|Year : 2021 | Volume
| Issue : 1 | Page : 32-37
Serum interleukin-22 and C-reactive protein in patients with vitiligo: a case–control study on 35 Egyptian patients
Tawfik M Yasmin1, Badran Y Aya1, Hosni Amal2, Kamel A Amira3, Gomaa S Ahmed4
1 Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Assiut, Egypt
2 Department of Clinical Pathology, Faculty of Medicine, Assiut, Egypt
3 Department of Biochemistry, Faculty of Medicine, Assiut, Egypt
4 Dermatology, Venereology and Andrology, Egypt
|Date of Submission||23-Feb-2020|
|Date of Acceptance||26-Jun-2020|
|Date of Web Publication||23-Dec-2020|
Badran Y Aya
Lecturer of Dermatology and Venereology, Assuit University Hospital, Faculty of Medicine, Assuit, 71515
Source of Support: None, Conflict of Interest: None
Background Vitiligo is a chronic depigmentary skin disorder caused by destruction of epidermal melanocytes. Various cytokines play an important role in its pathogenesis. Interleukin-22 (IL-22) is one of the cytokines produced by multiple immune cells such as lymphocytes and natural killer cells. It has a role in the proinflammatory process, and also it can induce production of C-reactive protein (CRP). The role of IL-22 has been studied and evaluated in many chronic inflammatory diseases such as psoriasis, rheumatoid arthritis, and inflammatory bowel diseases.
Aim This study was planned to study the effect of serum IL-22 and CRP in patients with vitiligo and to correlate their level with the severity of the disease using vitiligo area severity index, vitiligo extent score, and vitiligo disease activity score.
Patients and methods A prospective case–control study was conducted on 35 patients with vitiligo and 35 age-matched and sex-matched healthy volunteers. Both disease severity and disease activity were estimated using vitiligo area severity index and vitiligo disease activity score, respectively. All participants were subjected to measurement of serum IL-22 by enzyme-linked immunosorbent assay technique and measurement of serum CRP level by rate nephelometry.
Results We found that the most common type of vitiligo was the generalized type (88.6%), followed by segmental vitiligo (5.7%) and focal vitiligo (5.7%). We found that both IL-22 and CRP are significantly higher in patients with vitiligo compared with healthy participants (P=0.001), with a positive correlation with the disease activity.
Conclusion Both IL-22 and CRP have a role in vitiligo pathogenesis as their presence intensifies the severity of the disease. They could be considered useful tools for evaluating the disease activity.
Keywords: C-reactive protein, cytokines, interleukin-22, vitiligo
|How to cite this article:|
Yasmin TM, Aya BY, Amal H, Amira KA, Ahmed GS. Serum interleukin-22 and C-reactive protein in patients with vitiligo: a case–control study on 35 Egyptian patients. Egypt J Dermatol Venerol 2021;41:32-7
|How to cite this URL:|
Yasmin TM, Aya BY, Amal H, Amira KA, Ahmed GS. Serum interleukin-22 and C-reactive protein in patients with vitiligo: a case–control study on 35 Egyptian patients. Egypt J Dermatol Venerol [serial online] 2021 [cited 2022 Oct 1];41:32-7. Available from: http://www.ejdv.eg.net/text.asp?2021/41/1/32/304321
| Introduction|| |
Vitiligo is an acquired loss of pigmentation following destruction of epidermal melanocytes , which leads to appearance of milky white macules and patches that are seen clinically .
Vitiligo is a multifactorial polygenic disease. Four theories could explain its pathogenesis: autocytotoxicity, antioxidant theory, neural theory, and autoimmune theory . Of which, the autoimmune theory is the most important one, in which various cytokines and inflammatory mediators play a major role .
Skin acts as a biological barrier protecting our bodies against outside effects, and also it acts as a pigmentary system ,. Regarding its protective functions, the skin forms a coordinated neuroimmunoendocrine axes through establishing connections among epidermal keratinocytes, melanocytes, Langerhans cells, dermal fibroblasts, mast cells, and macrophages ,. All of them interact and communicate with each other through the release of cytokines.
