Diagnostics · Published 2026-07-31 · DOI 10.3390/diagnostics16152429
Chen Shen, Deze Li, Xiaotong Wang, Yang Sun, Huiwen Zheng, Hao Chen, Xin Ni, Shunying Zhao
<b>Background</b>: Severe <i>Mycoplasma pneumoniae</i> pneumonia (SMPP) presents with heterogeneous clinical complications and imaging manifestations, including pleural effusion (PE), bronchiolitis obliterans (BO), and distinct imaging/bronchoscopic phenotypes. The precise systemic immune subpopulation dynamics underlying these distinct phenotypes remain poorly defined. <b>Methods</b>: We conducted flow cytometric profiling of peripheral blood mononuclear cells (PBMCs) from pediatric patients to compare mild MPP (MMPP-N) and severe MPP subtypes. SMPP patients were stratified into subgroups including those with BO (SMPP&BO, <i>n</i> = 3), PE (SMPP&PE), and three imaging/bronchoscopic phenotypes: Group A (SMPP-GA, mucous plugs), Group B (SMPP-GB, mucosal necrosis), and Group C (SMPP-GC, diffuse bronchiolitis). Composite immune indices and multi-marker discriminant analysis were constructed for secondary analysis. <b>Results</b>: Comprehensive high-dimensional profiling suggested that a fundamental innate-adaptive immune rebalancing may represent a key pathophysiological axis in severe disease. Patients with PE exhibited massive CD16<sup>−</sup> monocyte expansion (Delta = 40.0%) coupled with CD8<sup>+</sup> Teff collapse (Delta = −9.2%). Preliminary data also suggest BO may be marked by CD56<sup>−</sup>CD11C<sup>+</sup> monocyte depletion (Delta = −23.1%, <i>n</i> = 3), warranting further validation. Imaging subgroup profiling revealed that SMPP-GC featured major B-cell maturation alterations (HLADR<sup>+</sup>CD45RA<sup>high</sup> expansion and CD38<sup>+</sup>CD25<sup>low</sup> depletion). Composite indices including the Adaptive Exhaustion Score suggested discriminatory power (AUC = 0.90 for PE vs. uncomplicated SMPP). The Innate-Adaptive Ratio increased progressively with severity (Spearman rho = +0.40, <i>p</i> = 0.0002). <b>Conclusions</b>: SMPP is not immunologically uniform. Innate-adaptive rebalancing underlies complication-specific phenotypes: inflammatory monocyte mobilization with adaptive exhaustion is strongly associated with PE, whereas B-cell maturation alterations characterize diffuse bronchiolitis. These findings identify potential biomarker candidates for patient stratification, though small-cohort observations require extensive validation in larger prospective studies.
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Shen, C., Li, D., Wang, X., et al. (2026). High-Dimensional Immune Profiling Reveals Innate-Adaptive Rebalancing and Subpopulation Trajectories in Pediatric Severe Mycoplasma pneumoniae Pneumonia. Diagnostics. https://doi.org/10.3390/diagnostics16152429