Evaluation of autoantibodies against vimentin and α-enolase in rheumatoid arthritis patients.

INTRODUCTION: Rheumatoid arthritis (RA) is categorized as an autoimmune disease with a frequency of 0.2-1% worldwide. It is reported that various autoantibodies are produced in the RA population, particularly against citrullinated peptides. Among various candidate markers for RA diagnosis, the citrullinated proteins have the highest specificity and sensitivity for both diagnosis and prognosis of RA. Anti-mutated citrullinated vimentin and α-enolase constitute a new class of autoantibodies for early detection of RA. MATERIAL AND METHODS: 45 serum samples and 19 synovial fluid (SF) specimens collected from RA patients were considered for American College of Rheumatology criteria and 20 serum samples and 10 SF specimens were provided from healthy subjects as a control group. To assess the quantity of anti-citrullinated protein antibodies (ACPA), anti-mutated citrullinated vimentin (MCV) and anti-α-enolase in the serum and SF of RA patients were determined by the enzyme-linked immunosorbent assay (ELISA) method. For the evaluation of disease activity and joint destruction, we used the Disease Activity Score of 28 joints based on erythrocyte sedimentation rate (ESR) Disease Activity Score 28 (DAS28). Furthermore, to measure the molecular weight of vimentin and α-enolase, electrophoresis on 10% SDS-PAGE was performed as described before. RESULTS: The anti-α-enolase level among serum samples from RA patients was significantly higher than in healthy subjects (4.49 ±0.20 ng/ml vs. 0.76 ±0.12 ng/ml) (p < 0.001). There was a direct relation between α-enolase quantity and (rheumatoid factor) RF and C-reactive protein (CRP) levels. The mean ESR value in positive and negative ACPA patients was 38.2 ±22.6 mm/h and 9.2 ±5.8 mm/h respectively (p < 0.0001). The mean DAS28-ESR was 3.3. The level of anti-MCV in the serum of RA patients (244.6 ±53.3 U/ml) was higher than in serum of the healthy group (148.73 ±71.8) (p < 0.0001). The level of anti-MCV in the SF of patients was 687.5 ±148.4 U/ml. CONCLUSIONS: In conclusion, both autoantibodies against MCV and α-enolase are two important markers that increase in serum and SF of RA patients and are specific for diagnosis of RA disease.

Adenosine Deaminase Activity and HLA-DRB as Diagnostic Markers for Rheumatoid Arthritis.

BACKGROUND: Rheumatoid Arthritis (RA) is a chronic multi systemic disorder with the unclarified ethiopathology. Although several markers have been presented for recognition of RA, but none of them has been specific. New markers such as HLA typing and activity of Adenosine Deaminase (ADA) isoenzymes could be useful and specific. OBJECTIVE: The aim of this study is to evaluate the pattern of ADA isoenzymes activity and HLA typing in both RA patients and healthy cases. METHODS: Blood samples were collected from 55 RA patients and 60 healthy subjects, over a period of 6 months. Levels of C-reactive Protein (CRP), Rheumatoid Factor (RF) and ADA (ADA1, ADA2, total ADA) were measured using AVITEX kit and HITACHI Auto Analyzer. In addition, HLA-DRB1*01,*04 and *10 was detected using PCR-SSP. RESULTS: ADA activity, particularly ADA2 level, was significantly higher among RA group (Pv <0.05). The concentrations of tADA in patients with RF and CRP positive were significantly higher (Pv <0.05). The allele prevalence of DRB1*01 was significantly higher in RA patients (13.1%) compared with control group (5.5%, respectively) (P <0.05, Bonferroni adjustment P<0.003). Calculated sensitivity and specificity for diagnostic tests in this study are listed as: CRP (75%), RF (80%), ADA (84%) and RF (90%), ADA (83%), CRP (72%), respectively. CONCLUSION: Increased tADA level and the frequency of DRB1*10 and *01 caused susceptibility to RA.

The Prevalence of Undetected Vertebral Fracture in Patients with Back Pain by Dual-Energy X-ray Absorptiometry (DXA) of the Lateral Thoracic and Lumbar Spine.

STUDY DESIGN: This is a prospective study. PURPOSE: This study is conducted to determine the prevalence of unrecognized vertebral fracture (VF) in patients who present with back pain. OVERVIEW OF LITERATURE: VF is often unrecognized, and significantly increases the risk of further fractures. Unfortunately, the patients at a high risk for VF usually do not receive adequate therapy to reduce the fracture risk. METHODS: This is a prospective study of 344 patients who presented with back pain from April 2008 to May 2009. The patients underwent dual-energy X-ray absorptiometry (DXA) evaluation and vertebral fracture assessment from T4 to L4 using a hologic densitometer. RESULTS: Three hundred forty four of 386 patients who presented with back pain were included. Forty two patients were excluded because of a prior history of VF or the lack of written consent. Most of the patients were female (95.3%). The mean age of the patients was 58.21 ± 11.74 years. According to the World Health Organization definition (based on the T-score), 13.4% of the patients had normal lumbar spine bone mineral density (BMD). 27.9% of them were osteopenic and 58.7% were osteoporotic. The overall prevalence of VF, as established by lateral vertebral assessment, was 39% (n = 134). Moreover, 62.6% (n = 84) of the patients with VF had more than one fracture and 64.1% (n = 86) of them had Grade 2 or 3 fracture. CONCLUSIONS: We recommend performing not only DXA scanning for BMD evaluation, but also VFA by DXA in old patients with back pain.