Serial immune-inflammatory recovery trajectories after acute ischemic stroke: associations with early neurological deterioration and 90-day functional outcome in a retrospective cohort

Background Systemic inflammation after acute ischemic stroke is usually assessed using admission biomarkers, which may not distinguish transient stress from sustained immune-inflammatory activation. We examined whether serial immune-inflammatory recovery trajectories were associated with early neurological deterioration (END) and 90-day functional outcome. Methods This single-center retrospective cohort included 760 adults with acute ischemic stroke identified from a hospital stroke database. NLR, SII, SIRI, and hs-CRP measured at admission, 24 h, 72 h, and day 7 were log-transformed and standardized, and equally weighted values were averaged at each observed time point. Latent class mixed models with 2–5 classes were compared without using outcome information, and a five-class solution was selected before association and prediction analyses. The primary outcome was 90-day mRS 3–6. END was defined as an NIHSS increase of ≥2 points within 72 h; the landmark END analysis excluded END within 24 h and tested 0–24 h immune change for END from 24 to 72 h. Results The five LCMM classes comprised 182 low-stable, 223 transient moderate, 161 delayed recovery, 122 persistent high, and 72 extreme persistent high patients. Among 751 patients with 90-day outcome data, the observed rate of mRS 3–6 increased from 21.5 to 30.6%, 44.2, 71.9, and 98.6% across these classes. After adjustment, persistent high (OR 2.46, 95% CI 1.31–4.61; p = 0.005) and extreme persistent high inflammation (OR 20.24, 95% CI 2.48–165.26; p = 0.005) were associated with mRS 3–6; a bias-reduced sensitivity estimate for the extreme class remained large (OR 13.61, 95% CI 2.34–79.26). Ordinal analysis showed progressively worse mRS for delayed recovery (common OR 2.73), persistent high (4.18), and extreme persistent high (6.72). The 0–24 h composite immune-change metric was not associated with landmark END (OR 1.12, 95% CI 0.92–1.36; p = 0.265). Adding LCMM-5 to the clinical model increased AUC from 0.828 to 0.841, but did not clearly outperform adding admission NLR/SII. Conclusion Longitudinal classification identified five immune-inflammatory recovery trajectories with a marked gradient in 90-day disability. Persistent-high and extreme persistent-high classes retained independent associations with poor functional outcome.