Evidence-Based Supplement & Herb Guides

HLA-B Genetic Test: Tissue Type, Drug Reaction Risk, and Results

Understand HLA-B genetic testing for tissue type, transplant matching, drug reaction alleles, HLA-B27 and HLA-B51 disease risk, result notation, and limitations.

An HLA-B genetic test identifies inherited alleles at the HLA-B locus, one of the most variable immune-system genes in humans. The same gene can...

HLA-B27 Test: Ankylosing Spondylitis Risk, Positive Result, and Meaning

Understand HLA-B27 testing for ankylosing spondylitis and axial spondyloarthritis, including positive and negative results, symptoms, imaging, related conditions, and next steps.

The HLA-B27 test checks whether a person carries an HLA-B allele group strongly associated with axial spondyloarthritis, including ankylosing spondylitis. It is a supporting...

HLA-B51 Test: Behcet Disease Risk and Results

Understand HLA-B51 testing for Behçet disease risk, including positive and negative results, HLA-B5 differences, clinical diagnosis, symptoms, limitations, and next steps.

The HLA-B51 test checks for an inherited HLA-B allele group associated with Behçet disease, a relapsing inflammatory disorder that can affect the mouth, genitals,...

HLA-B*15:02 Test: Carbamazepine Skin Reaction Risk and Results

Understand HLA-B*15:02 testing before carbamazepine, including who needs it, positive and negative results, SJS/TEN risk, medication choices, and urgent rash signs.

The HLA-B15:02 test checks whether a person carries an immune-system allele strongly linked to carbamazepine-induced Stevens–Johnson syndrome and toxic epidermal necrolysis. These rare reactions...

HLA-B*57:01 Test: Abacavir Hypersensitivity Risk and Results

Learn how HLA-B*57:01 testing prevents abacavir hypersensitivity, what positive and negative results mean, when to test, symptoms to recognize, and how results guide HIV treatment.

The HLA-B*57:01 test identifies people at high risk of an immune-mediated hypersensitivity reaction to abacavir, an antiretroviral medicine used in some HIV treatment combinations....

HLA-B*58:01 Test: Allopurinol Severe Skin Reaction Risk and Results

Learn how HLA-B*58:01 testing estimates allopurinol severe skin-reaction risk, who may need testing, what results mean, safer dosing, alternatives, and urgent warning signs.

The HLA-B*58:01 test checks for an inherited immune-system allele strongly associated with allopurinol-induced severe cutaneous adverse reactions. These reactions include Stevens–Johnson syndrome, toxic epidermal...

HLA-C Genetic Test: Tissue Type, Immune Matching, and Results

Understand HLA-C genetic testing for tissue type, stem cell matching, donor-specific antibodies, KIR ligands, allele results, mismatches, limitations, and transplant follow-up.

An HLA-C genetic test identifies the two HLA-C alleles a person inherited and helps describe immune-system tissue type. HLA-C is a class I human...

HLA-DP Genetic Test: Immune Matching and Results

Understand HLA-DP genetic testing, including DPA1 and DPB1 alleles, permissive mismatches, stem cell donor selection, donor-specific antibodies, results, and limitations.

An HLA-DP genetic test identifies inherited HLA-DPA1 and HLA-DPB1 alleles that combine to form HLA-DP class II molecules. These molecules present protein fragments to...

HLA-DQ Genetic Test: Celiac Disease, Autoimmune Risk, and Results

Understand HLA-DQ genetic testing for celiac susceptibility, DQA1 and DQB1 results, DQ2 and DQ8 meaning, autoimmune associations, transplantation, and next steps.

An HLA-DQ genetic test identifies inherited HLA-DQA1 and HLA-DQB1 alleles that pair to form HLA-DQ class II immune molecules. It is most commonly used...

HLA-DQ2 and HLA-DQ8 Test: Celiac Disease Risk and Results

Understand what HLA-DQ2 and HLA-DQ8 celiac genetic test results mean, when testing helps, how positive and negative findings differ, and what to do next.

