CD4


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CD4

 
designation for an antigen found on helper T cells; see under antigen.

CD4

a type I transmembrane protein found on helper/inducer T cells, monocytes, macrophages, and dendritic cells that is involved in T-cell recognition of antigens; expressed in mycosis fungoides, Sézary syndrome, and T-cell lymphomas.

CD4

(sē′dē-fôr′)
n.
A glycoprotein predominantly found on the surface of helper T cells. In humans, it is a receptor for HIV, enabling the virus to gain entry into its host.

CD4

(cluster designation 4) symbol for a glycoprotein expressed on the surface of helper T lymphocytes and other immune cells. CD4 serves as a receptor for human immunodeficiency virus envelope glycoprotein gp120. Binding of the viral glycoprotein gp120 to CD4 is the first step in viral entry, leading to the fusion of viral and cell membranes. CD4 count is used as an indicator of treatment timing in HIV patients.

CD4/CD8 count

the ratio of the number of helper T lymphocytes to the number of suppressor and cytotoxic T lymphocytes. The cells are counted with the use of monoclonal antibodies to the surface glycoproteins CD4 on helper T cells and CD8 on suppressor and cytotoxic T cells. In healthy individuals the ratio ranges from 1.6 to 2.2. The ratio is important in monitoring the function of the immune system in patients who have viral infections or who have undergone tissue transplantation, either of which may cause an increase in the number of suppressor T cells.

CD4

A transmembrane glycoprotein present on T helper/inducer cells, which participates in adherence of T cells to target cells, and is involved in thymic maturation and transmission of intracellular signals during T cell activation by the class II MHC; CD4 has inducer or helper activity for T cell, B cell, and macrophage interactions, and evokes T cell proliferation in response to soluble antigens or autologous non-T cells, providing appropriate signals for B cell proliferation and differentiation into Ig-secreting cells; CD4 is also a high-affinity receptor for HIV-1's gp120, binding 42–55 of the NH2 terminal domain amino acids, and has an Ig-like fold similar to the complementarity-determining region of the kappa light chain; CD4 also binds Igs independently of the Fc receptor, and is an accessory to the T-cell receptor

CD4

A type of protein molecule in human blood that is present on the surface of 65% of human T cells. CD4 is a receptor for the HIV virus. When the HIV virus infects cells with CD4 surface proteins, it depletes the number of T cells, B cells, natural killer cells, and monocytes in the patient's blood. Most of the damage to an AIDS patient's immune system is done by the virus' destruction of CD4+ lymphocytes. CD4 is sometimes called the T4 antigen.
Mentioned in: AIDS, AIDS Tests

CD4 (T4) lymphocyte,

n an immunologically important white cell that is responsible for cell-mediated immunity. It is the cell invaded by the human immunodeficiency virus and in which the virus replicates itself.

CD2

cluster of differentiation or cell differentiation glycoproteins.

CD antigen
a group of cell surface molecules which act as markers on T lymphocytes.
CD3
found on T helper (Th) and T cytotoxic (Tc) lymphocytes; associated with signal transduction.
CD4
found on T helper lymphocytes; an adhesion molecule that binds to class II MHC molecules.
CD8
found on T cytotoxic and variably on NK lymphocytes; an adhesion molecule that binds to class I MHC molecules.
References in periodicals archive ?
We expect that the VISITECT CD4 test will make a real difference in HIV treatment and prevention programs that care for many millions of patients worldwide, which is exactly what we set out to achieve.
Correlating CD4 values with TLC, we derive that in our study population 33 patients who had CD4 counts less than 200 had a mean TLC of 1198.
The percentages of patients with CD4 counts in the ranges of <100, 101-200, 201-350, 351-500 and >500 cells/[micro]L in the financial years 2010/11 and 2014/15 are set out in Table 1, according to province.
Measurement of naive CD4 cells reliably predicts potential for immune reconstitution in HIV.
Idiopathic CD4 Lymphocytopenia: Spectrum of opportunistic infections, malignancies, and autoimmune diseases.
Expected age at death for men and women with HIV differed according to CD4 count when antiretroviral therapy began.
Lab B was the Swazi national reference laboratory based in the capital city, 250 km away from the study setting, and had a turnover of 4 000 CD4 enumerations per month.
Point-of-care CD4 tests which can give results within half an hour are being developed, both to expand access to CD4 testing and to speed up processes within clinics.
CD4 per cent and CD8 per cent in healthy adult population
The diagnosis of PTB/HIV co-infection was based on criteria for diagnosing TB in poor resource settings where there are no facilities and manpower for mycobacterium tuberculosis culture: (a) the diagnostic criteria of TB given in the World Health Organisation (WHO) treatment of tuberculosis guideline for national programmes [5]; (b) specificity of clinical criteria in diagnosing TB patient [6, 10]; (c) Although Mantoux is usually negative in HIV infection because of loss of cell mediated immunity due to depletion of CD4 count, HIV patients who were smear negative for AAFB, but had positive Mantoux test with an area of induration [greater than or equal to]10mm diameter were considered diagnostic for tuberculosis.
The CD4 Count is a whole-blood quality control for verifying the accuracy of the BD FACSCount flow cytometer.