Immunoglobulin G (IgG) subclass deficiency in Thai children

Area of Science:

• Pediatric Immunology
• Infectious Diseases
• Clinical Diagnostics

Background:

• Immunoglobulin G (IgG) subclass deficiency is associated with recurrent sino-pulmonary infections.
• Understanding the epidemiology of IgG subclass deficiency in pediatric populations is crucial for diagnosis and management.

Purpose of the Study:

• To determine the epidemiology of IgG subclass deficiency in Thai children.
• To compare diagnostic criteria: low level vs. low percentage for IgG subclass deficiency.

Main Methods:

• Descriptive study of 55 children (up to 15 years) with recurrent infections.
• Children diagnosed with IgG subclass deficiency, excluding other primary immune deficiencies.
• Comparison of diagnosis using low level (less than 2 SD) and low percentage criteria.

Main Results:

• Isolated IgG3 subclass deficiency was most common (56.4%), found in 85.5% of cases.
• Recurrent sinusitis was the most frequent symptom (83.6%), with onset typically between birth and five years.
• Diagnosis by low percentage criteria (89.3%) was more common than by low level criteria (12.7%); all low level cases also had low percentages.

Conclusions:

• IgG3 subclass deficiency is the predominant type in Thai children, often presenting with recurrent sinusitis.
• Low percentage criteria are more effective for diagnosing IgG subclass deficiency in children with recurrent upper respiratory infections.
• No significant clinical or management differences were observed between diagnostic criteria groups.