Clinical application and safety observation of levofloxacin in children with refractory Mycoplasma pneumoniae pneumonia

To analyze the clinical manifestations of refractory Mycoplasma pneumoniae pneumonia (RMPP) which unresponded to methylprednisolone in the dosage of 2 mg/(kg·d) for 3 days. Retrospective analysis was performed on the clinical data of 110 children (64 boys and 46 girls) with RMPP. The patients were divided into "effective group" and "ineffective group" according to initial effect of 2 mg/(kg·d) methylprednisolone. The clinical manifestations, laboratory examination, radiological features and bronchofibroscopic findings of the children were compared. In order to seek the reference indexes which indicate nonresponsive to 2 mg/(kg·d) methylprednisolone, an ROC curve was made, of which the diagnostic cut-off was five independent correlation factors while grouping was made according to patients' different response to glucocorticosteroid. The effective group had 86 (86/110, 78.2%) children while ineffective group had 24 (24/110, 21.8%). The ineffective group children had the following performance: 16 children (16/24, 66.7%) in ineffective group had ultrahyperpyrexia (T ≥ 40 °C), which was significantly more severe compared to those in effective group (32/86, 37.3%, P < 0.01); the levels of white blood cell (WBC) count, percentage of neutrophils count (N), C-reactive protein (CRP), serum ferritin (SF), alanine transaminase (ALT), lactic dehydrogenase (LDH), creatine kinase isoenzyme (CK-MB) and fibrinogen (Fib) in ineffective group were significantly higher than those in effective group(P < 0.01); while percentage of lymphocyte count (L) was lower than that in effective group(P < 0.01). Proportion of mixed infection in ineffective group was higher than that in effective group (33.3% vs. 4.7%). Radiological manifestations: It was more frequently seen in ineffective group that chest CT scan indicated high density consolidation in no less than a whole pulmonary lobe and pulmonary necrosis (41.7% vs. 0%). Abundant secretions blockage (45.0% vs. 16.9%) and mucosal necrosis (37.5% vs. 8.1%) on bronchofibroscopy were more frequently seen in ineffective group. The critical values of the five independent correlation factors were CRP 110 mg/L, SF 328 mg/L, LDH 478 IU/L, N 0.78, L 0.13. Treatment with 2 mg/(kg·d) methylprednisolone can improve clinical symptoms and radiological manifestations of most children with RMPP quickly, but it may be ineffective in some situations such as lasting high fever or ultrahyperpyrexia for more than 7 days, CRP ≥ 110 mg/L, N ≥ 0.78, L ≤ 0.13, serum LDH ≥ 478 IU/L, SF ≥ 328 µg/L, chest CT scan indicating high density consolidation in more than a whole pulmonary lobe involved and moderate-abundant pleural effusion.

To study the correlation of galectin-3 level in bronchoalveolar lavage fluid (BALF) with Mycoplasma pneumoniae (MP) load and cellular immunity of neutrophils and macrophages in the airway in children with refractory MP pneumonia (RMPP). A total of 64 children with RMPP who were hospitalized from January 2013 to January 2017 were enrolled. In addition to the conservative medical treatment, all the 64 children with RMPP were given bronchoalveolar lavage in the acute stage (5-7 days after admission) and 48 out of the 64 children were given bronchoalveolar lavage in the recovery stage (10-14 days after admission). Four milliliters of BALF of the affected lung lobe or segment were collected. ELISA was used to measure the level of galectin-3 in BALF supernatant. RT-PCR was used to measure MP load. Hematoxylin and eosin staining was used to measure the percentage of neutrophils and macrophages. Six children with bronchial foreign bodies were enrolled as the control group. The RMPP group had a significantly higher level of galectin-3 in BALF in both the acute and recovery stages than the control group (P<0.01), and the level of galectin-3 in the acute stage was significantly higher than in the recovery stage (P<0.01). The RMPP group had a significantly higher percentage of neutrophils in BALF in both the acute and recovery stages than the control group (P<0.01), and the percentage of neutrophils in the acute stage was significantly higher than in the recovery stage (P<0.01). The RMPP group had a significantly lower percentage of macrophages in BALF in both the acute and recovery stages than the control group (P<0.01), but there was no significant difference in the percentage of macrophages between the acute and recovery stages (P>0.05). The RMPP group had a significantly higher MP load in BALF in both the acute and recovery stages than the control group (P<0.01), and the MP load in the acute stage was significantly higher than in the recovery stage (P<0.01). In the children with RMPP, galectin-3 level in BALF in the acute stage was positively correlated with MP load and the percentage of neutrophils (rs=0.789 and 0.726 respectively; P<0.01). Galectin-3 is involved in the process of airway inflammation in children with RMPP, and the level of galectin-3 in BALF is positively correlated with MP load. RMPP is a cellular immune inflammatory lesion with the increase of neutrophils and the reduction in macrophages. Galectin-3 is closely associated with neutrophil chemotaxis and luminal infiltration in children with RMPP. MP load gradually decreases with the recovery from RMPP, but it is not completely eliminated by the immune system in the recovery stage. MP infection can increase the consumption of macrophages in children with RMPP.

