Immunodeficiency

Disease Description (Causes and Symptoms)

• Definition: Immunodeficiency disease refers to a state in which normal defense against infections is impossible due to defects or reduced function of immune system components (secretory and cellular immunity, complement, phagocytes, etc.).
• Classification: Primary (congenital) immunodeficiency — caused by genetic defects (e.g., abnormalities of B cells, T cells, complement, or phagocytes). Secondary immunodeficiency — acquired due to HIV infection, medications (immunosuppressants), malnutrition, chronic diseases, etc.
• Epidemiology (reference): Primary immunodeficiency occurs in approximately 1 in 10,000 people; defects of the B-cell system account for approximately 55%, T-cell system 25%, phagocytes 18%, and complement 2%. Most patients are children, and X-linked diseases show a male predominance (approximately 70%).
• Pathophysiology summary: Deficiency or dysfunction of specific immune components causes recurrent and severe infections with pathogens that would normally be controlled by the immune system. Infections with atypical pathogens, infections at unusual sites, or delayed recovery from infection are characteristic.
• Main symptoms: Frequent fever, chronic or recurrent diarrhea, dermatitis (such as eczema and impetigo), perianal inflammation, lymph node enlargement or abscesses (including cervical lymphadenopathy), recurrent respiratory infections (otitis media, pneumonia), and severe infections caused by atypical pathogens.

Treatment Methods (Standard Treatment · Medications · Procedures · Lifestyle Management · Precautions)

• Treatment of acute infections: After identification of the pathogen, appropriate antibiotics, antifungals, or antivirals are administered (intravenously in severe cases). Treatment initially begins with empirical antibiotics and is adjusted according to the results.
• Infection prevention and replacement therapy:
  • Regular immunoglobulin replacement therapy (IVIG or SCIG): Reduces the frequency and severity of infections in patients with antibody deficiencies.
  • Long-term prophylactic antibiotics when necessary (according to the physician’s judgment).
  • Lifestyle and hygiene management (hand hygiene, avoiding contact with infected people, and taking precautions in crowded places).
  • Vaccines: Inactivated vaccines are recommended. Live vaccines (BCG, MMR, etc.) may be contraindicated in patients with certain T-cell deficiencies — consultation with a specialist is necessary.
• Definitive treatment:
  • Hematopoietic stem cell transplantation (HSCT): Performed with curative intent in some primary immunodeficiency diseases. The prognosis varies depending on the indications, timing, and technique.
  • Gene therapy: Applied at the clinical trial level for some diseases (ongoing).
• Monitoring and management of complications: Regular blood tests (immunoglobulins, CBC, etc.), monitoring of growth and development (in children), and surveillance for organ damage due to chronic infections (such as pulmonary fibrosis).
• Precautions:
  • Prompt evaluation and treatment are important when an infection is suspected (risk of sepsis).
  • Immune status must be confirmed before receiving live vaccines.
  • Inform the primary physician of any history of immunosuppressive medication or anticancer treatment, as well as the tendency toward infection risk.
  • Hypersensitivity reactions (headache, fever, and allergy) may occur during IVIG administration, and, rarely, thrombosis or kidney damage may occur — monitoring before and after administration is necessary.
• Complications: Chronic lung disease due to recurrent infections (such as bronchiectasis), growth delay, and, in severe cases, sepsis and organ damage.

Checklist Before an Outpatient Visit (Including Preparation Items and Sample Questions)

• Recommended items to bring:
  • A list of currently taken medications and supplements (including doses and administration times)
  • Previous test results (recent CBC, immunoglobulin levels, C3/C4, NBT, etc.) and culture and infection records (history of hospitalization, surgery, and use of major antibiotics)
  • Vaccination records (including whether live vaccines were administered)
  • Family history (similar symptoms, early death, or genetic diseases)
  • A record of changes in symptoms (frequency and duration of fever, frequency of diarrhea, photographs of skin lesions, etc.)
• Key information to tell the doctor during the outpatient visit:
  • Frequency and severity of infections within the past year (including whether hospitalization or intravenous antibiotics was required)
  • Current fever, respiratory symptoms, wounds, and lymph node status
  • Chronic diseases (diabetes, liver or kidney disease, etc.) or use of immunosuppressive medications
• Emergency warning signs before an outpatient visit (immediate medical attention is recommended in cases of fever or severe symptoms):
  • High fever, decreased consciousness, difficulty breathing, severe abdominal pain or persistent diarrhea, and signs suggestive of sepsis

General Sample Questions to Ask the Doctor

• How is the current status (severity) of this disease assessed? What is the prognosis?
• What additional tests (genetic testing or immune cell function tests) are needed?
• What is the need for IVIG, its schedule, and its expected side effects?
• How should vaccinations be managed? Are live vaccines possible?
• What precautions must be followed in daily life to prevent infections?

Disease-Specific Sample Questions

• Do I (or the patient) have indications for hematopoietic stem cell transplantation (HSCT)? What are the success rate and major complications?
• If a variant was identified through genetic testing, is it likely to be inherited by family members? Is family testing or genetic counseling necessary?