Immune activation and mucin dysregulation in pediatric refractory Mycoplasma pneumoniae pneumonia with mucus plugs

Children with RMPP and mucus plugs exhibited higher BALF cytokine levels, elevated epithelial injury markers (KL-6 and SP-A), and relatively increased MUC5B expression. Lower serum total protein was independently associated with mucus plug formation. These findings refine the pathophysiological understanding of RMPP with mucus plugs and may inform targeted anti-inflammatory and mucus-modulating therapeutic strategies.