Serum Expression Of Dkk-1 In Elderly Onset Rheumatoid Arthritis

Background and ObjectiveRheumatoid arthritis(RA)is a chronic inflammatory autoimmune disease characterized polyarthritis and constitutional manifestation, with erosive synovitis as the most common pathological presentations.The elderly-onset rheumatoid arthritis (EORA, age of onset≥60 years)has its clinical feature, which has been reported to differ from younger-onset rheumatoid arthritis(YORA).Wnt signal transduction pathway play an important role in bone metabolize and homeostasis. Dkk-1 is an inhibitory molecule that regulates the Wnt pathway, which controls osteoblastogenesis. Detecting the serum concentration of Dkk-1 in different ages RA patients, collect clinical materials, to evaluate the relation between Dkk-1 changing level and sex, age, duration and other index in RA patients, to evaluate the role of Dkk-1 in the pathogenesis of elderly-onset rheumatoid arthritis. Dkk-1 plays an important role in erosive bone disease, especially in osteolytic lesions coursed by cancer. RA as an erosive bone disease, the potential role of Dkk-1 is unclear. Though there are some animal models or vitro tests in other country, lack of human serum test. In order to analysis the EORA clinical feature and the Dkk-1 expression in EORA serum, we collected clinical materials,serum lab test, look foreword to explore the role of Dkk-1 in elderly-onset rheumatoid arthritis.MethodsSerum Dkk-1 levels were measured in 40 patients with EORA,51 patients with YORA,30 patients with non-elderly onset rheumatoid arthritis(NRORA),that YORA get into elder age, consistent with the reviewed classification criteria of ACR in 1987 and ACR/EULAR in 2009 as study group.select 30 middle aged and 44 elder aged healthy volunteer as control group.To analysis EORA NEORA YORA patients' clinical features, lab test, radiographic materials.Detect the serum level of Dkk-1 in different age and course RA patients and control group by sandwich enzyme-linked immunosorbent assay (ELISA).Analyze the correlation of Dkk-1 and other clinical index detected. All data analysis by SPSS11.0.Results1.EORA differed from YORA by a more equal gender distribution (P>0.05). a higher frequency of acute onset, more involvement of shoulder, knee and ankle joints as an initial presentation (P<0.05). The disease activity in patients with EORA was more severe than that in YORA patients(P<0.05).In addition, the number of patients with other disease, including interstitial lung disease or osteoarthritis, was higher in EORA group than in YORA group(P<0.05).2.The serum Dkk-1 levels were increased in patients with EORA,YORA, NEOR significantly (P<0.05);The Mean of Dkk-1 NEORA group was the highest, then the YORA group, the last was EORA, there were no difference among three groups.In EORA group Dkk-1 was higher in men than women (P<0.05);there was no signification gender difference in YORA, NEORA,health control groups (P>0.05).There was difference between long duration and short duration RA(P >0.05).3.In EORA group, Dkk-1 correlated to CRP,ESR(P<0.05).To analysis all groups RA patients, there was no correlation to age(P>0.05);But correlated to PLT, CRP, ESR(P<0.05,r=0.311,r=0.388,r=0.331,r=0.198,r=0.237, Pearson test)and disease duration, GLB, DAS(P<0.05,r=0.237, r=0.232,r=0.198, Pearson test)Conclusions1.EORA has its clinical feature:acute onset, more involvement of shoulder, knee and ankle joints as an initial presentation, severe disease activity.2.Serum Dkk-1 of EORA was in a higher level, and in male is higher than female;3.In EORA group Dkk-1 was related to CRP, ESR. In all RA patients, there were no relations between Dkk-1 with different ages, but related to DAS, disease duration.4.Dkk-1 partially related to RA's bone erosive.