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 Table of Contents  
ORIGINAL ARTICLE
Year : 2015  |  Volume : 42  |  Issue : 4  |  Page : 183-187

Interleukin-17 level in rheumatoid arthritis patients and its relation to disease activity: a clinical and ultrasound study


1 Department of Rheumatology, Physical Medicine and Rehabilitation, Faculty of Medicine, Elzagazig University, Egypt
2 Department of Physical Medicine and Rehabilitation, Menoufia University, Egypt
3 Department of Radiology, Faculty of Medicine, Menoufia University, Egypt

Date of Submission30-Jan-2015
Date of Acceptance27-Jul-2015
Date of Web Publication26-Oct-2015

Correspondence Address:
Alaa A Labib
Physical Medicine and Rehabilitation, Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Menoufia University
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1110-161X.168164

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  Abstract 

Objective
The aim of this study was to measure the level of interleukin-17A (IL-17A) in the serum and synovial fluid of patients with rheumatoid arthritis (RA) and its relation to disease activity.
Patients and methods
A total of 100 patients suffering from RA were chosen from the outpatient clinic, Department of Physical Medicine and Rehabilitation, Menoufia University Hospital. The patient group was divided into three subgroups - mild, moderate, and severe - according to the disease activity score. All patients were subjected to clinical, laboratory, and ultrasound evaluation and to measurement of IL-17A in the serum and synovial fluid by means of the enzyme-linked immunosorbent assay technique. Fifty healthy individuals were evaluated for IL-17A level in the blood, and served as the control group.
Results
The present study revealed an increase in serum (P = 3.1) and synovial fluid (P = 5.2) IL-17A levels in RA patients with increased disease activity. The ultrasound study showed an increase in serum IL-17A levels with increased erosion of the knee (P = 5.99) and wrist (P = 5.03). There was an increase in serum IL-17A with increased effusion of the knee (P = 22.6) and wrist (P = 33.3). There was an increase in serum IL-17A with increased synovial hypertrophy of the knee (P = 6.39), wrist (P = 12.23), and second metacarpophalangeal (MCP) (P = 53.34). Finally, there was an increase in the blood IL-17A level, dryness of the eye (P = 3.8), dryness of the mouth (P = 3.2), and number of subcutaneous nodules (P = 2.5).
Conclusion
In our study; the mean serum and synovial IL-17A levels were found in high titers in patients with disease activity, and with extra-articular manifestations like dry eyes, dry mouth, and subcutaneous nodules. Also erosions, synovial hypertrophy, and effusions were found with significantly high titers of IL-17A, denoting its usefulness as a measurement tool for high disease activity and destruction. Also targeting IL-17A may be useful as a treatment option for aggressive disease and for rheumatoid patients with poor prognosis.

Keywords: disease activity score, interleukin-17, rheumatoid arthritis, ultrasonography


How to cite this article:
Elhewala AI, Soliman SG, Labib AA, Mousa WA, Salah D. Interleukin-17 level in rheumatoid arthritis patients and its relation to disease activity: a clinical and ultrasound study. Egypt Rheumatol Rehabil 2015;42:183-7

How to cite this URL:
Elhewala AI, Soliman SG, Labib AA, Mousa WA, Salah D. Interleukin-17 level in rheumatoid arthritis patients and its relation to disease activity: a clinical and ultrasound study. Egypt Rheumatol Rehabil [serial online] 2015 [cited 2019 Apr 23];42:183-7. Available from: http://www.err.eg.net/text.asp?2015/42/4/183/168164


  Introduction Top


Rheumatoid arthritis (RA) is a complex, chronic autoimmune disease characterized by an inflammatory infiltration of immune cells, in particular T cells, which represent ~40% of the synovial cellular infiltration and participate in a number of inflammatory and destructive events, such as synovial hyperplasia, pannus setting, cartilage and bone erosion, and joint destruction [1],[2] .

Various cells from the immune system and from the synovium are involved, and a panel of cytokines are produced, expressed, and become functionally active even in the early stages of RA [2] . Among the cytokines produced by T cells, interleukin-17A (IL-17A) (previously known as IL-17) and IL-17F constitute the signature cytokines of the newly described T-helper cell subset (Th17) [3] .

IL-17 responds by stabilizing the mRNA of cytokines, enhancing the receptor expression, and increasing migration, chemokine gene expression, and invasiveness of synoviocytes, and contributes to disease chronicity by inhibiting synoviocyte apoptosis [3] .

