NETs in the spotlight: exploring NETosis markers for tracking disease activity in IgA vasculitis

The role of neutrophil extracellular traps (NETs) in IgA vasculitis (IgAV) pathogenesis is emerging, with NETosis-associated markers potentially linked to disease activity. This study aimed to explore the relationship between NETosis biomarkers and IgAV disease phases.

A longitudinal study involving 33 paediatric IgAV patients and 26 healthy controls was conducted. Blood and urine samples were collected from healthy controls and patients during active and inactive disease phases. NETosis markers, including cell-free DNA (cf-DNA), neutrophil elastase, MPO and citrullinated histone H3 (cit-H3) were measured using ELISA kits. Statistical analyses were conducted to compare differences for NETosis markers between groups and to evaluate correlations among variables using appropriate statistical tests.

There was no significant difference in gender and age between the patient and control groups. The serum cf-DNA level was significantly higher in the active patient group compared with the control and inactive patient groups (P = 0.04; P = 0.04, respectively). In urine, MPO levels were significantly lower in the active phase of patients than controls (P = 0.009), while cit-H3 levels were higher in both active and inactive phases compared with controls (P = 0.01 and P = 0.03, respectively). A cf-DNA threshold of 935 ng/ml was identified, which achieved a sensitivity of 93% (correctly identifying 93% of active patients) and a specificity of 72% (correctly identifying 72% of healthy controls).

Elevated serum cf-DNA and urine cit-H3 suggest a potential role for NETosis in IgAV activity, highlighting these markers as potential indicators for disease monitoring. Further studies are warranted to establish standardized protocols for NETosis marker assessment in IgAV.