reports and our clinical experience. Following improvement, in our opinion, the glucocorticoids should be tapered slowly to prevent relapse (1 to 2 mg per month once the dose has reached 10 mg). If the patient is intolerant of the side effects of systemic glucocorticoid,  administer intrapleural glucocorticoids (eg, 120 to 160 mg of depo-methylprednisolone acetate). Intrapleural glucocorticoid therapy carries an increased risk of pleural infection. The initial management of cholesterol effusions due to rheumatoid pleurisy focuses on treatment of the underlying rheumatoid inflammation, usually with prednisone and sometimes an additional immunosuppressive agent (eg, methotrexate). [1]

Therapeutic thoracentesis for urgent control of dyspnea

The main role of therapeutic thoracentesis is acute relief of dyspnea in a patient with a moderate to large pleural effusion, as long as the effusion is not associated with lung entrapment or trapped lung. For patients with dyspnea at rest or with minimal exertion, a therapeutic thoracentesis will often provide relief of respiratory symptoms while waiting for the effects of enhanced anti-inflammatory treatments. [1]

Pleurodesis and decortication 

Use of chemical pleurodesis and decortication are reserved for refractory effusions and trapped lung from a fibrous pleural peel, respectively.

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Case reports of rheumatoid effusions

(from Avnon LS, Abu-Shakra M, Flusser D, Heimer D, Sion-Vardy N. Pleural effusion associated with rheumatoid arthritis: what cell predominance to anticipate? Rheumatol Int. 2007 Aug;27(10):919-25.) Pleural involvement is the most frequent manifestation of rheumatoid arthritis (RA) in the chest. We report here two patients who presented with large exudative pleural effusions and subsequently developed sero-positive RA. In both cases, the differential cell count of the pleural effusion suggested empyema. A literature review identified that RA-associated pleural effusion afflicts more men than women and 95% of the patients have high titers of rheumatoid factor (RF). In 46% of cases, RA-associated pleural effusion is diagnosed in close temporal relationship with the diagnosis of RA. The effusion is an exudate and is characterized by low pH and glucose level, and high lactic dehydrogenase (LDH) and cell count. At diagnosis there is a tendency for predominant neutrophils to occur consistent with an empyema and 7-11 days later, the cells in the pleural effusion are replaced by lymphocytes. Pleural effusion with predominant eosinophilia is rare. RA patients with acidic effusion and low glucose content with neutrophils predominance should be treated with thoracic drainage and antibiotics until an infection is ruled out. The histo-pathologic findings in pleural fluid of tadpole cells and multinucleated giant cells and the replacement of the mesothelial cells on the parietal pleural surface with a palisade of macrophage derived cells are described as pathogonomic for RA. Treatment with systemic steroids and intra-pleural steroids are effective in most cases. [2]