Is It Necessary to Combine Detection of Anticitrullinated Protein Antibodies in the Diagnosis of Rheumatoid Arthritis?

A study of the roles of some immunological biomarkers in the diagnosis of rheumatoid arthritis

Autoimmune rheumatoid arthritis (RA) is a systemic condition closely correlated with a variety of autoantibodies (Abs) that could be considered diagnostic and prognostic markers. The current research was designed to detect the diagnostic values for a number (n) of these auto-Abs in RA detection and to evaluate the accuracy of a combined diagnostic scheme. This prospective study was conducted between September 2021 and August 2022 and included 110 subjects with RA, 70 individuals with other autoimmune disorders as positive controls (PC), and 50 unrelated, apparently healthy individuals as healthy controls (HC). The eligibility criteria for all study groups were followed stringently. An enzyme-linked immunosorbent assay (ELISA) was employed to measure rheumatoid factors (RF), cyclic citrullinated peptide antibodies (CCP-Abs), mutated citrullinated vimentin antibodies (MCV-Abs), anti-perinuclear factor antibodies (APF-Abs), and anti-keratin antibodies (AKA). We calculated the specificity, sensitivity, and predictive values of all auto-Abs. Significantly higher levels of anti-CCP-Abs, anti-MCV-Abs, APF-Abs, and AKAs were reported in the RA patients compared to the HC and PC subjects. RF levels, however, were only statistically elevated when compared to the HC individuals. Anti-APF-Abs had a higher sensitivity rate (70.9%), and anti-CCP-Abs had a higher specificity rate (94.16%) compared to other auto-Abs, whereas the combined detection scheme revealed a higher sensitivity (81.81%) and excellent specificity (90.83%) compared to the two former auto-Abs. Anti-perinuclear factor-Ab was a highly sensitive test, and CCP-Ab was a surpassingly specific assay for identifying RA. Furthermore, the combined detection scheme is an essential serological approach for RA diagnosis and crucial in differentiating this disease from other autoimmune diseases, thus promoting early diagnosis and treatment.

Nanomedical approaches in the realm of rheumatoid arthritis

Rheumatoid arthritis (RA) is a heterogeneous autoimmune inflammatory disorder defined by the damage to the bone and cartilage in the synovium, which causes joint impairment and an increase in the mortality rate. It is associated with an incompletely elucidated pathophysiological mechanism. Even though disease-modifying antirheumatic drugs have contributed to recent improvements in the standard of care for RA, only a small fraction of patients is able to attain and maintain clinical remission without the necessity for ongoing immunosuppressive drugs. The evolution of tolerance over time as well as patients' inability to respond to currently available therapy can alter the overall management of RA. A significant increase in the research of RA nano therapies due to the possible improvements they may provide over traditional systemic treatments has been observed. New approaches to getting beyond the drawbacks of existing treatments are presented by advancements in the research of nanotherapeutic techniques, particularly drug delivery nano systems. Via passive or active targeting of systemic delivery, therapeutic drugs can be precisely transported to and concentrated in the affected sites. As a result, nanoscale drug delivery systems improve the solubility and bioavailability of certain drugs and reduce dose escalation. In the present paper, we provide a thorough overview of the possible biomedical applications of various nanostructures in the diagnostic and therapeutic management of RA, derived from the shortcomings of conventional therapies. Moreover, the paper suggests the need for improvement on the basis of research directions and properly designed clinical studies.

