# Expression of Tim-3 on neutrophils as a novel indicator to assess disease activity and severity in ankylosing spondylitis

## TL;DR

This study shows that Tim-3 on neutrophils is higher in ankylosing spondylitis patients and correlates with disease severity and inflammation, decreasing with treatment.

## Contribution

Tim-3 on neutrophils is identified as a novel indicator for assessing ankylosing spondylitis activity and severity.

## Key findings

- Tim-3 expression on neutrophils was higher in AS patients compared to healthy controls.
- Tim-3 levels correlated with ESR, CRP, and ASDAS, indicating disease activity and severity.
- Treatment reduced Tim-3 levels, suggesting its potential as a feedback mechanism to reduce inflammation.

## Abstract

To investigate the expression of Tim-3 on neutrophils in ankylosing spondylitis (AS) patients and its correlation with disease activity, severity, and inflammatory markers.

Sixty-two AS patients from Guangdong Second Provincial General Hospital and 38 healthy controls (HC) were enrolled. Clinical data, physical exams, and laboratory measurements were recorded. Flow cytometry measured Tim-3 and PD-1 expression on neutrophils, real-time PCR quantified mRNA levels and protein expression of Tim-3 was determined by Western blot. We analyzed the correlation between Tim-3 mean fluorescence intensity (MFI) on neutrophils, inflammatory markers, and AS disease activity and severity.

Tim-3 expression on neutrophils was higher in AS patients than in HC, showing a positive correlation with erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), and Ankylosing Spondylitis Disease Activity Score (ASDAS). Active AS patients (ASDAS ≥ 1.3) had increased Tim-3 MFI compared to inactive ones (ASDAS < 1.3). Regular treatment with non-steroidal anti-inflammatory drugs (NSAIDs), biological disease-modifying anti-rheumatic drugs (bDMARDs), and conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) over a month significantly reduced Tim-3 MFI in AS patients.

Elevated Tim-3 expression on neutrophils correlates with increased inflammatory markers and AS activity. Treatment lowered Tim-3 MFI, suggesting its potential as an indicator for assessing AS disease activity and severity and as a feedback mechanism to reduce tissue damage from inflammation.