[A case of pulmonary sarcoidosis with B lymphocytosis in peripheral blood]

A 24-year-old man was admitted on October 14, 1988, with bilateral cotton-like shadows on chest X-ray film. Chest CT demonstrated multiple nodular shadows in bilateral lung fields. Laboratory data on admission showed peripheral blood lymphocytosis and slight decrease of serum IgG and IgA. ACE was within normal limits, and BALF findings showed no increase of lymphocytes. Surface marker analysis of peripheral blood lymphocytes showed an increase of B lymphocytes of antibody independent stage (B1, B4, J5, OKB7, sIgM, and sIgD positive cells were increased). Southern blot analysis of peripheral blood showed no rearrangement of immunoglobulin chains (H chain and L chain). In order to differentiate sarcoidosis from lymphoproliferative disorder, open lung biopsy was performed. Pathologic study revealed multiple epithelial granulomas without caseation. Immunohistochemical study demonstrated no accumulation of B cells of the lung. This patient was pathologically diagnosed as having pulmonary sarcoidosis. The abnormal chest shadows gradually improved without therapy; however, B cell lymphocytosis and slight decrease of serum IgG and IgA persisted. In general, lymphocytopenia of peripheral blood is usual in sarcoidosis. We report a rare case of pulmonary sarcoidosis with polyclonal B lymphocytosis of antibody independent stage in peripheral blood.