Overview: Immunoglobulin D (IgD) TestIntroduction: The Immunoglobulin D (IgD) Test measures IgD levels to diagnose immune disorders, causing recurrent infections. Aligned with 2023 AAAAI guidelines, it uses immunoassays for high accuracy, supporting immune screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in immunology for patients with suspected immune deficiencies.
Other Names: IgD Assay, Serum IgD Test.
FDA Status: Laboratory-developed test (LDT), meeting immunology standards for diagnostic accuracy.
Historical Milestone: IgD testing began in the 1960s with immune research. Immunoassay-based methods improved in the 1990s, enhancing diagnostic precision.
Purpose: Measures IgD levels to diagnose immune disorders, guides treatment, and evaluates patients with recurrent infections.
Test Parameters: 1. Immunoglobulin IgD
Pretest Condition: No fasting required. Collect serum, plasma, or saliva at any time. Report history of recurrent infections or immune disorders.
Specimen: 2-5 mL serum (SST), 2-4 mL plasma (EDTA), or 1-2 mL saliva (sterile container). Transport in a biohazard bag.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 7 days
Sample Stability at Frozen: 6 months
Medical History: Document recurrent infections, immune disorders, or family history of immune deficiencies. Include current medications, especially immunoglobulins.
Consent: Written consent required, detailing the tests purpose, immune disorder implications, and potential need for immunoglobulin therapy.
Procedural Considerations: Uses immunoassays to measure IgD levels. Results are available in 3-5 days, supporting clinical decisions. Performed in laboratories, often for immune assessment.
Factors Affecting Result Accuracy: Improper sample handling or contamination can affect results. Recent infections may influence IgD levels.
Clinical Significance: Abnormal IgD levels suggest immune disorders, guiding immunoglobulin therapy or infection management. Normal levels may require further immune testing.
Specialist Consultation: Consult an immunologist for result interpretation and treatment planning.
Additional Supporting Tests: IgA, IgG, IgM levels, or lymphocyte subset analysis to assess immune function.
Test Limitations: IgD levels are not specific to one disorder; clinical correlation is needed. Limited diagnostic role compared to other immunoglobulins.
References: AAAAI Immune Deficiency Guidelines, 2023; Journal of Allergy and Clinical Immunology, Bonilla FA, 2022.
