Objective We studied the short-term effects of air pollutant concentrations in Suzhou City on respiratory infections in children of different age groups. Methods We employed clinical data from children hospitalized with respiratory infections at the Children’s Hospital of Soochow University during 2014–2016, and air quality for Suzhou City covering the same period.We investigated the relationships between the air pollutant concentrations and respiratory tract infections in children by causative pathogen using time series models with lagged effects. Results The results of single-pollutant models showed that PM2.5, PM10, NO2, SO2 and CO had statistically significant associations with respiratory tract infections in children under 3 years, with the largest effect sizes at a lag of 3 weeks. Notably, the multi-pollutant model found PM2.5 was significantly associated with viral respiratory in children under 7 months, and bacterial respiratory infections in other age groups, while PM10 concentrations were associated with viral infections in preschool children. Conclusion PM2.5, PM10 and NO2 are the main atmospheric pollutants in Suzhou. The associations between pollutant concentrations and viral and bacterial respiratory infections were stronger among children under 3 years than for older age group.s PM2.5 had the strongest influence on viral and Mycoplasma pneumoniae respiratory infections when multiple pollutants were tested together.

Objectives This study aimed to compare the clinical features and laboratory tests of infectious mononucleosis (IM) and hemophagocytic syndrome (HLH) caused by Epstein-Barr virus (EBV) in 1–3-year-old children and to explore the risk factor of HLH caused by EBV (EBV-HLH). Methods The clinical data of 92 children with EBV infection admitted in our hospital from 2011 to 2019 were collected; 61 cases were diagnosed as EBV-IM, and 31 cases were diagnosed as EBV-HLH. The subjects’ clinical manifestations and laboratory tests were analyzed retrospectively. Results Compared with EBV-IM patients, EBV-HLH patients had longer durations of fever, both before hospitalization and overall, and a higher probability of hepatomegaly. The levels of ALT, AST, LDH, TG, SF, D-Dimer and the plasma EBV DNA load of EBV-HLH patients were significantly higher than those of EBV-IM patients. The absolute values of CD3+, CD4+, CD8+, NK, and CD3-CD19+ cells and IgA and IgM levels of EBV-HLH patients were significantly lower than those of EBV-IM patients. The plasma EBV DNA load was positively correlated with the PT, TT, α-HBDH, AST, LDH, CK, Scr, BUN, UA, TG, and CRP levels in EBV-HLH patients, and the plasma EBV DNA load was positively correlated with the D-Dimer level in the EBV-IM patients. Among the 10 different potential markers, at the cut-off point of 1721.500 μg/L, the sensitivity and specificity of D-Dimer was 88.90 and 90.20%, respectively. Conclusion The D-Dimer level may be a good prognostic indicator of EBV-HLH caused by EBV.

Objectives: This study aimed to compare the clinical features and laboratory tests of infectious mononucleosis (IM) and hemophagocytic syndrome (HLH) caused by Epstein-Barr virus (EBV) in 1-3-year-old children and to explore the risk factor of HLH caused by EBV (EBV-HLH).Methods: The clinical data of 92 children with EBV infection admitted in our hospital from 2011 to 2019 were collected; 61 cases were diagnosed as EBV-IM, and 31 cases were diagnosed as EBV-HLH. The subjects’ clinical manifestations and laboratory tests were analyzed retrospectively.Results: Compared with EBV-IM patients, EBV-HLH patients had longer durations of fever, both before hospitalization and overall, and a higher probability of hepatomegaly. The levels of ALT, AST, LDH, TG, SF, D-Dimer and the plasma EBV DNA load of EBV-HLH patients were significantly higher than those of EBV-IM patients. The absolute values of CD3+, CD4+, CD8+, NK, and CD3-CD19+ cells and IgA and IgM levels of EBV-HLH patients were significantly lower than those of EBV-IM patients. The plasma EBV DNA load was positively correlated with the PT, TT, α-HBDH, AST, LDH, CK, Scr, BUN, UA, TG, and CRP levels in EBV-HLH patients, and the plasma EBV DNA load was positively correlated with the D-Dimer level in the EBV-IM patients. Among the 10 different potential markers, at the cut-off point of 1721.500 µg/L, the sensitivity and specificity of D-Dimer was 88.90% and 90.20%, respectively.Conclusion: The D-Dimer level may be a good prognostic indicator of EBV-HLH caused by EBV.

Objectives This study aimed to compare the clinical features and laboratory tests of infectious mononucleosis (IM) and hemophagocytic syndrome (HLH) caused by Epstein-Barr virus (EBV) in 1-3-year-old children and to explore the risk factor of HLH caused by EBV (EBV-HLH). Methods The clinical data of 92 children with EBV infection admitted in our hospital from 2011 to 2019 were collected; 61 cases were diagnosed as EBV-IM, and 31 cases were diagnosed as EBV-HLH. The subjects’ clinical manifestations and laboratory tests were analyzed retrospectively. Results Compared with EBV-IM patients, EBV-HLH patients had longer durations of fever, both before hospitalization and overall, and a higher probability of hepatomegaly. The levels of ALT, AST, LDH, TG, SF, D-Dimer and the plasma EBV DNA load of EBV-HLH patients were significantly higher than those of EBV-IM patients. The absolute values of CD3+, CD4+, CD8+, NK, and CD3-CD19+ cells and IgA and IgM levels of EBV-HLH patients were significantly lower than those of EBV-IM patients. The plasma EBV DNA load was positively correlated with the PT, TT, α-HBDH, AST, LDH, CK, Scr, BUN, UA, TG, and CRP levels in EBV-HLH patients, and the plasma EBV DNA load was positively correlated with the D-Dimer level in the EBV-IM patients. Among the 10 different potential markers, at the cut-off point of 1721.500 µg/L, the sensitivity and specificity of D-Dimer was 88.90% and 90.20%, respectively. Conclusion The D-Dimer level may be a good prognostic indicator of EBV-HLH caused by EBV.

Background : Mycoplasma pneumoniae pneumonia (MPP) is a common respiratory illness in children, particularly those with allergic constitutions. NK cells and cytokines are thought to be involved; however, understanding of the immunopathology of MPP is incomplete. Methods : Peripheral blood samples were collected from 51 children hospitalized with with MPP, 26 with an allergic constitution and 25 without, and 29 healthy controls. NK cell subsets were analyzed by flow cytometry and the expression of interleukin (IL)-1 alpha and IL-18 was detected by ELISA. The relationship between NK cell subsets and the expression of IL-18 and IL-1 alpha was determined. Results : The number of CD3 − CD56 + NK cells and CD3 − CD56 dim CD16 bright NK cells in children with MPP was lower than in healthy controls (P < 0.05). The percentage of CD3 − CD56 + NK cells, CD3 − CD56 dim CD16 bright NK cells and the number of CD3 − CD56 dim CD16 bright NK cells in the MPP allergic group were lower than in the non-allergic group (P < 0.05). The expression of IL-18 was significantly increased in the MPP groups (P < 0.05), and the absolute number of CD3 − CD56 dim CD16 bright NK cells negatively correlated with IL-18 levels in the peripheral blood (P < 0.05). Conclusion : Reduced numbers of NK cell subsets were identified in children with MPP and MPP with an allergic predisposition compared with healthy controls. Concomitant increases in IL-18 in children with MPP suggest the involvement of IL-18 in the immunopathogenesis of MPP and may be related to the reduced CD3 − CD56 dim CD16 bright NK cells.