Alterations in CD8αβ and CD8αα T Cell Levels in Patients With Rheumatoid Arthritis

Study Overview
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Brief Summary
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To evaluate the changes in the frequencies of circulating CD4+ and CD4- T cells expressing CD8αα and CD8αβ in peripheral blood of RA patients in comparison with healthy controls. Also, to correlate circulating and synovial fluid levels of these cells with disease activity score (DAS28) and other indices of disease severity.

Detailed Description
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Rheumatoid arthritis (RA) is a chronic, inflammatory, systemic autoimmune disease of the joints . CD4+ T cells are predominant in the synovial tissue with increased number of CD8 effector and memory T cells in synovial fluid and tissue of RA patients . CD8 functions as a dimer; including homodimer CD8αα and heterodimer CD8αβ . CD8αβ is a superior T-cell co-receptor that enhances functional avidity, CD8αα functions as a TCR corepressor to negatively regulate T cell activation . CD8αα T cells are found in human intestine and peripheral blood . CD8αα T cells increased markedly in the lesions of psoriasis where they played a pro-inflammatory role . The lower percentage of CD8αα+ mucosa associated-invariant T (MAIT) cells was found to be associated with MAIT cell dysfunction in gut immunity in necrotizing enterocolitis patients . T cells express the CD8β chain either at a high (CD8βhigh) or low density (CD8βlow ). There was a relative increase in CD8βlow cells in patients with SLE which were associated with an increased disease activity . Double positive (DP) T lymphocytes, include CD4CD8αβhigh and CD4CD8αα T cell subsets in the human blood . DP8α cells decreased in the blood and colonic mucosa of patients with inflammatory bowel disease compared with healthy individuals . CD4CD8αβhigh T cells are present at higher frequencies in some auto-immune diseases . Whether CD8αα or CD8αβ T cells contribute to the pathogenesis of RA, has not been clarified so far. investigators hypothesize that, an alteration in the frequency and distribution of these T cell subsets in RA patients might be associated with disease activity

Official Title
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Alterations in CD8αβ and CD8αα T Cell Levels in Patients With Rheumatoid Arthritis

Conditions
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Rheumatoid Arthritis

Intervention / Treatment
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* Diagnostic Test: flow cytometry


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with RA who fulfilled the 2010 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) revised criteria for RA (12). Patients having knee effusion . Exclusion Criteria: Patients with autoimmune diseases other than RA. Patients or controls with tumors, infections, or other severe organ damage.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| patients group<br>. Inclusion criteria: Patients with RA who fulfilled the 2010 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) revised criteria for RA (1 Patients having knee effusion . Exclusion criteria: Patients with autoimmune diseases other than RA. Patients or controls with tumors, infections, or other severe organ damage. | Diagnostic Test: flow cytometry<br>* Levels of circulating and synovial fluid CD4+ and CD4- T cells expressing CD8αα and CD8αβ will be assessed by flow cytometry using fluorochrome-labelled monoclonal antibodies against CD3, CD4, CD8α and CD8β surface markers. Levels of the following cells will be assessed: CD3+CD4-CD8αα+ CD3+CD4-CD8α+CD8βlow CD3+CD4-CD8α+CD8βhigh CD3+CD4+CD8αβhigh CD3+CD4+CD8αα+<br>|
| controls group<br>healthy subjects | Diagnostic Test: flow cytometry<br>* Levels of circulating and synovial fluid CD4+ and CD4- T cells expressing CD8αα and CD8αβ will be assessed by flow cytometry using fluorochrome-labelled monoclonal antibodies against CD3, CD4, CD8α and CD8β surface markers. Levels of the following cells will be assessed: CD3+CD4-CD8αα+ CD3+CD4-CD8α+CD8βlow CD3+CD4-CD8α+CD8βhigh CD3+CD4+CD8αβhigh CD3+CD4+CD8αα+<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| detection the level of circulating CD4+ and CD4- T cells expressing CD8αα and CD8αβ in peripheral blood and synovial fluid aspirates of RA patients. | The frequencies of circulating CD4+ and CD4- T cells expressing CD8αα and CD8αβ in RA patients in comparison with healthy controls. and Comparing the frequencies of these cells between peripheral blood and synovial fluid aspirates of RA patients. | baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| numbers of patients have remission | To assess the relation between the level of these cells and numbers of patients have remission | baseline |