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FLASC
57281
LPMAF
60593
Philadelphia, Churchill Livingstone, 2000, pp 2504-2518
Lyme Serum and CSF Analysis
Reference Values:
A final report will be faxed under separate cover.
Test Performed by: IMUGEN Reference Diagnostic Division
315 Norwood Park South
Norwood, MA 02062
Lymphocyte Proliferation Panel for Mitogens and Antigens
Clinical Information: Several classes of ligands are capable of inducing blastogenesis and
stimulating proliferation of lymphocytes in vitro, including plant mitogens (phytohemagglutinin [PHA],
pokeweed [PWM], and concanavalin A [Con A]), bacterial products and superantigens (potent bacterial
toxins that at low concentrations have the ability to activate large numbers of T cells), and phorbol esters.
Cellular proliferation follows a complex series of signals that begins with engagement of lymphocyte
surface receptors by a mitogenic or antigenic ligand. Subsequent signals, including gene activation and
secretion of cytokines, result in synthesis of DNA and cell division. Measurement of mitogen-induced
lymphocyte proliferation in vitro provides a semiquantitative assessment of total cell-mediated
immunity.(1) The proliferative responses to PHA and Con A involve T lymphocytes, and the response to
PWM involves both T and B lymphocytes in a T-dependent manner. Diminished proliferative responses
to lectin mitogens occur in a variety of primary and secondary immunodeficiency diseases including
diseases that affect T lymphocytes, B lymphocytes, and T and B lymphocytes.(2) Specific antigen
recognition involves T-cell receptor recognition of specific peptide in the context of the appropriate MHC
molecule on an antigen-presenting cell. T cells activate and proliferate in response to specific antigenic
stimulus. The recall antigens (eg, Candida albicans and tetanus toxoid) are used to assess antigen-specific
T-cell responses. The absolute counts of lymphocyte subsets are known to be influenced by a variety of
biological factors, including hormones, the environment, and temperature. The studies on diurnal
(circadian) variation in lymphocyte counts have demonstrated progressive increase in CD4 T-cell count
throughout the day, while CD8 T cells and CD19+ B cells increase between 8:30 a.m. and noon, with no
change between noon and afternoon. Natural killer (NK) cell counts, on the other hand, are constant
throughout the day.(3) Circadian variations in circulating T-cell counts have been shown to be negatively
correlated with plasma cortisol concentration.(4-6) In fact, cortisol and catecholamine concentrations
control distribution and, therefore, numbers of naive versus effector CD4 and CD8 T cells.(4) It is
generally accepted that lower CD4 T-cell counts are seen in the morning compared with the evening (7),
and during summer compared to winter.(8) These data, therefore, indicate that timing and consistency in
timing of blood collection is critical when serially monitoring patients for lymphocyte subsets.
Useful For: Evaluating patients suspected of having diminished cellular immune function Evaluating
patients with primary and secondary immunodeficiency diseases that affect T lymphocytes, including
combined immunodeficiency diseases (eg, severe combined immunodeficiency, cellular
immunodeficiency diseases, and some patients with humoral immunodeficiency diseases (eg, common
variable immunodeficiency) Evaluating functional T-cell recovery post-hematopoietic stem cell transplant
or immunosuppressive therapy for solid-organ transplantation or in other clinical contexts
Interpretation: Diminished responses to lectin mitogens and/or antigens may be consistent with a
primary or secondary immunodeficiency disease. Abnormal results are not specific for a particular
disease, and the magnitude of the abnormality is not necessarily related to the degree of
immunodeficiency. In the case of antigen-specific proliferative responses, it is possible to have low or
absent responses if a long interval has passed since the original or booster vaccination (tetanus toxoid).
Reference Values:
LYMPHOCYTE PROLIFERATION TO ANTIGENS
Viability of lymphocytes at day 0: > or =75.0%
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