Effects of oral steroids on immunoglobulins in bronchoalveolar lavage fluid in active sarcoidosis

Immunoglobulin (Ig) levels increase in the lower respiratory tract of patients with pulmonary sarcoidosis. We evaluated the effects of prednisone therapy upon Ig concentrations in bronchoalveolar lavage (BAL) fluid of ten patients with active disease (> 30% T-lymphocytes in BAL and positive ⁶⁷Gallium (⁶⁷Ga) lung scan). Therapy significantly lowered T-lymphocyte percentages in BAL and ⁶⁷Ga lung scan indices and was followed by a slight improvement of the studied functional parameters. Biochemical analysis of BAL showed a significant decrease of both IgG/albumin (baseline 1.24 ± 0.21; after therapy 0.40 ± 0.12) and IgA/albumin (baseline 0.55 ± 0.07; after therapy 0.14 ± 0.03) ratios in all patients. Conversely, comparisons of IgM/albumin ratios did not show any change over the study period (baseline 0.05 ± 0.01; after therapy 0.06 ± 0.03). Thus oral steroid treatment suppresses the alveolitis of pulmonary sarcoidosis, as shown not only by the reduction of lung T-cells and ⁶⁷Ga lung uptake, but also by the decreased Ig levels in the alveolar spaces.