We report a case of pleural effusion due to MAI infection in a patient with chronic sarcoidosis on systemic glucocorticoid therapy. We have not found any previous descriptions in the medical literature of this association.
A 39-year-old African-American female presented with acutely worsening dyspnea. Seven years previously, she had been diagnosed with pulmonary and cutaneous sarcoidosis, but refused treatment. She re-presented five years later with evidence for advanced interstitial lung disease and agreed to begin systemic glucocorticoids. She also had a past medical history of asthma and hypertension. Her presentation with acute dyspnea occurred while on maintenance prednisone of 15 mg/day. The dyspnea was different from her usual asthma exacerbations. She was afebrile. Chest auscultation revealed decreased breath sounds over the right hemithorax. Chest radiograph showed whiteout of the right hemithorax; left lung infiltrates unchanged from previous radiograph (Figure 1). Chest CT confirmed a massive right effusion with no new parenchymal disease. She denied fever, night sweats, chest pain and weight loss. She worked at a nursing home and had negative purified protein derivative(PPD)skin tests over the previous five years. CBC and serum chemistries were normal. Thoracentesis and pleural biopsy were performed. Pleural fluid was straw-colored with pH 7.48, WBC 2190/mm3, RBC 1200/mm3 (16% segs, 81% lymphs, 3% monos), glucose 100mg/dl, protein 6.9 g/dl, LDH 481U/L. Pleural fluid to serum ratio of protein was 0.84, and of LDH was 1.1. Cytology showed lymphocytes and plasma cells but no AFB or malignant cells. Pleural biopsy revealed chronic granulomatous pleuritis (Figure 2). Special stains showed beaded Fite- positive forms suggestive of mycobacteria. She was started on four-drug therapy for presumed M. tuberculosis. Within one week the fluid had reaccumulated, resulting in severe dyspnea. 80 mg/day prednisone was administered for one week with dramatic decrease in volume of fluid. Within one month, pleural fluid culture grew AFB, positive for MAI complex by nucleic acid probe. She was switched to tri-weekly azithromycin 600 mg, rifabutin 600 mg and ethambutol 1600 mg. Prednisone dose had been reduced to her maintenance levels. She continued to improve clinically with resolution of the pleural effusion over several months.
Incidence of pleural effusion in sarcoidosis is reported to be 0-5% and is a diagnosis of exclusion. These effusions are mostly seen in stage 2 or 3 disease. They may resolve spontaneously within two weeks to six months. Steroids may help with quicker resolution of pleural effusion in some cases 1. MAI infections are rare in immunocompetent patients. They usually occur in immunocompromised patients with AIDS or patients with chronic lung disease. MAI infections involving the pleural space are also rare. There are few case reports of MAI-associated pleuritis in healthy individuals. The diagnosis is considered when MAI is isolated from pleural tissue or fluid in association with granulomatous inflammation 2. Anti-tuberculous chemotherapy is effective with resolution of pleural effusion and minimal pleural thickening and adhesions 3. There are no reported long-term pulmonary complications.
Pleural effusions are uncommon in both sarcoidosis and disseminated atypical mycobacterial infections. Pleural effusion caused by MAI in chronic sarcoidosis on glucocortoid therapy has not been reported. MAI pleural effusion in our patient resolved with chemotherapy for MAI infection.
A.I. Malik, None.