GENETIC INSIGHTS INTO GIANT CELL ARTERITIS: A CASE REPORT WITH NARRATIVE REVIEW

Abstract

Giant Cell Arteritis (GCA) is the most common primary vasculitis affecting medium- and large-sized arteries in individuals over 50 years of age. It is a medical emergency, as delayed diagnosis and treatment may result in irreversible complications, particularly permanent vision loss. Although the diagnosis of Giant Cell arteritis is primarily based on clinical evaluation supported by laboratory and imaging findings, recent advances have highlighted the contribution of genetic susceptibility to disease pathogenesis. Variants within the HLA region, particularly HLA-DRB1, together with several non-HLA genes involved in immune regulation and inflammatory pathways, have been associated with an increased risk of GCA and may influence disease severity and therapeutic response. We report the case of a 68-year-old male who presented with persistent bilateral temporal headache, intermittent fever, and markedly elevated inflammatory markers. Colour doppler ultrasonography and magnetic resonance vessel wall imaging demonstrated characteristic inflammatory changes involving the superficial temporal arteries confirming the diagnosis of Giant Cell Arteritis. The patient showed marked clinical improvement following prompt initiation of high-dose corticosteroid therapy. This case is presented alongside a narrative review of the current literature on the genetic basis of GCA, emphasizing established and emerging susceptibility loci, their role in disease pathogenesis, and their evolving clinical significance. While genetic testing is not yet routinely incorporated into clinical practice, ongoing advances in genomics have improved our understanding of disease mechanisms and may contribute to the future risk stratification, biomarker discovery and personalized therapeutic strategies. This article highlights the importance of maintaining a high index of suspicion for GCA in older adults presenting with persistent headache and systemic inflammatory changes while illustrating the growing role of genetics in understanding and managing this complex vasculitis.