Finally, it enhances metalloprotease secretion, leading to cartilage damage. These properties support the combined inhibition of IL-17A and IL-17F to control RA inflammation and joint destruction [3] .


  Patients and methods Top


This study was performed at the Department of Rheumatology and Rehabilitation, Faculty of Medicine, Menoufia University Hospital, and was approved by its ethical committee.

After giving their informed consent, 100 patients suffering from RA [1] were enrolled in the study, with 50 healthy individuals serving as controls. Patients were divided into three groups - G1 (mild), G2 (moderate), and G3 (severe) - according to the disease activity score (DAS28), where a DAS28 score greater than 5.1 implies highly active disease, a DAS28 score less than 5.1 and greater than 3.2 implies moderately active disease, a DAS28 score less than 3.2 implies low active disease, and a DAS28 score less than 2.6 implies remissions [4] .

All patients were subjected to clinical examination to determine the number of tender joints and the number of swollen joints and were also evaluated on the basis of the visual analogue scale. Laboratory measurements were taken of erythrocyte sedimentation rate, complete blood count, C-reactive protein, rheumatoid factor, anticyclic citrullinated peptide, and IL-17A in the serum and synovial fluid [5] by means of the enzyme-linked immunosorbent assay (ELISA) technique [6] . The control group was subjected to measurement of IL-17A in the serum.

The patients were subjected to ultrasound evaluation of knees, wrists, and second MCP, in accordance with European Society of Musculoskeletal Radiology techniques [7] , to assess erosion, effusion, vascularity, and synovial thickness.

Cytokine detection

Venous blood samples of 3 ml each were collected in sterile plane tubes, allowed to stand for 30 min at room temperature, and then centrifuged at 300g for 5 min. Sera were separated immediately, and stored at −20°C until the time of analysis. The IL-17A assay kit, The RayBio Human IL-17 ELISA kit, is an in-vitro ELISA for the quantitative measurement of human IL-17A in serum, plasma, cell culture supernatants, and urine. This assay uses an antibody specific to human IL-17A coated on a 96-well plate. Standards and samples are pipetted into the wells, and IL-17A present in a sample is bound to the wells by the immobilized antibody. The wells are washed and biotinylated anti-human IL-17A antibody is added. After washing away unbound biotinylated antibody, horseradish peroxidase-conjugated streptavidin is pipetted into the wells. The wells are again washed, a TMB substrate solution is added, and the color develops in proportion to the amount of IL-17A bound. The stop solution changes the color from blue to yellow, and the intensity of the color is measured at 450 nm RayBiotech [6] .

Statistical analysis: The data collected were tabulated and analyzed with SPSS (Statistical Package for the Social Science software), version 16, on an IBM compatible computer [8] .

Descriptive statistics were derived as percentage (%), mean (X), and SD.

Analytic statistics were subjected to the χ2 -test, the Student t-test, and the F-test.


  Results Top


Our study involved 100 patients suffering from RA, recruited from the outpatient rheumatology clinic of the Department of Rheumatology and Rehabilitation, Faculty of Medicine, Menoufia University Hospital. The study included both sexes. Seventy-eight patients were female and 22 were male. Their ages ranged between 20 and 69 years (mean age of G1, 42.7 ± 11.3; mean age of G2, 42.8 ± 11.6; mean age of G3, 46.5 ± 12.2). Their disease duration ranged from 2 to 23 years (mean disease duration in G1, 6.8 ± 4.1; mean disease duration in G2, 6.82 ± 4.9; mean disease duration in G3, 9.1 ± 6.4). The ages of controls ranged from 22 to 64 years (mean age, 41.8 ± 12.6).

The comparison of IL-17A level in the blood samples of the studied groups showed significant increase in IL-17A in the patient groups in comparison with the control group (P < 0.05) ([Table 1]).
Table 1 Comparison between serum interleukin-17A in the studied groups in relation to disease activity score


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The comparison of IL-17A level in the synovial fluid of the patient groups with that of the control group showed significant increase in IL-17A in the synovial fluid of the patient group (P < 0.05) ([Table 2]).
Table 2 Comparison between synovial interleukin-17A level in the studied group in relation to disease activity score


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The comparison of IL-17A levels in the blood as well as erosions of the knee, wrist, and the second MCP in the patient groups with its corresponding values in the control group showed highly significant increase in IL-17A level in the blood, with increased erosion of the knee and wrist (P < 0.001) and insignificant increase as regards the second MCP in the patient groups (P > 0.05) ([Table 3]).
Table 3 Comparison between serum interleukin-17A in the patients group and erosion of the knee, wrist, and second MCP