To compare the demographic and clinical features, laboratory and imaging findings in mycoplasma pneumoniae pneumonia (MPP) children with non-MPP (NMPP) children and general MPP (GMPP) children with refractory MPP (RMPP) children and analysis the relationship with the severity of disease. The study included 265 children with MPP and 230 children with NMPP in the Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University from 2020 to 2021. The children with MPP included RMPP (n = 85) and GMPP (n = 180). Demographic and clinical characteristics, laboratory and imaging findings of all children were measured as baseline data within 24 h after admission and the differences between MPP and NMPP, RMPP and GMPP patients were compared. ROC curves were used to evaluate the diagnostic and predictive value of different indicators for RMPP. Fever duration and hospital stay in children with MPP were longer than those with NMPP. The number of patients with imaging features of pleural effusion, lung consolidation and bronchopneumonia in MPP group was significantly higher than that in NMPP group. Compared with NMPP group, the levels of C-reactive protein (CRP), procalcitonin (PCT), serum amyloid A (SAA), erythrocyte sedimentation rate (ESR), lactic dehydrogenase (LDH), prothrombin time (PT), fibrinogen (FIB) and D-dimer and inflammatory cytokines (interleukin [IL]-6, IL-8, IL-10 and IL-1β) in MPP group were significantly higher (P < 0.05). The clinical symptoms and pulmonary imaging findings were more severe in RMPP group. The levels of white blood cell (WBC), CRP, PCT, SAA, ESR, alanine aminotransferase (ALT), LDH, ferritin, PT, FIB, D-dimer and inflammatory cytokines in RMPP group were higher than those in GMPP group. There was no significant difference in the level of lymphocyte subsets between the RMPP and GMPP group. IL-6, IL-10, LDH, PT, D-dimer and lung consolidation were independent risk factors for RMPP. IL-6 levels and LDH activity were good predictors of RMPP. In conclusion, there were differences in clinical characteristics and serum inflammatory markers between MPP group and NMPP group, RMPP group and GMPP group. IL-6, IL-10, LDH, PT and D-dimer can be used as predictive indicators for RMPP.

ObjectiveTo investigate the prevalence of mutations in domain V of Mycoplasma pneumoniae (MP) 23S ribosomal RNA (rRNA) and the clinical characteristics of pediatric MP pneumonia (MPP) in Nanjing, China.MethodsDomain V of 23S rRNA was sequenced in MP strains collected from children diagnosed with MPP in Nanjing. Clinical and laboratory data were obtained.ResultsAmong the 276 MP strains, 255 (92.39%) harbored mutations, primarily A2063G in domain V of MP 23S rRNA. When children were stratified according to the presence or absence of mutations, no significant differences were found in sex, age, the MP DNA load at enrollment, lymphocyte counts, pulmonary complications, immunomodulator levels, fever duration, the duration of fever after macrolide therapy, and hospital stay. The prevalence of refractory MPP in the two groups was similar. Children with refractory MPP exhibited higher MP DNA loads than those with non-refractory MPP.ConclusionsDespite the high prevalence of the A2063G mutation in domain V of MP 23S rRNA, mutations were not associated with the clinical characteristics of MPP. The MP DNA load significantly differed between refractory and non-refractory MPP.

