Clinical,laboratory, and radiological characteristics of patients with late-onset spondylarthritis

IntroductionSpondylarthritis (SpA) is a chronic inflammatory disease that rarely began after 50 years of age. Aim of the work: To investigate the clinical, laboratory, and radiological characteristics of late-onset SpA (LOSpA) and compare them to early-onset (EOSpA). Patients and methods: A single-center cross-sectional study included 117 SpA patients and those with their initial symptoms starting after the age of 50 years were considered late-onset. Results: There were 102 patients (87.2%) with EOSpA and 15 (12.8%) with LOSpA. The mean age at onset for the EOSpA and LOSpA groups was 28.6 ± 9.1 and 54.5 ± 2.9 respectively. Female sex and presence of comorbidities were more associated with older age at onset (p = 0.03 and p = 0.008, respectively). Delay in diagnosis was shorter in the LOSpA group (p = 0.05), and they had less alternating buttock pain and hip involvement at onset of the disease (p = 0.005 and p < 0.001, respectively). Patients with EOSpA had more axial forms (p = 0.03). Uveitis, inflammatory bowel diseases (IBD), and human leucocyte antigen B27 (HLA-B27) positivity were significantly more common in the LOSpA group (p = 0.04; p = 0.05 and p = 0.04, respectively). There was no significant difference between the two groups in the laboratory investigations, anthropometric measures, and disease indices. Radiological findings were also comparable. Multiple logistic regression analysis revealed that only axial forms and HLA-B27 positivity were independently associated with the age of the disease onset. Conclusion: The late onset of the disease is more frequent in females with HLA-B27. The LOSpA patients had a shorter delay in diagnosis, more comorbidities, uveitis, and IBD.