Molecular Vision 2009; 15:1537-1541 <>
Received 8 July 2009 | Accepted 5 August 2009 | Published 8 August 2009

Monocyte chemoattractant protein (MCP)-1 2518 A/G SNP in Chinese Han patients with VKH syndrome

Shengping Hou,1 Peizeng Yang,1 Lin Xie,2 Liping Du,1 Hongyan Zhou,3 Zhengxuan Jiang1

1The First Affiliated Hospital, Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, and Chongqing Eye Institute, Chongqing, P.R. China; 2Department of Ophthalmology, Daping Hospital, the Third Military Medical University, Chongqing, P.R. China; 3Uveitis Study Center, Sun Yat-sen University, Guangzhou, P.R. China

Correspondence to: Professor Peizeng Yang, M.D., Ph.D., the First Affiliated Hospital, Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, and Chongqing Eye Institute, Chongqing, P.R. China, 400016; Phone: +8623 89012851; FAX: +8623 89012851; email:


Purpose: Vogt-Koyanagi-Harada (VKH) syndrome is an autoimmune disease. The monocyte chemoattractant protein-1 (MCP-1) gene has been implicated in the pathogenesis of certain autoimmune diseases. The aim of this study was to examine whether a MCP-1 polymorphism was associated with VKH syndrome.

Methods: A case-control analysis was performed using genomic DNA samples from 307 VKH patients and 319 age-, sex-, and ethnically-matched healthy controls. The MCP-1 polymorphism at the −2518 A/G locus was genotyped using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay.

Results: The distribution of genotypic frequency of the MCP-1 −2518 A/G polymorphism in all subjects did not deviate from Hardy–Weinberg equilibrium (HWE; p>0.05). Allelic and genotypic frequency analysis revealed no significant difference between VKH patients and healthy controls for the MCP-1 −2518 A/G polymorphism (p>0.05). No significant differences were found according to gender and neither was found according to extraocular findings including neck stiffness, tinnitus, alopecia, poliosis, dysacusia, scalp hypersensitivity, and vitiligo.

Conclusions: The result suggests that the susceptibility to VKH syndrome in Chinese Han patients may be not influenced by the MCP-1 −2518 A/G polymorphism.


Vogt-Koyanagi-Harada (VKH) syndrome is a multisystem disorder mainly affecting pigmented tissues in the eye, auditory, integumentary, and central nervous systems. The clinical features of VKH syndrome include bilateral granulomatous panuveitis frequently associated with extraocular findings including pleocytosis in the cerebrospinal fluid (CSF), dysacusis, alopecia, poliosis, and vitiligo [1-3]. Although the etiology and pathogenesis of VKH syndrome remain unclear, numerous studies have suggested that this syndrome is considered to be a cell-mediated autoimmune disease directed against melanocytes. Epidemiological studies show that VKH syndrome is more prevalent in certain racial and ethnic groups, particularly in pigmented groups [3] such as Asian and Latin-American populations and displays an adventive familial aggregation pattern [4]. Two human leukocyte antigen (HLA) genes, HLA-DR4 and HLA-DRw53, have been shown to be associated with VKH patients in various ethnic groups including the Chinese and Japanese [5-7]. These evidences suggest that immune-associated genetic factors may play a crucial role in the pathogenesis of VKH syndrome. However, the previously reported genetic risks for VKH syndrome such as HLA-DR4 and HLA-DRw53 account for only a small portion of the overall estimated risk for this syndrome, suggesting that non-HLA genes may confer a substantial proportion of genetic susceptibility to this syndrome. Therefore, studies on the disease association with genes involved in the immune response may highlight the genetic susceptibility to VKH syndrome.

MCP-1 is a potent chemokine released by lymphocyte, monocytes, mast cells, and eosinophils during inflammation and also produced by ocular cells such as the retinal pigment epithelial cell cultured in vitro [8]. MCP-1 has been implicated in the recruitment of leukocytes into the site of inflammation. The elevated MCP-1 concentration in the aqueous humor of active anterior uveitis patients [9] and ocular fluids and tissues during ocular inflammation [9-13] combined with the recent reports showing an association of MCP-1 −2518 A/G polymorphism with uveitis [14-16] and multiple autoimmune diseases [17-19] suggest that MCP-1 may be involved in the pathogenesis of VKH syndrome. The present study was therefore designed to examine the association of the MCP-1 −2518 A/G polymorphism with VKH syndrome using a case–control association study.