Objective To study clinical manifestations, laboratory variables, imaging features and therapies of refractory Mycoplasma pneumoniae pneumonia(RMPP). Methods The retrospective analysis of clinical data was conducted in 45 children with RMPP and 74 children with Mycoplasma pneumoniae pneumonia (MPP)admitted to department of pediatrics. The general data, clinical manifestations, laboratory variables, imaging features and therapies were compared between two groups. Results As compared to MPP, the age(6.14 ±3.35)y,febrile days(9.49±5.28)d, the hospitalized days(11.45±3.42)d were significantly higher than that of MPP group(P<0.001);RMPP had higher rations of unilateral pulmonary infiltration[41(91.11%)],large consolidation shadows[35(77.78%)], pulmonary[21(46.67%)]and extrapulmonary complications[24(51.33%)](P<0.05);CRP,ESR,LDH and IgM were increased, the difference was statistically significant(P<0.01); Thirty-seven cases(82%)of RMPP had to add ceftriaxone sodium, thirty-two cases(71.7%)of RMPP had to add glucocorticoid,,Bronchofiberoscope lavages were used in six cases of RMPP. Only one case of RMPP occured sequela. Conclusion The older children, the persistent high fever, large consolidation shadows of pulmonary, pulmonary and extrapulmonary complications, high level of serum CRP,ESR,LDH and Ig M are the clinical related factors of RMPP. The combination of cephalosporins and(or)glucocorticoid might consider for the cases who have no effect with macrolides. The effect is sure for RMPP with Bronchofiberoscope lavages. Key words: Pneumoniae mycoplasma; Child

Objective To explore the levels and clinical significances of T-cell subset, interleukin(IL)-6, interferon(IFN)-γ, and monocyte chemotactic protein(MCP)-1 in bronchoalveolar lavage fluid(BALF) of children with mycoplasma pneumoniae pneumonia(MPP). Methods Thirty-six children with pneumonia were admitted in our hospital from October 2014 to March 2016.They were divided into refractory mycoplasma pneumoniae pneumonia (RMPP) group (n=18) and MPP group(n=18). Sixteen cases with bronchial foreign body were selected as the control group.The levels of IL-6, MCP-1, IFN-γ and T-cell subset in BALF were detected by ELISA and alkaline phosphatase-anti-alkaline phosphatase(APAAP) bridging enzyme linked immunosorbent assay. Results (1)The levels of CD3+ and CD8+ T cells in BALF of MPP group and RMPP group were higher than those in the control group (P 0.05). (2) The level of IL-6 in acute phase of RMPP group was higher than that in the control group (P<0.05). The levels of IL-6 in acute phase of RMPP group and MPP group were both higher than that in recovery period (P<0.05, respectively). (3)The levels of IFN-γ in the acute phase of RMPP group and MPP group were higher than that in the control group, and the differences were statistically significant (P<0.05). The IFN-γ levels in acute and recovery phases of RMPP group were both significantly higher than those in MPP group respectively(P< 0.05). (4)The level of MCP-1 in BALF in control group was lower than those in the acute phase of RMPP group and MPP group(P<0.05). The level of MCP-1 in RMPP acute group was significantly higher than that in MPP acute group, and higher in acute phase than those in recovery phase both in two groups(P<0.05). Conclusion There are cell immune regulation and function disorders when children are infected mycoplasma pneumoniae.IL-6, IFN-γ and MCP-1 may participate in the pathogenesis of MPP, and more importantly, IFN-γ and MCP-1 may be the important indicator to forecast the severity of MPP. Key words: Mycoplasma pnuemoniae; Bronchoalveolar lavage fluid; T-cell subset; Cytokine,

