TB PLEURAL EFFUSION WITH MODEST ELEVATION OF ADENOSINE DEAMINASE

Abstract

SESSION TITLE: Monday Fellow Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Tuberculous pleural effusion (TBPE) occurs in 4% of all tuberculosis cases in the United States. Pleural fluid adenosine deaminase (pfADA) can help distinguish TBPE from other etiologies of pleural effusion. We present a case of TBPE with modest elevation of pfADA. CASE PRESENTATION: A 40 year old African American male with no past medical history, remote history of incarceration, presented with 4 days of fever and nonproductive cough. He denied any night sweats, chills or recent weight loss. Vitals on presentation: temperature 101.6○F, heart rate 115 bpm, blood pressure 129/84 mmHg, respiratory rate 20 breaths/min, pulse oximetry 96% on room air. On exam, he was tachypneic with left lower lung zone rhonchi. Initial investigations revealed leukocyte count of 8.2 (X10ˆ3/μL), elevated CRP at 129 mg/L and normal basic metabolic panel. A chest radiograph showed a large left pleural effusion. Vancomycin and levofloxacin were empirically initiated for suspected left sided pneumonia with parapneumonic effusion. Thoracentesis yielded 1800cc of clear yellow pleural fluid. Analysis revealed a lymphocyte-predominant exudate. (pH of 7.34, neutrophil count 3340, LDH 1551, Protein 4.8). CT of the chest on day 2 of admission demonstrated a new loculated inferior and lateral left base pleural fluid collection. Despite antibiotic therapy, patient continued to be febrile during days 3 and 4. Testing for influenza, HIV, Histoplasma, ANCA and ANA was negative. During a video-assisted thoracoscopy on Day 5, he was found to have fibrinous thick exudates indicating an early empyema with adhesions. Empyema was drained and decorticated, with complete re-expansion of the lung. Pathology of pleural biopsies revealed caseating granulomas indicative of tuberculosis. A quantiferon GOLD test returned positive. pfADA was mildly elevated at 20.5 units/L (normal: 0.0 – 9.4). He was started on treatment for presumptive pleural tuberculosis. Due to nonproductive nature of cough, patient underwent bronchoscopy for a BAL sample on Day 9, and subsequent AFB stain and culture was negative. He was discharged on INH, Rifampin and Pyrazinamide with vitamin B for 2 months, and continued on INH and Rifampin for a further 4 months. DISCUSSION: Measurement of pfADA may be useful to establish a presumptive diagnosis of TBPE relatively expeditiously when AFB stain and culture are negative. Based on several meta-analyses, pfADA levels >45 to 60 units/L is thought to be 97 percent specific for TBPE. Definitive diagnosis is often by the identification of M. Tuberculosis or necrotizing granulomas in pleural tissue or pleural fluid. In the presented case, despite a mildly elevated pfADA level, the diagnosis was clinched with histopathological evidence of tuberculous granulomas. CONCLUSIONS: While pfADA may have a supplementary role in the investigation of AFB-negative pleural effusion, pleural biopsy remains necessary for diagnosis of TBPE. Reference #1: 1. Klimiuk J1, Krenke R, Safianowska A, Korczynski P, Chazan R. 2015. Adv Exp Med Biol. 852:21-30. https://doi.org/10.1007/5584_2014_105 Reference #2: 2. Porcel JM. 2009. Tuberculous pleural effusion. Lung 187:263–270. https://doi.org/10.1007/s00408-009-9165-3. Reference #3: 3. Bays AM, Pierson DJ. Tuberculous Pleural effusion. Respiratory Care Oct 2012, 57 (10) 1682-1684; https://doi.org/10.4187/respcare.01443 DISCLOSURES: No relevant relationships by Dhruv Desai, source=Web Response No relevant relationships by Nikky Keer, source=Web Response No relevant relationships by Ngozika ORJIOKE, source=Web Response