Program cell death 1 (PD1) and program cell death ligand 1 (PDL1) expression in pulmonary aspergillosis with and without SARS-CoV-2 virus infection.

Aims: The effects of COVID-19 virus on chronic pulmonary aspergillosis had not been investigated. This study is to observe the expression of PD1/PDL1 on surface of white blood cells from pripheral blood in patients with pulmonary aspergillosis with or without COVID-19 viral infection. Method: The peripheral blood from patients with Aspergillosis and without Aspergillosis as controll group were collected. Surface marker PD1 and PDL1 expressure on peripheral blood monoculear cells (PBMC) and polymorphic neuclear cells (PMN) were measured by flowcytometry. Results: Among 72 blood samples from 33 patients without Aspergillosis and 35 patients with Aspergillosis, the proportion of PD1 positive cells in PBMC were 44.5±20.6% v.s. 34.8±13.8%, respectively (P>0.05) and the proportion of PDL1 positive cells in PBMC were 14.3±19.2% v.s. 8.3±10.3%, respecitlvey (p>0.05). The expression of PD1 and PDL1 in PMN were not different between the two groups if without viral infection. Among patients with Aspergillosis, the expression of PD1 and PDL1 on surface of PBMC were significantly higher than those with Aspergillosis and were not infected with COVID-19 virus (p<0.05). The proportion of PDL1 positive cells in PBMC were significantly increased in pateints with Aspergillosis after COVID-19 virus infection (p<0.05) (Figure 1). Conclusion: The PD1/PDL1 expression was increased in patients with aspergillosis after COVID-19 virus infection.