A rare case of IgG4 related disease presented by recurrent pleural effusion

초록

Introduction: Immunoglobulin G4 (IgG4)-related disease is characterized by lymphoplasmacytic infiltration and elevated serum IgG4 level. IgG4-related would involve various organs such as pancreas, kidney, or retroperitoneum, but there is a rare condition that involves the pleura and presents as pleural effusion. Case Report: A 65-year-old man came to the hospital due to ten days of dyspnea. In the past medical history, he was diagnosed as pulmonary tuberculosis and tuberculous pleurisy and took anti-tuberculosis (TB) medication three years ago. On initial chest CT scan, loculated right pleural effusion and diffuse pleural thickening were observed. At the pleural fluid analysis, the pleural effusion showed lymphocyte-dominant, exudate pattern, and the ADA level was 188 IU/L. Malignant cells were not observed in pleural cytology, and acid-fast bacilli (AFB) stain of sputum and pleural fluid were negative. Although the AFB result was confirmed negative, we diagnosed pleural effusion as tuberculous pleurisy considering pleural fluid analysis and elevated ADA level. Even after a month of anti-TB medication, the pleural effusion did not improve. VATS with pleural biopsy was done, and the pathologic findings showed the lymphoplasmacytic infiltration. Total IgG level in serum was 1824.7 mg/dL, IgG4 subclass level was 75.2 mg/dL and IgG1 subclass level was 1273.4 mg/dL. On abdominal CT, there was no evidence of invasion into the pancreas or kidney. Based on all the results, he was diagnosed as IgG4-related pleural disease and took the systemic steroids (prednisolone 0.5 mg/kg). At discharge, the patient's dyspnea improved. Two months later, pleural effusion was completely resolved on chest radiography in the outpatient clinic. Discussion: We report a rare case which confirmed IgG4-related pleural effusion and fully recovered after systemic steroid treatment.