Acute bilateral pleural effusions in ankylosing spondylitis

Ankylosing spondylitis is a relatively common chronic inflammatory disease that affects the spine, sacroiliac joints, peripheral joints and affects multiple other tissues, which can progress to bony fusion of the spine. Pleural and pulmonary manifestations are rare, though upper lobe fibro cavitary disease is recognized in Ankylosing spondylitis. We present a 38-year old man with bilateral pleural effusion with accompanying fever, who responded to steroid therapy.


Introduction
Ankylosing spondylitis is a relatively common chronic inflammatory disease that affects the spine, sacroiliac joints, peripheral joints and affects multiple other tissues, which can progress to bony fusion of the spine. Pleural and pulmonary manifestations are rare, though upper lobe fibro cavitary disease is recognized in Ankylosing spondylitis. We present a 38-year old man with bilateral pleural effusion with accompanying fever, who responded to steroid therapy.

Case report
A 38 -year-old man presented with dyspnea, left sided pleuritic chest-pain and fever. He had no history of hemoptysis, cough and weight loss. He had been on sulfasalazine for 8 months before his presentation and specific physiotherapy for his back pain and shoulder pain. On examination, he was febrile, tachypnoeic, with a pulse rate of 90 /min, and a blood pressure of 140/80 mmHg. He had features suggestive of bilateral pleural effusions. Spinal movements and movements of both shoulders were mildly restricted in all directions. He had no evidence of active arthritis. Rest of his examination was normal.
His chest X-ray showed a homogenous opacity obscuring lingual lobe and lower lobe of left lung and lower lobe of right lung compatible with a pleural effusion ( Figure 1A). Obliteration of his sacroiliac joints as well as calcification of the anterior longitudinal ligament, squaring of vertebrae and fusion of syndesmophytes were remarkable on his pelvic and spine X-rays ( Figure  2).
His complete blood count showed normal cell count with differential count (Haemoglobin-12.8g/dL, White cell count-5800/mm3 with 75% neutrophils

Acute bilateral pleural effusions in ankylosing spondylitis
Aravinthan Narani 1 , Selladurai Pirasath 2 and 15% lymphocytes). His inflammatory markers were high (Erythrocyte Sedimentation Rate-108 mm/h, C-Reactive protein 211 mg/dL). His serum electrolyte, urine analysis, renal and liver function tests were all within normal limits. No bacterial growth was observed on urine and blood cultures. Both retroviral and syphilitic screenings were negative. Sputum for Acid fast bacilli was negative on 3 occasions and his mantoux was negative. Antinuclear antibody and rheumatoid factor were negative.
Pleural fluid aspiration revealed an exudative effusion with a lactate dehydrogenase of 2208 IU/dL, glucose level of 50 mg/dL and total protein of 4 g/dL, Culture, including for tubercle bacilli, was negative. Pleural fluid for tuberculosis polymerase chain reaction was negative. Pleural fluid cytology showed lymphocytic rich effusion with reactive mesothelial cells and no malignant cells. Serum angiotensin converting enzyme level was normal. Mycoplasma IgM was negative, IgG was positive, however there was no four-fold increase between the initial and convalescent samples. However pleural fluid adenosine deaminase level was slightly elevated at 52IU/L (45-160 U/L with a mean level of 100U/L suggestive of tuberculosis). Contrast enhanced computed tomography of chest showed bilateral pleural effusion due to ankylosing spondylotis or infection.   Meanwhile, an intercostal tube was inserted on his left side to drain pleural fluid and he was started with Co-amoxiclav and Meropenam and with antituberculosis treatment as tuberculosis is endemic in Sri Lanka. Despite therapy, his inflammatory markers continued to be markedly elevated and he continued to have bilateral pleural effusions. A course of prednisolone 50 mg daily was begun with a diagnosis as spondylitic pleural effusion after excluding possible aetiology. He responded quickly to treatment and all his symptoms completely resolved within a few days. Bilateral pleural effusions completely resolved on chest X-ray after few days of starting steroids (Figure 1 B). Steroid-dose was gradually tapered to 10 mg/daily and was continued for 9 months.

Discussion
Ankylosing spondylitis (AS) is a chronic seronegative spondyloarthritis associated with HLA B27 [1]. Pulmonary manifestations are rare causing upper lobe fibro cavitary disease [1]. These have a significant variation in the literature [2]. Dudley-Hart et a1 [3] reported two patients with history of pleurisy and one of them had a pleural effusion in 1950. Zorab has reported one tuberculous and one non-tuberculous pleural effusion among 53 cases of ankylosing spondylitis in 1962 [4]. Crompton et al noted bilateral pleural calcification in out of 255 patients with ankylosing spondylitis unrelated to tuberculosis or asbestos exposure in 1974 [5]. Kinnear and Shneerson had reported only pleural effusion without apical involvement [6]. These effusions were bilateral [1] or unilateral [2,6] and recurrent [6,7]. There were pleural effusions coexistent with pericardial effusion in some cases [8]. Spencer et al described bilateral pleural thickening in one out of 200 patients with ankylosing spondylitis [9]. The temporal relationship between activity in the spinal and pleural disease or of the response to treatment were not observed. Pleural fluid analysis had no specific features and is usually exudative with normal cell count and glucose [4]. In our case, the fluid was an exudate with a normal glucose content and pH. These results are similar to reported cases in AS. Pleural effusion resolves spontaneously in some cases. However, systemic or local steroids or phenylbutazone had been effective in the pleural effusion [10]. Our patient resolved completely after systemic administration of steroids. Pleural effusion occurs in autoimmune connective tissue diseases as a part of the inflammatory component. Here, it could also be due to serositis related to ankylosing spondylitis [11].
In summary, we present a case of AS who had pleural effusion and responded well to prednisolone. The clinician should be aware of this presentation of AS without apicobullous disease.