Introduction: Early diagnosis, monitoring of disease activity, prediction of treatment response, and structural outcome remain major challenges in spondyloarthritis (SpA). Biomarkers could play a role in addressing these challenges, but in SpA there is a lack of suitable biomarkers.Areas covered: As SpA is clinically and pathophysiologically closely related to psoriasis and inflammatory bowel disease (IBD), we reviewed in literature, the value of serum biomarkers in these conditions with the aim to find potential candidates for assessing SpA.Expert commentary: Candidates of interest were antimicrobial peptides, including serum human beta defensin-2 (hBD-2) and lipocalin-2 (LCN-2), and class-1 MHC molecule beta2-microglobulin. Since these biomarkers are relevant in psoriasis and/or IBD from a pathophysiological point of view, and may play a role in the pathogenesis of SpA, we recommend further exploration of their value as biomarker in the diagnosis and prognosis of SpA.