Flow cytometry of peripheral blood lymphocytes can be helpful in the initial triage of a patient with a suspected combined immunodeficiency.
In combined immunodeficiency there is often a combination of abnormalities affecting lymphocytes:
(1) quantitative: decreased or absent
(2) qualitative: present but dysfunctional
Flow cytometry can be used to quantitate lymphocyte subsets.
T cells |
B Cells |
NK Cells |
Diagnosis to Consider |
normal |
normal |
normal |
ZAP70-related SCID |
decreased |
normal |
normal |
IL7RA-related SCID |
decreased |
normal |
decreased |
JAK3-related SCID, CD45 deficiency, X-linked SCID (IL2RG) |
decreased |
decreased |
normal |
RAG1 deficiency, RAG2 deficiency, ARTEMIS (SCID Athabascan) |
decreased |
decreased |
decreased |
ADA deficiency |
Additional testing is needed to identify dysfunction. These may be in vivo (response to antigenic stimulus) or in vitro.
Specialty: Immunology/Rheumatology, Infectious Diseases
ICD-10: ,