{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,16]],"date-time":"2026-02-16T12:21:25Z","timestamp":1771244485018,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,2,16]],"date-time":"2026-02-16T00:00:00Z","timestamp":1771200000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: Nonalcoholic fatty liver disease (NAFLD) is common in rheumatoid arthritis (RA), and methotrexate (MTX) use raises concern about hepatotoxicity. We evaluated whether HLA-DRB1, PNPLA3, SLCO1B1, and MTHFR variants are associated with NAFLD, liver fibrosis, or MTX toxicity\/pharmacokinetics in RA, after accounting for clinical covariates. Methods: In a cross-sectional cohort of 159 patients with RA, NAFLD, and fibrosis were assessed by FibroScan (CAP \u2265 275 dB\/m; LSM &gt; 8 kPa). We compared baseline characteristics by NAFLD status and fitted multivariable models for NAFLD, fibrosis, ALT elevation, and MTX toxicity; MTX pharmacokinetics were analyzed in 111 MTX-treated patients. Multiple testing was controlled using the Benjamini\u2013Hochberg method. Results: The prevalence of NAFLD was 36%, and that of fibrosis was 11%. NAFLD patients had higher CAP and LSM, and markedly greater adiposity indices (body weight, BMI, waist and hip circumference, WC). BMI and WC were independently associated with NAFLD (BMI OR 1.27 per kg\/m2, 95% CI 1.16\u20131.40; WC OR 1.06 per cm, 95% CI 1.01\u20131.12). No HLA-DRB1, PNPLA3, SLCO1B1, or MTHFR variant showed an association that survived multiple-comparison correction. Among MTX users, 21\/111 (19%) experienced toxicity. SLCO1B1 and MTHFR variants did not influence MTX pharmacokinetics; age was associated with lower dose-normalized MTX exposure, and cumulative dose was positively associated with exposure. Conclusions: In RA, adiposity\u2014not the tested candidate pharmacogenes\u2014drives NAFLD risk, and SLCO1B1\/MTHFR variants do not support MTX dose adjustment. The findings emphasize routine clinical risk factors over single-gene testing for NAFLD and MTX hepatotoxicity in this setting.<\/jats:p>","DOI":"10.3390\/jcm15041568","type":"journal-article","created":{"date-parts":[[2026,2,16]],"date-time":"2026-02-16T11:11:28Z","timestamp":1771240288000},"page":"1568","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["HLA DRB1*01 and *04 Predisposition to Rheumatoid Arthritis and Polymorphisms of the SLCO1B1, MTHFR and PNPLA3 Genes Are Not Associated with Fatty Liver and Hepatotoxicity"],"prefix":"10.3390","volume":"15","author":[{"given":"Tatjana","family":"Zeki\u0107","sequence":"first","affiliation":[{"name":"Department of Rheumatology and Clinical Immunology, Clinical Hospital Center Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2742-9275","authenticated-orcid":false,"given":"Nata\u0161a","family":"Katalini\u0107","sequence":"additional","affiliation":[{"name":"Clinical Institute for Transfusion Medicine, Clinical Hospital Center Rijeka, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7779-0237","authenticated-orcid":false,"given":"Nada Star\u010devi\u0107","family":"\u010cizmarevi\u0107","sequence":"additional","affiliation":[{"name":"Institute for Medical Biology and Genetics, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aleksandar","family":"\u010cubrani\u0107","sequence":"additional","affiliation":[{"name":"Clinical Institute for Transfusion Medicine, Clinical Hospital Center Rijeka, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"},{"name":"Department of Gastroenterology and Hepatology, Clinical Hospital Center Rijeka, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"18001","DOI":"10.1038\/nrdp.2018.1","article-title":"Rheumatoid Arthritis","volume":"4","author":"Smolen","year":"2018","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2023","DOI":"10.1016\/S0140-6736(16)30173-8","article-title":"Rheumatoid Arthritis","volume":"388","author":"Smolen","year":"2016","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.gene.2019.03.033","article-title":"Genetic Implications in the Pathogenesis of Rheumatoid Arthritis; an Updated Review","volume":"702","author":"Karami","year":"2019","journal-title":"Gene"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3949","DOI":"10.1002\/art.23127","article-title":"Fine Specificity of the Anti-Citrullinated Protein Antibody Response Is Influenced by the Shared Epitope Alleles","volume":"56","author":"Verpoort","year":"2007","journal-title":"Arthritis Rheum."