Relationship between IL-10, IL-17, lymphocyte subsets and prognosis of patienos with concurrent infections of Mycoplasma pneumoniac and streptococcus

OBJECTIVE To explore the levels of interleukin-10 (IL-10), IL-17, lymphocyte subsets in patients infected with Mycoplasma pneumoniae (MP) complicated with Streptococcus pneumoniae, as well as the relationship between each index and prognosis.

METHODS One hundred and twenty patients with Mycoplasma pneumoniae pneumonia (MPP) complicated with Streptococcus infection in Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine from Jan. 2021 to Dec. 2023 were selected as the study group, and 100 healthy subjects with normal physical examination during the same period were included in healthy group. According to the disease conditions of patients within 2 months of discharge follow-up, the patients were divided into the good prognosis group with 94 cases and the poor prognosis group with 26 cases. The IL-10, IL-17 levels and lymphocyte subsets of patients in each group were compared. Pearson correlation analysis was used to explore the correlation between peripheral blood IL-10, IL-17, lymphocyte subsets and acute physiology and chronic health evaluationⅡ (APACHEⅡ) and clinical pulmonary infection score (CPIS) in patients with MPP complicated with Streptococcus infection. Multivariate logistic regression model was applied to analyze the factors affecting the prognosis of patients with MPP complicated with Streptococcus infection.

RESULTS The levels of IL-10, CD₄⁺ and CD₄⁺/CD₈⁺ in the study group were (6.85±0.83) ng/L, (35.51±5.97)% and (1.23±0.39), respectively, lower than those in the healthy group, while the levels of IL-17 and CD₈⁺ were (23.04±3.64) ng/L and (35.24±5.62)%, higher than those in the healthy group (all P < 0.05). The IL-10, CD₄⁺ and CD₄⁺/CD₈⁺ levels of the poor prognosis group were lower than those of the good prognosis group, while the levels of IL-17 and CD₈⁺ were higher than those of the good prognosis group (all P < 0.05). The APACHE Ⅱ score and CPIS scores were higher in the poor prognosis group than in the healthy group (all P < 0.05). IL-10, CD₄⁺ and CD₄⁺/CD₈⁺ in patients with MPP and Streptococcus infection were negatively correlated with APACHE Ⅱ score (r=-0.509, -0.502, -0.494, all P < 0.001), as well as CPIS score (r=-0.623, -0.630, -0.616, all P < 0.001), while IL-17 and CD₈⁺ were positively correlated with APACHE Ⅱ score (r=0.494, 0.505, all P < 0.001), as well as CPIS score (r=0.624, 0.618, all P < 0.001). IL-17 (OR=1.817, 95%CI: 1.074-3.072, P=0.026) and APACHE Ⅱ score (OR=2.330, 95%CI: 1.254-4.329, P=0.008) were risk factors affecting the prognosis of MPP patients with streptococcal infection.

CONCLUSIONS Patients with MPP complicated with Streptococcus infection has low expression of peripheral blood IL-10, high expression of IL-17 and immune imbalance, and the changes of levels correlate with their disease condition and prognosis. IL-17 level and APACHE Ⅱ score are risk factors affecting the prognosis of MPP patients with Streptococcus infection.