Know Your Labs, Part 2

With respect to RA, I predict less reliance on the misnamed rheumatoid factor test, better recognition that RA is also probably a spectrum of related diseases (not just seropositive and seronegative RA) and that, likewise, better serological, and genetic testing will help define patient subsets. I strongly believe that different subsets of  “RA” patients will have antibodies to different citrullinated proteins, and that we will end up having a RA-citrullinated panel of tests. Hopefully, this subsetting with coupling of better therapies, probably guided by genomics, will improve treatment.

Progress in rheumatology serology has been slow through the 1940s (RF and LE cell prep), 1950s (ANA and anti-DNA), 1960s (Sm, RNP, Ro, La), and 1990s (CCP). However, the understanding of the genetics of the disorders discussed here—as well as the therapies for them—has been accelerating. Let us hope that the future will bring new and better discoveries.

Acknowledgement: I am indebted to the work of many authors of UpToDate in Medicine, whose work provided a useful framework for the development of this paper as well as to Drs. Robert Shmerling, David Lee, and Donald Bloch with whom I have written papers/chapters on this same subject.

Dr. Schur is professor of medicine at Harvard Medical School and the division of rheumatology, immunology and allergy in the department of medicine at Brigham and Women’s Hospital in Boston.

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