BackgroundThe levels of serum D-dimer (D-D) in children with Mycoplasma pneumoniae pneumonia (MPP) were assessed to explore the clinical significance of D-D levels in refractory MPP (RMPP).MethodA total of 430 patients with MPP were enrolled between January 2015 and December 2015 and divided into a general MPP (GMPP) group (n = 306) and a RMPP group (n = 124). Clinical data, D-D level, white blood cell (WBC) count, proportion of neutrophils (N%), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), alanine transaminase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were compared between the two groups. Multivariate logistic regression was performed to identify independent predictors of RMPP.Results(1) Hospitalization time, preadmission fever duration, total fever duration, WBC, N %, CRP, LDH, ESR, ALT, AST, and D-D were significantly higher in the RMPP group than those in the GMPP group (all P < 0.05). (2) Correlation analysis showed that D-D was positively correlated with WBC, CRP, ESR, and LDH, and could be used to jointly evaluate the severity of the disease. (3) Multivariate logistic regression analysis identified preadmission fever duration, CRP, LDH and DD as independent risk factors for RMPP (all P < 0. 05). D-D had the highest predictive power for RMPP (P < 0.01). The D-D level also had a good ability to predict pleural effusion and liver injury (all P < 0.01).ConclusionSerum D-D levels were significantly increased in patients with RMPP, indicating that excessive inflammatory response and vascular endothelial injury with prolonged duration existed in this patient population. Increased levels of serum D-D may be used as an early predictor of RMPP and the occurrence of complications. Our findings provide a theoretical basis for the early diagnosis of RMPP, early intervention and excessive inflammatory response in the pathogenesis of mycoplasma.

目的本研究基于倾向性评分匹配法，分析不同剂量糖皮质激素（GC）治疗重症肺炎支原体肺炎（SMPP）患儿的临床特征及GC治疗不同疗效的临床特征。方法回顾性收集2021年1月1日–2022年12月31日期间天津市儿童医院住院并接受GC治疗的271例SMPP患儿临床资料，按GC剂量分为低剂量组〔甲泼尼龙≤2 mg/(kg·d)〕和高剂量组〔甲泼尼龙>2 mg/(kg·d)〕。采用1∶1倾向性评分匹配（匹配变量包括发病至住院时间、发热至GC使用时间、GC使用至复查胸部X线时间）以减少混杂因素，低剂量组和高剂量组共计成功匹配90对患儿，比较匹配后两组的临床特征，进一步应用多因素logistic回归分析使用高剂量GC的危险因素。又以临床疗效将90对患儿分为无效组（n=38）和有效组（n=142），比较两组临床特征，并用多因素logistic回归分析使用GC后临床无效的风险因素。结果高剂量组患儿年龄较小、血小板计数较高、肺不张发生率较高（均P<0.05）。高剂量组较低剂量组体温恢复时间及热程较短，药物不良反应（恶心、呕吐、腹痛、腹泻、皮疹等）发生率较高（均P<0.05），但两组均未见高血糖、高血脂、高血压、消化道出血或穿孔等严重不良反应。影像学评估显示，高剂量组显著吸收的病例明显多于低剂量组（P = 0.009）。但两组住院时长、咳嗽缓解时间及湿啰音吸收时间差异无统计学意义（均P>0.05）。多因素logistic回归分析显示，年龄小、合并肺不张及血小板偏高是选择高剂量GC治疗的危险因素。与GC治疗有效组相比，无效组难治性肺炎支原体肺炎（RMPP）比例、胸痛发生率及中性淋巴细胞比值、热峰、降钙素原、铁蛋白、乳酸脱氢酶、谷丙转氨酶、谷草转氨酶和D-二聚体水平均显著升高（均P<0.05），而淋巴细胞计数降低（P<0.05）。两组在年龄及高剂量GC使用率上差异无统计学意义（均P>0.05）。多因素分析显示，RMPP和高热峰是GC治疗无效的独立危险因素。结论高剂量GC治疗虽可促进体温恢复、缩短发热病程并提高肺部病变吸收率，但其总体疗效与低剂量组无明显差异，且不良反应发生率更高。年龄较小、合并肺不张及血小板计数偏高是患儿接受高剂量GC治疗的主要影响因素。值得注意的是，RMPP和高热峰是GC治疗无效的独立危险因素，与GC剂量无关。临床需严格评估高剂量GC治疗的个体化风险收益比。

