STAGE 1
- History and physical examination
- FBC and differential
- Quantitative Immunoglobulin levels IgG, IgM, IgA
STAGE 2
- Specific antibody responses (tetanus, diphtheria, pneumococcus)
- Lymphocyte surface markers CD3/CD4/CD8/CD19/CD56
- Total IgE
STAGE 3
- Lymphocyte proliferation studies (mitogen/antigen stimulation or skin delayed-type hypersensitivity)
- Neutrophil oxidation burst (if indicated)
- Response to pneumococcal vaccine (for ages 2 years old and above)
STAGE 4
- Complement screening CH50, specific complement components, AH50
- Enzyme activity measurements (e.g., adenosine deaminase, purine nucleoside phosphorylase)
- Phagocyte studies (e.g., surface glycoproteins, mobility, phagocytosis)
- Neo antigen response to test antibody production
- Other surface molecules for detailed immunophenotype (e.g., memory B cells, T/NK cell subpopulations)
- Specific protein levels
- Other function receptor quantification
- Genetic test
