There were significant differences in the level of cytokines when comparing viral ARDS with bacterial ARDS.Key messages? In the influenza-related inhibitor Brefeldin A ARDS group, the levels of IL-6, IL-8, IL-9, IL-12, IL-15, IP-10 and TNF�� are significantly increased versus the control group. In the bacterial sepsis-ARDS group, levels of IL-6, IL-8, IL-9, IL-15, IL-17, IP-10 and TNF�� are also increased versus the control group. When comparing these two groups, the levels of IL-8, IL-17 and TNF�� are significantly higher in bacterial ARDS versus viral ARDS, and IL-12 is increased only in viral ARDS whereas IL-17 is increased only in bacterial ARDS. When comparing the mild nvA(H1N1) and critical ARDS influenza A groups, IL-6, IL-8, IL-15 and TNF�� are significantly higher in critical ARDS patients being hallmarks of disease severity.
? The serum levels of IL-15, IL-6, IL-8 and IFN�� according to the interval between symptom onset and admission in hospitalized nvA(H1N1) patients are significantly higher when this interval is longer than 5 days.? In nonsurvivors versus survivors from the nvA(H1N1)-ARDS group, IL-6 and IL-15 are increased at admission and stay higher 3 days later – which seems to further contribute to pulmonary damage and death.? There is a positive correlation of IL-6, IL-8 and IL-15 levels with C-reactive protein and with > 5-day interval between symptom onset and hospital admission, and a negative correlation with the PaO2:FiO2 ratio.? The obese patients versus nonobese patients with nvA(H1N1) infection have a significant level of IL-8.
AbbreviationsAPACHE: Acute Physiology and Chronic Health Evaluation; ARDS: acute respiratory distress syndrome; ELISA: enzyme-linked immunosorbent assay; ICU: intensive care unit; IFN: interferon; IL: interleukin; IP-10: interferon-inductible protein-10; nvA(H1N1): novel A(H1N1) virus; PaO2/FiO2: pressure of oxygen in arterial blood/fraction of inspired oxygen; PCR: polymerase chain reaction; SOFA: Sepsis-related Organ Failure Assessment; Th: T-helper type; TNF: tumor necrosis factor.Competing interestsThe authors declare that they have no competing interests.Authors’ contributionsNH and AS designed the study, coordinated patient recruitment, supervised laboratory works and wrote the article. DNG and SO performed cytokine profiling and wrote the report. DSD, ESB and MMa collected clinical and laboratory data, and wrote the report.
CC assisted in the design of the study and assisted in writing the paper. MMl, RLG and CL supervised clinical aspects, participated in patient recruitment. RH contributed to the statistical analysis. MP provided GSK-3 pulmonary histopathological analysis. DMS assisted in the design of the study, coordinated patient recruitment, analyzed and interpreted the data. All authors read and approved the final manuscript.