Evidence-Based Supplement & Herb Guides

HLA-B51 Test: Behçet Disease Risk, Positive Result, and Meaning

Understand what a positive or negative HLA-B51 test means, how it affects Behçet disease risk, and why symptoms—not genetics alone—determine diagnosis.

The HLA-B51 test looks for a genetic marker associated with Behçet disease, a relapsing inflammatory disorder that can cause recurrent mouth and genital ulcers,...

IgA Blood Test for IgA Vasculitis: High Levels, Kidney Risk, and Meaning

Learn what high or normal serum IgA means in IgA vasculitis and why urine protein, blood pressure, creatinine, and eGFR determine kidney risk.

An IgA blood test measures immunoglobulin A circulating in serum. In IgA vasculitis, the result may be elevated, but it is neither sensitive nor...

IgG4 Blood Test: IgG4-Related Disease, Inflammation, and Organ Involvement

Understand high, normal, and borderline IgG4 blood results, how IgG4-related disease affects organs, and why imaging and biopsy often determine diagnosis.

An IgG4 blood test measures one subclass of immunoglobulin G. It is most often ordered when a clinician suspects IgG4-related disease, a systemic fibroinflammatory...

Large Vessel Vasculitis Blood Test Panel: CRP, ESR, IL-6, and Disease Activity

Understand how CRP, ESR, IL-6, blood counts, and imaging are used to diagnose and monitor giant cell arteritis and Takayasu arteritis.

A large vessel vasculitis blood test panel usually centers on CRP and ESR, supported by a complete blood count, kidney and liver tests, and...

Microscopic Polyangiitis Blood Test Panel: MPO-ANCA, CRP, ESR, and Kidney Risk

Learn how MPO-ANCA, CRP, ESR, urine testing, creatinine, and kidney biopsy are combined to diagnose microscopic polyangiitis and assess kidney risk.

A microscopic polyangiitis blood test panel is designed to recognize a pattern of small-vessel inflammation and, above all, identify kidney or lung injury before...

MPO-ANCA Antibody Test: MPA, EGPA, Vasculitis, Positive Result, and Meaning

Understand positive, negative, and borderline MPO-ANCA results, their links to MPA and EGPA, and the organ tests needed to confirm active vasculitis.

The MPO-ANCA antibody test detects autoantibodies directed against myeloperoxidase, an enzyme inside neutrophils. A positive result is most strongly associated with microscopic polyangiitis and...

p-ANCA Test: Microscopic Polyangiitis, MPO Antibodies, and Meaning

Learn what a p-ANCA pattern means, how it differs from MPO-ANCA, and when results support microscopic polyangiitis versus bowel, liver, drug, or infection causes.

A p-ANCA result describes a perinuclear fluorescence pattern seen when a patient’s serum reacts with ethanol-fixed neutrophils. It does not identify one disease or...

PR3-ANCA Antibody Test: GPA Vasculitis, Positive Result, and Meaning

Understand positive, negative, and changing PR3-ANCA results, their link to GPA, and why organ testing—not the antibody number alone—determines urgency.

The PR3-ANCA antibody test detects antibodies against proteinase 3, a neutrophil enzyme. A clearly positive result is strongly associated with granulomatosis with polyangiitis, especially...

Soluble IL-2 Receptor Test: Sarcoidosis, Immune Activation, and Inflammation

Understand what high or normal soluble IL-2 receptor means in sarcoidosis and why immune activation, lymphoma, infection, kidney function, imaging, and biopsy affect interpretation.

The soluble interleukin-2 receptor test measures circulating soluble CD25, a protein released mainly by activated T lymphocytes. It can be elevated in sarcoidosis and...

Vasculitis Blood Test Panel: ANCA, MPO, PR3, CRP, ESR, Complement, and Diagnosis

Learn how ANCA, MPO, PR3, CRP, ESR, complement, urine tests, imaging, and biopsy work together in a focused vasculitis diagnostic evaluation.

A vasculitis blood test panel is not one fixed bundle that can confirm or exclude every form of blood vessel inflammation. Vasculitis includes many...

14-3-3 Eta Protein Test: Rheumatoid Arthritis, Joint Damage Risk, and Disease Activity

Understand the 14-3-3 eta protein test, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

The 14-3-3 eta protein test test measures the extracellular 14-3-3η protein, a signaling protein released in inflamed joint tissue. It can add useful information...

Ankylosing Spondylitis Blood Test Panel: HLA-B27, CRP, ESR, and Diagnosis

Understand the ankylosing spondylitis blood test panel, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

HLA-B27 genetic status plus CRP and ESR inflammation markers is not diagnosed by a single blood result. The panel combines genetic and inflammatory clues...

Anti-Carbamylated Protein (Anti-CarP) Test: Rheumatoid Arthritis Marker and Prognosis

Understand the anti-carbamylated protein (anti-CarP) antibody test, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

The anti-carbamylated protein (anti-CarP) antibody test test measures antibodies against proteins altered by carbamylation, a chemical modification distinct from citrullination. It can add useful...

Anti-CCP Antibody Test: Rheumatoid Arthritis Diagnosis, Positive Result, and Prognosis

Understand the anti-CCP antibody test, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

The anti-CCP antibody test test measures IgG antibodies that bind laboratory cyclic citrullinated peptides and serve as a standardized ACPA assay. It can add...

Anti-Citrullinated Protein Antibody (ACPA) Test: Rheumatoid Arthritis Diagnosis and Disease Risk

Understand the anti-citrullinated protein antibody (ACPA) test, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

The anti-citrullinated protein antibody (ACPA) test test measures a family of autoantibodies directed against citrullinated proteins; anti-CCP is the most common clinical assay. It...

Anti-Mutated Citrullinated Vimentin (Anti-MCV) Test: Rheumatoid Arthritis Activity and Meaning

Understand the anti-mutated citrullinated vimentin (anti-MCV) antibody test, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

The anti-mutated citrullinated vimentin (anti-MCV) antibody test test measures antibodies against a modified, citrullinated form of vimentin found in inflamed tissue. It can add...

Anti-RA33 Antibody Test: Rheumatoid Arthritis Marker, Early Disease, and Meaning

Understand the anti-RA33 antibody test, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

The anti-RA33 antibody test test measures autoantibodies against heterogeneous nuclear ribonucleoprotein A2/B1, historically called the RA33 antigen. It can add useful information when rheumatoid...

Anti-Sa Antibody Test: Rheumatoid Arthritis Marker, Positive Result, and Meaning

Understand the anti-Sa antibody test, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

The anti-Sa antibody test test measures antibodies to citrullinated vimentin, originally identified through the Sa antigen system. It can add useful information when rheumatoid...

Cartilage Oligomeric Matrix Protein (COMP) Test: Joint Damage, Cartilage Breakdown, and Arthritis

Understand the cartilage oligomeric matrix protein (COMP) test, including what it measures, positive and negative results, diagnostic limits, rheumatoid arthritis risk, and appropriate follow-up.

The cartilage oligomeric matrix protein (COMP) test test measures fragments or circulating levels of COMP, an extracellular-matrix protein abundant in cartilage and also present...

CCP IgG Antibody Test: Rheumatoid Arthritis Risk, Early Diagnosis, and Meaning

The CCP IgG antibody test test measures IgG-class antibodies against cyclic citrullinated peptides. It can add useful information when rheumatoid arthritis (RA) is suspected,...