RECURRENT PLEURAL EFFUSION: THE INITIAL PRESENTATION OF RHEUMATOID ARTHRITIS

TOPIC: Pulmonary Manifestations of Systemic Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Pleural effusion is an uncommon complication of rheumatoid arthritis (RA), affecting roughly 2-3% of patients. Rheumatoid pleural effusions are typically observed in patients with an existing diagnosis of RA and are seldom the first manifestation of this disease. CASE PRESENTATION: A 48-year-old Hispanic man with no significant past medical history presented to the emergency department (ED) with three weeks of non-productive cough, pleuritic chest pain, and shortness of breath with exertion. On initial presentation, vital signs were within normal limits. Physical exam was remarkable for decreased breath sounds bilaterally with increased prominence in the right lower lobe, dullness to percussion of the right lower lobe, and no crackles. Laboratory studies were notable for mild leukocytosis with a neutrophilic predominance. Computed tomography (CT) angiography of the chest revealed a right sided pleural effusion with compressive atelectasis of the right lower lobe and patchy consolidation of the right middle lobe. The patient underwent right sided thoracentesis with removal of 200 ml of fluid. Pleural fluid analysis demonstrated 19% eosinophils, a glucose of 21 mg/dL, and a lactate dehydrogenase (LDH) of 856 units/L. Cytology was unremarkable. His presentation was attributed to a parapneumonic effusion and he was was discharged on oral antibiotics. He ultimately returned to the ED 9 days later with a similar clinical presentation. Repeat CT of the chest revealed recurrence of the right sided pleural effusion. A chest tube was placed with removal of 500 mL of cloudy yellow fluid. Pleural fluid analysis was remarkable for 7% eosinophils, glucose of 40 mg/dL, LDH of 600 units/L, and a pH of 8.0. Cytology displayed mixed inflammatory cells. Pleural fluid was suggestive of RA pleurisy. Further laboratory workup revealed RA titers of 1:32, A-DNA of 10.0 IU/mL, positive antinuclear antibody, and cyclic citrullinated peptide of 289.4 U/mL. The patient had no symptoms of polyarthritis. Patient was treated with prednisone and methotrexate with complete resolution of symptoms. DISCUSSION: RA should be considered as an etiology in unexplained cases of exudative pleural effusion, particularly when pleural fluid analysis shows low glucose, low pH, and high LDH. Pathognomonic cytologic features of rheumatoid pleuritis include the presence of large, elongated macrophages, giant multinucleated cells, and granular background material. CONCLUSIONS: Rheumatoid pleural effusions can occur before, concurrently with, or after the onset of joint symptoms. Thus, clinicians should not exclude the diagnosis of RA in patients without the typical symptoms of polyarticular joint disease. REFERENCE #1: Chou CW, Chang SC. Pleuritis as a presenting manifestation of rheumatoid arthritis: diagnostic clues in pleural fluid cytology. Am J Med Sci. 2002;323(3):158-161. REFERENCE #2: Rodriguez-Zarco E, Vallejo-Benitez A, Otal-Salaverri C. Pleural Effusion Associate with Rheumatoid Arthritis: Diagnostic Clues. J Cytol. 2019;36(4):222-223. DISCLOSURES: No relevant relationships by Gustavo Avila, source=Web Response No relevant relationships by Jessica Baek, source=Web Response No relevant relationships by Mauricio Hernandez Zuniga, source=Web Response No relevant relationships by Renuka Reddy, source=Web Response No relevant relationships by Claudia Tejera Quesada, source=Web Response