Introduction

Rheumatoid arthritis is a chronic systemic inflammatory disorder that may affect many tissue organs –skin, blood vessels, heart, lungs, and muscles but principally affect joints, producing a non suppurative synovitis that often progress to tissue destruction of articular cartilage and ankylosis of joints ₂,₃. The prevalence of Rheumatoid arthritis is approximately 0.8% of the population (range 0.3 to 2.1%) but in India it is exactly not known. Women are affected three times more than men. Rheumatoid arthritis usually appears during 3^rd to 5 ^th decades of life. Their prevalence increases with age. While pleuro-pulmonary manifestations are more likely to be observed in males. The most common lung manifestation is pulmonary fibrosis followed by Pleuritis, Pleural effusion, pulmonary nodules, pulmonary hypertension, and progressive loss of lung volume, secondary amyloidosis, sclerosing mediastinitis and bronchocentric granulomatosis in decreasing order.

Method

During the intake period of 3 year from July 2003 to august 2006, 17 patients of rheumatoid arthritis admitted to the Department of Pulmonary Medicine were evaluated for pleuro-pulmonary manifestations. All patients were classified as rheumatoid arthritis on the basis of American Rheumatism Association 1987 revised classification criteria₁, complete blood counts, C - reactive protein (CRP), serum rheumatoid factor and X-ray Hand & wrist, were done for all patients. Evaluations for pleuro-pulmonary manifestation were done by Chest x-ray PA view, Spirometry and High resolution computerized tomography (HRCT) of thorax. Sputum for AFB was done on three consecutive days in all patients to exclude tuberculosis.

Result

Of the 17 patients with rheumatoid arthritis, 10 were males while 7 were females (Ratio M: F; 1.4:1). The mean age of study group were 52.6 years (Range 18-66). Mean duration of rheumatoid arthritis was 11.9 years. Mean duration of respiratory complaints was 10.3 months (Range 2-14 months). Dyspnoea and dry cough were most common presenting symptoms (76.47 %). Sputum for AFB was negative in all patients. Others system were with in normal limits. Spirometry showed restrictive pattern in 52.9 % cases (Mean FEV1/FVC 86 % and Mean FVC 1.16 Litre) and obstructive pattern noted in 11.8 % while 6 (35.3 %) patients did not cooperate. (Table 1: Shows patient's characteristics of study group).

Figure 1

Table 1

Interstitial lung disease was the most common Pleuro-pulmonary disease pattern being present in 15 patients (88.2 %). Among Interstitial lung disease (ILD), Usual Interstitial Pneumonia (UIP) was most common pattern noted in 13 (88.7 %), followed by Bronchiolitis obliterans organizing pneumonia (BOOP) in 2 (13.33 %). Pleural effusion was observed in 2 (11.8 %) of all patients. (Table 2: Showing pleuro-pulmonary abnormality seen on HRCT Thorax).

Figure 2

Table 2

Discussion

It is now known that Interstitial Lung Disease is both the most common and most serious pleuro-pulmonary complication of rheumatoid arthritis₄. Ellman and Ball first noted the association between pulmonary fibrosis and rheumatoid arthritis in 1948₅.

ILD is a relatively common complication in RA being reported in 19-44% in four prospective studies₆,₇,₈,₉. Generally two patterns of Interstitial Lung Disease are more common amongst RA, Usual Interstitial Pneumonia (UIP) and Bronchiolitis obliterans organizing pneumonia (BOOP). These patients have complaints of breathlessness and dry cough. Physical examination reveals bibasilar crepts. Chest x-ray shows interstitial infiltrates mostly basal and in peripheral parts of lungs. HRCT Thorax is characteristic in Usual Intestitial Pneumonia (UIP) and is characterized by presence of reticular opacity predominatly in the subpleural regions of lung bases and often associated with cystic air spaces measuring 2 to 20 mm (honey combing)₁₀,₁₁,₁₂. Disease activity is characterized by presence of patchy areas of hazy increased density (Ground glass opacity) ₁₃. While Bronchiolitis obliterans organizing pneumonia (BOOP) is characterized by patchy unilateral or bilateral air space consolidation₁₄.

Pleuritis is reported in 21 % cases. Pleural effusion is occasional manifestation being reported in 3-5% of cases in different studies₁₅. The patients are usually asymptomatic but sometimes complicated by severe pluritic pain, fever, breathlessness. Pleural effusion is usually small and unilateral but may be large and bilateral. Pleural fluid is characteristic and shows exudative type (protein usually >3.0gm/dl), low sugar (<50 mg/dl) in about 75% of patients, raised LDH, raised cholesterol and high Titer of RF ₁₆,₁₇. Another typical abnormality is high pleural fluid/blood ratio of neuron specific enolase, rising 10 or more times ₁₈.

Others less common pleuro-pulmonary manifestations of rheumatoid arthritis are rheumatic nodules ₁₉, Caplan's syndrome ₂₀, upper zone fibrosis and cavitation, upper airway obstruction occasionally resulting into stridor₂₁ and Obstructive sleep apnoea as well as Central sleep apnoea. Others rare lung manifestation of rheumatoid arthritis are, Pulmonary hypertension₂₂, progressive loss of lung volume due to diapharagmatic dysfunction₂₃, secondary amyloidosis₂₄, sclerosing mediastinitis₂₅ and bronchocentric granulomatosis₂₆ .

The present study has shown that Interstitial Lung Disease, predominantly usual interstitial pneumonia (UIP) is the most common pleuropulmonary manifestation in Rheumatoid arthritis patients.

Correspondence to

Dr. R.Prasad M.D., FAMS Professor & Head Department of Pulmonary Medicine C.S.M. Medical University,UP, Lucknow, India-226003 E-mail: rprasad2@sancharnet.in rprasad2@rediffmail.com Phone: 0522-2255167 FAX: 0522-2255167