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The comparison of IL-17A levels in the blood as well as effusion (as per the musculoskeletal US study - [Figure 1] and [Figure 2]) of the knee, wrist, and second MCP in the patient group with the corresponding values in the control group showed highly significant increase in IL-17A in the blood, with increased effusion of the knee and wrist (P < 0.001) and insignificant increase as regards second MCP effusion (P > 0.05) in the patient group ([Table 4]).
Figure 1 This figure shows moderate effusion of the knee joint at suprapatellar pouch (Grade 2).

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Figure 2 This figure shows moderate synovial hypertrophy with synovial thickness (4.6) mm oflt the wrist.

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Table 4 Comparison between serum interleukin-17A in the patient group and effusion of the knee, wrist, and second MCP


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The comparison of IL-17A level in the blood in the patient group as well as synovial hypertrophy (as per the musculoskeletal US study - [Figure 2]) with the corresponding values in the control group showed highly significant increase in IL-17A level in the blood, with increased synovial hypertrophy of the knee, wrist, and second MCP (P < 0.001) ([Table 5]).
Table 5 Comparison between serum interleukin-17A level in the studied groups and synovial hypertrophy


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There were highly significant statistical differences between the clinical signs of severity as regards dry eye, dry mouth, and subcutaneous nodules but insignificant statistical differences as regards chest complain, Raynaud's phenomenon, and IL-17A level in the blood of the patient group (P < 0.001) ([Table 6]).
Table 6 Comparison between the clinical signs of severity and interleukin-17A in the blood of the patient group


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There were insignificant statistical differences between the clinical signs of severity and IL-17 level in the synovial fluid in the patient group (P > 0.05) ([Table 7]).
Table 7 Comparison between the clinical signs of severity and interleukin-17A measured as pg/ml in the synovial fluid in the patient group


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  Discussion Top


In this study we found a statistically significant increase in IL-17A level in the blood and synovial fluid in the patient group in comparison with the control group. Roşu et al. [2] reported that simultaneous IL-17A assessment in serum and synovial fluid was valuable for defining activity.

This study also reported that there was a highly significant increase in clinical signs of severity as regards dry eye, dry mouth, subcutaneous nodules, and IL-17A level in the blood of the patient group.

This is in agreement with the results of Metawi et al. [9] , who reported that there was a direct relation between the serum level of IL-17A and disease activity and severity in RA patients.

Also, Sarkar et al. [10] found that IL-17A increases during inflammatory arthritis and that neutralization of IL-17A reduces the severity of arthritis. Moreover, significantly higher levels of IL-17A were detected in the peripheral blood and synovial fluid of patients with rheumatoid.

We also observed significant increase in IL-17A level in the blood with increased number of erosions of the knee and wrist in the RA patients in the studied groups, when evaluated on the basis of their musculoskeletal US measurement.

This is in agreement with the findings of Brentano F et al. [11] , who suggested that IL-17A cytokine could be used as a parameter for prediction of pre-erosive and destructive changes and rapid disease progression in RA patients.

In our study, we found significant differences in IL-17A levels in the blood samples were associated with high level of serum and synovial IL-17A.

This is commensurate with the results of Kim et al. [12] , who suggest that Th-17 cells and IL-17 play an important role in RA pathogenesis, and that the level of IL-17A in the peripheral blood and synovial fluid is associated with increased disease activity and articular destructive effects, such as joint erosion, synovitis, and effusion in RA patients.

Pavlovic et al. [13] found that the mean serum IL-17A levels in patients with early RA corresponded with disease activity and severity. This might highlight the usefulness of the serum IL-17A level in defining the activity and predictive patterns, to aid in aggressive disease therapy, and it might express specific therapeutic targets.

Guggino et al. [14] suggest that treatment with MTX and methyl prednisolone could ameliorate RA disease activity by normalizing the distribution/imbalance of Th-17/Treg and could indicate a new regulatory role of IL-17 cells in RA patients, suggesting the role of IL-17 in RA activity.


  Conclusion Top


In our study, the mean serum and synovial IL-17A levels were found in high titers in patients with disease activity, and with extra-articular manifestations like dry eyes, dry mouth, and subcutaneous nodules. Also, erosions, synovial hypertrophy, and effusions were found with significantly high titers of IL-17A, denoting its usefulness as a measurement tool for high disease activity and destruction. Also, targeting IL-17 A may be a treatment option for aggressive disease and for rheumatoid patients with poor prognosis.

