ANALYSIS OF IL17 AND IL17RA POLYMORPHISMS IN SPANISH PSORIASIS PATIENTS: ASSOCIATION WITH RISK FOR DISEASE.

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1 ANALYSIS OF IL17 AND IL17RA POLYMORPHISMS IN SPANISH PSORIASIS PATIENTS: ASSOCIATION WITH RISK FOR DISEASE. Batalla A, Coto E*, González-Lara L, González- Fernández D, Maldonado-Seral C, García-García B, Coto-Segura P. Departments of Dermatology and *Molecular Genetics. Hospital Universitario Central de Asturias (Oviedo Spain).

2 INTRODUCTION Psoriasis is considered a multifactorial systemic disease The genetic background, environmental and immunological factors interact to confer individual s susceptibility. The number of studies about the role of genetic variations (polymorphisms) on psoriasis risk is raising. The IL-17 pathway plays an important role in the pathogenesis of psoriasis. Polymorphisms on the IL-17 pathway have been related to susceptibility for autoimmune, inflammatory or infectious diseases. Nevertheless, genetic variations on IL-17 family in psoriasis have rarely been evaluated.

3 OBJECTIVE To determine whether the variation of IL- 17A/IL17RA genes is related to an increased susceptibility to psoriasis and influence disease severity or the risk for psoriatic arthritis.

4 METHODS Observational cross-sectional study. 548 psoriasis patients and 567 healthy controls. Genotyping of three single nucleotide polymorphisms (SNPs) (Real Time Taqman) IL17A (rs ) IL17RA (rs , rs879577). Search for new coding nucleotide variants 90 patients With severe psoriasis and receiving biological treatments Next Generation Sequencing (NGS) (Ion Torrent Personal Genome Machine) IL17A and IL17RA Sanger sequencing IL17RA promoter

5 Main characteristics of the 548 patients with Psoriasis Gender (male/female) 295 (54%) / 253 (46%) RESULTS Mean age (years ± SD)* 47 ± 16 Cw (43%) Family history of psoriasis 295 (54%) Early-onset psoriasis # 415 (76%) Mean age (years±sd)* 34 ± 14 Cw (48%) Late-onset psoriasis # 133 (24%) Mean age (years±sd)* 59 ± 9 Cw6+ 32 (24%) Non-severe psoriasis (PASI < 10)* 297 (52%) Severe psoriasis (PASI 10)* 251 (48%) Arthritis Non-Arthritis 153 (28%) 395 (72%)

6 RESULTS Genotype and minor allele frequencies (MAF) for the Il17RA rs SNP Il17RA Promotor rs AA AG GG A G Controls n=567 (%) 360 (63) 187 (33) 20 (4) HW controls Patients n=548 (%) 311 (57) 212 (39) 25 (4) HW patients AG+GG vs. AA Patients vs. controls: p=0.02, OR=1.32, 95%CI= PASI <10 n=297 (54%) 174 (59) 110 (37) 13 (4) PASI 10 n=251 (46%) 137 (54) 102 (41) 12 (5) No PsA n= 395 (72%) 229 (58) 146 (37) 20 (5) PsA n= 153 (28%) 82 (54) 66 (43) 5 (3) Cw6-negative n=315 (57%) 190 (60) 114 (36) 11 (4) Cw6-positive n=233 (43%) 121 (52) 98 (42) 14 (6) AG+GG vs. AA Cw6+ vs. controls: p=0.002, OR=1.61, 95%CI = AG+GG vs. AA Higher frequencies of IL17RA rs G carriers among psoriasis patients (p=0.02, OR=1.32, 95%CI= ). The difference was more significant between Cw6 positive patients. None of the IL17A and IL17RA SNPs was related with disease severity or psoriatic arthritis. Cw6+ vs. CW6 : p=0.05. OR=1.4, 95%CI =

7 RESULTS TFsearch program The rs SNP was in complete linkage disequilibrium with rs G/A and rs G/A SNPs in the IL17RA promoter This psoriasis risk haplotype (G-A-G) would interfere with binding sites for transcription in the rs location.

8 RESULTS NGS of 90 patients with severe psoriasis and under biological treatment Identification of two rare IL17RA missense variants in three patients. No coding variants were identified. Next Generation Sequencing Variants found through NGS in at least one of the DNA pools and minor allele frequencies (MAF) in the patients (n=90). Gene Sym. Ref. Variant Position Type of variant MAF IL17A G A INTRONIC SNP IL17RA c.c152t C>T p.t51m (rs ) 2.6 IL17RA G A INTRONIC SNP 1.39 IL17RA C T INTRONIC SNP IL17RA c.c367t T p.a367v ( rs879577) 9.75 IL17RA G A p.k379k IL17RA c.g1174t G>T V392L ( rs ) 1.61 IL17RA C T p.i486i 9.36 IL17RA C T p.p720p 17.9 IL17RA T C UTR SNP 12.30

