Evidence-Based Supplement & Herb Guides

Serum Amyloid A (SAA) Test: Acute Inflammation, High Levels, and Disease Activity

Learn what a serum amyloid A test measures, why SAA rises in acute inflammation, how it tracks disease activity, and when persistent elevation raises AA amyloidosis concern.

Serum amyloid A (SAA) is a group of acute-phase proteins that can rise sharply when the body responds to infection, tissue injury, or inflammatory...

White Blood Cell (WBC) Count Test: High Levels, Infection, Inflammation, and Causes

Understand what a WBC count measures, why white blood cells rise with infection, inflammation, stress, medicines, or blood disorders, and how results are evaluated.

A white blood cell (WBC) count measures the total number of leukocytes circulating in a blood sample. These immune cells help identify and respond...

Activated T-Cell Marker Test: HLA-DR, CD38, Immune Activation, and Inflammation

Learn how HLA-DR and CD38 flow cytometry measures activated T cells, what high results may mean, why ranges vary, and how clinicians plan follow-up.

An activated T-cell marker test uses flow cytometry to estimate how many T lymphocytes are showing signs of recent or ongoing stimulation. Laboratories may...

B-Cell Count Test: CD19, CD20, Immune Function, and Antibody Production

Understand how CD19 and CD20 B-cell counts are measured, why results may be high or low, how anti-CD20 therapy affects them, and which follow-up tests assess antibody function.

A B-cell count test measures the number and percentage of B lymphocytes in blood, usually by flow cytometry. Laboratories most often identify B cells...

CD4 Count Test: Helper T Cells, Immune Function, HIV Monitoring, and Meaning

Learn what a CD4 count measures, how HIV affects helper T cells, what common ranges and thresholds mean, why results fluctuate, and how the test guides monitoring and infection prevention.

A CD4 count measures helper T cells, a group of lymphocytes that coordinate immune responses against infections and support B cells, macrophages, and cytotoxic...

CD4/CD8 Ratio Test: Immune Balance, High and Low Ratio, and Meaning

Learn how the CD4/CD8 ratio is calculated, what low or high results may mean, why an inverted ratio is nonspecific, and how the test adds context in HIV and immune monitoring.

The CD4/CD8 ratio compares helper T cells with cytotoxic T cells in a blood sample. It is calculated by dividing the absolute CD4 count...

CD8 Count Test: Cytotoxic T Cells, Immune Function, and Viral Response

Learn what a CD8 count measures, why cytotoxic T-cell numbers may rise or fall, how viral infections affect results, and why cell quantity does not equal antiviral function.

A CD8 count measures a major group of T lymphocytes involved in recognizing and removing virus-infected, damaged, or abnormal cells. The cells are often...

Chemokine Panel Test: Immune Signaling, Inflammation, and Cell Migration Markers

Understand what a chemokine panel measures, why immune-signaling and cell-migration markers rise or fall, and how specialists interpret patterns and limitations.

A chemokine panel measures several small immune-signaling proteins that help direct white blood cells toward infection, injury, tumors, or inflamed tissue. Unlike a routine...

Cytokine Panel Test: IL-1, IL-6, IL-8, TNF-Alpha, Interferon-Gamma, and Immune Activation

Learn what a cytokine panel measures, how IL-1, IL-6, IL-8, TNF-alpha, and interferon-gamma patterns are interpreted, and why results require clinical context.

A cytokine panel measures a group of proteins that immune and tissue cells use to communicate. Common targets include interleukin-1 beta, interleukin-6, interleukin-8, tumor...

Cytokine Storm Blood Test Panel: IL-6, Ferritin, CRP, D-Dimer, and Severe Inflammation

Understand how IL-6, ferritin, CRP, D-dimer, blood counts, and clotting tests help evaluate cytokine storm, CRS, HLH, MAS, and severe inflammation.

A “cytokine storm blood test panel” is not one standardized laboratory test. It is a group of tests used to look for severe, dysregulated...

Flow Cytometry Immune Panel: Lymphocyte Markers, Immune Cells, and Immune Deficiency

Learn how a flow cytometry immune panel counts T cells, B cells, and NK cells, what abnormal patterns may mean, and why function, age, and context matter.

A flow cytometry immune panel identifies and counts immune-cell populations by detecting markers on or inside individual cells. A basic lymphocyte panel usually reports...

Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) Test: Immune Activation and Inflammation

Understand what a GM-CSF test measures, why high or low levels are difficult to interpret, and how anti-GM-CSF antibodies differ in pulmonary alveolar proteinosis.

A granulocyte-macrophage colony-stimulating factor test measures GM-CSF, also called CSF2, in blood or another specimen. GM-CSF is a cytokine that helps myeloid cells—including monocytes,...

Interferon-Alpha Test: Antiviral Immune Activity and Inflammation Meaning

Understand what an interferon-alpha test measures, why IFN-α or interferon signatures may be high or low, and how specialists interpret antiviral and inflammatory results.

An interferon-alpha test looks at one part of the body’s early antiviral defense system. Interferon-alpha, usually written IFN-α, is a family of type I...

Interferon-Gamma Test: Immune Activation, Infection Response, and T-Cell Activity

Learn how serum interferon-gamma tests, IFN-γ release assays, and anti-IFN-γ antibody tests differ, and what high, low, positive, or indeterminate results may mean.

An interferon-gamma test can mean several different laboratory procedures, and the distinction changes the interpretation. Interferon-gamma, or IFN-γ, is a cytokine made mainly by...

Interleukin-1 Beta (IL-1β) Test: Inflammation, Immune Activation, and Autoinflammatory Disease

Learn what an IL-1β test measures, why levels may be high or undetectable, how inflammasomes release IL-1 beta, and how specialists evaluate autoinflammatory disease.

An interleukin-1 beta test measures a powerful inflammatory cytokine, but it is not a general-purpose test that can diagnose inflammation by itself. Interleukin-1 beta,...

Interleukin-2 (IL-2) Test: T-Cell Activation, Immune Response, and Meaning

Understand what an IL-2 test measures, why serum and stimulated results differ, what high or low values may mean, and which immune tests provide useful follow-up.

An interleukin-2 (IL-2) test measures a cytokine that activated T cells release to coordinate immune-cell growth, survival, and regulation. Although IL-2 is often described...