Objective:To explore the clinical characteristics and predictive factors for plastic bronchitis (PB) in children with severe Mycoplasma pneumoniae pneumonia (SMPP). Methods:A retrospective cohort enrolled children with a clinical diagnosis of SMPP who were treated at the Department of Respiratory Medicine of Tianjin Children′s Hospital Machang District from January 1, 2018, to October 31, 2023. According to the bronchoscopy and pathological examination results, the patients were divided into 142 cases in the PB group and 274 cases in the non-PB group. The clinical manifestations, laboratory data, imaging findings, and treatments were analyzed.Mann-Whitney U test and Chi-square test were used to analyze the differences between the two groups, and multivariate Logistic regression was used to analyze the risk factors. The receiver operating characteristic (ROC) curve was used to explore the predictive value of PB in SMPP. Results:Among 416 SMPP children, there were 197 males and 219 females; PB group 142 cases, non-PB group 274 cases, the age of disease onset was (6.9±2.9) years and (6.6±2.8) years in the PB group and the non-PB group respectively. The incidence of wheezing symptoms, hypoxemia, heat peak >40 ℃, the duration of fever, neutrophil-lymphocyte ratio, mean platelet volume, C-reactive protein, procalcitonin, interleukin-6, alanine transaminase, aspartate aminotransferase and ferritin were higher in the PB group (16 cases (11.3%) vs. 15 cases (5.5%), 14 cases (9.9%) vs. 12 cases (4.4%), 57 cases (40.1%) vs. 67 cases (24.5%), 10 (8, 12) vs. 9 (8, 12) d, 6.1 (4.1, 13.1)×10 9vs. 5.0 (3.7, 6.8)×10 9/L, 10.2 (9.6, 10.8) vs. 9.4 (8.9, 10.1) fl, 33.4 (16.0, 67.5) vs. 23.0 (10.4, 56.1) mg/L, 0.24 (0.12, 0.48) vs. 0.16 (0.09, 0.31) &mu;g/L, 39.9 (25.1, 81.4) vs. 31.3 (18.3, 59.3) ng/L, 16.0 (12.0, 29.0) vs. 14.0 (10.0, 24.3) U/L, 38.5 (28.0, 52.5) vs. 33.0 (25.0, 44.0) U/L, 233 (136, 488) vs. 156 (110, 293) &mu;g/L, χ2=4.55, 4.79, 11.00, Z=2.25, 4.00, 6.64, 2.76, 2.98, 3.09, 2.22, 2.62, 4.18, all P<0.05). Multivariate Logistic regression analysis showed that the dyspnea ( OR=2.97, 95% CI 1.35-6.55, P=0.007), the diminution of respiration ( OR=2.40, 95% CI 1.27-4.52, P=0.006), neutrophil-lymphocyte ratio (NLR) ( OR=2.07, 95% CI 1.71-2.51, P<0.001), lactate dehydrogenase (LDH) ( OR=1.01, 95% CI 1.00-1.01, P<0.001), mean platelet volume/platelet count (MPV/PLT) ( OR=1.39, 95% CI 1.13-1.71, P=0.002), pleural effusion ( OR=2.23, 95% CI 1.21-4.13, P=0.011),≥2/3 lobe consolidation ( OR=1.84, 95% CI 1.04-3.00, P=0.039) and atelectasis ( OR=1.98, 95% CI 1.02-3.48, P=0.044) were independent predictors of PB in children with SMPP. ROC curve analysis showed that the cut-off values for NLR, LDH and MPV/PLT in the diagnosis of PB were 2.79 (sensitivity 0.89, specificity 0.69, area under the curve (AUC)=0.86, P<0.001), 474 U/L (sensitivity 0.63, specificity 0.65, AUC=0.70, P=0.003) and 0.04 (sensitivity 0.75, specificity 0.53, AUC=0.68, P=0.005) respectively. Children in the PB group had longer hospital stays and corticosteroid treatment course than those in the non-PB group, the proportion of children in the PB group who received bronchoscopy treatment twice or more was higher (9 (8, 12) vs. 8 (6, 10) d, 7 (5, 8) vs. 6 (5, 7) d, 128 cases (90.1%) vs. 218 cases (79.6%), 106 cases (74.7%) vs. 54 cases (19.7%), Z=6.70, 5.06, χ2=7.48, 119.27, all P<0.05). Conclusions:The dyspnea, respiration diminution, NLR level elevation (>2.79) and pleural effusion were predictive factors for PB in children with SMPP. This provides a basis for the early identification of PB in children with SMPP.

Objective:To explore the value of circ_0054633 in early diagnosis and prognosis prediction of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) in children with severe pneumonia.Methods:A retrospective case-control study was conducted on children with diagnosed severe pneumonia admitted to Tianjin Children's Hospital from July 1, 2022, to February 29, 2024. The clinical data was collected by electronic medical record system and clinical follow-up, including gender, age, lung injury prediction score (LIPS), pediatric critical illness score (PCIS), serum circ_0054633, interleukin-6 (IL-6), the indicators of the arterial blood-gas analysis, oxygenation index (PaO 2/FiO 2) within 24 hours of admission and the survival status of 28 days. According to whether ALI/ARDS occurred, they were divided into the ALI/ARDS group and the non-ALI/ARDS group. The differences of clinical data between the two groups were compared, and multivariate Logistic regression was used to analyze the risk factors for ALI/ARDS in children with severe pneumonia. The receiver operator characteristic curve (ROC curve) will be used to explore the early diagnostic value of ALI/ARDS in children with severe pneumonia. The patients of ALI/ARDS were divided into mild group, moderate group and severe group according to the level of PaO 2/FiO 2. The levels of serum circ_0054633 and IL-6 in various severity ALI/ARDS were compared. The differences of serum circ_0054633, IL-6 levels, PCIS score and LIPS score were compared between the two groups of ALI/ARDS patients according to different prognoses in 28 days, as well as the correlation between various risk factors and circ_0054633. Results:A total 74 children with severe pneumonia were included, with 34 cases in the ALI/ARDS group and 40 cases in the non-ALI/ARDS group. In ALI/ARDS group, there were 9 cases in the mild group, 15 cases in the moderate group and 10 cases in the severe group; while 12 cases died and 22 cases survived after 28 days. The serum circ_0054633, IL-6 level and LIPS score were higher in the ALI/ARDS group than the non-ALI/ARDS group, while the PCIS score was lower, and the two groups had significant difference. Multivariate Logistic regression analysis showed that circ_0054633 was independent predictors of ALI/ARDS in children with severe pneumonia [odds ratio ( OR) = 3.853, 95% confidence interval (95% CI) was 1.912-7.805, P = 0.017]. ROC curve analysis showed that the cut-off values for circ_0054633 in the diagnosis of ALI/ARDS were 3.955, sensitivity was 79.4%, specificity was 92.5%, area under the ROC curve (AUC) was 0.892. The serum circ_0054633 and IL-6 levels were higher in the children who died in 28 days than the children who were survived, while the PCIS score was lower, and the two groups had significant difference. Spearman correlation analysis showed that the level of circ_0054633 in children with ALI/ARDS was positively correlated with 28-day mortality and IL-6 ( r value was 0.675, 0.763, respectively, all P < 0.001), but negatively correlated with PCIS score ( r = -0.626, P < 0.001), while no significant correlation with LIPS score ( r = 0.389, P = 0.023). Conclusion:The level of serum circ_0054633 has a better value in early diagnosis and prognosis prediction of ALI/ARDS caused in children with severe pneumonia.