To investigate cytokine level in bronchoalveolar lavage fluid (BALF) in children with refractory Mycoplasma pneumoniae pneumonia (RMPP) and the effects of methylprednisolone on RMPP. Sixty cases with RMPP and 20 cases with bronchial foreign body with no respiratory tract infection as control group hospitalized in Department of Pulmonary Diseases, the Children's Hospital Affiliated to Medical School of Zhejiang University from February 2012 to February 2013 were enrolled. The RMPP patients were divided into two groups randomly (30 cases in each). Steroid group were given methylprednisolone 2 mg/(kg·d) intravenously for 3 days, and the cases in non steroid group were not given steroid therapy. Patients whose fever relieved after steroid treatment were classified as defervesced group while the others were classified as non defervesced group. Each patient was examined with fiberoptic bronchoscopy and bronchoalveolar lavage 3 days after admission and cytokine level in BALF of each patient was detected. (1) In steroid group, the proportion of patients whose fever disappeared within 3 days after steroid therapy was 9/30 cases (30%), and in non steroid group no one responded within 3 days after medication, showing statistically significant difference (χ² = 14.073, P=0.002), at the same time, the duration of cough in steroid group was significantly shorter than that in non steroid group (5.1 d vs. 7.0 d, t=-2.276, P=0.027). The total fever time of steroid group was 4.7 days, which as compaired with non steroid group (6.7 days) was shorter, but the difference was not significant (t=-1.351, P=0.134). (2) IL-1 β, IL-4, IL-6, IL-8, IL-10, IFN-γ in BALF of steroid group and non steroid group were both significantly higher than that of control group. But the same comparison between steroid group and non steroid group showed no significant difference. (3) In steroid group, IL-2 and IL-8 in BALF of patient whose fever disappeared after steroid therapy were both significantly lower than that of patients who still had fever (t=2.771, 2.054, P=0.010, 0.049) , but no significant difference was found between the two groups in BALF IL-1 β, IL-4, IL-6, IL-10, IFN-γ levels (P>0.05). (1) Three days of 2 mg/(kg·d) methylprednisolone therapy had the antipyretic effect in children with RMPP, and could shorten the length of cough. (2) Incresed BALF IL-1 β, IL-4, IL-6, IL-8, IL-10, IFN-γ levels were observed in RMPP and high level of BALF IL-2 and IL-8 might have some relevance with persistent fever of RMPP in children.

To summarize the early diagnose and treatment approaches of Refractory Mycoplasma Pneumoniae Pneumonia (RMPP). Medical documents of 68 cases of RMPP were reviewed. Lab and radiology evident such as CBC, CRP, MP-IgM, X-ray, etc. were collected. 100% RMPP patients suffered from high fever. Positive sign of lung became clear with the development of the disease. Complications as impairment of liver function, cardiac function and rush developed in few patients. 2-4 rounds treatment of macrolides and Methyllprednisolone were necessary for RMPP while antibiotic may be considered when there were evidence of bacteria infection. Immunoglobulin was recommended to the patients when macrolides and steroid seemed ineffective. Bronchofibroscope played an active role regarding the diagnosis and treatment of RMPP. Early diagnosis is crucial in RMPP. Combination of multitreatment approaches is the key to cure RMPP.

Mycoplasma pneumoniae (MP) is a leading cause of community-acquired pneumonia in children and young adults. Although MP pneumonia is usually benign and self-limited, in some cases it can develop into life-threating refractory MP pneumonia (RMPP). However, the pathogenesis of RMPP is poorly understood. The identification and characterization of proteins related to RMPP could provide a proof of principle to facilitate appropriate diagnostic and therapeutic strategies for treating paients with MP. In this study, we used a quantitative proteomic technique (iTRAQ) to analyze MP-related proteins in serum samples from 5 patients with RMPP, 5 patients with non-refractory MP pneumonia (NRMPP), and 5 healthy children. Functional classification, sub-cellular localization, and protein interaction network analysis were carried out based on protein annotation through evolutionary relationship (PANTHER) and Cytoscape analysis. A total of 260 differentially expressed proteins were identified in the RMPP and NRMPP groups. Compared to the control group, the NRMPP and RMPP groups showed 134 (70 up-regulated and 64 down-regulated) and 126 (63 up-regulated and 63 down-regulated) differentially expressed proteins, respectively. The complex functional classification and protein interaction network of the identified proteins reflected the complex pathogenesis of RMPP. Our study provides the first comprehensive proteome map of RMPP-related proteins from MP pneumonia. These profiles may be useful as part of a diagnostic panel, and the identified proteins provide new insights into the pathological mechanisms underlying RMPP.

