Levels of Toll-Like Receptor 2, Myeloid Differentiation Primary Response 88 and Mucin 5AC, Oligomeric Mucus/Gel-Forming in Bronchoalveolar Lavage Fluid for Predicting Severe

Objective: This study aimed to investigate the value of measuring levels of toll-like receptor 2 (TLR2), myeloid differentiation primary response 88 (MyD88) and mucin 5AC, oligomeric mucus/gel-forming (MUC5AC) in bronchoalveolar lavage fluid (BALF) for assessing disease severity and predicting severe Methods: A total of 151 children with MPP were enrolled between July 2023 and February 2025. The patients with MPP were divided into SMPP (n = 60) and non-SMPP (n = 91) groups. Bronchoalveolar lavage fluid levels of TLR2, MyD88 and MUC5AC were measured via enzyme-linked immunosorbent assay. Clinical data and laboratory indices, including C-reactive protein (CRP), procalcitonin, serum amyloid A, interleukin-6, D-dimer and fibrinogen, were compared among groups. Diagnostic value was evaluated using receiver operating characteristic curves, and independent risk factors were identified via logistic regression. Results: Multivariate logistic regression identified respiratory effort, CRP, lactate dehydrogenase, MyD88 and TLR2 as independent risk factors for SMPP (all Conclusion: Elevated levels of TLR2, MyD88 and MUC5AC in BALF are associated with SMPP. However, only TLR2 and MyD88 (along with clinical and laboratory indicators) were independent risk factors. The combined model shows good performance (AUC = 0.950) but requires external validation. These findings are associational and warrant further study.