Objective To investigate the difference in plasma cytokine levels between children with severe and non-severe community-acquired pneumonia（CAP） to guide the clinical treatment and related research. Methods Eighty children with CAP admitted to Tianjin Rehabilitation Center from May 2017 to May 2020 were selected as the study subjects. According to whether the child progressed to severe pneumonia

subjects were assigned to the non-severe group（n=37） and the severe group（n=43）. After blood samples were collected from the two groups on days 3

5

and 7

the levels of B7 homolog 1（B7-H1）

interferon-γ（IFN-γ）

interleukin-4（IL-4）

interleukin-17（IL-17）

interleukin-36α（IL-36α）

and granulocytemacrophage colony-stimulating factor（GM-CSF） were analyzed and compared between the two groups. The sensitivity

specificity

and accuracy of B7-H1

IFN-γ

IL-17

IL-36α

and GM-CSF levels in assessing CAP severity were analyzed. Results The levels of B7-H1

IFN-γ

IL-17

IL-36α

and GM-CSF in the severe group were higher than those in the nonsevere group on the 3rd

5th

and 7th day

while the levels of IL-4 were significantly lower than those in the non-severe group（P<0.05）. The sensitivity

specificity

and accuracy of B7-H1 in assessing CAP severity were 83.56%

90.25%

and 94.15%

respectively. The sensitivity

specificity

and accuracy of IFN-γ in assessing CAP severity were 72.16%

70.12%

and 72.54%

respectively. Conclusion The plasma levels of B7-H1

IFN-γ

IL-17

IL-36α

and GM-CSF are highly expressed in children with severe CAP

but the plasma levels of IL-4 are on the opposite. In addition

B7-H1

IFN-γ

IL-17

IL-36α

and GM-CSF levels showed high sensitivity

specificity

and accuracy in assessing severe and non-severe CAP. Therefore

changes in plasma cytokine levels in children with CAP are helpful to assess the severity of the children’s condition

which also provides a corresponding theoretical basis for further determination of treatment options in children with CAP.