JUN 12, 2018 3:39 PM PDT

Auto-antibody Detection for Rheumatoid Arthritis Patients

WRITTEN BY: Kara Marker

No case of rheumatoid arthritis (RA), an autoimmune disease, is the same. Now, researchers want RA diagnostic approaches to match its pathological diversity. From Uppsala University, scientists demonstrate the importance of a broad diagnostic approach to identifying cases of RA.

Histology section from rheumatoid arthritis tissue, showing inflammation and joint damage. Credit: Jensflorian

“RA patients with and without ACPA probably have different diseases with separate causes, but start with a similar clinical picture," explained research team leader Johan Rönnelid.

ACPAs, or anti-citrullinated protein antibodies, are produced by the immune system as part of the autoimmune response present in RA. Autoimmune diseases affecting different body tissues and systems are all caused by the body’s accidental attack on its own tissues, responding as if the tissues were pathogenic. A key part of this autoimmune response is the production of “auto-antibodies,” like ACPAs, that target the body’s own proteins, like the amino acid citrulline, as opposed to targeting bacterial or viral proteins.

RA is an autoimmune disease characterized by chronic inflammation in the joints and other parts of the body. Inflammation in the joints causes tissue to thicken, resulting in swelling and pain experienced by RA patients. The disease often affects the hands, feet, wrists, elbows, knees, and ankles. Approximately 1.5 million people are diagnosed with RA in the United States, disproportionately women.

Researchers from the present study are dedicated to improving RA diagnosis with a new technique that measures a variety of citrulline antibodies. Looking for a variety of citrulline antibodies as opposed to one type or just a few types will help scientists detect severe inflammation and joint damage.

A broader test is necessary to detect the various proteins and protein fragments that are targeted in each case of RA. No case is the same, so the test has to account for all of the possibilities. The test looks for various auto-antibodies, which bind to host proteins and form immune complexes that then trigger inflammation that leads to the physical symptoms experienced by RA patients. The current study is the first to observe ACPA immune complexes in body fluids from RA patients.

ACPAs are produced as a result of RA-mediated inflammation, and they are observed in more than half of all RA patients, but not all. In the past, researchers have identified genetic differences between patients with and without these antibodies. Additionally, ACPA-positive RA cases are linked to patients who smoke, and ACPA-positive patients have more joint inflammation than ACPA-negative RA patients.

Researchers developed the new test by first extracting immune complexes from different types of body fluid (serum, synovial fluid, immune complexes) from 77 RA patients, then measuring 19 different ACPAs. They found that no single ACPA stood out from the rest. In fact, a broader range of ACPAs in immune complexes are responsible for driving inflammation and joint damage characteristic of RA.

The present study was published in the journal Annals of the Rheumatic Diseases.

Sources: Arthritis Foundation, Uppsala University

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
JUL 22, 2019
Immunology
JUL 22, 2019
How to Kill Superbugs
https://www.technologynetworks.com/immunology/news/enhancing-the-infection-fighting-potential-of-natural-products-321553...
AUG 04, 2019
Immunology
AUG 04, 2019
New Research In Reversing Deafness
Hair cells inside the human ear are responsible for sensing and relaying sound to the brain.  In all mammals except humans, these cells can regenerate...
OCT 31, 2019
Cancer
OCT 31, 2019
Unpacking lactate's role in the Warburg effect
In a recent issue of Nature, the findings of one study made a particularly big splash: how and why cancer cells use energy differently than healthy cells. ...
NOV 26, 2019
Immunology
NOV 26, 2019
The Immune System's Hand in Toxic Shock
While rare, toxic shock is a dangerous condition that acts fast and can be fatal. A new study identified a new target for treating toxic shock, a component...
DEC 16, 2019
Drug Discovery & Development
DEC 16, 2019
Drug Targets Against The Nipah Virus
The Nipah virus, first identified in 1998 and is transmitted from pigs and bats, has resulted in a high mortality rate killing more than half of all infect...
FEB 13, 2020
Cancer
FEB 13, 2020
Can Ebola help treat glioblastomas?
You might want to sit down for this. New research published in the Journal of Virology has named a surprising new ally to brain tumors: Ebola. Yes, yo...
Loading Comments...