Signalling profiles of circulating leucocytes in patients recovered from reactive arthritis

NF-κB1/IKKε Gene Expression and Clinical Activity in Patients With Rheumatoid Arthritis

Objective

Rheumatoid arthritis (RA) is a systemic and autoimmune disorder whose primary characteristic is the chronic inflammation of joints. The objective of this study was to evaluate whether there was an association between nuclear factor kappa beta1/IKK epsilon (NF-κB1/IKKε) gene expression and clinical activity in RA.

Methods

Sixty patients with RA were included in the study: 30 with clinical activity and 30 with clinical remission. NF-κB1/IKKε gene expression was performed by real-time quantitative polymerase chain reaction through relative quantification with Taqman probes. A ROC curve for NF-κB1 and IKKε was also constructed.

Results

There were significant differences in NF-κB1 and IKKε gene expression (P ≤ .001 and P ≤ .029, respectively) between RA patients with clinical activity and clinical remission. The multivariate lineal general model showed that the use of nonsteroidal anti-inflammatory drugs influenced the NF-κB1 (P = .046) and IKKε (P = .005) expression. The ROC curves for the event "clinical activity" showed the greater area under the curve for NF-κB1 (0.827, 95% CI 0.717-0.937), P ≤ .001.

Conclusion

Although the use of NSAIDs influences the NF-κB1/IKKε pathway, the IKKε expression might be a useful laboratorial analysis to evaluate the RA clinical activity.

Constitutive STAT3 Phosphorylation in Circulating CD4+ T Lymphocytes Associates with Disease Activity and Treatment Response in Recent-Onset Rheumatoid Arthritis

The aim of the present study was to examine constitutive signal transducer and activator of transcription 3 (STAT3) phosphorylation in circulating leukocytes as a candidate biomarker in rheumatoid arthritis (RA). 25 patients with recent-onset, untreated RA provided samples for whole blood flow cytometric determination of intracellular STAT3 phosphorylation, expressed as relative fluorescence units. The occurrence of constitutive STAT3 phosphorylation was evaluated by determining proportion of STAT3-phosphorylated cells among different leukocyte subtypes. Plasma levels of interleukin (IL)-6, IL-17 and IL-21 were measured by immunoassay, radiographs of hands and feet were examined and disease activity score (DAS28) was determined. Biomarkers were restudied and treatment response (according to European League Against Rheumatism) was determined after 12 months of treatment with disease-modifying antirheumatic drugs. At baseline, constitutive phosphorylation of STAT3 occurred in CD4⁺ T cells of 14 (56%) patients, CD8⁺ T cells of 13 (52%) patients, in CD19⁺ B cells of 7 (28%) patients, and in CD14⁺ monocytes of 12 (48%) patients. STAT3 phosphorylation levels of CD4⁺ T cells associated with DAS28, and those of all leukocyte subtypes studied associated with erosive disease. The presence of constitutive STAT3 phosphorylation in CD4⁺ T lymphocytes, pSTAT3 fluorescence intensity of CD4⁺ and CD8⁺ T cells and C-reactive protein (CRP) levels at baseline associated with good treatment response. In conclusion, constitutive STAT3 phosphorylation in circulating CD4⁺ T cells is common in recent-onset untreated RA and associates with good treatment response in patients characterized by high disease activity and the presence of systemic inflammation.