Structure of type II collagen from sturgeon cartilage and its effect on adjuvant-induced rheumatoid arthritis in rats

The purpose of this paper was to extract and characterize type II collagen of sturgeon cartilage (SC-CII), and to explore the effects of taking SC-CII orally on rheumatoid arthritis (RA) in rats. SC-CII showed a triple-helix structure (RPN = 0.12), with d1 of 11.82 Å and d2 of 4.08 Å, which was analyzed by FT-IR, CD, XRD, and MS. It was constructed of the repeating tripeptide unit Gly-X-Y, where X and Y are generally Pro or Hyp, proved by amino acid composition and peptide mass fingerprinting. Furthermore, the effects of SC-CII on RA were evaluated. Ankle thickness was significantly decreased in SC-CII groups, with changes in lymphocyte proliferation also observed. Compared with the model control group, there was an evident decrease in TNF-α, IL-1β, COX-2, MCP-1, and TLR-4 mRNA levels, but no remarkable differences in APF, MMP-3, and MyD88 mRNA levels in the SC-CII groups. In addition, TNF-α, IL-1β, RF, Anti-CII Ab were significantly reduced in the SC-CII groups, proved by ELISA. Therefore, SC-CII showed alleviating effects on RA through the TLR4/MyD88-NFκB pathway.

Diagnostic accuracy of anti-keratin antibody for rheumatoid arthritis: a meta-analysis

OBJECTIVES

Anti-keratin antibody (AKA) is a serum antibody for patients with rheumatoid arthritis (RA), and it has a high specificity. Diagnostic role of AKA in RA was evaluated in this study.

METHODS

PubMed, EMBASE, and Web of Science were searched to acquire eligible studies. Articles published before 15 March 2018 were considered to be included. Quality Assessment of Diagnostic Accuracy Studies 2 was used to evaluate the risk of bias and application concern of the included articles. Pooled analysis of diagnostic indicators of AKA for RA was conducted by using a random effects model. Subgroup analysis was employed to explore the potential influencing factors. RevMan 5.3, Stata 11.0, and Meta-DiSc 1.4 software were used in this study.

RESULTS

A total of 15 studies (2350 positive and 2067 negative participants) were included. The pooled sensitivity was 0.46 (95% CI 0.44-0.48), pooled specificity was 0.94 (95% CI 0.93-0.95), and pooled diagnostic odds ratio was 15.86 (95% CI 9.48-26.52). In addition, the area under the curve was 0.7194.

CONCLUSIONS

The current evidence indicated that AKA has high diagnostic specificity in RA and may be useful for RA diagnostic application in clinic.

Anti-perinuclear Factor as Diagnostic Marker in Rheumatoid Arthritis

INTRODUCTION

Rheumatoid Arthritis (RA) is a systemic autoimmune disease. It is associated with several auto antibodies which can serve as diagnostic and prognostic markers.

AIM

In this study, Anti perinuclear Factor (APF) was evaluated as a biomarker in comparison with Rheumatoid Factor (RF) in Rheumatoid Arthritis.

MATERIALS AND METHODS

Fifty two sera of patients with RA (mean age 48±15.8), 23 sera of Patient control group (mean age 32.5 ± 16.9) and 30 sera of Healthy control group (mean age 32.1± 16.9) were analysed. The method is based on the binding of APF to perinuclear keratohyalin granules of buccal mucosal cell and its detection using a fluorescently labeled anti human total antiserum.

RESULTS

APF were found in 71.2 %(37/52) of patients with RA. The sensitivity and specificity for APF from 1/5 serum dilution was 71.2% and 94.3% respectively. RF test had higher sensitivity (88.5%) compare to the APF test (71.2%), but its specificity was (86.8%) less than APF (94.3%). There was no significant relationship between the onset of APF and severity of disease but there was significant relationship between the APF titer and severity of disease (p<0.05).

CONCLUSION

It is concluded that APF test is a valuable serological tool for the diagnosis of the disease and a useful serological marker to differentiate from the other inflammatory rheumatoid diseases.

