Persistent Lymphopenia After Diagnosis of COVID-19 Predicts Acute Respiratory Distress Syndrome: A Retrospective Cohort Study

Abstract BACKGROUND: Acute respiratory distress syndrome (ARDS) is a main characterized by severe Coronavirus disease-2019(COVID-19). Lymphopenia is a marker of immunosuppression following infection. This study was designed to establish whether persistent lymphopenia on the seventh day following the diagnosis of COVID-19 predicts ARDS. METHODS: A retrospective cohort study of 125 patients with COVID-19 admitted to government-designated treatment center between January 14, 2020, and March 20, 2020. All complete blood cell counts during the day 0th, 3rd, and 7th following the diagnosis of COVID-19 were recorded. Patients were grouped based on the depression of the lymphocyte cell count, their return, or their failure to normal. The primary outcome was ARDS, and Secondary outcomes included the development of vital organ dysfunction and hospital lengths of stay. RESULTS: 17.6% (22/125) patients developed ARDS. The lymphocyte counts with ARDS and non-ARDS were 0.94×109/L, 1.20×109/L at admission, respectively (P=0.02). At 3rd and 7th day, the median of lymphocyte count in ARDS was significantly lower compared with that of non-ARDS, Multivariable logistic regression adjusting for potentially confounding factors (including age, comorbidities, APACH II score) showed persistent lymphopenia within 7th day was found to be independently associated with ARDS (OR, 3.94 [95%CI, 1.26-12.33, P=0.018); Further, patients with persistent lymphopenia had longer hospital lengths of stay (p<0.001). CONCLUSION: The results showed persistent lymphopenia on the seventh day following the confirmed COVID-19 predicts ARDS，and it may be a target for immunostimulation for COVID-19 associated ARDS.