Abstract
Seronegative spondyloarthritis (SpA) comprises a heterogeneous group of rheumatic diseases characterized by axial and peripheral joint involvement, as well as extra-articular manifestations, including uveitis, psoriasis, and inflammatory bowel disease. Although renal involvement in SpA is less understood, evidence suggests it may result from disease activity, chronic inflammation, or therapeutic agents. The underlying pathophysiology remains unclear. This systematic review evaluates the prevalence and risk factors associated with renal abnormalities in SpA. A systematic literature search was conducted following the latest Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data from 26 studies published between 1980 and 2025 were synthesized. Extracted variables included study author, year and location of publication, sample size, renal assessment parameters, prevalence of renal involvement, presence of control groups, and statistical significance of findings. Renal involvement in SpA, assessed through hematuria, proteinuria, estimated glomerular filtration rate, and International Classification of Diseases codes, showed considerable variability, with prevalence ranging from 0.2 to 77.5%. Nephrolithiasis was also more common among SpA patients, with reported rates between 1.6% and 29.1%. Potential risk factors, including age, disease activity, comorbidities, and HLA-B27 status, were explored, though findings remained inconsistent. This review highlights significant methodological discrepancies among studies assessing renal involvement in SpA. Further research is needed to clarify the renal complications associated with SpA and establish reliable risk factors. PROSPERO Registration: CRD42024579791.