This study was approved by the ethics committees of our hospitals and adhered to the tenets of the Declaration of Helsinki. Additionally, informed consent was obtained from each participant or each participant’s guardian. After giving informed consent, blood samples were collected from 307 Chinese Han VKH patients and 319 age- and sex-matched, unrelated, healthy Chinese Han controls, which were recruited from Zhongshan Ophthalmic Center, Sun Yat-sen University (Guangzhou, P.R. China) and the First Affiliated Hospital, Chongqing Medical University (Chongqing, P.R. China) from April 2005 to March 2009. All VKH patients were diagnosed according to the revised criteria for VKH syndrome [20].

DNA extraction

Genomic DNA was prepared from peripheral blood mononuclear cells (PBMCs) of VKH patients and healthy controls using the QIAamp DNA Mini Blood Kit (Qiagen, Hilden, Germany) according to manufacturer’s instructions. DNA samples were collected in a 1.5 ml Eppendorf tube and stored at −20 °C until use.


Genotyping for the MCP-1 polymorphism (−2518A/G, rs1024611 in dbSNP database) was performed using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The forward primer, 5′-CCG CAT TCA ATT TCC CTT TAT-3′, and reverse primer, 5′-TTC CAA AGC TGC CTC CTC A-3′, were designed using primer premier 5.0 software (Premier Biosoft International, Palo Alto, CA). PCR reactions were performed under the following conditions: 10 min at 94 °C followed by 35 cycles at 95 °C for 45 s, 55 °C for 45 s, 72 °C for 45 s, and then for 3 min at 72 °C. The PCR products were incubated with PvuII at 37 °C (New England Biolabs Inc., Ontario, Canada) for at least 3 h and separated on 2% agarose gels. Ten percent of the PCR samples were directly sequenced to confirm the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) results (Invitrogen Biotechnology Co., Shanghai, P.R. China).

Statistical analysis

Statistical analysis was performed with the SPSS version 12.0 for Windows (SPSS Inc., Chicago, IL). Hardy–Weinberg Equilibrium (HWE) was tested by the χ2 test. We evaluated the frequency of genotypes and alleles in this study using the χ2 test. All statistical tests were two-sided, and statistical significance was taken when p<0.05.


Clinical findings of VKH patients and characteristics of controls are presented in Table 1. The mean age of VKH patients was 34.3±10.3 years and that of healthy controls was 34.7±11.6 years (Table 1). There was no significant difference in the distribution of age between VKH patients and controls (p>0.05).

Three hundred and seven VKH patients and 319 healthy controls were genotyped for the MCP-1 −2518 A/G polymorphism. The result of genotyping was matched with that of direct sequencing for 10% of the samples. The distribution of genotypic frequency of this single nucleotide polymorphism (SNP) in all subjects did not show a significant deviation from Hardy–Weinberg equilibrium (HWE; p>0.05).

The distributions of genotypic and allelic frequencies of the MCP-1 −2518 A/G polymorphism are shown in Table 2. No genetic association was demonstrated between the −2518A/G polymorphism of MCP-1 and VKH syndrome in an allele and genotype analysis, although the roles of MCP-1 in the immune diseases suggest its possible involvement in the development of VKH syndrome. In addition, our results did not indicate a significant difference when allelic and genotypic frequencies of the MCP-1 −2518 A/G polymorphism were analyzed according to gender and any one of extraocular findings including neck stiffness, tinnitus, alopecia, poliosis, dysacusia, scalp hypersensitivity, and vitiligo.


The present study was to investigate the association of the MCP-1 polymorphism with VKH syndrome in the Chinese Han population. The results showed that there was no association between the MCP-1 polymorphism and VKH syndrome. The stratification analysis according to gender or extraocular findings did not show any association.