The cytokine interleukin-22 (IL-22) is a member of a family of IL-10–related cytokines that include IL-19, IL-20, IL-24, and IL-26. It was termed IL-TIF, for IL-10–related T cell–derived inducible factor . IL-22 was discovered 20 years ago through genome analysis ,.
CD4+ T cells, γδ-T cells, natural killer cells, NKT cells, and lymphoid tissue inducer are the major source of IL-22, which is considered a remarkable mediator of signaling from immune cells to tissues during infection and inflammation . However, epidermal keratinocytes are thought to be the major targets of IL-22 .
Among all the IL-10–related cytokines, IL-22 is the best studied and has been examined in chronic skin inflammation such as psoriasis . IL-22 together with other cytokines has the ability to induce gene expression for antimicrobial peptides, chemokines, matrix metalloproteinases, cytokines, and acute-phase proteins from epithelial cells in the skin, gut, lung, or liver .
It is well known that the C-reactive protein (CRP) is an inflammatory indicator produced by the liver cells (hepatocytes) within 1–2 days in response to inflammation or tissue damage . Its level in the blood stream is considered an excellent indictor of inflammation ,.
We planned the study to estimate the level of serum IL-22 and CRP in vitiligo in Egyptian patients using enzyme-linked immunosorbent assay technique and to correlate their level with the duration, type, and severity of the disease using vitiligo area scoring index (VASI), vitiligo extent score, and vitiligo disease activity score (VIDA).
| Patients and methods|| |
The is a prospective case–control study conducted at the Vitiligo Outpatient Clinic of the Dermatology and Venereology Department, Assiut University Hospital. The study was approved by the institutional ethics committee, and a written informed consent was obtained from all patients and controls.
The study included 35 patients with vitiligo and 35 age-matched and sex-matched healthy volunteers as a control group. However, we excluded patients with any skin disease other than vitiligo, patient with chronic systemic diseases (renal or liver failure), and pregnant women.
All patients were subjected to detailed medical history (name, age years, sex, marital state, residence, occupation, age at onset of vitiligo, duration of vitiligo, stability of vitiligo, and family history of vitiligo) and meticulous physical examination (skin phototype, vitiligo clinical type, and leukotrichia). Both disease severity and disease activity were estimated using VASI and VIDA scores, respectively.
VASI was calculated using the formula of Hamzavi et al.  as follows:
VASI= Є (Hand units in all body sites)×residual depigmentation.
VIDA score is a six-point scale based on patient’s own reports of disease activity based on disease activity and time period, with a grading from +4 to −1 .
Overall, 2 ml of venous blood was obtained by venipuncture from all participants. Quantitative evaluation of human IL-22 by enzyme-linked immunosorbent assay kit (Catalog No:E-EL-H0106; Elabscience, Wuhan, China) was made according to the manufacturer’s instruction. In addition, CRP was performed on Beckman Coulter device by quantitative determination in human serum by rate nephelometry.
All data were collected, tabulated and statisticallyanalyzed using SPSS 20.0 for windows (SPSS Inc., Chicago, IL, USA). Categorical variables were described by number and percent, whereas continuous variables were described by mean and SD. P value was considered statistically significant when P value less than 0.05.
| Results|| |
This study included 35 patients with vitiligo and 35 age-matched and sex-matched healthy volunteers as a control group. Of 35 patients with vitiligo, 15 (42.9%) were male and 20 (57.1%) were female. Their ages ranged from 4 to 55 years, with a mean±SD of 23.89±2.58 years. The majority of the patients were nonsmokers [30 (85.7%)]. Family history of vitiligo was positive in nine (25.7%) patients. Other demographic and clinical data of the study group are illustrated in [Table 1].
The average serum levels of IL-22 in patients with vitiligo was significantly higher when compared with healthy participants (P≤0.001) ([Table 2]).
|Table 2 The levels of interleukin-22 and C-reactive protein in patients with vitiligo and controls|
Click here to view
Moreover, the average serum levels of CRP in patients with vitiligo was significantly higher when compared with healthy participants (P≤0.001) (P=0.018) ([Table 2]).
