NPPB and chlamydia trachomatis infectious disease: To further understand the fundamental aspects of IVIG resistance, we used the SHAP algorithm to analyze the CatBoost model, which identified eight features with a considerable impact on IVIG resistance: winter onset, chlamydial infections, conjunctival congestion, fever duration, and hemoglobin, NT-proBNP, serum ALB, and TBIL levels.