Background Acute respiratory distress syndrome (ARDS) has a very poor prognosis and high mortality. To improve the early diagnosis of ARDS, there is an urgent need for novel biomarkers of ARDS. This project aims to detect novel biomarkers from peripheral blood , which can improve the early diagnosis and develop a more efficient therapy to enhance ARDS patient survival rate. Clinical data and blood sample were recorded before treatment and after treatment. Acute Physiology And Chronic Health Evaluation III (APACHE III) scores were calculated at enrolment. Different kinds of lymphocytes from blood samples would be detected by flow cytometry ,which could be used for discovering high sensitivity and specificity ARDS biomarker.~Eligibility Ages Eligible for Study: 18 years and older Genders Eligible for Study: Both Accepts Healthy Volunteers: Yes Sampling Method: Probility Samples~Study Population Patients who have ARDS and admitted in hospital~Primary Outcome Measures:~ILC2 and ILC3 number from peripheral blood of ARDS patients~Secondary Outcome Measures:~APACHE III score [ Time Frame: baseline, 1week, 2 weeks ] PaO2/FiO2 ratio[ Time Frame: baseline, 1week, 2 weeks ] Mortality or multi-organ failure [ Time Frame: 1 month ]~Groups:~Mild ARDS PaO2/FiO2=201～300 mmHg，and PEEP or CPAP≤5 cm~Moderate ARDS PaO2/FIO2=101～200 mmHg，and PEEP≥5 cm H2O~Severe ARDSPaO2/FIO2≤100 mmHg，and PEEP≥10 cm H2O~Healthy
Acute respiratory distress syndrome (ARDS) has a very poor prognosis and high mortality. To improve the early diagnosis of ARDS, there is an urgent need for novel biomarkers of ARDS. This project aims to detect novel biomarkers from peripheral blood , which can improve the early diagnosis and develop a more efficient therapy to enhance ARDS patient survival rate. Clinical data and blood sample were recorded before treatment and after treatment. Acute Physiology And Chronic Health Evaluation III (APACHE III) scores were calculated at enrolment. Different kinds of lymphocytes from blood samples would be detected by flow cytometry ,which could be used for discovering high sensitivity and specificity ARDS biomarker.