Thymosin α1 Therapy in Critically Ill Patients with COVID-19: a Multicenter Retrospective Cohort Study

Wu, Ming; Ji, Jing-jing; Zhong, Li; Shao, Zi-yun; Xie, Qi-feng; Liu, Zhe-ying; Wang, Cong-lin; Su, Lei; Feng, Yong-wen; Liu, Zhi-feng; Yao, Yong-ming

BACKGROUND: COVID-19 characterized by refractory hypoxemia increases patient mortality because of immunosuppression effects. This study aimed to evaluate the efficacy of immunomodulatory with thymosin α1 for critical COVID-19 patients. METHODS: This multicenter retrospective cohort study was performed in 8 government-designated treatment centers for COVID-19 patients in China from Dec. 2019 to Mar. 2020. Thymosin α1 was administrated with 1.6 mg qd or q12 h for more than 5 days. The primary outcomes were the 28-day and 60-day mortality, the secondary outcomes were hospital length of stay and the total duration of the disease. Subgroup analysis was carried out according to clinical classification. RESULTS: Of the 334 enrolled COVID-19 patients, 42 (12.6%) died within 28 days, and 55 (16.5%) died within 60 days of hospitalization. There was a significant difference in the 28-day mortality between the thymosin α1 and non-thymosin α1-treated groups in adjusted model (P=0.016), without obvious differences in the 60-day mortality and survival time in the overall cohort (P>0.05). In the subgroup analysis, it was found that thymosin α1 therapy significantly reduced 28-day mortality (HR, 0.11, 95% CI 0.02-0.63, P=0.013) via improvement of Pa0(2)/FiO(2) (P=0.036) and prolonged the hospital length of stay (P=0.024) as well as the total duration of the disease (P=0.001) in the critical type patients, especially those aged over 64 years, with white blood cell >6.8×10(9)/L, neutrophil >5.3×10(9)/L, lymphocyte <0.73×10(9)/L, PaO(2)/FiO(2)<196, SOFA >3, and APACHE II >7. CONCLUSION: These results suggest that treatment with thymosin α1 can markedly decrease 28-day mortality and attenuate acute lung injury in critical type COVID-19 patients.