Peripheral Immune Profile and Neutrophil-to-Lymphocyte Ratio in Parkinson's Disease.
Level 3 - non-randomized controlled study
Meta-analysis of observational/case-control studies combined with a primary case-control study
PubMed 34101890 · doi:10.1002/mds.28685
What was done
A case-control study was conducted comparing 377 Parkinson's disease (PD) patients and 355 healthy controls (HCs) to measure leukocyte counts, subpopulations, and the neutrophil-to-lymphocyte ratio (NLR). Multivariate linear regression was used to evaluate differences between groups and to assess associations between NLR and PD clinical characteristics. Additionally, a meta-analysis was performed to evaluate the relationship between NLR and PD.
What was found
In the case-control cohort, NLR was significantly higher in PD patients than in healthy controls (2.47 ± 1.1 vs. 1.98 ± 0.91, P < 0.001). NLR showed no association with age at onset, disease severity, or disease duration. The meta-analysis also indicated that NLR was likely higher in PD patients (no specific numerical effect size, confidence interval, or study count reported in the abstract).
Why it matters
This paper provides combined primary cohort and meta-analytic evidence that systemic peripheral inflammation, as reflected by NLR, is elevated in Parkinson's disease, though it does not appear to correlate with disease stage or progression markers.
Limits
The observational design cannot establish whether elevated NLR is a cause, biomarker, or downstream consequence of PD. The abstract does not report numerical findings, study numbers, or sample sizes for the meta-analysis component, nor does it detail potential systemic inflammatory confounders or medication effects.
Cited by
- supports Parkinson's disease patients have highly elevated neutrophil counts in blood.