Acknowledgements

The authors thank Professor Dr Abd Elsamad Ibrahim Elhewala, Professor of Rheumatology, Physical Medicine and Rehabilitation, Faculty of Medicine, Zagazig University, and Professor Dr Samar Gaber Soliman, Professor of Physical Medicine and Rehabilitation, Faculty of Medicine, Menoufia University.

The authors are also grateful to all staff members of the rheumatology and physical medicine unit and to all patients for their cooperation.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
Aletaha D, Neogi T, Silman AJ, Funovits J, Felson DT, Birnbaum NS, et al. 2010 Rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum 2010; 62 :2569-2581.  Back to cited text no. 1
    
2.
Roşu A, Mărgăritescu C, Stepan A, Muşetescu A, Ene M. IL-17 patterns in synovium, serum and synovial fluid from treatment-naïve, early rheumatoid arthritis patients. Rom J Morphol Embryol 2012; 53 :73-80.  Back to cited text no. 2
    
3.
Benedetti G, Miossec P. Interleukin 17 contributes to the chronicity of inflammatory diseases such as rheumatoid arthritis. Eur J Immunol 2014; 44 :339-347.  Back to cited text no. 3
    
4.
Fransen J, van Riel PL. The Disease Activity Score and the EULAR response criteria. Clin Exp Rheumatol 2005; 23 (Suppl 39):93-99.  Back to cited text no. 4
    
5.
P Courtney. Joint aspiration and injection and synovial fluid analysis. Best Pract Res Clin Rheumatol 2009; 23 :161-192.  Back to cited text no. 5
    
6.
Inas A, Ahmed G. Serum level of il17, il 22 and IFN in psoriasis. Egypt Dermatol Online J 2009; 5 :1-4.  Back to cited text no. 6
    
7.
European Society of Musculoskeletal Radiology (ESSR). Musculoskeletal ultrasound: technical guidelines edited by the Ultrasound Subcommittee of the Insights Imaging (2010). 1 :99-141  Back to cited text no. 7
    
8.
Morton RF, Hebel JR, McCarter RJ. Medical statistics. In study guide to epidemiology and biostatistics 5th ed. Gaithersburg, Maryland: Aspen Publication; 2001. 5 :71-74.  Back to cited text no. 8
    
9.
Metawi SA, Abbas D, Kamal MM, Ibrahim MK. Serum and synovial fluid levels of interleukin-17 in correlation with disease activity in patients with RA. Clin Rheumatol 2011; 30:1201-1207.  Back to cited text no. 9
    
10.
Sarkar S, Justa S, Brucks M, Endres J, Fox DA, Zhou X, et al. Interleukin (IL)-17A, F and AF in inflammation: a study in collagen-induced arthritis and rheumatoid arthritis. Clin Exp Immunol 2014; 177 :652-661.  Back to cited text no. 10
    
11.
Brentano F, Ospelt C, Stanczyk J, Gay RE, Gay S, Kyburz D. Abundant expression of the interleukin (IL)23 subunit p19, but low levels of bioactive IL23 in the rheumatoid synovium: differential expression and Toll-like receptor-(TLR) dependent regulation of the IL23 subunits, p19 and p40, in rheumatoid arthritis. Ann Rheum Dis 2009; 68 :143-150.  Back to cited text no. 11
    
12.
Kim J, Kang S, Kim J, Kwon G, Koo S. Elevated levels of T helper 17 cells are associated with disease activity in patients with rheumatoid arthritis. Ann Lab Med 2013; 33: 52-59.  Back to cited text no. 12
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13.
Pavlovic V, Dimic A, Milenkovic S, Krtinic D. Serum levels of IL-17, IL-4, and INFγ in Serbian patients with early rheumatoid arthritis. J Res Med Sci 2014; 19 :18-22.  Back to cited text no. 13
    
14.
Guggino G, Giardina A, Ferrante A, Giardina G, Schinocca C, Sireci G, et al. The in vitro addition of methotrexate and/or methylprednisolone determines peripheral reduction in Th17 and expansion of conventional Treg and of IL-10 producing Th17 lymphocytes in patients with early rheumatoid arthritis. Rheumatol Int 2015; 35:171-175.  Back to cited text no. 14
    


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]



 

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