rheumatoid factor


Definition of rheumatoid factor

: 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 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 The doctor on call had the presence of mind to do a rheumatoid factor test, which tests for a type of protein that your immune system produces that can attack healthy tissue. Natasha Lavender, SELF, 15 Oct. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'rheumatoid factor.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of rheumatoid factor

1949, in the meaning defined above

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Time Traveler for rheumatoid factor

Time Traveler

The first known use of rheumatoid factor was in 1949

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Dictionary Entries Near rheumatoid factor

rheumatoid arthritis

rheumatoid factor


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Cite this Entry

“Rheumatoid factor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rheumatoid%20factor. Accessed 16 May. 2022.

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More Definitions for rheumatoid factor

rheumatoid factor


Medical Definition of rheumatoid factor

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

More from Merriam-Webster on rheumatoid factor

Britannica.com: Encyclopedia article about rheumatoid factor


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