The Clinical Significance Of Combined Detection Glucose-6-Phosphate Isomerase And Anti-Cyclic Citrullinated Peptide Antibody In Rheumatoid Arthritis

Objective: To investigate the clinical significance of serum glucose-6-phosphate (GPI) and anti-cyclic citrullinated peptide (CCP) antibody in rheumatoid arthritis (RA).Methods: Sera from 41 active rheumatoid arthritis patients were analyzed by enzyme linked immunosorbent assay (ELISA) for GPI and anti-CCP antibody at baseline and after 12 and 24 weeks of therapy, and then to analyze the relationship between them and clinic.Results: 1. The level of serum GPI and anti-CCP antibody in patients with active RA were (3.18±1.89)μg/ml and (84.10±36.26)U/ml, in normal controls were (0.22±0.19)μg/ml and (2.05±1.18)U/ml. Both of them were significantly higher than those in normal controls(p < 0.001). 2. The sensitivity and specificity of serum GPI for RA were 87.8% and 83.3%. The sensitivity and specificity of serum anti-CCP antibody for RA were 90.2% and 96.7%. The differences in specificity and specificity between GPI and anti-CCP antibody showed no statistical significance(p > 0.05). 3. GPI was not associated with anti-CCP antibody(p>0.05). 4. GPI was associated with tender joint count, swollen joint count, ESR and CRP by Spearman correlation analysis(p<0.05), not associated with duration of disease, duration of morning stiffness and X-Ray's classification(p > 0.05). Anti-CCP antibody was not associated with these indexes(p > 0.05). 5. The level of serum GPI and anti-CCP antibody after 12 weeks of therapy were (2.07±1.92)μg/ml and (83.24±41.05)U/ml. The difference in the level of GPI between at baseline and at 12th week showed statistical significance(p <0.001), but that in the level of anti-CCP antibody didn't(p>0.05). The level of serum GPI and anti-CCP antibody after 24 weeks of therapy were (1.44±1.75)μg/ml and (78.09±29.70)U/ml. The difference in the level of GPI between at 12th week and at 24th week showed statistical significance(p < 0.001), but that in the level of anti-CCP antibody didn't(p>0.05). 6. The duration of morning stiffness, tender joint count, swollen joint count, serum RF, CRP, ESR and DAS28 decreased significantly after 12 weeks of therapy(p<0.05). All these indexes, as compared with those at 12th week, didn't show significant decreases after 24 weeks of therapy(p>0.05).Conclusion: 1. It was similar to anti-CCP antibody that the GPI abnormally increased in patients with active RA. 2. The GPI was highly sensitive and specific to RA, so it could be considered as a new marker for diagnosing RA. It could elevate the diagnostic rate of RA when the GPI and anti-CCP antibody were detected simultaneously. 3.The GPI serum level was positively associated with the activity of RA. Dynamic detection the GPI serum level may be helpful for evaluating the activity of RA.