Twenty patients with bacterial sepsis-ARDS were included to compare the cytokine levels in viral and bacterial ARDS. Immune suppression (six patients with cancer) was more common in the bacterial sepsis-ARDS group (P = 0.044). The mean (standard deviation) APACHE II score, SOFA score and PaO 2 :FiO 2 ratio were similar in both groups ( Table 1 ). The leukocyte count, C-reactive protein and procalcitonin levels were higher in the bacterial ARDS group than in the nvA (H1N1)-ARDS group (P = 0.047, P = 0.05 and P < 0.001, respectively) ( Table 2) .