# Serum IgE and IgA Levels in Pediatric Henoch–Schönlein Purpura: Clinical Characteristics and Immunological Correlations in the Context of Infectious Diseases—A Five-Year Retrospective Analysis

## TL;DR

This study examines IgE and IgA levels in children with Henoch–Schönlein purpura and finds a link to infectious diseases and disease recurrence.

## Contribution

The study identifies a novel correlation between elevated IgE levels and infectious diseases in pediatric HSP patients.

## Key findings

- Elevated IgE levels are strongly associated with infectious diseases in pediatric HSP patients.
- Patients with recurrent infections show elevated IgE and normal IgA levels despite no identified allergens.
- Higher IgE levels correlate with an increased risk of HSP recurrence.

## Abstract

Immunoglobulin A vasculitis (IgAV), previously known as Henoch–Schönlein purpura (HSP), is a type of non-thrombocytopenic small-vessel vasculitis. HSP is the most common systemic vasculitis in pediatric patients, and it is characterized by purpura, arthritis or arthralgia, gastrointestinal pain, and renal dysfunction. This retrospective analysis also examines a range of demographic factors, including sex, geographic and environmental influences, age, and medication, to evaluate their potential effects on the pediatric population affected by HSP. The five-year hospital-based retrospective analysis included 138 hospitalized children diagnosed with HSP during hospitalization. Blood sample analysis was conducted to assess various immunological parameters, including levels of immunoglobulins (IgA and IgE), complement components (C3 and C4), C-reactive protein, fibrinogen, the erythrocyte sedimentation rate (ESR), and allergen panels. Elevated IgE levels and normal IgA serum concentrations were found to be strongly associated with infectious diseases in pediatric HSP patients. Patients with recurrent infectious diseases consistently exhibited elevated IgE levels and normal IgA levels during treatment despite no identified allergens, alongside an increased risk of disease recurrence.