9 RESULTS Transcript analysis Sanger sequencing Exon 7-8 x 13 gave a major fragment of 526 bp in the six cdna samples that corresponded to the full IL17RA transcript A very faint band of approximately 424 bp (the size of the transcript lacking exon 11) was also observed in the six cdnas. The transcript lacking exon 11 was present in leukocytes from individuals with the three rs genotypes Being responsible of the soluble form of the receptor

10 DISCUSSION Higher frequency of rs G allele in Psoriasis. Only two reports dealing with SNPs at IL-17 family genes and psoriasis. Shibata et al. 153 Japanese with psoriasis and 103 healthy controls IL-17F (rs763780) No significant allelic or genotypic differences between patients and controls Catanoso et al. 118 Italian patients with psoriatic arthritis and 254 healthy controls SNPs at IL-23A, IL-23R, IL-17A and IL-17RA No significant differences between the two groups Weak association between rs , rs and rs in IL-17RA and rs in IL-17A and the subgroup of peripheral psoriatic arthritis

11 Higher frequency of rs G allele in Psoriasis. DISCUSSION rs was previously linked to the susceptibility or protection to Aspirin-exacerbated respiratory disease Alopecia areata End-stage kidney disease New onset diabetes after renal transplantation Papillary thyroid carcinoma

12 DISCUSSION Higher frequency of rs G-carriers in the Cw6+ subgroup Differences in genotype frequencies for other polymorphisms associated with Psoriasis risk, between Cw6-positive and negative patients have been reported. HLA-Cw6 would interact with variants at ERAP1, LCE and IL12B genes

13 DISCUSSION Hypothesis that could explain the association between rs and Psoriasis. The rs SNP is located in the promoter region of IL17RA. It could have a functional effect by inducing or inhibiting the transcription of the gene.

14 DISCUSSION Hypothesis that could explain the association between rs and Psoriasis. Differences in the level of the soluble form of IL17RA Presence of this alternative transcript in leukocytes of individuals with the three genotypes No all/nothing alternative splicing effect for the rs alleles. Due to the limit number of samples studied, we cannot exclude that this SNP was linked to differences in the amount of the soluble form.

15 CONCLUSION We identified the IL17RA rs polymorphism as a risk factor for psoriasis Mainly among Cw6 positive patients. None of the studied SNPs was associated with disease severity of risk for psoriatic arthritis

16 FUNDING SOURCES This work was supported by a grant from the Spanish Instituto de Salud Carlos III-European FEDER founds (grant PI 13/00680). Authors thank Novartis for supporting this work. Authors thank Astucor for their suport.

17 REFERENCES 1. Perera GK, Di Meglio P, Nestle FO. Psoriasis. Annu Rev Pathol. 2012;7: Puig L, Julia A, Marsal S. The Pathogenesis and Genetics of Psoriasis. Actas Dermosifiliogr. 2014;105: Gu C, Wu L, Li X. IL-17 family: cytokines, receptors and signaling. Cytokine. 2013;64: Arisawa T, Tahara T, Shibata T, Nagasaka M, Nakamura M, Kamiya Y, et al. The influence of polymorphisms of interleukin-17a and interleukin-17f genes on the susceptibility to ulcerative colitis. J Clin Immunol. 2008;28: Lew BL, Cho HR, Haw S, Kim HJ, Chung JH, Sim WY. Association between IL17A/IL17RA Gene Polymorphisms and Susceptibility to Alopecia Areata in the Korean Population. Ann Dermatol. 2012;24: Shibata S, Saeki H, Tsunemi Y, Mitsui T, Yokohama A, Handa H, et al. IL-17F single nucleotide polymorphism is not associated with psoriasis vulgaris or atopic dermatitis in the Japanese population. J Dermatol Sci. 2009;53: Catanoso MG, Boiardi L, Macchioni P, Garagnani P, Sazzini M, De Fanti S, et al. IL- 23A, IL-23R, IL-17A and IL-17R polymorphisms in different psoriatic arthritis clinical manifestations in the northern Italian population. Rheumatol Int. 2013;33: Park JS, Park BL, Kim MO, Heo JS, Jung JS, Bae DJ, et al. Association of single nucleotide polymorphisms on Interleukin 17 receptor A (IL17RA) gene with aspirin hypersensitivity in asthmatics. Hum Immunol. 2013;74: Kim YG, Kim EY, Ihm CG, Lee TW, Lee SH, Jeong KH, et al. Gene polymorphisms of interleukin-17 and interleukin-17 receptor are associated with end-stage kidney disease. Am J Nephrol. 2012;36: Kim YG, Ihm CG, Lee TW, Lee SH, Jeong KH, Moon JY, et al. Association of genetic polymorphisms of interleukins with new-onset diabetes after transplantation in renal transplantation. Transplantation. 2012;93: Strange A, Capon F, Spencer CC, Knight J, Weale ME, Allen MH, et al. A genome-wide association study identifies new psoriasis susceptibility loci and an interaction between HLA-C and ERAP1. Nat Genet. 2010;42: