Analysis of albumin levels and the neutrophil–lymphocyte ratio in acute inflammatory demyelinating polyneuropathy

Background Acute inflammatory demyelinating polyneuropathy (AIDP) is characterized by the acute onset of ascending motor deficits and areflexia. While acute-phase proteins, such as albumin, and novel inflammatory markers, such as the neutrophil–lymphocyte ratio (NLR), fluctuate during the disease course, their association with AIDP severity and outcomes remains unclear. Methods This observational cohort study included 69 patients diagnosed with AIDP admitted to a tertiary care centre for intravenous immunoglobulin (IVIG/Plasmapheresis) treatment. Clinical and laboratory variables were compared pre- and post-treatment, including demographic data, clinical symptoms (measured by the Hughes Disability Scale), serum albumin levels, neutrophil percentage, lymphocyte percentage, and the NLR. Disease severity was assessed at admission and seven days post-treatment. The prognostic value of serum albumin and the NLR was evaluated by correlating admission albumin and NLR with the Hughes score on the seventh day of treatment. Results The mean age of the 69 patients was 48.1 ( ± 16.7) years. Following treatment, there was a statistically significant improvement in Hughes scores (median decreased from 4 to 2 (p < 0.001), an increase in serum albumin levels (p < 0.001), and a reduction in NLR (p < 0.001). NLR showed a significant, weak positive correlation with Hughes severity score both before (Spearman’s ρ = 0.308, p = 0.01) and after treatment (ρ = 0.349, p = 0.003). Admission NLR was also significantly correlated with Day-7 Hughes score (ρ = 0.372, p = 0.0016), though this association was attenuated after adjusting for admission disease severity and age. Admission albumin showed no correlation with severity at either time point or with Day-7 outcome. Conclusion Serum albumin and NLR each changed significantly with treatment, but only NLR showed a weak positive correlation with the Hughes Disability Scale; albumin showed no such correlation at either time point. These findings suggest NLR, more than albumin, may be a useful indicator of disease activity and short-term outcome in AIDP. Nonetheless, further validation is required before these biomarkers can be reliably used to predict the clinical course of AIDP.