Laboratory examination revealed a hemoglobin of 9.9 g/dL, hematocrit of
28.6%, WBC count of 14.6 × 109/L, and platelet count
of 433 × 109/L. His blood chemistries were within
normal limits, with a lactate dehydrogenase level of 198 U/L and a
total protein level of 6.3 g/dL. The erythrocyte sedimentation rate was
147 mm/h and the reticulocyte count was 7%. An arterial blood gas on
32% supplemental oxygen revealed a pH of 7.45, a
Pco2 of 32 mm Hg, and a
Po2 of 69 mm Hg. The patient underwent a
diagnostic thoracentesis, which revealed turbid fluid, 5,944 nucleated
cells (1% segmented neutrophils, 96% lymphocytes, and 3%
histiocytes), protein 4.3 g/dL, glucose 85 mg/dL, amylase 66 U/L,
lactate dehydrogenase 182 U/L, and triglycerides 1,050 mg/dL. Cytologic
examination of the pleural fluid revealed no malignant cells. Serum
assay revealed an IgG level of 2,730 mg/dL (normal range, 694 to 1,618
mg/dL) and an IgA level of 453 mg/dL (normal range, 63 to 378 mg/dL).
The IgM level was normal at 89 mg/dL, and no paraprotein was found.
Blood, sputum, and urine cultures revealed no microbial growth. The
patient was seronegative for HIV-1 and HIV-2. CT scan of the thorax
revealed bilateral pleural effusions, compressive atelectasis of the
lower lobes bilaterally, and mediastinal adenopathy.