Approach to primary immunodeficiency.

Area of Science:

• Immunology
• Genetics

Background:

• Primary immunodeficiency diseases (PIDs) are inherited disorders affecting innate or adaptive immunity.
• These defects lead to increased susceptibility to infections and immune dysregulation.
• PIDs encompass a wide spectrum, including antibody deficiencies, combined immunodeficiencies, and innate immune defects.

Purpose of the Study:

• To outline the diverse clinical manifestations of primary immunodeficiency diseases.
• To highlight characteristic infections associated with specific immune defects.
• To introduce newborn screening methods for early detection of T-cell lymphopenia.

Main Methods:

• Clinical observation and analysis of infection patterns.
• Description of immunological assays and genetic testing principles.
• Introduction of T-cell receptor excision circle (TREC) analysis for newborn screening.

Main Results:

• Specific infections correlate with distinct immune system defects (e.g., encapsulated bacteria with antibody deficiency, viral/fungal with T-cell impairment).
• Neutrophil dysfunction and complement deficiencies present with characteristic infection patterns.
• Newborn screening using TREC analysis effectively identifies T-cell lymphopenia, including severe combined immunodeficiency and 22q11.2 syndrome.

Conclusions:

• Understanding the relationship between immune defects and infection types is crucial for diagnosing PIDs.
• Early detection through newborn screening, like TREC analysis, is vital for managing severe PIDs.
• Continued research into PIDs will improve diagnostic and therapeutic strategies.