|Year : 2017 | Volume
| Issue : 2 | Page : 133-135
Serum level of interleukin-22 in patients with psoriasis and its correlation with disease severity
Eman R. M. Hofny1, Hanan Morsy1, Ashraf Hasaball2, Howida Twisy M.Sc 1
1 Department of Dermatology Venereology and Andrology, Assiut University, Assiut, Egypt
2 Department of Clinical Pathology, Assiut University, Assiut, Egypt
|Date of Submission||29-Aug-2016|
|Date of Acceptance||04-Sep-2016|
|Date of Web Publication||6-Nov-2017|
Department of Venerology and Dermatology, Assiut University, Assiut 71111
Source of Support: None, Conflict of Interest: None
Psoriasis is a T-cell-mediated inflammatory disease where T-helper (Th) lymphocytes (Th1, Th17, and Th22) play an important role in its pathogenesis. The aim of the present study was to assess the serum levels of interleukin (IL)-22 and its correlation with disease severity.
Materials and methods
The present study included 25 psoriatic patients and 25 healthy controls. Using serum samples collected from psoriatic patients and healthy controls, the concentrations of IL-22 were examined using ELISA kits. The severity of psoriatic skin lesions was assessed using psoriasis area and severity index scores.
IL-22 concentrations were significantly higher in psoriatic patients in comparison with the control group. A significant, positive correlation between the concentrations of IL-22 and the severity of psoriasis was found.
The results of our study suggest that Th22 along with its cytokine responses may contribute to the skin and systemic inflammatory conditions characteristic of psoriasis. It seems that early identification of soluble biomarkers and initiation of well-matched treatment may prevent exacerbation and progression of psoriasis.
Keywords: interleukin 22, psoriasis, serum
|How to cite this article:|
Hofny ER, Morsy H, Hasaball A, Twisy H. Serum level of interleukin-22 in patients with psoriasis and its correlation with disease severity. J Curr Med Res Pract 2017;2:133-5
|How to cite this URL:|
Hofny ER, Morsy H, Hasaball A, Twisy H. Serum level of interleukin-22 in patients with psoriasis and its correlation with disease severity. J Curr Med Res Pract [serial online] 2017 [cited 2018 Oct 16];2:133-5. Available from: http://www.jcmrp.eg.net/text.asp?2017/2/2/133/217734
| Introduction|| |
Knowledge about the role of cytokines in psoriasis has developed in the last several years. Initially, only T-helper-1 (Th1) cells and cytokines secreted by these cells, such as tumor necrosis factor-α, interferons-γ, and interleukin (IL)-2, were associated with the development and maintenance of chronic inflammatory diseases such as psoriasis . In the 1990s, Th17 cells were described as another T-cell population that produces IL-17, IL-6, IL-21, IL-22, and tumor necrosis factor . Cytokines produced by Th17 cells were found to initiate acanthosis, hyperkeratosis, and parakeratosis. Th17 cells demonstrated involvement in neutrophil and monocyte chemotaxis, T-cell migration and activation, and neovascularization . Th22 cells have been lately described as inflammatory CD4+ T cells that produce cytokines such as IL-22, IL-26, and IL-13 of which IL-22 is the most important functional cytokine. Th22 cells do not express IL-17A or interferons-γ ([3–7]). The aim of the present study was to assess the serum levels of IL-22 in psoriatic patients and its correlation with disease severity.
| Materials and Methods|| |
Clinical assessment and patient materials
Serum samples were collected from 25 psoriasis patients and 25 healthy individuals. Patients and controls were pair matched for age and sex. The disease severity of each patient was assessed using the psoriasis area and severity index (PASI) score. All patients enrolled in our study had no other autoimmune or systemic diseases and underwent no systemic treatment including glucocorticoids, immunosuppressive drugs, or phototherapy at least 1 month before the PASI score evaluation and sample collection period. Informed consent was obtained from all the patients and healthy controls. Research protocol has been accepted and monitored throughout the conduction of research by the local Ethical Commitee, Assiut Faculty of Medicine, Assiut University.
Assessment of serum interleukin-22 concentrations in psoriatic patients
Patients and controls
Blood samples were collected from psoriatic patients and controls, and were centrifuged for 15 min at 1000g. Next, the serum samples were subdivided into small aliquots to be stored at −80°C until analysis for cytokine levels. ELISA kits were used to determine serum IL-22 (PRC; Elabscience (Bethesda, MD, USA)) levels, according to the manufacturer's instructions.
Mann–Whitney's U-test was used to compare continuous data between the psoriasis group and the control group. Pearson's correlation coefficient was used for correlation analyses. A P greater than 0.05 was considered to be statistically significant.
| Results|| |
Characteristics of study individuals
This study included 25 patients with psoriasis and 25 age-matched and sex-matched controls as listed in [Table 1]. Disease duration, BSA, and the PASI score are listed in [Table 2].
Serum interleukin-22 levels in patients with psoriasis and healthy controls
We found significantly higher levels of IL-22 in patients with psoriasis vulgaris with a mean ± SD of 11.62 ± 10.21 pg/ml compared with controls who had a mean ± SD of 1.77 ± 1.61 pg/ml (P = 0.000) ([Figure 1]).
Correlation between serum interleukin-22 levels and psoriasis area and severity index scores in patients with psoriasis
There was a significant, positive correlation between IL-22 levels and disease severity (r = 0.688; P = 0.000) ([Figure 2]).
|Figure 2: Correlation between interleukin-22 levels and disease severity. PASI, psoriasis area and severity index.|
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| Discussion|| |
IL-22 has a pathogenetic role in psoriasis, where it is responsible for the altered proliferation and differentiation of keratinocytes and induces inflammatory molecules .
With regard to IL-22, our study showed that there were significantly higher levels of IL-22 in patients with psoriasis vulgaris (11.62 ± 10.21 pg/ml) compared with controls (1.77 ± 1.61 pg/ml) (P = 0.000).
Our study agrees with the study by Michalak-Stoma et al.  who showed that significantly higher levels of IL-22 were observed in psoriatic patients compared with healthy controls (P < 0.001). In the study by Boniface , IL-22 was detected in the serum of 22 of 33 psoriatic patients (59 ± 21 pg/ml), compared with only a single serum sample (27 pg/ml) among 20 normal individuals (P < 0.001). The results of all these studies confirm the involvement of IL-22 in psoriasis pathogenesis.
In our study, a significant, positive correlation was found between IL-22 levels and disease severity (r = 0.688; P = 0.000).
Michalak-Stoma et al.  also found a significant, positive correlation between IL-22 concentrations and psoriasis severity as measured by the PASI score (r = 0.557; P < 0.001).
In the study by Boniface , the circulating levels of IL-22 in patients were dispersed, but not to the index of disease severity.
| Conclusion|| |
Serum levels of IL-22, which correlated with the clinical severity of psoriasis, may be an objective parameter for successful treatment and may be used for the follow-up of patients.
The authors thank the patients and control individuals for their participation in the present study.
This research was funded by the Faculty of Medicine, Assuit University.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2]