Protective reactive thymus hyperplasia in COVID-19 acute respiratory distress syndrome

Abstract Background Patients with COVID-19 (COVID) may develop acute respiratory distress syndrome or without sepsis, coagulopathy and visceral damage. While chest CT scans are routinely performed in the initial assessment of patients severe pulmonary forms, thymus involvement reactivation have not been investigated so far. Methods In this observational study, we systematically scored enlargement lung involvement, using scans, all adult admitted to ICU for COVID any other cause (control group) at one centre between March April 2020. Initial biological investigations included nasal detection SARS-CoV-2 ribonucleic acid by polymerase chain reaction (PCR). a subgroup 24 different degrees hypertrophy, plasma cytokine concentrations were measured export mature T cells from was estimated simultaneously PCR quantification cell receptor excision circles (TRECs). Results Eighty-seven studied: 50 37 controls. Non-atrophic enlarged more commonly observed than controls (66% vs. 24%, p < 0.0001). Thymus associated extensive injury score on (4 [3–5] 2 [1.5–4], = 0.01), but lower mortality rate (8.6% 41.2%, 0.001). Other factors age, lymphopaenia, high CRP co-morbidities. had higher IL-7 (6.00 [3.72–9.25] 2.17 [1.76–4.4] pg/mL; 0.04) thymic production new lymphocytes (sj/?TREC ratio 2.88 [1.98–4.51] 0.23 [0.15–0.60]; 0.004). Thymic also correlated scan ( r 0.38, 0.03) inversely number 0.56, 0.007). Conclusion patients, frequent increased lymphocyte production, which appears be beneficial adaptation virus-induced lymphopaenia. The lack activity/reactivation older infected could contribute worse prognosis.