Regarding the correlation coefficients (r) of different tested variables in patients with vitiligo, a highly significant positive correlation was present between IL-22 and CRP, between IL-22 and VIDA score, and between CRP and VIDA score; however, there was no significant correlation between IL-22 and CRP, and these variables are shown in [Table 3].
|Table 3 The correlations between the level of interleukin-22, C-reactive protein and the levels of different tested variables in the vitiligo patients|
Click here to view
A significant difference was found between means of both serum IL-22 and CRP levels in generalized type of vitiligo when compared with nongeneralized type (focal and segmental) and in active vitiligo (VIDA score equals to 1, 2, 3, or 4) when compared with stable vitiligo (VIDA score equals to 0 or −1) (P≤0.001) ([Table 4]).
|Table 4 Correlation between the levels of interleukin-22 and C-reactive protein in types of vitiligo|
Click here to view
| Discussion|| |
Vitiligo is a depigmentation disorder; its cause is complex and not fully understood. Moretti et al.  have suggested the involvement of epidermal cytokines in the pathogenesis of vitiligo as they found a significant difference in cytokine level in vitiligo skin compared with uninvolved skin and with healthy controls skin.
The progression of many autoimmune diseases including vitiligo is associated with shifting from Th2 and T regulatory cells toward (Th)1 and Th17 . The Th17 cells secrete cytokines such as IL-17, IL-6, IL-22, and tumor necrosis factor (TNF), which stimulate the release of IL-1a, IL-6, and TNF in keratinocytes. Th17 also acts with these inflammatory mediators to inhibit proliferation of melanocytes .
IL-22 is the most important cytokines secreted by Th17 cell . It has been established in several autoimmune conditions, and it was found in high level in blood samples in patients with Crohn’s disease , and in rheumatoid arthritis synovial tissues .
The expression of many antimicrobial peptides, including β-defensin 2 (hBD-2), S100A7, S100A8, and S100A9 which are proinflammatory molecules belonging to the S100 family calcium-binding proteins, is induced by IL-22 ,, and this supports the role of IL-22 in innate immunity and its proinflammatory role in vitiligo .
IL-22 role in the proinflammatory process is confirmed by causing upregulation of the matrix metalloproteinase 3, the platelet-derived growth factor A, and the CXCL5 chemokine. In addition, it induces migration of keratinocytes in an in vitro injury model and downregulation of the expression of seven genes included in keratinocytes differentiation .
Few studies investigated the level of IL-22 in serum to find out its role in patients with vitiligo ,,. In the current study, we found that serum levels of IL-22 in patients with vitiligo were significantly higher than in controls (P<0.001). Moreover, a significant difference between generalized and localized (focal and segmental) vitiligo was noted (P<0.001). Similar results were obtained in a study by Sushama et al. , as they found that cytokines secreted by Th17 cells (IL-2, TNF-a, IL-6, IL-17, and IL-22) were higher in patients with vitiligo compared with age-matched and sex-matched healthy controls and that serum levels of IL-17 and IL-22 were significantly higher in generalized cases compared with localized cases. They stated that those cytokines play an important role as they increase in line with vitiligo extent.
Similarly, Ratsep et al.  found that IL-22 was significantly higher in patients with vitiligo, both by the mRNA expression and protein level in sera. It was two to four folds higher than controls, especially during the active stage of the disease.
The same results were obtained by Elela et al. , where serum levels of IL-17 and IL-22 were significantly higher in patients than controls.
In the current study, no correlation was obtained between the disease severity (VASI) and serum IL-22, and this finding was similar to Sushama and colleagues but in contrast to other studies, which noted a positive correlation between them ,.
A highly significant positive correlation was noted between disease activity (VIDA) and serum IL-22. Similarly, Ratsep et al.  found that IL-22 was higher in active vitiligo compared with stable vitiligo and stated that IL-22 provokes inflammatory pathway causing destruction of melanocytes.