VKH syndrome is a multifactorial autoimmune disease that may result from interactions between susceptibility genes and environmental factors. Several studies have been performed to investigate the genetic risk for VKH syndrome. Recently, we reported two susceptible genes to VKH syndrome including cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and programmed cell death 1 (PDCD1) in the Chinese population [21,22]. Horie and coworkers [23,24] showed a lack of association of the tyrosinase gene family (TYR, TYRP1, and DCT) and interferon-γ with VKH syndrome in Japanese patients. In this study, we tested whether the −2518 A/G polymorphism of MCP-1, a crucial chemokine, was associated with Chinese Han VKH patients. As a case–control association study may be influenced by various factors including population composition and stratification, the present study drew up the following attempts to ensure the analysis results. First, the controls and patients were strictly matched according to the place where they were born to exclude the possible influence of stratification of the population. Individuals with any autoimmune disease and ocular inflammation were excluded from the controls by careful inquiry of history and, if necessary, by relevant examinations. Second, we restricted our study population to Chinese Han descent to minimize confounding by ethnic variation. Third, the number of donors enrolled in this study (307 VKH patients and 319 age-, sex-, ethnically-matched healthy controls) was large enough to avoid a bias of the results. Finally, direct sequencing for 10% of the samples was performed to validate the result of genotyping.

Several studies have been focused on the association of the MCP-1 −2518 A/G polymorphism with certain autoimmune diseases [15,25,26]. The investigated polymorphism, which is located in the promoter region of MCP-1, has been shown to affect the transcriptional activation of this gene [19]. Therefore, this polymorphism is considered a good candidate in the genetic predisposition to autoimmune diseases. Thus, we focused our study on the association of this polymorphism with VKH syndrome. Unexpectedly, no association was found in these VKH patients. As VKH syndrome is a multisystem disorder characterized by ocular and various extraocular findings, we further performed an association study of the MCP-1 polymorphism with these extraocular findings. Similarly, we did not find any association of this polymorphism with any one of these clinical findings. This result is consistent with the recent reports, which demonstrated a lack of association of the MCP-1 −2518 A/G polymorphism with multiple sclerosis (MS) and ulcerative colitis (UC) [27]. Contrary to our observation, this polymorphism was found to be significantly associated with rheumatic arthritis (RA), systemic lupus erythematosus (SLE), and juvenile rheumatoid arthritis (JRA) [25,28,29]. Taken together, these data suggest that the MCP-1 −2518 A/G polymorphism may play a role in certain but not all autoimmune diseases.

Likewise with other candidate gene studies, several possible limitations exist in our study. A complex multigenic disease involves the interaction of various genetic and environmental factors. Therefore, it is unlikely that any single gene has an exclusive effect on the development of VKH syndrome. The present study only examined the association of the MCP-1 polymorphism with VKH syndrome but did not refer to the association study of the other susceptible genes. Furthermore, the tested polymorphism in this study is only one of the polymorphisms of MCP-1. It is necessary to examine all the tag SNPs of MCP-1 to understand the precise association of MCP-1 with VKH syndrome. In addition, the patients enrolled in this study were recruited from Chinese Han individuals, and so the results presented here need to be confirmed using different ethnic populations.

In summary, the present study suggests that there was no association between the MCP-1 −2518 A/G polymorphism and VKH syndrome. This result remained in stratification analysis according to the gender and various clinical findings.


This work was supported by Key Project of Natural Science Foundation (30630064), National Supporting Project of P.R. China, Key Project of Health Bureau of Chongqing (2008–1-15), Key Project of Natural Science Foundation of Chongqing (CSTC, 2009BA5037), and Project of Chongqing Key Laboratory of Ophthalmology (CSTC, 2008CA5003). The authors would also like to thank all donors enrolled in the present study.


