Ivanka Marinović1,2, Esma Čečuk-Jeličić3,4, Dijana Perković5,6, Daniela Marasović Krstulović5,6, Jure Aljinović7,4, Daniela Šošo7, Ela Škorić7, Dušanka Martinović Kaliterna5,6. 1. Department of Physical Medicine and Rehabilitation with Rheumatology, University Hospital of Split, Spinčićeva 1, 21000, Split, Croatia. imarinovic27@gmail.com. 2. Department of Health Studies, University of Split, Ruđera Boškovića 35, 21000, Split, Croatia. imarinovic27@gmail.com. 3. Department of Blood Transfusion Tissue Typing Laboratory, University Hospital of Split, Spinčićeva 1, 21000, Split, Croatia. 4. Department of Health Studies, University of Split, Ruđera Boškovića 35, 21000, Split, Croatia. 5. Department of Rheumatology and Clinical Immunology, University Hospital of Split, Spinčićeva 1, 21000, Split, Croatia. 6. University of Split School of Medicine, Šoltanska 2, 21000, Split, Croatia. 7. Department of Physical Medicine and Rehabilitation with Rheumatology, University Hospital of Split, Spinčićeva 1, 21000, Split, Croatia.
Abstract
OBJECTIVE: The aim of this study was to investigate the distribution of HLA-DRB1 alleles in patients with rheumatoid arthritis (RA) in the Sinj Region (SR) and the rest of the Split-Dalmatia County (SDC) in Croatia and to determine their relationship with disease severity. METHODS: A total of 74 RA patients and 80 healthy controls from the SR, and 74 RA patients and 80 healthy controls from the rest of the SDC were genotyped using sequence-specific oligonucleotide primed PCR. High-resolution typing of HLA-DRB1*04 alleles was performed using the single specific primed polymerase chain reaction (PCR-SSP) method. Serum anti-CCP, rheumatoid factor, C‑reactive protein, and erythrocyte sedimentation rate were measured in all RA patients, whereas disease activity was assessed by DAS-28 and functional status by the Health Assessment Questionnaire Disability Index. RESULTS: The HLA-DRB1*04 allele was more frequent in patients with RA from the SR than that in patients from the rest of the SDC (18.2% vs. 9.5%; P = 0.014), whereas the HLA-DRB1*15 allele was more frequent in patients with RA from the rest of the SDC than in patients from the SR (16.2% vs. 7.4%; P = 0.010). Shared epitope (SE) positive patients from the SR had significantly higher serum anti-CCP and RF antibody levels (P = 0.014 and P = 0.004, respectively), higher disease activity (P = 0.043), and worse functional status (P < 0.001), than SE-positive patients from the rest of the SDC. CONCLUSION: The observed higher incidence of more severe forms of RA in the SR in comparison to the rest of the SDC might be associated with the higher incidence of HLA-DRB1*04 allele in the SR.
OBJECTIVE: The aim of this study was to investigate the distribution of HLA-DRB1 alleles in patients with rheumatoid arthritis (RA) in the Sinj Region (SR) and the rest of the Split-Dalmatia County (SDC) in Croatia and to determine their relationship with disease severity. METHODS: A total of 74 RA patients and 80 healthy controls from the SR, and 74 RA patients and 80 healthy controls from the rest of the SDC were genotyped using sequence-specific oligonucleotide primed PCR. High-resolution typing of HLA-DRB1*04 alleles was performed using the single specific primed polymerase chain reaction (PCR-SSP) method. Serum anti-CCP, rheumatoid factor, C‑reactive protein, and erythrocyte sedimentation rate were measured in all RA patients, whereas disease activity was assessed by DAS-28 and functional status by the Health Assessment Questionnaire Disability Index. RESULTS: The HLA-DRB1*04 allele was more frequent in patients with RA from the SR than that in patients from the rest of the SDC (18.2% vs. 9.5%; P = 0.014), whereas the HLA-DRB1*15 allele was more frequent in patients with RA from the rest of the SDC than in patients from the SR (16.2% vs. 7.4%; P = 0.010). Shared epitope (SE) positive patients from the SR had significantly higher serum anti-CCP and RF antibody levels (P = 0.014 and P = 0.004, respectively), higher disease activity (P = 0.043), and worse functional status (P < 0.001), than SE-positive patients from the rest of the SDC. CONCLUSION: The observed higher incidence of more severe forms of RA in the SR in comparison to the rest of the SDC might be associated with the higher incidence of HLA-DRB1*04 allele in the SR.