Serum Interleukin-1β and High-Sensitivity C-Reactive Protein Across Schizas Morphological Grades in Degenerative Lumbar Spinal Stenosis: An Exploratory Cross-Sectional Study

Abstract

Background: In degenerative lumbar spinal stenosis (LSS), symptom severity often bears little relation to the narrowing seen on imaging, and inflammation may contribute.

Objective: To determine whether the Schizas grade of the dural sac is associated with serum interleukin-1β (IL-1β) and high-sensitivity C-reactive protein (hs-CRP) after confounder control.

Methods: Thirty non-obese patients with LSS (body mass index [BMI] <30 kg/m²) at Dr. Mohammad Hoesin General Hospital, Palembang, were studied after a verified 7-day anti-inflammatory washout. Two blinded radiologists graded axial T2-weighted magnetic resonance imaging (MRI): Grade A, n = 10; B, n = 11; C/D, n = 9 (κ = 0.84). Morning IL-1β and hs-CRP were compared with Kruskal–Wallis tests and bootstrapped regression.

Results: BMI (p = 0.312) and sex (p = 0.927) were similar across grades, but age and symptom duration rose with grade (both p < 0.001). IL-1β medians climbed from 5.60 [4.90–6.40] pg/mL in Grade A to 8.45 [7.20–9.50] pg/mL in Grade B and 11.20 [9.10–13.80] pg/mL in Grade C/D (p < 0.001); hs-CRP medians were 2.15 [1.80–2.60], 3.40 [2.90–4.10] and 4.90 [3.80–6.20] mg/L (p = 0.003). With age and BMI in the model, grade remained associated with IL-1β (B = 2.05, β = 0.46, p = 0.012, R² = 0.41) and hs-CRP (B = 1.12, β = 0.49, p = 0.009, R² = 0.44); no variance inflation factor reached 2.5.

Conclusion: Greater dural sac compression went with higher serum IL-1β and hs-CRP, independent of age and BMI. Larger longitudinal cohorts are needed before these markers are used alongside MRI.