Early studies suggested that IL-22 may induce an acute-phase response ,. Dumoutier et al.  identified an IL-22–dependent induction of acute-phase protein gene expression from the HepG2 hepatocellular carcinoma-derived cell line and from the liver. Wolk et al.  subsequently reported increased circulating levels of serum amyloid A (SAA) after administration of IL-22.
We aimed to measure the serum level of CRP in patients with vitiligo as it was evaluated in few studies , and to find out the relation between it and serum IL-22.
CRP levels were elevated in many autoimmune and inflammatory diseases ,. In a study by Botta et al. , high level of CRP was noted with active rheumatoid arthritis. Moreover, Cao and Li  have noted a significantly higher level in patients with nonalcoholic steatohepatitis than in the patients with nonalcoholic fatty liver disease.
In our study, we noted a significantly higher level of mean serum CRP in patients with vitiligo compared with age-matched and sex-matched control (P<0.000). Moreover, a significant difference was noted between the generalized and localized groups, with a higher level in the generalized vitiligo group (P<0.000). Regarding disease activity, a higher level was noted in patients with active vitiligo compared with stable group, with a positive correlation between the serum CRP and the VIDA score (r=0.718, P<0.000), whereas no correlations were detected between it and vitiligo extent and severity (vitiligo extent score and VASI).
Similar results were obtained in a study by Ghaderi and Nezafati  which stated that there was an association between increased serum CRP level and generalized vitiligo. They implied that CRP could intensify the severity of vitiligo; thus, its level might be useful as a novel biomarker for evaluating the disease activity of vitiligo. The mean serum CRP level was significantly higher in patients with active compared with stable and control group (P<0.001). However, no significant different was seen between stable and control (P=0.053) .
Solak et al.  found that serum CRP levels and neutrophil-to-lymphocyte ratio were significantly higher in generalized vitiligo than localized vitiligo and healthy controls.To the best of our knowledge, this is the first study to evaluate the correlation between serum IL-22 and CRP in patients with vitiligo in humans. A positive correlation was noted between them. Many studies have been done on mice that prove our result and confirm the association between IL-22 and CRP ,,.
Liang et al.  have noted that single administration of IL-22 results in elevation of the acute-phase protein CXCL1 and chemokine that leads to the transient elevation of circulating neutrophils. Moreover, hepatic gene expression and elevation of SAA, the major acute-phase protein in mice, and maintained elevation of its level were noted after exposure to IL-22.
Misse et al.  have proposed a relationship between SAA and IL-22 in disease prevention; they proposed that protection from viral infection is caused by the increased production of IL-22 by T cells that induce novel SAA fragment.
Ivanov et al.  found that both SAA and IL-22 have the ability to amplify the expression and the function of each other, where SAA-induced IL-6 and IL-23 from intestinal dendritic cells enable the differentiation of Th17 cells, including the expression of IL-22.
Moreover, Kelly et al.  noticed that IL-22 mediate renal alterations by acting on IL-22R expressed on epithelial cells of the renal proximal tubules and the induction of SAA.
Our results revealed that the IL-22 levels and CRP are significantly higher in patients with vitiligo than controls, with positive correlation with the disease activity, which may signify its role in the inflammatory process in active vitiligo.
| Conclusion|| |
We found an association between increased serum IL-22 and CRP level in patient with vitiligo. Both of them intensify the severity of vitiligo and are useful for evaluating the disease activity. Positive correlation between them suggests that an intertwined interplay exist. Further studies with larger samples and combination of IL-22 and CRP with other markers are recommended.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Kalkanli N, Kalkanli S. Classification and comparative study of vitiligo in Southeast of Turkey with biochemical and immunological parameters. Clin Ter 2013; 164:397–402.
Sheth VM, Gunasekera NS, Silwal S, Qureshi AA. Development and pilot testing of a vitiligo screening tool. Arch Dermatol Res 2015; 307:31–38.