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1222","DOI":"10.1016\/j.jhep.2019.02.014","article-title":"EASL Clinical Practice Guidelines: Drug-Induced Liver Injury","volume":"70","author":"Andrade","year":"2019","journal-title":"J. Hepatol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"11088","DOI":"10.3748\/wjg.v21.i39.11088","article-title":"Genetic Background in Nonalcoholic Fatty Liver Disease: A Comprehensive Review","volume":"21","author":"Macaluso","year":"2015","journal-title":"World J. Gastroenterol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1038\/nrrheum.2016.175","article-title":"Mechanism of Action of Methotrexate in Rheumatoid Arthritis, and the Search for Biomarkers","volume":"12","author":"Brown","year":"2016","journal-title":"Nat. Rev. Rheumatol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"689","DOI":"10.1038\/s41397-018-0047-z","article-title":"Genetic Markers in Methotrexate Treatments","volume":"18","author":"Giletti","year":"2018","journal-title":"Pharmacogenomics J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"559","DOI":"10.2217\/ijr.12.57","article-title":"Prediction of Response and Adverse Events to Methotrexate Treatment in Patients with Rheumatoid Arthritis","volume":"7","author":"Verstappen","year":"2012","journal-title":"Int. J. Clin. Rheumtol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1033","DOI":"10.1080\/14728222.2021.2018418","article-title":"PNPLA3 as a Therapeutic Target for Fatty Liver Disease: The Evidence to Date","volume":"25","author":"Cherubini","year":"2021","journal-title":"Expert Opin. Ther. Targets"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e16704","DOI":"10.1097\/MD.0000000000016704","article-title":"Analysis of Human Leukocyte Antigen Allele Polymorphism in Patients with Non Alcoholic Fatty Liver Disease","volume":"98","author":"Karrar","year":"2019","journal-title":"Medicine"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1124","DOI":"10.1002\/hep4.1529","article-title":"Genome-Wide Association Study of Lean Nonalcoholic Fatty Liver Disease Suggests Human Leukocyte Antigen as a Novel Candidate Locus","volume":"4","author":"Yoshida","year":"2020","journal-title":"Hepatol. Commun."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"11","DOI":"10.21037\/tgh-23-31","article-title":"Genetic and Epigenetic Determinants of Non-Alcoholic Fatty Liver Disease (NAFLD) in Lean Individuals: A Systematic Review","volume":"9","author":"Njei","year":"2024","journal-title":"Transl. Gastroenterol. Hepatol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"e186424","DOI":"10.1172\/JCI186424","article-title":"Human Genetics of Metabolic Dysfunction-Associated Steatotic Liver Disease: From Variants to Cause to Precision Treatment","volume":"135","author":"Chen","year":"2025","journal-title":"J. Clin. Investig."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/cld.605","article-title":"Genetics in Liver Diseases: From Diagnostics to Precise Therapy: Genetics in Liver Diseases","volume":"9","author":"Weber","year":"2017","journal-title":"Clin. Liver Dis."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Meroni, M., Longo, M., Tria, G., and Dongiovanni, P. (2021). Genetics Is of the Essence to Face NAFLD. Biomedicines, 9.","DOI":"10.3390\/biomedicines9101359"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"240S","DOI":"10.1177\/1076029618805863","article-title":"Associations of the SLCO1B1 Polymorphisms with Hepatic Function, Baseline Lipid Levels, and Lipid-Lowering Response to Simvastatin in Patients with Hyperlipidemia","volume":"24","author":"Wu","year":"2018","journal-title":"Clin. Appl. Thromb. Hemost."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1080\/03009742.2020.1818821","article-title":"SLCO1B1 Variants as Predictors of Methotrexate-Related Toxicity in Children with Juvenile Idiopathic Arthritis","volume":"50","author":"Roszkiewicz","year":"2021","journal-title":"Scand. J. Rheumatol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Magadmi, R., Alharthi, A.M., Alqurashi, L.A., Jali, I.M., Sharawi, Z.W., Jamal, M.H., Bawazir, Y., Mustafa, M., BaHLAs, S.M., and Jamal, B.T. (2025). Association of SLCO1B3 and SLCO1B1 Polymorphisms with Methotrexate Efficacy and Toxicity in Saudi Rheumatoid Arthritis Patients. Pharmaceuticals, 18.","DOI":"10.3390\/ph18071069"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"116166","DOI":"10.1016\/j.bcp.2024.116166","article-title":"Impact of Liver Diseases and Pharmacological Interactions on the Transportome Involved in Hepatic Drug Disposition","volume":"228","author":"Marin","year":"2024","journal-title":"Biochem. Pharmacol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1074","DOI":"10.1111\/liv.13362","article-title":"Impaired N-Linked Glycosylation of Uptake and Efflux Transporters in Human Non-Alcoholic Fatty Liver Disease","volume":"37","author":"Clarke","year":"2017","journal-title":"Liver Int."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"803","DOI":"10.1097\/FPC.0b013e3283557c98","article-title":"Intronic Variants in SLCO1B1 Related to Statin-Induced Myopathy Are Associated with the Low-Density Lipoprotein Cholesterol Response to Statins in Chinese Patients with Hyperlipidaemia","volume":"22","author":"Hu","year":"2012","journal-title":"Pharmacogenetics Genom."