# The IgA Vasculitis Study: the evolution of a cross-sectional cohort into a trial-ready cohort

## TL;DR

This study tracks children with IgA vasculitis to understand disease progression and develop better treatments for kidney complications.

## Contribution

The study evolved a cross-sectional cohort into a trial-ready framework for IgA vasculitis research.

## Key findings

- Most children with IgA vasculitis had rash and musculoskeletal symptoms, while 23% developed nephritis.
- Children with IgAV nephritis had more hospital visits and admissions compared to others.
- Older age and gastrointestinal involvement at presentation increased odds of developing nephritis.

## Abstract

The aim of this report is to describe a single-centre cohort study and its evolutionary stages into a trial-ready cohort with the vision of stopping kidney failure secondary to IgA vasculitis (IgAV).

The IgA Vasculitis Study was established as a single-centre, cross-sectional cohort study recruiting children with a clinical diagnosis of IgAV and has evolved into a trial-ready framework. Sociodemographic and clinical data, as well as corresponding biosamples, were collected longitudinally and the natural history of the first 100 recruits is provided.

The IgA Vasculitis Study commenced in June 2019. The first 100 children recruited to the study had a mean age of 7.3 years (s.d. 3.7) and a male:female ratio of 1.5:1. At presentation, all children had a lower limb–predominant rash, 76% had musculoskeletal involvement, 43% gastrointestinal involvement and 23% met the definition of nephritis. Most children (54%) were discharged after 6 months, however, 17% required paediatric nephrology input. The mean timing of onset for nephritis was 25.5 days (s.d. 22.9) following disease presentation (range 0.0–101 days). Fourteen children with IgAV nephritis (IgAV-N) received immunosuppression. Children with an older age, residing in more affluent areas, with gastrointestinal involvement or a positive urine dipstick (for proteinuria and/or haematuria) at presentation had greater odds of developing nephritis. Children with IgAV-N had statistically significantly more hospital visits and unplanned hospital admissions (P < 0.001).

Nephritis remains a serious consequence of IgAV with little evidence to guide management. This report outlines an exemplar study to advance the field towards better interventions.