Kumar R, Prasad D. Melanocytorrhagy and apoptosis in vitiligo connecting jigsaw pieces. Indian J Dermatol Venereol Leprol 2012; 78:19–23.
Tu CX, Gu JS, Lin XR. Increased interleukin-6 and granulocyte-macrophage clony stimulating factor levels in the sera of patients with non-segmental vitiligo. J Dermatol Sci 2003; 31:73–78.
Slominski A. Neuroendocrine system of the skin. Dermatology 2005; 211:199–208.
Costin GE, Hearing VJ. Human skin pigmentation: melanocytes modulate skin color in response to stress. FASEB J 2007; 21:976–994.
Skobowiat C, Dowdy JC, Sayre RM, Tuckey RC, Slominski A. Cutaneous hypothalamic-pituitary-adrenal axis homolog: regulation by ultraviolet radiation. Am J Physiol Endocrinol Metab 2011; 301:484–493.
Weiss E, Mamelak AJ, La Morgia S, Wang B, Feliciani C, Tulli A, Sauder DN. The role of interleukin 10 in the pathogenesis and potential treatment of skin diseases. J Am Acad Dermato 2004; l50:657–675.
Dong J, An X, Zhong H, Wang Y, Shang J, Zhou J. Interleukin-22 participates in the inflammatory process of vitiligo. Oncotarget 2017; 8:109161–109174.
Ouyang W, Rutz S, Crellin NK, Valdez PA, Hymowitz SG. Regulation and functions of the IL-10 family of cytokines in inflammation and disease. Annu Rev Immunol 2011; 29:71–109.
Xie MH, Aggarwal S, Ho WH, Foster J, Zhang Z, Stinson J et al.
Interleukin (IL)-22, a novel human cytokine that signals through the interferon receptor related proteins CRF2-4 and IL-22R. J Biol Chem 2000; 275:31335–31339.
Zenewicz LE. IL-22: there is a gap in our knowledge. Immuno Horizons 2018; 22:198–207.
Dumoutier L, Van Roost E, Ameye G, Michaux L, Renauld JC. IL-TIF/IL-22: genomic organization and mapping of the human and mouse genes. Genes Immun 2000; 1:488–494.
Wolk K, Kunz S, Witte E, Friedrich M, Asadullah K, Sabat R. IL-22 increases the innate immunity of tissues. Immunity 2004; 21:241–254.
Baumann H, Gauldie J. The acute phase response. Immunol Today 1994; 15:74–80.
Oimbra S, Oliveira H, Reis F, Belo L, Rocha S, Quintanilha A. C-reactive protein and leucocyte activation in psoriasis vulgaris according to severity and therapy. J Eur Acad Dermatol Venereol 2010; 24:789–796.
Beygi S, Lajevardi V, Abedini R. C-reactive protein in psoriasis: a review of the literature. J Eur Acad Dermatol Venereol 2014; 28:700–711.
Ridker PM, Cushman M, Stampfer MJ. HS.CRP in the primary prevention setting. New Engl J Med 2011; 324:836–843.
Hamzavi H, Jhon D, McLen J, Shepiro H, Zang H, Lui H. Parametric modeling of narrowband UV-B phototherapy for vitiligo. Arch Dermatol 2004; 140:677–683.
Njoo MD, Das PK, Bos JD, Westerhof W. Association of the Köbner phenomenon with disease activity and therapeutic responsiveness in vitiligo vulgaris. Arch Dermatol 1999; 135:407–413.
Moretti S, Spallanzani A, Amato L, Hautmann G. New insights into the pathogenesis of vitiligo: imbalance of epidermal cytokines at sites of lesions. Article Pigment Cell Res 2002; 15:87–92.
Weaver CT, Harrington LE, Mangan PR. Th17: an effector CD4 T cell lineage with regulatory T cell ties. Immunity 2006; 24:677–688.
Habeb AM, Hefnawy AM, Elsayed SB, Abo Bkr AE, Elhefnawy AM. Expression of interleukin-17 mRNA in vitiligo patients. Egypt J Dermatol Venereol 2003; 33:67–70.
