Behind the scenes: Primary immunodeficiencies in pediatric eosinophilic gastrointestinal diseases

Primary immunodeficiencies (PIDs) and eosinophilic gastrointestinal diseases (EGIDs) may share common underlying defects. However, no studies have investigated the frequency of PIDs among patients with EGIDs. In this study, we aimed to assess the frequency and spectrum of PIDs among our pediatric EGIDs patients.

Patients were prospectively evaluated over a two-year period. All patients were questioned according to ten warning signs of the Jeffrey Model Foundation. Routine laboratory tests and basic immunologic tests [serum immunoglobulin levels, isohemagglutinin titres, anti-HBs and anti-rubella Ig G titres] were performed on all participants. Advanced immunologic workup was performed in selected cases. All PID diagnoses were established according to the European Society for Immunodeficiencies' criteria. Electronic health records were screened for EGIDs' specific features, comorbidities, and previous laboratory tests.

A total of 88 EGID patients [76% male, mean age: 12.02 years, 78 patients (88.6%) with EoE] were included. Fourteen patients were diagnosed with predominantly antibody deficiencies [unclassified antibody deficiency (n = 11), selective Ig A deficiency (n = 2), transient hypogammaglobulinemia of infancy (n = 1)]. Eighteen patients had abnormal Ig levels. Comparisons across the groups revealed no statistically significant differences in demographic, endoscopic, and pathologic features. Only topical swallowed budesonide unresponsiveness was significantly higher among cases with PID (p = .004).

PIDs may not be rare among patients with EGIDs. JMF's warning signs alone may be insufficient to identify affected patients in this population; therefore, additionally, basic immunologic tests as first step and advanced evaluation in suspected cases may be appropriate. Neither the key diagnostic endoscopic and pathological features nor the presence of strictures reliably distinguish PIDs.