ObjectiveTo investigate the genotyping and drug resistance of Mycoplasma pneumoniae (MP) epidemic strains in children and analyze the risk factors for refractory Mycoplasma pneumoniae pneumonia (RMPP).MethodNasopharyngeal aspirates (NPA) were collected from hospitalized children with MP infection from September to October 2023. Tracheoscopy was performed when necessary, and Bronchoalveolar Lavage Fluid (BALF) was collected. Polymerase Chain Reaction (PCR) capillary electrophoresis were used to detect respiratory pathogens, and a nested PCR based on the MP P1 gene monitored MP subtypes. The MP-23 S rRNA V region was amplified and sequenced. Clinical data and laboratory results were analyzed for RMPP risk factors.ResultFrom 261 children diagnosed with Mycoplasma pneumoniae pneumonia (MPP), cough (100%) and fever (93.1%) were the most common symptoms. Moist rales (65.5%) were the prevalent pulmonary signs. Bronchoscopy was required in 44.4% of cases. Drug resistance genes were detected in 258 cases (98.9%). Genotyping showed 192 cases (73.56%) as type I and 69 cases (26.4%) as type II. Type I required more bronchoscope interventions (54.2%) compared to type II (17.4%, P < 0.001). Among the children, 92 (35.2%) were classified as RMPP. The RMPP group had longer hospitalization (9.14 ± 4.38 vs. 6.7 ± 1.81 days), higher fever ratio (100% vs. 89.9%), and longer febrile duration (8.72 ± 2.52 vs. 4.56 ± 2.50 days) (all P < 0.05). Higher rates of shortness of breath (7.6% vs. 1.2%) and decreased breath sounds (30.4% vs. 16.6%) were noted in the RMPP group (P < 0.05). Additionally, higher proportions of elevated CRP, ALT, AST, LDH, and D-D dimer were found in the RMPP group, along with a greater need for bronchoscopy (70.7% vs. 43.2%). Multivariate logistic regression identified total febrile duration, mucus plug formation, elevated AST, LDH, and D-D dimer as RMPP risk factors. Receiver operator characteristic (ROC) curve indicated that total febrile duration, LDH, and D-D dimer could serve as predictive markers for RMPP.ConclusionType I predominated among MP strains in Suzhou, with a high prevalence of drug resistance. Type I infections were associated with a higher likelihood of requiring bronchoscopy. Prolonged fever, mucus plug formation, elevated AST, LDH, and D-D dimer were independent risk factors for RMPP, with total febrile duration, LDH, and D-D dimer serving as predictive markers.Clinical trial numberNot applicable.

To investigate clinical characteristics and predictive factors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in children so as to recognize and treat the disease earlier. The data including febrile time, inflammatory markers (WBC, neutrophil, CRP) and radiological features of 213 children hospitalized with Mycoplasma pneumoniae pneumonia (MPP) (72 with refractory MPP and 141 with mild MPP were retrospectively analyzed). The primary diagnostic criteria of refractory MPP: the patient's condition still deteriorates after treatment with macrolides for more than 5 days. The independent variables which had significant difference in univariate analysis was analyzed by multivariate logistic regression analysis. The predictive criteria of RMPP were further applied in 100 other patients prospectively. Kappa test was used to evaluate the accuracy rate. Refractory MPP patients: febrile time was more than 10 days, white blood cell (WBC) count was (3.8 - 18.5)×10(9)/L in peripheral blood routine test, CRP was 38 mg/L - > 160 mg/L, large lobar consolidation with high density (> 2/3 pulmonary lobe, CT value 40 - 50 HU, without air bronchogram). Mild MPP patients: febrile time was less than 10 days, CRP was often less than 40 mg/L. Independent risk factors for RMPP were febrile time, CRP, large consolidation area with high density in lungs with or without pleural effusion (OR = 1.586, P = 0.017; OR = 4.344, P = 0.001; OR = 2.660, P = 0.012), CT value 40 - 50 HU which were demonstrated by logistic regression analysis. The specificity, sensitivity and Youden index for this diagnostic test were respectively 0.96, 0.94 and 0.90 at a CRP cut off of 40 mg/L. The sensitivity, specificity, and Kappa value for the above criteria to diagnose RMPP were respectively 0.96, 0.94 and 0.9. The predictive factors for RMPP are febrile time (> 10 days), CRP (> 40 mg/L), large lobar consolidation with high density (> 2/3 pulmonary lobe, CT value > 40 HU with or without pleural effusion) for the purpose of treating earlier.

