Neutrophils in Arthritis and COVID-19 Diverge
A study comparing neutrophil gene activity finds that rheumatoid arthritis and COVID-19 share few overlapping immune signals.
Updated on Nov. 4, 2026 in Arthritis
Researchers analysed publicly available neutrophil RNA-seq data to compare gene expression in rheumatoid arthritis and COVID-19. The analysis found 11,355 differentially expressed genes in RA neutrophils, while COVID-19 neutrophils showed 420.
Why it matters
The findings suggest that neutrophil involvement in rheumatoid arthritis and COVID-19 is not uniform across these conditions. Understanding where the two diverge may inform how immune responses are studied in autoimmune and infectious disease.
The analysis used publicly available neutrophil RNA-seq count data and found 11,355 differentially expressed genes in RA neutrophils versus 420 in COVID-19 neutrophils. Of the 90 RA genes with a log2 fold change of at least 2, 27 changed significantly in the opposite direction in COVID-19, and it remains unclear whether these patterns reflect disease-specific biology.
The details
Researchers used DESeq2 for differential expression and fgsea with Hallmark gene sets, plus topGO with Gene Ontology terms, for pathway enrichment. Twenty-four Hallmark gene sets were positively enriched in RA neutrophils, led by interferon alpha and interferon gamma responses, while no Hallmark gene set reached significance in COVID-19 neutrophils.
Health Landscape
The study builds on the use of the Gene Expression Omnibus repository to compare immune cell profiles across diseases. It adds a direct contrast between rheumatoid arthritis and COVID-19 neutrophils, areas where interferon signalling has been studied separately.
For people living with rheumatoid arthritis, the study points to interferon-related immune activity in neutrophils as a feature that differs from COVID-19. Findings at this stage do not change treatment options, which remain set by clinicians.
The takeaway
Immune cell signals that look similar on the surface can differ substantially between diseases. Researchers comparing conditions should check gene-level patterns rather than assuming overlap.
Further reading
For more on the joint condition at the centre of this comparison, see Arthritis.
Source note: This article includes information reported by Biorxiv.
