Immune System
Antibody levels, complement proteins and immune cell counts.
28 tests explained
Common follow-up tests
- Albumin, SPEP (percent of total protein)The share of your serum protein that is albumin, measured by protein electrophoresis. Albumin is the largest of the protein groups.
- Alpha-1 Globulin, SPEP (g/dL)The amount of serum protein in the alpha-1 zone on electrophoresis, mostly alpha-1 antitrypsin. Reported in g/dL.
- Alpha-1 Globulin, SPEP (percent)The share of your serum protein in the alpha-1 zone on electrophoresis, mostly alpha-1 antitrypsin. Reported as a percent of total protein.
- Alpha-2 Globulin, SPEP (g/dL)The amount of serum protein in the alpha-2 zone on electrophoresis, including haptoglobin, alpha-2-macroglobulin and ceruloplasmin. Reported in g/dL.
- Alpha-2 Globulin, SPEP (percent)The share of your serum protein in the alpha-2 zone on electrophoresis, including haptoglobin, alpha-2-macroglobulin and ceruloplasmin. Reported as a percent.
- Beta Globulin (total), SPEP (g/dL)The amount of serum protein in the beta zone on electrophoresis, mostly transferrin plus complement and some IgA and IgM. Reported in g/dL.
- Beta Globulin (total), SPEP (percent)The share of your serum protein in the beta zone on electrophoresis, mostly transferrin plus complement and some IgA and IgM. Reported as a percent.
- C1 Esterase Inhibitor, antigenic (protein level)The amount of C1 inhibitor protein in your blood. A low level is one clue in the testing for hereditary angioedema.
- C1 Esterase Inhibitor, functionalHow well your C1 inhibitor protein works, shown as a percent of normal. A low result is a key clue in testing for hereditary angioedema.
- CD16+/CD56+ NK Cells, absoluteHow many natural killer (NK) cells are in a microliter of blood. NK cells are white blood cells that help the body handle viruses and damaged cells.
- CD16+/CD56+ NK Cells, percentThe share of your lymphocytes that are natural killer (NK) cells. NK cells are white blood cells that help the body handle viruses and damaged cells.
- CD19+ B Cells, absoluteHow many B cells are in a microliter of blood. B cells are the white blood cells that grow into antibody-making cells.
- CD19+ B Cells, percentThe share of your lymphocytes that are B cells. B cells are the white blood cells that grow into antibody-making cells.
- CD3+ T Cells, absoluteHow many T cells are in a microliter of blood. T cells are white blood cells that direct and carry out much of the immune response.
- CD3+ T Cells, percentThe share of your lymphocytes that are T cells, which carry a marker called CD3. The absolute count is usually more useful.
- CD4/CD8 RatioCD4 helper T cells divided by CD8 cytotoxic T cells. It shows how those two groups of T cells balance.
- CD4+ T Helper Cells, absoluteThe number of CD4+ T helper cells in a microliter of blood. These white blood cells help direct your immune response.
- CD4+ T Helper Cells, percentThe share of your lymphocytes that are CD4+ T helper cells. It is read together with the CD4 count.
- CD8+ T Cells, absoluteThe number of CD8+ T cells in a microliter of blood. These cytotoxic cells destroy infected or damaged cells.
- CD8+ T Cells, percentThe share of your lymphocytes that are CD8+ T cells. It is read together with the CD8 count and the CD4 results.
- Complement C3The most abundant complement protein in your blood. Complement is part of the immune system, and C3 sits at its center.
- Complement C4A protein in the complement system, part of your immune defense. Low or high levels are read together with C3 and your symptoms.
- Cryoglobulin ScreenChecks whether proteins in your blood clump when cold and dissolve when warmed. A negative result means none were seen.
- Gamma Globulin, SPEP (g/dL)The amount of protein in the gamma zone on serum electrophoresis, mostly antibodies. Reported in g/dL.
- Gamma Globulin, SPEP (percent)The share of your serum protein in the gamma zone on electrophoresis, mostly antibodies. Reported as a percent.
- Immunoglobulin A (IgA)An antibody that guards the linings of your gut, airways and mouth. It is also the control for celiac blood tests.
- Immunoglobulin G (IgG)The most common antibody in your blood. It shows how much of this main infection-fighting protein your body makes.
- Immunoglobulin M (IgM)The first antibody your body makes against a new germ. Reported in mg/dL in the US and in g/L in many other countries.