rheumatoid factor

noun

: an autoantibody of high molecular weight that reacts against IgG immunoglobulins and is often present in rheumatoid arthritis

Examples of rheumatoid factor in a Sentence

Recent Examples on the Web

These can check for particular antibodies like Anti-SSA (Ro) and Anti-SSB (La) ones, as well as ANA and rheumatoid factor. — Bruce Y. Lee, Forbes.com, 21 July 2026

Only one type of JIA, polyarticular arthritis positive for IgM rheumatoid factor, is believed to be the same disease as adult RA. — Lana Barhum, Verywell Health, 5 June 2024

One of these blood tests measures the amount of rheumatoid factor (RF), a protein produced by your immune system that can attack healthy tissue, in your body. — Women's Health, 4 Apr. 2023

Nearly everyone who is evaluated for psoriatic arthritis will have their blood tested for rheumatoid factor (RF), a protein produced by the immune system that attacks healthy joints. — Sara Gaynes Lev, SELF, 30 July 2021

Word History

First Known Use

1949, in the meaning defined above

Rhymes for rheumatoid factor

• bioreactor
• acter
• actor
• tractor
• attractor
• cofactor
• compactor
• contactor
• contractor
• distractor
• extractor
• impactor

Medical Definition

rheumatoid factor

noun

: an autoantibody of high molecular weight that reacts against immunoglobulins of the class IgG and is often present in rheumatoid arthritis