From the Guidelines
Immunodeficiency disorders are conditions where the immune system's ability to fight infections and diseases is compromised, and can be primary (genetic or congenital) or secondary (acquired due to medications, infections, or other conditions). These disorders can affect various components of the immune system, including B cells, T cells, phagocytes, or complement proteins, leading to increased susceptibility to infections and diseases. Common primary immunodeficiencies include Severe Combined Immunodeficiency (SCID), Common Variable Immunodeficiency (CVID), and X-linked agammaglobulinemia, as noted in the practice parameter for the diagnosis and management of primary immunodeficiency 1. Secondary immunodeficiencies include HIV/AIDS, medication-induced immunosuppression, and malnutrition. Treatment depends on the specific disorder but often includes immunoglobulin replacement therapy, prophylactic antibiotics, and in severe cases, stem cell transplantation, as recommended by the American Academy of Allergy, Asthma & Immunology (AAAAI) and other national allergy and immunology societies 1. Patients should receive inactivated vaccines according to schedule, avoid live vaccines, practice good hygiene, and promptly treat infections. Early diagnosis is crucial as delayed treatment can lead to recurrent infections, organ damage, and reduced quality of life. Some immunodeficiency disorders have characteristic clinical presentations, such as recurrent sinopulmonary infections with encapsulated bacteria, or severe mycobacterial and Salmonella species infections, as outlined in Table E3 1. The underlying mechanism involves defects in immune cells or proteins, disrupting the body's defense against pathogens. It is essential to consult with physicians experienced in immunodeficiencies for accurate diagnosis and management, as noted in the practice parameter for the diagnosis and management of primary immunodeficiency 1. In addition to medical treatment, patients with immunodeficiency disorders should be aware of the importance of preventive measures, such as avoiding close contact with people who have infections, and practicing good hygiene, to reduce the risk of infections. Overall, immunodeficiency disorders require a comprehensive approach to management, including medical treatment, preventive measures, and lifestyle modifications, to improve quality of life and reduce morbidity and mortality.
From the Research
Definition and Classification of Immunodeficiency Disorders
- Immunodeficiency disorders refer to a group of conditions characterized by a compromised immune system, resulting in increased susceptibility to infections and other immune-related complications 2, 3, 4, 5.
- These disorders can be classified into primary immunodeficiencies, which are genetic conditions, and secondary immunodeficiencies, which are acquired due to various factors such as immunosuppressive therapies, renal or gastrointestinal immunoglobulin losses, or chronic medical conditions 2, 4, 5.
- Primary immunodeficiencies can be further categorized into disorders of adaptive immunity (e.g., T cell, B cell, or combined immunodeficiencies) and disorders of innate immunity (e.g., phagocyte and complement disorders) 5.
Clinical Manifestations and Diagnosis
- The clinical manifestations of immunodeficiency disorders are highly variable, but common features include recurrent infections, failure to thrive, and poor response to antibiotics 3, 5.
- Diagnostic testing often involves a combination of laboratory tests, including complete blood counts, serologic tests, flow cytometry, and genetic testing 3, 4, 5.
- A careful medical history and physical examination are essential to guide the diagnostic workup and identify the underlying immunodeficiency disorder 3, 4, 5.
Treatment and Management
- The treatment of immunodeficiency disorders is complex and requires both supportive and definitive strategies 5.
- Immunoglobulin replacement therapy is a mainstay of therapy for B cell disorders and is also used as a supportive treatment for many patients with combined immunodeficiency disorders 2, 5.
- Other treatment options include antifungal and antibiotic prophylaxis, cytokine replacement, vaccinations, and bone marrow transplantation, depending on the specific type of immunodeficiency disorder 5, 6.