Persistent Hyper IgA as a Marker of Immune Deficiency: A Case Report

Area of Science:

• Immunology
• Pediatric Medicine
• Clinical Diagnostics

Background:

• Selective antibody deficiency syndromes (SADS) represent a heterogeneous group of primary immunodeficiencies characterized by impaired antibody production against specific antigens.
• Hyperimmunoglobulin D syndrome (HIDS) is a rare autoinflammatory disorder typically presenting with recurrent fevers, lymphadenopathy, and elevated IgM and IgA.
• Distinguishing between different antibody deficiencies and autoinflammatory conditions is crucial for accurate diagnosis and management.

Observation:

• A 10-year-old male presented with an elevated immunoglobulin A (IgA) level one year after experiencing pneumococcal sepsis.
• Further investigation revealed a broad-based IgG-specific antibody deficiency syndrome.
• The patient's clinical presentation and laboratory findings were analyzed in the context of existing literature.

Findings:

• An elevated IgA level, exceeding two standard deviations above the age-appropriate range, was identified as a potential marker.
• This finding led to the diagnosis of a broad-based IgG-specific antibody deficiency syndrome.
• While an association with indolent hyper-IgD syndrome was considered, the lack of vaccine-specific antibody response was atypical for HIDS.

Implications:

• Elevated IgA levels in pediatric patients, particularly after infectious episodes like sepsis, warrant a comprehensive workup for selective antibody deficiency syndromes.
• This case highlights a potential, albeit atypical, association between elevated IgA and indolent forms of hyper-IgD syndrome.
• Recognizing these immunological nuances is vital for refining diagnostic pathways and improving patient outcomes in primary immunodeficiencies.