Lymphocyte numbers and CD4/8 ratio are interpreted in conjunction with clinical findings, lymphocyte morphology and other immune measurements.
In HIV infection, low absolute CD4 count (< 0.35 x 109/L) is predictive of disease progression, and < 0.20 x 109/L CD4 is associated with an increased risk of opportunistic infection.
T cells are increased in reactive disorders and in some infections (eg, Infectious mononucleosis).
B cells (CD19) are absent in X-linked hypogammaglobulinaemia but are usually present in common variable immunodeficiency. Increased B cell numbers occur in B cell proliferative diseases; monoclonality suggests leukaemia/lymphoma.
NK (CD16) cell numbers are reduced in some immunocompromised patients, patients with cancer, and in Chediak Higashi syndrome. NK cells may be increased in reactive conditions, hepatitis C virus infection, IV drug abuse, lymphomas.
See also Flow cytometry, Table 1, Table 2.