HyperCKemia and the neutrophil-to-lymphocyte ratio in patients with Guillain–Barré syndrome: a retrospective study

Aims: Guillain–Barré syndrome (GBS) is an autoimmune disorder with a heterogeneous clinical course, and reliable prognostic biomarkers remain limited. This study evaluated the associations of serum creatine kinase (CK) with clinical severity, electrophysiological subtypes, and short-term (in-hospital) outcomes in GBS, and examined the relationship between the neutrophil-to-lymphocyte ratio (NLR) and clinical and laboratory parameters.Methods: We retrospectively reviewed patients hospitalized with GBS between January 2019 and October 2025. Fifty-nine eligible patients were included. Electrophysiological subtypes (AIDP/AMAN/AMSAN/normal) were obtained from hospital records. Serum CK was measured once at admission; hyperCKemia was defined as CK ≥200 IU/L. NLR was calculated from admission complete blood counts. Disease severity was assessed using the Hughes Functional Grading Scale at admission and discharge. Requirement for intensive care unit (ICU) admission and length of hospital stay were recorded. Results: The mean age was 48.27±16.46 years, and 59.32% of patients were male. HyperCKemia was observed in 50.85% (30/59). Electrophysiological subtypes were 42.37% AIDP, 20.34% AMAN, 27.12% AMSAN, and 10.17% normal. ICU admission was required in 18.64% (11/59). HyperCKemia was not associated with length of hospital stay, ICU requirement, or Hughes scores at admission or discharge (all p>0.05), but was associated with higher aspartate aminotransferase levels (p=0.004) and more frequent antecedent infection (p=0.024). NLR showed no association with age, length of stay, CK, C-reactive protein, or Hughes scores (all p>0.05), but was significantly higher in patients requiring ICU care (p=0.006). Conclusion: HyperCKemia is common in GBS but does not predict short-term outcomes. Elevated NLR in patients requiring ICU admission may help identify severe disease and warrants validation in larger prospective studies.