We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us


VEDALAB focuses on the development, production and marketing of in vitro immunodiagnostic reagents and instruments. I... read more Featured Products: More products

Download Mobile App


ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.

Regulatory and Other Rheumatoid Factors Analyzed in RA Patients

By LabMedica International staff writers
Posted on 06 Jan 2022
Print article
Image: The RF direct latex test for the detection of rheumatoid factor (RF) in serum (Photo courtesy of VedaLab)
Image: The RF direct latex test for the detection of rheumatoid factor (RF) in serum (Photo courtesy of VedaLab)
Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involved, with the same joints typically involved on both sides of the body.

Despite numerous studies, the only properties definitively established for rheumatoid factor (RF) are that RF is an antibody to the Fc portion of modified IgG, and that elevated RF levels are a diagnostic marker for RA. Both the mechanisms by which RF level is elevated in autoimmune and infectious diseases and the role that RF plays in healthy and disease states remain speculative.

Immunologists at the Udmurt State University (Izhevsk, Russian Federation) studied a total of 32 patients with an established diagnosis of rheumatoid arthritis. Of those, 22 patients had high to moderate rheumatoid arthritis activity. Several of the patients had systemic manifestations, such as anemia, rheumatoid nodules, Sjögren's syndrome. The duration of disease in the sample of RA patients studied was 2 to 20 years, with a mean of 8 ± 5.9 years and 35% of patients were receiving combination therapy.

The RF direct latex test (VedaLab, Alençon, France) was used to detect rheumatoid factor in the sera of arthritis patients. The regulatory rheumatoid factor (regRF) titer was determined in an agglutination test using human IgG-loaded tanned human erythrocytes. RegRF depletion from rheumatoid arthritis sera was also performed. Lyophilized human IgG was used to prepare an agglutination test system for detecting regRF. Size exclusion chromatography was performed using a Sephacryl S 100 26/400 column (Cytiva, Marlborough, MA, USA). A Genesys 10S UV-Vis Spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA) was used for the analysis.

The investigators reported that patients in remission had regRF levels higher than in healthy subjects. The regRF in remission was characterized by tight binding to its antigen, as in healthy subjects. The regRF levels in patients with active RA varied dramatically, and regRF binding to its antigen was weak. The exacerbation of Still's disease coincided with low regRF levels and affinity, while an improvement in patient condition was associated with an increase in regRF levels and affinity. The RF specific to RA, which was detected by the RF latex-fixation method, was a nonhomogeneous population of antibodies that included RF to lyophilized IgG, to IgG immobilized on polystyrene, and to rabbit IgG.

The authors concluded the RA remission is associated with an increase in regRF levels and affinity. Results of an analysis of a clinical case of Still's disease were consistent with the results obtained when patients with active rheumatoid arthritis were compared with those in remission. The study was published on December 24, 2021 in the Journal of Clinical Laboratory Analysis.

Related Links:
Udmurt State University
Thermo Fisher Scientific

Unit-Dose Twist-Tip BFS
Gold Supplier
ESR Analyzer
Portable Coagulation Monitor
Gold Supplier
CLIA Analyzer

Print article


Clinical Chem.

view channel
Image: Electrochemical cells etched by laser on wooden tongue depressor measure glucose and nitrite in saliva (Photo courtesy of Analytical Chemistry)

Biosensor-Fabricated Wooden Tongue Depressor Measures Glucose and Nitrite in Saliva

Physicians often use tongue depressors to examine a patient's mouth and throat. However, it is hard to imagine that this simple wooden tool could actively assess a patient's health. This idea has led to... Read more

Molecular Diagnostics

view channel
Image: Medication, sepsis and inadequate blood supply to the kidneys are potential causes of AKI (Photo courtesy of Freepik)

Blood- And Urine-Based Biomarker Tests Could Identify Treatment of Acute Kidney Injury

Hospitalized patients who experience an acute kidney injury (AKI) often face unfavorable outcomes post-discharge, with limited effective treatment options. AKI can stem from various causes, such as sepsis,... Read more


view channel
Image: The Atellica HEMA 570 and 580 hematology analyzers remove workflow barriers (Photo courtesy of Siemens)

Next-Gen Hematology Analyzers Eliminate Workflow Roadblocks and Achieve Fast Throughput

Hematology testing is a critical aspect of patient care, utilized to establish a patient's health baseline, track treatment progress, or guide timely modifications to care. However, increasing constraints... Read more


view channel
Image: New method reveals bacterial reaction to antibiotics within minutes (Photo courtesy of Freepik)

New Method to Reveal Bacterial Reaction to Antibiotics in Five Minutes Could Help Create Rapid Molecular Test

Severely sick patients suffering from bacterial infections often require immediate treatment to prevent serious health complications, making it vital for physicians to quickly identify the appropriate antibiotic.... Read more


view channel
Image: navify digital solutions can helping labs mitigate unique quality challenges (Photo courtesy of Roche)

Cloud-Based Digital Solution Allows Labs to Track Test Samples along Entire Diagnostic Journey

Diagnosing a disease involves a meticulous procedure of monitoring a patient's diagnostic sample throughout its entire journey, which aids in clinical decision-making. However, there aren't any standardized... Read more


view channel
Electronic biosensor uses DNA aptamers for detecting biomarkers in whole blood samples (Photo courtesy of Freepik)

Electronic Biosensor Detects Biomarkers in Whole Blood Samples without Addition of Reagents

The absence of robust, reliable, and user-friendly bioanalytical tools for early and timely diagnosis of cardiovascular diseases, particularly sudden cardiac arrest, leads to preventable deaths and imposes... Read more


view channel
Image: The global hemostasis diagnostics market is expected to reach USD 3.95 billion by 2025 (Photo courtesy of Freepik)

Global Hemostasis Diagnostics Market Driven by Increase in Invasive Surgical Procedures

Injury or surgery naturally creates bleeding in living beings, which must be stopped to prevent excessive blood loss. The human body implements a protective mechanism known as hemostasis to stop excessive bleeding.... Read more
Copyright © 2000-2023 Globetech Media. All rights reserved.