4
Diagnosis
Table 1A. International Union of Immunological Societies
(IUIS) Classification of Human IEI 2024
Subtable I Immunodeficiencies affecting cellular and humoral immunities
1. T-B+ severe combined immunodeficiency (SCID)
2. T-B–SCID
3. Combined immunodeficiencies. Generally less profound than SCID.
Subtable II Combined immunodeficiencies with associated or syndromic features
1. Immunodeficiency with congenital thrombocytopenia
2. DNA repair defects
3. Thymic defects with additional congenital anomalies
4. Immuno-osseus dysplasias
5. Hyper IgE syndromes
6. Defects of vitamin B12 and folate metabolism
7. Anhidrotic ectodermal dysplasia with immunodeficiency
8. Calcium channel defects
9. Other defects
Subtable III Predominantly antibody deficiencies
1. Severe reduction of all serum immunoglobulins with profoundly
decreased B-cell numbers
2. Severe reduction of at least 2 serum immunoglobulin isotypes with
normal or low B-cell numbers, common variable immune deficiency
(CVID)
3. Severe reduction in serum IgG and IgA levels with normal/elevated
IgM level and normal B-cell numbers, hyper IgM
4. Isotype, light chain, or functional deficiencies with generally normal
B-cell numbers
Subtable IV Diseases of immune dysregulation
1. Familial hemophagocytic lymphohistiocytosis (FHLH)
2. FHLH syndromes with hypopigmentation
3. Regulatory T-cell defects
4. Autoimmunity with or without lymphoproliferation
5. Immune dysregulation with colitis
6. Autoimmune lymphoproliferative syndrome (ALPS)
7. Susceptibility to Epstein-Barr virus (EBV) and lymphoproliferative
conditions
Subtable V Congenital defects of phagocyte number or function
1. Congenital neutropenia
2. Defects of motility
3. Defects of respiratory burst
4. Other nonlymphoid defects
