JUN 12, 2018 03:39 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
AUG 17, 2018
Health & Medicine
AUG 17, 2018
Is Influenza Different in Obese Patients?
There are many health risks for obese patients. Cardiovascular disease, diabetes and even some forms of cancer. The immune system can be disrupted when a p...
AUG 18, 2018
Immunology
AUG 18, 2018
Two Proteins Play Unexpected Role in Immune System Regulators
Two proteins, PLD3 and PLD4, discovered to have role in immune system detection and response to pathogens....
SEP 07, 2018
Health & Medicine
SEP 07, 2018
What's Behind the Massive Measles Outbreak in Europe?
Measles is a disease that many believe was eradicated years ago. That's true, to a point, but like a bad penny, it's back. In the United States, th...
SEP 26, 2018
Neuroscience
SEP 26, 2018
Therapeutic antibodies for Alzheimer's disease: challenges and hopes
Solanezumab: this simple name evokes at the same time one of the greatest hopes and the worst disillusions for Alzheimer’s Disease (AD) patients. Two...
OCT 08, 2018
Immunology
OCT 08, 2018
Natural Killer Cells to Aid in Cancer Therapy
Researchers utilize nanoparticles to stimulate NK cells that induce tumor cells to express PDL1, a protein involved in immune response messaging...
NOV 05, 2018
Drug Discovery
NOV 05, 2018
Anti-Parasitic Drug Improves Long-term Clinical Outcomes in Chagas Disease
In a recent study published in PLOS Neglected Tropical Diseases, an anti-parasite drug by the name of ‘benznidazole’ may hold potential in impr...
Loading Comments...