Presently, 6 cases of IgG4-related pleuritis have been reported. We encountered a patient who developed chylothorax due to IgG4-related disease. To our knowledge, such patients have not been reported. This patient developed right-sided chylothorax and left-sided non-chylothorax lymphocyte-predominant pleuritis. Elevated serum and pleural IgG4 concentrations and histopathological analysis of pleural biopsy confirmed the diagnosis of IgG4-related pleuritis. Left-sided pleuritis improved with corticosteroid therapy, but right-sided chylothorax persists. IgG4-related disease can be one cause of chylothorax.
Case ReportA 69-year-old man presented to our hospital complaining of cough and dyspnea on exertion in 2003. He had been diagnosed as having bronchial asthma based on his symptoms and change in peak expiratory flow (morning, 180 mL/s; evening, 420 mL/s). He had also undergone an operation for sinusitis. Infiltration of plasma cells, lymphocytes, and eosinophils was found on pathologic examination.Chest X-ray on his initial presentation showed bronchial wall thickening (Fig. 1A), and computed tomography showed bilateral centrilobular nodules (Fig. 1B). Total cell count in the bronchoalveolar lavage fluid in the right middle lobe was 1,500/mm 3 (neutrophils, 52%; lymphocytes, 4%; eosinophils, 33%; macrophages, 11%). Surgical lung biopsy of the lateral basal segment of the left lower lobe showed bronchiolitis with many plasma cells, lymphocytes, and foamy cells in the bronchial wall, leading to a diagnosis of diffuse panbronchiolitis. After administration of fluticasone/ salmeterol and clarithromycin was started, his symptoms improved. However, in July 2011, dyspnea developed, with a percutaneous oxygen saturation on room air of 94% and bilateral pleural effusions ( Fig. 2A). He was admitted to our hospital for further evaluation.On admission, no superficial lymph node or salivary gland swelling was noted. His white blood cell count was 5,800/mm 3 (eosinophils, 6.1%), and serum IgG, IgG4, and IgE were 1,539 mg/dL, 277 mg/dL (normal range, 4-108 mg/dL), and 2,641 IU/mL, respectively. Serum IL-6 was <8 pg/mL, and his serum angiotensin converting enzyme value was within normal range. Autoantibodies were negative. Computed tomography showed bilateral pleural effusions, bronchiectasis with bronchial wall thickening, and centrilobular nodules (Fig. 2B). The right pleural effusion appeared as a white turbid fluid with a total cell count of 3,980/mm 3 (lymphocytes, 92.0%), total protein of 6.1 g/dL, cholesterol of 92 mg/dL, triglyceride of 215 mg/dL, and adenosine deaminase of 40.8 U/L, with no malignant cells. He was diagnosed as having chylothorax according to the established criteria (1). The left pleural effusion appeared as a clear yellow fluid with a total cell count of 5,870/mm 3 (lymphocytes, 88.5%), total protein of 6.3 g/dL, cholesterol of 79 mg/dL, triglyceride of 8 mg/dL, and adenosine deaminase of 39.9 U/L, with no malignant cells. The IgG4 concentrations in the right and left pleural effusions were 57...