The HLA-DQ2 and HLA-DQ8 test looks for immune-system gene combinations that make celiac disease possible. It is most useful for ruling celiac disease out...

HLA-DQB1 Test: Type 1 Diabetes, Celiac Disease, and Results

Learn how HLA-DQB1 test results relate to type 1 diabetes, celiac disease, DQ2/DQ8 haplotypes, narcolepsy risk, testing methods, and follow-up.

An HLA-DQB1 test identifies inherited variants in a gene that helps the immune system present protein fragments to T cells. Certain DQB1 alleles contribute...

HLA-DR Genetic Test: Transplant Matching, Autoimmune Risk, and Results

Understand HLA-DR genetic test results for transplant matching, donor selection, autoimmune susceptibility, HLA antibodies, crossmatch findings, and follow-up.

An HLA-DR genetic test identifies variants in immune-system genes that encode HLA class II proteins, especially HLA-DRB1 and, when present, DRB3, DRB4, or DRB5....

HLA-DRB1 Test: Rheumatoid Arthritis Risk, Shared Epitope, and Results

Learn what an HLA-DRB1 shared epitope test means for rheumatoid arthritis susceptibility, positive and negative results, smoking interaction, diagnosis, and follow-up.

An HLA-DRB1 test can identify “shared epitope” alleles associated with a higher chance of developing rheumatoid arthritis, especially rheumatoid factor–positive or anti-CCP–positive disease. The...

Killer Cell Immunoglobulin-Like Receptor (KIR) Test: Immune Genetics and Results

Understand KIR genetic test results, activating and inhibitory receptors, HLA-C ligands, AA and B/x genotypes, transplant uses, limitations, and next steps.

A killer cell immunoglobulin-like receptor, or KIR, test identifies inherited genes and sometimes alleles that regulate natural killer cells. Natural killer cells help control...

Panel Reactive Antibody (PRA) Test: Transplant Sensitization and Results

Understand PRA and calculated PRA transplant results, sensitization percentages, donor-specific antibodies, crossmatch testing, waiting-list impact, and next steps.

A panel reactive antibody test estimates how broadly a transplant candidate has antibodies against human leukocyte antigens, or HLA. Modern programs often use calculated...

Periodic Fever Syndrome Genetic Panel: Autoinflammatory Genes and Results

Understand periodic fever syndrome genetic panel results, including MEFV, MVK, TNFRSF1A, NLRP3, positive findings, VUS results, negative tests, and follow-up.

A periodic fever syndrome genetic panel looks for inherited or newly occurring variants in genes that regulate innate immunity and inflammation. It can help...

Primary Immunodeficiency Genetic Panel: Immune Disorder Genes and Results

Understand primary immunodeficiency genetic panel results, including immune disorder genes, pathogenic variants, VUS findings, negative tests, treatment impact, and family testing.

A primary immunodeficiency genetic panel tests many genes linked to inborn errors of immunity, a large group of disorders that can cause unusual infections,...

Severe Combined Immunodeficiency (SCID) Genetic Test: Immune Deficiency Genes and Results

Learn how SCID genetic testing identifies immune deficiency genes, explains positive, negative, carrier, and VUS results, and guides urgent treatment and family testing.

A severe combined immunodeficiency genetic test looks for inherited changes that prevent T cells—and often B cells or natural killer cells—from working normally. SCID...

Autosomal Dominant Genetic Test: Inheritance Risk and Results

Learn how autosomal dominant genetic tests work, what a 50% inheritance risk means, and how to interpret positive, negative, de novo, and VUS results.

An autosomal dominant genetic test looks for a disease-causing change in a gene where one altered copy can be enough to affect health. The...

Autosomal Recessive Genetic Test: Carrier Risk and Results

Understand autosomal recessive genetic tests, carrier results, 25% pregnancy risk, partner testing, residual risk after a negative result, and reproductive options.

An autosomal recessive genetic test looks for harmful changes in genes where a person usually needs two disease-causing copies—one from each biological parent—to have...