Intraindividual changes of dipeptidyl peptidase-IV in peripheral blood of patients with rheumatoid arthritis are associated with the disease activity

Abstract

BackgroundDipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of several autoimmune diseases. The aim of this study was to evaluate the association of DPP-IV presence in blood plasma and mononuclear cells with the disease activity in rheumatoid arthritis (RA).MethodsPatients with active RA (n = 27) were examined at the study enrolment and a follow-up examination was performed after the regression of the joint effusions and at least 6 months after the first investigation. The control group comprised patients with a noninflammatory joint disease, i.e. osteoarthritis (OA; n = 15). The DPP-IV-like enzymatic activity was measured by a kinetic fluorimetric method, the concentration of DPP-IV in the blood plasma was determined using ELISA and the expression of DPP-IV in leukocytes was assayed by flow cytometry.ResultsBlood plasma DPP-IV-like enzymatic activity (median ± SD 220.15 ± 83.6 pkat/mL in RA vs. 376.9 ± 144.9 pkat/mL in OA, p < 0.001) and concentrations (median ± SD 465.1 ± 215.6 ng/mL in RA vs. 953.3 ± 368.4 ng/mL in OA, p < 0.001) were lower in patients with active RA compared to OA. In RA patients, the blood plasma DPP-IV-like enzymatic activity negatively correlated with the CRP concentration (r = −0.39, p = 0.044). No significant differences were observed in the DPP-IV-like enzymatic activity and DPP-IV expression in blood mononuclear cells between the RA and OA groups. At follow-up, 18 RA patients had a less active disease as demonstrated by an improved DAS28 score. In this group, comparison of the entry and the follow-up values in individual patients revealed an increase of the blood plasma DPP-IV-like enzymatic activity (median ± SD 141 ± 46 % of the patient’s entry values, p = 0.011) and DPP-IV concentration (median ± SD 168 ± 25 %, of the patient’s entry values, p = 0.033). In contrast to the blood plasma, the DPP-IV expression in blood mononuclear cells was reduced in these patients as evidenced by a decrease in the cell surface DPP-IV-like enzymatic activity as well as the median fluorescence intensity of DPP-IV staining in lymphocytes (median ± SD 66 ± 56 %, p = 0.018 and 63 ± 31 % of the patient’s entry values, p = 0.005, respectively).ConclusionsThe association between RA activity and the changes in blood plasma and blood mononuclear cell DPP-IV in individual patients supports the possible relationship of DPP-IV to RA pathophysiology.

Correlation between high-frequency ultrasonography of patients with early rheumatoid arthritis and anti-CCP antibody

“…Some clinical indices can be used to assess the disease activity, such as SJC, TJC, patients’ assessment of pain and overall severity, the assessment of dysfunction and the acute-phase response. [22] In imaging examinations, ultrasonography is a sensitive method to detect the activity of joint inflammation, and it is also one of the research hotspots worldwide in recent years. High-frequency ultrasonography can show thickening of synovium at different degrees and increased blood flow signals in the synovium.…”

A novel iterative mixed model to remap three complex orthopedic traits in dogs

“…The marker at BICF2P1242852 on CFA7 is ~55 kb from dipeptidyl peptidase-4 ( DPP4 ), which is a plasma membrane peptidase that selectively cleaves an N-terminal dipeptide from peptides with a proline or alanine residue [ 43 ]. Dipeptidyl peptidase-4 is widely expressed, and is involved in T cell function [ 44 , 45 ].…”

Incretins in patients with rheumatoid arthritis

“…Of note, a recent study involving 50 patients with RA revealed a decrease in DPP-4 serum activity but not in DPP-4/CD26 expression [ 34 ]. In another study involving 27 patients with RA, there was also an elevation in blood plasma DPP-4 but a decrease of DPP-4/CD26 in peripheral blood mononuclear cells after clinical improvement following treatment [ 35 ]. Taking these observations into account, we feel that the number of peripheral T lymphocytes expressing DPP-4/CD26 is higher in the blood of patients with active RA.…”