Medical Glossary
Plain-language definitions of biologic and immunology terms.
Key Terms
Biologic
A medication derived from living organisms (such as cells or proteins) rather than chemically synthesized. Biologics target specific components of the immune system.
Biosimilar
An FDA-approved medication that is highly similar to an already-approved biologic (the reference product), with no clinically meaningful differences in safety, purity, or potency.
TNF-alpha
Tumor Necrosis Factor-alpha, a protein involved in systemic inflammation. Many biologics (Humira, Enbrel, Remicade) work by blocking TNF-alpha.
IL-23
Interleukin-23, a signaling protein that promotes inflammation in psoriasis and inflammatory bowel disease. Blocked by medications like Skyrizi and Stelara.
IL-17A
Interleukin-17A, a cytokine involved in psoriasis and psoriatic arthritis. Blocked by Cosentyx (secukinumab) and Taltz (ixekizumab).
JAK Inhibitor
Janus kinase inhibitors (like Rinvoq, Xeljanz) are oral targeted synthetic DMARDs that block JAK enzymes involved in inflammatory signaling.
Prior Authorization
An insurance requirement for pre-approval before covering a medication. BiologicHealthPlus handles all PA submissions and appeals at no cost.
Monoclonal Antibody
A type of biologic made from identical immune cells that targets a specific protein. Most injectable biologics for autoimmune diseases are monoclonal antibodies.
Autoimmune Disease
A condition where the immune system mistakenly attacks healthy tissue. Examples include psoriasis, rheumatoid arthritis, Crohn's disease, and lupus.
Remission
A period where symptoms of a disease are significantly reduced or absent. Many patients achieve remission with biologic therapy.
DMARD
Disease-Modifying Antirheumatic Drug. A category of medications that slow the progression of autoimmune diseases. Biologics are a type of DMARD.
Subcutaneous
Administered by injection into the tissue just below the skin. Most self-injectable biologics are given subcutaneously.