The purpose of this study was to analyze the clinical features of Mycoplasma pneumonia in children, especially refractory Mycoplasma pneumoniae pneumonia (RMPP), and to build a clinical prediction model to separate RMPP from general Mycoplasma pneumoniae pneumoniae (GMPP). A total of 234 children with MPP were enrolled in this study, out of which 152 were GMPP and 82 were RMPP. Independent predictors of RMPP were screened via univariate and multivariate logistic regression, analyzing clinical characteristics, laboratory indicators (including inflammatory markers like the neutrophil-to-lymphocyte ratio (NLR), systemic immuneinflammation index (SII), and systemic inflammation response index (SIRI)), and blood immune parameters. Based on these predictors, a clinical prediction model was constructed, and its predictive efficacy and clinical value were evaluated using the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA). Compared to GMPP patients, those with RMPP had extended hospital stays and total fever days, a higher percentage of high-grade fever, a greater percentage of pulmonary atelectasis and unilateral lung lesions, and increased monocyte counts, platelet counts, CRP levels, SII, and SIRI. CRP, platelet count, monocyte count, SII, and SIRI were significantly associated with the risk of developing RMPP. CRP, monocyte count, and SII were independent predictors of RMPP, with CRP contributing the most, followed by SII. The constructed prediction model achieved an AUC of 0.82 (95% CI, 0.70 to 0.94) in the validation set. The DCA plot showed that the net benefit of the model was already greater than 0 at a high-risk threshold of approximately 0.1, and the smaller the threshold, the greater the net benefit in the range of 0.1 to 0.9. The constructed model accurately distinguishes RMPP from GMPP, with high predictive efficacy and clinical value.

This study investigates the current status of macrolide resistance in Mycoplasma pneumoniae (MP) and analyzes the relationship between mutations at the 23S rRNA A2063G and/or A2064G loci and refractory Mycoplasma pneumoniae pneumonia (RMPP). A retrospective analysis was conducted on 205 hospitalized children diagnosed with MPP at the Third Ward of the department of paediatrics, Jingzhou Central Hospital, from October 2023 to October 2024. Diagnosis was confirmed by pharyngeal MP nucleic acid testing and MP antibody titers (MP-Ab ≥ 1:160). All patients were screened for macrolide-resistant gene mutations (A2063G/A2064G). Patients were categorized based on the presence of macrolide-resistant gene mutations and RMPP diagnosis. Clinical features, laboratory results, and treatments were compared between groups. Multiple logistic regression was used to identify independent risk factors for RMPP. Among 205 children with MPP, 157 (76.6%) harbored A2063G/A2064G mutations. Of the 77 children with RMPP, 71 (92.2%) carried these mutations, showing a significant association (P < 0.05). Compared to the non-resistant group, children with resistant mutations had prolonged fever duration, delayed defervescence after azithromycin, and required more bronchoscopic alveolar lavage (P < 0.05). The RMPP group exhibited more severe symptoms, longer fever and hospital stays, higher inflammatory markers (CRP, LDH, D-dimer, ESR, PCT; P < 0.001), and more frequent pulmonary consolidation, pleural effusion, plastic bronchitis, and extrapulmonary involvement. Multivariate analysis identified macrolide-resistant mutations, fever duration, and D-dimer level as independent risk factors for RMPP. The widespread macrolide resistance in M. pneumoniae (76.6% in this cohort) was associated with point mutations at the A2063G and/or A2064G loci in the 23S rRNA gene. The development of RMPP is linked to macrolide-resistant mutations, duration of fever and D-dimer levels. D-dimer emerged as the most predictive risk factor.