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1007\/s40272-024-00643-9","article-title":"Methotrexate Intolerance in Juvenile Idiopathic Arthritis: Definition, Risks, and Management","volume":"26","author":"Wibrand","year":"2024","journal-title":"Paediatr. Drugs"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"782","DOI":"10.1002\/cpt.2705","article-title":"PharmVar GeneFocus: SLCO1B1","volume":"113","author":"Ramsey","year":"2023","journal-title":"Clin. Pharmacol. Ther."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Sun, M.-Y., Zhang, L., Shi, S.-L., and Lin, J.-N. (2016). Associations between Methylenetetrahydrofolate Reductase (MTHFR) Polymorphisms and Non-Alcoholic Fatty Liver Disease (NAFLD) Risk: A Meta-Analysis. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0154337"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1016\/j.jhep.2023.02.018","article-title":"Methotrexate-Induced Liver Fibrosis: The End of a Long-Held Belief","volume":"78","year":"2023","journal-title":"J. Hepatol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"589","DOI":"10.1089\/omi.2011.0142","article-title":"Pharmacogenetic Polymorphisms Contributing to Toxicity Induced by Methotrexate in the Southern Spanish Population with Rheumatoid Arthritis","volume":"16","author":"Aguilera","year":"2012","journal-title":"OMICS"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e00467","DOI":"10.1016\/j.heliyon.2017.e00467","article-title":"Association of MTHFR C677T and A1298C Gene Polymorphisms with Methotrexate Efficiency and Toxicity in Algerian Rheumatoid Arthritis Patients","volume":"3","author":"Berkani","year":"2017","journal-title":"Heliyon"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"916","DOI":"10.1002\/cpt.2858","article-title":"Genome-Wide Association Study of Methotrexate-Induced Liver Injury in Rheumatoid Arthritis Patients","volume":"113","author":"Eektimmerman","year":"2023","journal-title":"Clin. Pharmacol. Ther."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"63","DOI":"10.2217\/pgs.12.183","article-title":"Genetic Risk Factors for Drug-Induced Liver Injury in Rheumatoid Arthritis Patients Using Low-Dose Methotrexate","volume":"14","author":"Swen","year":"2013","journal-title":"Pharmacogenomics"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e70287","DOI":"10.1111\/liv.70287","article-title":"Impact of PNPLA3 I148M on Drug-Induced Hepatocellular Liver Injury: A Systematic Review and Meta-Analysis","volume":"45","author":"Gatzios","year":"2025","journal-title":"Liver Int."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Rom\u00e3o, V.C., Canh\u00e3o, H., and Fonseca, J.E. (2013). Old Drugs, Old Problems: Where Do We Stand in Prediction of Rheumatoid Arthritis Responsiveness to Methotrexate and Other Synthetic DMARDs?. BMC Med., 11.","DOI":"10.1186\/1741-7015-11-17"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Gupta, R., Rajpoot, K., Tekade, M., Sharma, M.C., Safavi, M., and Tekade, R.K. (2022). Factors Influencing Drug Toxicity. Pharmacokinetics and Toxicokinetic Considerations, Elsevier.","DOI":"10.1016\/B978-0-323-98367-9.00014-7"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1038\/s41397-024-00326-1","article-title":"A Review of Real-World Evidence on Preemptive Pharmacogenomic Testing for Preventing Adverse Drug Reactions: A Reality for Future Health Care","volume":"24","author":"Chenchula","year":"2024","journal-title":"Pharmacogenomics J."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1002\/cpt.2350","article-title":"An Evidence-Based Framework for Evaluating Pharmacogenomics Knowledge for Personalized Medicine","volume":"110","author":"Huddart","year":"2021","journal-title":"Clin. Pharmacol. Ther."},{"key":"ref_36","first-page":"465","article-title":"Is Pharmacogenetic Panel Testing Applicable to Low-Dose Methotrexate in Rheumatoid Arthritis?\u2014A Case Report","volume":"15","author":"Jeiziner","year":"2022","journal-title":"Pharmacogenomics Pers. Med."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"589","DOI":"10.2217\/pgs-2019-0004","article-title":"Pharmacogenetic Testing in Primary Care Practice: Opinions of Physicians, Pharmacists and Patients","volume":"20","author":"Frigon","year":"2019","journal-title":"Pharmacogenomics"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"464","DOI":"10.1038\/clpt.2010.279","article-title":"CPIC: Clinical Pharmacogenetics Implementation Consortium of the Pharmacogenomics Research Network","volume":"89","author":"Relling","year":"2011","journal-title":"Clin. Pharmacol. Ther."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/4\/1568\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,16]],"date-time":"2026-02-16T11:46:40Z","timestamp":1771242400000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/4\/1568"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,16]]},"references-count":38,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["jcm15041568"],"URL":"https:\/\/doi.org\/10.3390\/jcm15041568","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,16]]}}}