  1. Moorthy RS, Inomata H, Rao NA. Vogt-Koyanagi-Harada syndrome. Surv Ophthalmol. 1995; 39:265-92. [PMID: 7725227]
  2. Forster DJ, Cano MR, Green RL, Rao NA. Echographic features of the Vogt-Koyanagi-Harada syndrome. Arch Ophthalmol. 1990; 108:1421-6. [PMID: 2222275]
  3. Yang P, Ren Y, Li B, Fang W, Meng Q, Kijlstra A. Clinical characteristics of Vogt-Koyanagi-Harada syndrome in Chinese patients. Ophthalmology. 2007; 114:606-14. [PMID: 17123618]
  4. Rutzen AR, Ortega-Larrocea G, Schwab IR, Rao NA. Simultaneous onset of Vogt-Koyanagi-Harada syndrome in monozygotic twins. Am J Ophthalmol. 1995; 119:239-40. [PMID: 7832237]
  5. Zhao M, Jiang Y, Abrahams IW. Association of HLA antigens with Vogt-Koyanagi-Harada syndrome in a Han Chinese population. Arch Ophthalmol. 1991; 109:368-70. [PMID: 2003797]
  6. Zhang XY, Wang XM, Hu TS. Profiling human leukocyte antigens in Vogt-Koyanagi-Harada syndrome. Am J Ophthalmol. 1992; 113:567-72. [PMID: 1575232]
  7. Islam SM, Numaga J, Fujino Y, Hirata R, Matsuki K, Maeda H, Masuda K. HLA class II genes in Vogt-Koyanagi-Harada disease. Invest Ophthalmol Vis Sci. 1994; 35:3890-6. [PMID: 7928186]
  8. Holtkamp GM, De Vos AF, Peek R, Kijlsta A. Analysis of the secretion pattern of monocyte chemotactic protein-1 (MCP-1) and transforming growth factor-beta 2 (TGF-beta2) by human retinal pigment epithelial cells. Clin Exp Immunol. 1999; 118:35-40. [PMID: 10540157]
  9. Verma MJ, Lloyd A, Rager H, Strieter R, Kunkel S, Taub D, Wakefield D. Chemokines in acute anterior uveitis. Curr Eye Res. 1997; 16:1202-8. [PMID: 9426952]
  10. Bian ZM, Elner SG, Strieter RM, Kunkel SL, Lukacs NW, Elner VM. IL-4 potentiates IL-1beta- and TNF-alpha-stimulated IL-8 and MCP-1 protein production in human retinal pigment epithelial cells. Curr Eye Res. 1999; 18:349-57. [PMID: 10372996]
  11. Crane IJ, McKillop-Smith S, Wallace CA, Lamont GR, Forrester JV. Expression of the chemokines MIP-1alpha, MCP-1, and RANTES in experimental autoimmune uveitis. Invest Ophthalmol Vis Sci. 2001; 42:1547-52. [PMID: 11381059]
  12. Elner SG, Elner VM, Bian ZM, Lukacs NW, Kurtz RM, Strieter RM, Kunkel SL. Human retinal pigment epithelial cell interleukin-8 and monocyte chemotactic protein-1 modulation by T-lymphocyte products. Invest Ophthalmol Vis Sci. 1997; 38:446-55. [PMID: 9040478]
  13. Elner VM, Burnstine MA, Strieter RM, Kunkel SL, Elner SG. Cell-associated human retinal pigment epithelium interleukin-8 and monocyte chemotactic protein-1: immunochemical and in-situ hybridization analyses. Exp Eye Res. 1997; 65:781-9. [PMID: 9441701]
  14. Wegscheider BJ, Weger M, Renner W, Posch U, Ulrich S, Hermann J, Ardjomand N, Haller-Schober EM, El-Shabrawi Y. Role of the CCL2/MCP-1 −2518A>G gene polymorphism in HLA-B27 associated uveitis. Mol Vis. 2005; 11:896-900. [PMID: 16280979]
  15. Ahad MA, Missotten T, Abdallah A, Lympany PA, Lightman S. Polymorphisms of chemokine and chemokine receptor genes in idiopathic immune-mediated posterior segment uveitis. Mol Vis. 2007; 13:388-96. [PMID: 17417600]