Concurrent rheumatoid arthritis and ankylosing spondylitis in one patient: the importance of new classification criteria

We report the case of concomitant ankylosing spondylitis and rheumatoid arthritis in a 65-year-old Caucasian male, who had symmetric polyarthritis with erosion of the metacarpophalangeal joint on conventional X-ray, inflammatory low back pain with HLA-B27 positivity, and sacroiliitis. Laboratory analysis showed high levels of rheumatoid factor and anti-cyclic citrullinated peptide antibody (anti-CCP). Clinical features of previously reported cases were compared with those of our case. This is the first case report on the coexistence of both diseases in the same patient, for whom anti- CCP testing and the latest versions of axial ASAS criteria and ACR/EULAR criteria for the classification of ankylosing spondylitis and rheumatoid arthritis, respectively, were used.

Anti-microtubule organizing center with microtubule by autoimmune target test is also useful serological marker in rheumatoid arthritis evaluation

Seropositivity of rheumatoid factor (RF) or anti-cyclic citrullinated peptide antibody (anti-CCP) is one domain of scoring system in new American College of Rheumatology/European League against Rheumatism classification criteria for rheumatoid arthritis (RA). We investigated usefulness of antiperinuclear factor (APF) and autoantibody to microtubule organizing center with microtubule (anti-MTOC-MT), which was detected by autoimmune target (AIT) test, as serological markers for the diagnosis of early RA. The test results of 3,503 patients from the outpatient clinic of The Hospital for Rheumatic Diseases who underwent test for RF, APF, anti-CCP and anti-MTOC-MT simultaneously for the work-up of RA were analyzed. Four kinds of tests showed same results only in 53.1% (1,861/3,503) of all subjects. The kappa coefficient between each test was distributed from -0.011 to 0.622. The agreement was best between RF and anti-CCP (kappa coefficient: 0.622), but the agreement was poor between anti-MTOC-MT and other 3 tests (kappa coefficient: 0.007 to -0.025). In both of RF- and anti-CCP-negative patients, the patients who showed positive result for APF were 4.6% (160/3,503) and for anti-MTOC-MT were 13.2% (464/3,503). RF and anti-CCP positivity could not include all of APF and anti-MTOC-MT positivity. Anti-MTOC-MT detected by AIT test was independent serological marker, and it might be also helpful for the diagnosis of early RA. Therefore, the combined detection of all four serologic markers can be useful for the evaluation of suspected RA patients.

Bilateral recurrent wrist flexor tenosynovitis and rice body formation in a patient with sero-negative rheumatoid arthritis: A case report and review of literature

INTRODUCTION

Rice body formation has been traditionally observed in the joint and tendon sheaths of patients with tuberculosis. Few case reports exist that describe rice body formation in patients with rheumatoid arthritis. We describe a case report of bilateral recurrent wrist flexor tenosynovitis with rice body formation in a patient with sero-negative rheumatoid arthritis.

PRESENTATION OF CASE

This case report describes a 72 year old lady presenting with severe bilateral, flexor tenosynovitis of the wrists. Ultrasonography revealed significant echogenic fluid on the palmer aspect of wrist joint surrounding flexor tendons with intact neurovascular bundles and no bony erosion. Laboratory tests demonstrated elevated erythrocyte sedimentation rate (50 mm/h) and negative rheumatoid factor. A sequential subtotal flexor tenosynovectomy was carried out with decompression of the carpal tunnel. During the operation, multiple rice bodies among the flexor tendons with adherent synovitis were found. Histology revealed disrupted synovial tissue containing several areas of fibrinoid necrosis, bounded by a layer of vaguely pallisaded histiocytes but no epitheloid granulomata or germinal centre. A revision surgery with debulking of the fibro-osseous canal was undertaken following recurrence. The patient presently has complete resolution of symptoms at one year follow-up.

DISCUSSION

The combined clinical, laboratory, ultrasound and histology findings of the patient indicated that the cause of the rice body formation was due to a sero-negative arthritis rather than tuberculosis.

CONCLUSION

Rice body formation can be caused by sero-negative arthritis. Bilateral wrist flexor tensosynovitis can recur within five months of a previous synovectomy in a patient with sero-negative arthritis.