Liang SC, Tan XY, Luxen Berg DP. Interleukin (IL)-22 and IL-17 are coexpressed by Th17 cells and cooperatively enhance expression of antimicrobial peptides. J Exp Med 2006; 203:2271–2279.
Andoh A, Zhang Z, Inatomi O. Interleukin-22, a member of the IL-10 subfamily, induces inflammatory responses in colonic subepithelial myofibroblasts. Gastroenterology 2005; 129:969–984.
Wolk K, Witte E, Hoffmann U. IL-22 induces lipopolysaccharide-binding protein in hepatocytes: a potential systemic role of IL-22 in Crohn’s disease. J Immunol 2007; 178:5973–5981.
Ikeuchi H, Kuroiwa T, Hiramatsu N. Expression of interleukin-22 in rheumatoid arthritis: potential role as a proinflammatory cytokine. Arthritis Rheum 2005; 52:1037–1046.
Boniface K, Bernard FX, Garcia M, Gurney A, Lecron J, Morel F. IL-22 inhibits epidermal differentiation and induces proinflammatory gene expression and migration of human keratinocytes. J Immunol 2005; 174:3695–3702.
Sushama S, Dixit N, Gautam R, Arora P. Cytokine profile (IL-2, IL-6, IL-17, IL-22, and TNF-a) in vitiligo − new insight into pathogenesis of disease. J Cosmet Dermatol 2019; 18:337–341.
Ratsep R, Kingo K, Karelson M, Reimann E, Raud K, Silm H. Gene expression study of IL-10 family genes in vitiligo skin biopsies, peripheral blood mononuclear cells and sera. Br J Deramtol 2008; 156:1275–1281.
Elela MA, Hegazy RA, Fauzy MM, Rashed LA, Rasheed H. Interleukin 17, interleukin 22 and Fox P3 expression in tissue and serum of non-segmental vitiligo: a case-controlled study on eighty-four patients. Eur J Dermatol 2013; 23:350–355.
Dumoutier L, Van Roost E, Colau D, Renauld JC. Human interleukin-10-related T cell-derived inducible factor: molecular cloning and functional characterization as an hepatocyte-stimulating factor. Proc Natl Acad Sci USA 2000; 97:10144–10149.
Ghaderi R, Nezafati P. A new biomarker in patients with vitiligo: a case-control study. J Immunol 2016; 3:106–120.
Solak B, Dikicier BS, Cosansu NC, Erdem T. Neutrophil to lymphocyte ratio in patients with vitiligo. Adv Dermatol Allergol 2017; 468–470
Botta E, Meroño T, Saucedo C, Martín M, Tetzlaff W. Associations between disease activity, markers of HDL functionality and arterial stiffness in patients with rheumatoid arthritis. Atherosclerosis 2016; 251:438–444.
Cao Y, Li L. Relationship of non-alcoholic steatohepatitis with arterial endothelial function and atherosclerosis. Zhonghua Gan Zang Bing Za Zhi 2014; 22:205–208.
Liang SC, Nickerson-Nutter C, Pittman D, Carrier Y, Goodwin DG, Shields KM et al.
IL-22 induces an acute-phase response. J Immunol 2010; 185:5531–5538.
Misse D, Yssel H, Trabattoni D, Oblet C, Lo Caputo S, Mazzotta F et al.
IL-22 participates in an innate anti- HIV-1 host-resistance network through acute-phase protein induction. J Immunol 2007; 178:407–415.
Ivanov II, Atarashi K, Manel N, Brodie EL, Shima T, Karaoz U et al.
Induction of intestinal Th17 cells by segmented filamentous bacteria. Cell 2009; 139:485–498.
Kelly KJ, Kluve-Beckerman B, Dominguez JH. Acute-phase response protein serum amyloid A stimulates renal tubule formation: studies in vitro and in vivo. Am J Physiol Renal Physiol 2009; 296:1355–1363.
[Table 1], [Table 2], [Table 3], [Table 4]