  16. Chen Y, Vaughan RW, Kondeatis E, Fortune F, Graham EM, Stanford MR, Wallace GR. Chemokine gene polymorphisms associate with gender in patients with uveitis. Tissue Antigens. 2004; 63:41-5. [PMID: 14651522]
  17. Szalai C, Kozma GT, Nagy A, Bojszko A, Krikovszky D, Szabo T, Falus A. Polymorphism in the gene regulatory region of MCP-1 is associated with asthma susceptibility and severity. J Allergy Clin Immunol. 2001; 108:375-81. [PMID: 11544456]
  18. Karrer S, Bosserhoff AK, Weiderer P, Distler O, Landthaler M, Szeimies RM, Müller-Ladner U, Schölmerich J, Hellerbrand C. The -2518 promotor polymorphism in the MCP-1 gene is associated with systemic sclerosis. J Invest Dermatol. 2005; 124:92-8. [PMID: 15654958]
  19. Rovin BH, Lu L, Saxena R. A novel polymorphism in the MCP-1 gene regulatory region that influences MCP-1 expression. Biochem Biophys Res Commun. 1999; 259:344-8. [PMID: 10362511]
  20. Read RW, Holland GN, Rao NA, Tabbara KF, Ohno S, Arellanes-Garcia L, Pivetti-Pezzi P, Tessler HH, Usui M. Revised diagnostic criteria for Vogt-Koyanagi-Harada disease: report of an international committee on nomenclature. Am J Ophthalmol. 2001; 131:647-52. [PMID: 11336942]
  21. Du L, Yang P, Hou S, Lin X, Zhou H, Huang X, Wang L, Kijlstra A. Association of the CTLA-4 gene with Vogt-Koyanagi-Harada syndrome. Clin Immunol. 2008; 127:43-8. [PMID: 18282809]
  22. Meng Q, Liu X, Yang P, Hou S, Du L, Zhou H, Kijlstra A. PDCD1 genes may protect against extraocular manifestations in Chinese Han patients with Vogt-Koyanagi-Harada syndrome. Mol Vis. 2009; 15:386-92. [PMID: 19234630]
  23. Horie Y, Takemoto Y, Miyazaki A, Namba K, Kase S, Yoshida K, Ota M, Hasumi Y, Inoko H, Mizuki N, Ohno S. Tyrosinase gene family and Vogt-Koyanagi-Harada disease in Japanese patients. Mol Vis. 2006; 12:1601-5. [PMID: 17200659]
  24. Horie Y, Kitaichi N, Takemoto Y, Namba K, Yoshida K, Hirose S, Hasumi Y, Ota M, Inoko H, Mizuki N, Ohno S. Polymorphism of IFN-gamma gene and Vogt-Koyanagi-Harada disease. Mol Vis. 2007; 13:2334-8. [PMID: 18199975]
  25. Lima G, Soto-Vega E, Atisha-Fregoso Y, Sanchez-Guerrero J, Vallejo M, Vargas-Alarcon G, Llorente L. MCP-1, RANTES, and SDF-1 polymorphisms in Mexican patients with systemic lupus erythematosus. Hum Immunol. 2007; 68:980-5. [PMID: 18191726]
  26. Gonzalez-Escribano MF, Torres B, Aguilar F, Rodriguez R, Garcia A, Valenzuela A, Nunez-Roldan A. MCP-1 promoter polymorphism in Spanish patients with rheumatoid arthritis. Hum Immunol. 2003; 64:741-4. [PMID: 12826377]
  27. Li KS, Wang BY, Liu SY, Yao SP, Guo L, Mao DW. The combination of polymorphisms within MCP-1 and IL-1beta associated with ulcerative colitis. Int J Immunogenet. 2009; 36:135-9. [PMID: 19392835]
  28. Ozyurek AR, Gurses D, Ulger Z, Levent E, Bakiler AR, Berdeli A. Allelic frequency of the MCP-1 promoter −2518 polymorphism in the Turkish population and in Turkish patients with juvenile rheumatoid arthritis. Clin Rheumatol. 2007; 26:546-50. [PMID: 16835702]
  29. Ye DQ, Hu YS, Li XP, Yang SG, Hao JH, Huang F, Zhang XJ. The correlation between monocyte chemoattractant protein-1 and the arthritis of systemic lupus erythematosus among Chinese. Arch Dermatol Res. 2005; 296:366-71. [PMID: 15611878]