To investigate why human leukocyte-associated antigen-DRB1*0301 (HLA-DRB1*0301) positive Scandinavian patients have a better prognosis than HLA-DRB1*0301 negative patients, the present authors examined patterns of cytokine expression in bronchoalveolar lavage (BAL) cells and BAL fluid (BALF) from patients with pulmonary sarcoidosis and controls.Using real-time PCR, the mRNA expression of selected cytokines in BAL cells from newly diagnosed, untreated nonsmoking patients (n525) and controls (n511) was quantified. Cytokine protein levels in BALF from patients (n534) and controls (n511) were assessed using cytometric bead array. The patients were evaluated and stratified into two subgroups: HLA-DRB1*0301 positive (all with an acute onset) and HLA-DRB1*0301 negative (all with an insidious onset).When comparing patients and controls, BAL cells of the patients expressed significantly higher levels of interferon (IFN)-c and interleukin (IL)-10 mRNA. There were significantly decreased IFN-c and tumour necrosis factor (TNF)-a mRNA levels, and a tendency toward higher levels of transforming growth factor-b1 mRNA in HLA-DRB1*0301 positive compared with HLA-DRB1*0301 negative patients. Protein levels of IL-1b, IL-2, IL-6, IL-12p70 and TNF-a in BALF were significantly higher in patients. HLA-DRB1*0301 positive patients exhibited tendencies to lower levels of most cytokines in BALF.In conclusion, the present data show a reduced expression of T-helper cell type-1 cytokines in human leukocyte-associated antigen-DRB1*0301 positive patients, which may relate to their good prognosis.