This test looks at the ratio of two important types of white blood cells in your blood.

Lymphocytes are a type of white blood cell in your immune system. This test looks at two of them, CD4 and CD8.

CD4 cells lead the fight against infections. CD8 cells can kill cancer cells and other invaders.

This test looks at the ratio of two important types of white blood cells in your blood.

Lymphocytes are a type of white blood cell in your immune system. This test looks at two of them, CD4 and CD8.

CD4 cells lead the fight against infections. CD8 cells can kill cancer cells and other invaders.

The CD4/CD8 ratio is a critical marker of immune system health. It measures the balance between CD4+ T-helper cells and CD8+ cytotoxic T cells, two major subtypes of T lymphocytes. These cells play complementary roles in immune defense:

• CD4+ T-helper cells coordinate immune responses by activating other immune cells.
• CD8+ cytotoxic T cells directly attack infected or cancerous cells.

The ratio is calculated by dividing the absolute count of CD4+ cells by that of CD8+ cells, and it provides insight into the state of immune regulation, activation, and balance.

The CD4/CD8 ratio (CD3+) is an important marker that reflects the balance between two major subsets of T lymphocytes—CD4+ helper T cells and CD8+ cytotoxic T cells—within the total T-cell population (CD3+). This ratio is a key indicator of immune system health, especially in conditions involving immune deficiency, chronic infections, inflammation, and immune reconstitution.

Understanding the Components

• CD3+ T cells: Represent all mature T lymphocytes. Both CD4+ and CD8+ T cells fall under this category.

• CD4+ T cells: Also known as helper T cells, they coordinate immune responses by signaling other immune cells.

• CD8+ T cells: Also known as cytotoxic T cells, they destroy infected, damaged, or cancerous cells.

• CD4/CD8 Ratio (CD3+): The ratio of helper T cells to cytotoxic T cells within the CD3+ T-cell population.

CD56 is an adhesion molecule mediating homophilic and heterophilic adhesion in neurons, natural killer cells, and a small subset of CD4- and CD8-positive T cells. It is expressed in tumors with neuroendocrine differentiation (small cell lung carcinoma and neural-derived tumors) or natural killer cell lineage (subset of lymphomas). In normal small intestine, the ganglion cells in the muscle wall and nerves will show strong staining. Scattered lymphocytes may also be positive.

CD56 is an adhesion molecule mediating homophilic and heterophilic adhesion in neurons, natural killer cells, and a small subset of CD4- and CD8-positive T cells. It is expressed in tumors with neuroendocrine differentiation (small cell lung carcinoma and neural-derived tumors) or natural killer cell lineage (subset of lymphomas). In normal small intestine, the ganglion cells in the muscle wall and nerves will show strong staining. Scattered lymphocytes may also be positive.

CD56+CD3- % is a key immunological marker identifying natural killer (NK) cells, essential in innate immunity. Elevated levels can indicate an active immune response or certain malignancies, while decreased levels may suggest impaired immunity, as seen in HIV/AIDS or post-chemotherapy. This parameter is crucial in transplant immunology for monitoring immune reconstitution and in assessing the effectiveness of immunotherapies, particularly in cancer treatments. CD56+CD3- % thus plays a significant role in diagnosing, monitoring, and treating immune and hematological disorders.

CD56+CD3- (absolute) cells are crucial in the immune system, primarily acting as natural killer (NK) cells. Their unique combination of CD56 positivity and CD3 negativity makes them essential for defending against pathogens and cancer cells. These cells are pivotal in diagnosing and managing immune-related conditions and cancers, highlighting their role in personalized medicine.

The CD57 test is offered in some clinical laboratories and is being used by some health practitioners to evaluate and follow patients diagnosed with chronic Lyme disease.

The CD57 test is offered in some clinical laboratories and is being used by some health practitioners to evaluate and follow patients diagnosed with chronic Lyme disease.

This figure is rarely used for making treatment decisions.

CD4 and CD8 are two types of white blood cells in your blood. CD4 cells are also called T-helper cells, T-suppressor cells, and cytotoxic T-cells. They help the body fight infections. CD8 cells are also called cytotoxic T-lymphocytes. They help fight cancer and germs that live inside your cells (intracellular pathogens).

The absolute number of all CD8 cells, which include both killer and suppressor T cells. The normal range for an HIV-negative person is 150 to 1,000. It is usually higher in a person with HIV.

The "CD8-CD57+ Lymphocytes (Absolute)" marker on an HNK1 (CD57) panel from Labcorp represents a specific measurement of immune cells within your blood, quantified absolutely rather than as a percentage of total lymphocytes. This test focuses on a subset of natural killer (NK) cells and T lymphocytes, both critical components of your immune system's arsenal against infections and malignancies. These CD8-CD57+ cells, often referred to in the context of natural killer cell function due to their ability to directly attack and kill virus-infected cells or tumor cells without the need for prior activation, are unique. When you have a higher or lower than normal absolute count of these cells, it can be indicative of various health conditions. For example, a low absolute count of CD8-CD57+ lymphocytes is often observed in patients suffering from chronic conditions like Lyme disease, indicating a weakened immune response possibly due to the prolonged battle against the infection. On the other hand, understanding the high end of these counts is less straightforward but could suggest an active immune response to an infection or stress. This marker is particularly useful for clinicians in the context of diagnosing and managing chronic infectious diseases, as it provides insight into the state of the immune system's natural killer cell function. However, interpreting the results of this marker should always be done within the broader context of a patient's overall health, symptoms, and other laboratory findings to ensure a comprehensive understanding of their immune status.

The CD57 test is offered in some clinical laboratories and is being used by some health practitioners to evaluate and follow patients diagnosed with chronic Lyme disease.