% CD4

Laboratory assay overview

To aid in the diagnosis of chronic lymphocytic leukemia or lymphoma. Initial markers evaluated: CD2, CD3, CD4, CD5, CD7, CD8, CD10, CD11c, CD19, CD20, CD23, CD38, CD56, CD64, FMC7, sKappa, sLambda. CD45 is used for gating.

Laboratory assay overview

To aid in the follow-up diagnosis of chronic lymphocytic leukemia or lymphoma. Initial markers evaluated: CD3, CD4, CD5, CD7, CD8, CD10, CD11c, CD19, CD20, CD23, CD38, HLA-Dr, sKappa, sLambda. CD45 is used for gating.

Laboratory assay overview

This panel may be used in the initial evaluation of patients with clinical suspicion of hematologic neoplasms. Immunophenotyping by flow cytometry can aid in the diagnosis and classification of leukemia and lymphoma [1]. Subsequent testing of additional cell surface antigens may be needed to help establish a diagnosis. Leukemias and lymphomas are heterogenous morphologically and clinically. Identification of cell surface markers (T cell, B cell, progenitor, and myeloid markers) by flow cytometry can help assign a cell lineage to neoplastic cells. Accurate immunotyping aids in the diagnosis, classification, and prognosis of hematologic neoplasm and may inform treatment decisions [1]. This immunotyping panel is designed to expedite the evaluation of patients without provisional diagnosis of a certain type of hematologic neoplasm. The results of this panel must be interpreted with cytological, histological, genetic, and clinical findings to generate accurate diagnosis. Additional cell surface markers not included in this panel may be needed to evaluate certain hematologic malignancies (eg, hairy cell leukemia). Because non-viable cells lead to non-specific antibody binding, specimens should be processed as early as possible. The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings. Reference 1. Bain BJ, et al. Leukaemia Diagnosis. 5th ed. John Wiley & Sons;2017:69-134.

Laboratory assay overview

Immunophenotypic analysis may assist in evaluating cellular immunocompetency in suspected cases of primary and secondary immunodeficiency states.

Laboratory assay overview

T-lymphocyte count assists in evaluating cellular immunocompetency.

Laboratory assay overview

T-lymphocyte count assists in evaluating cellular immunocompetency.

Laboratory assay overview

This panel separately reports CD4+ T cells (CD4) and CD8+ T cells (CD8) in the blood, as well as a calculated CD4/CD8 ratio. This panel may provide information of the immune status of individuals living with HIV. It can be used to help establish baseline values and track antiretroviral (ARV)-related treatment progress. It can also be used to evaluate helper and suppressor cell immune status in individuals with other immunodeficiency diseases. The CD4 count is the most valuable indicator of immune status in HIV-infected individuals. It can help determine the need for prophylaxis for opportunistic infections and the urgency of ARV initiation. The CD8 count reflects the level of immune activation in response to HIV. In the early stages of infection, CD4 levels and the CD4/CD8 ratio typically decline after seroconversion occurs. However, after seroconversion, CD8 cells increase in an attempt to mount a response against HIV. In ARV-treated patients with controlled viral load, CD8 counts. Post-therapy, persistently elevated CD8 counts have been linked to increased risk of non--AIDS-defining diseases, independent of CD4 count, including cardiovascular, renal, respiratory, metabolic diseases, and cancer [1-3]. This panel can be used to establish baseline CD4 and CD8 levels, as well as percentages and ratios, which help determine how long the virus has been present in the blood and the overall prognosis. During ARV treatment, this panel can help assess CD4 recovery and CD8 response to treatment [1,2]. During the first 2 years of ARV therapy, The National Institutes of Health recommends testing CD4 every 3 to 6 months. Patients who develop viremia while on therapy or whose CD4 count stays below 300 cells/µL. should also have their CD4 levels tested every 3 to 6 months. After 2 years of ARV therapy, with consistently suppressed viral load and a CD4 count of 300 to 500 cells/µL, CD4 counts should be tested every 12 months. CD4 testing should also be conducted if therapy fails. Note that CD4 testing is optional when CD4 counts are >500 cells/µL [1]. References 1. Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Department of Health and Human Services. https://aidsinfo.nih.gov/contentfiles/lvguidelines/adultandadolescentgl.pdf. Updated July 10, 2019. Accessed November 10, 2019. 2. Warren JA, et al. Front Immunol. 2019;10:291. Published February 26, 2019. doi:10.3389/fimmu.2019.00291 3. Cao W, et al. J Int AIDS Soc. 2016;19:20697. Published March 3, 2016. doi: 10.7448/IAS.19.1.20697

Laboratory assay overview

This panel is used to measure CD4+ T cells (CD4) in the blood (absolute CD4 cell count, %CD4, absolute lymphocytes). The CD4+ T-cell (CD4) count is the most valuable indicator of immune status in HIV-infected individuals. This panel can be used to establish a baseline CD4 level and to monitor treatment progress. It can also be used to facilitate differential diagnoses between congenital and acquired immunodeficiency diseases [1]. A significant reduction in CD4 count can lead to opportunistic infections, and the CD4 cell count/percentage can he used to make decisions regarding opportunistic infection prophylaxis as per guidelines [1]. During the first 2 years of antiretroviral (ARV) therapy, CD4 levels should be tested every 3 to 6 months. Patients who develop viremia while on therapy or whose CD4 count stays below 300 cells/µL should also have their CD4 levels tested every 3 to 6 months. After 2 years of ARV therapy, with consistently suppressed viral load and a CD4 count of 300 to 500 cells/µL, CD4 counts should be tested every 12 months. Note that when CD4 counts are > 500 cells/ µL, CD4 testing is optional [1]. CD4 testing should also be conducted if therapy fails. Refer to current HIV management guidelines for further information on recommended testing frequency [1]. Reference 1. Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Department of Health and Human Services. https://aidsinfo.nih.gov/contentfiles/lvguidelines/adultandadolescentgl.pdf. Updated July 10, 2019. Accessed November 10, 2019.