Giant cell arteritis (GCA) is a serious autoimmune disease which can causes inflammation of the arteries. GCA affects older people and can cause significant health problems including visual loss. The exact cause of GCA is currently unknown. However, we think that environmental factors, such as infections, may trigger the immune system to behave abnormally, causing damage and inflammation to the blood vessels.
During the COVID-19 pandemic our hospital has seen more cases of GCA than normal. We noticed increased numbers of GCA cases happened when rates of COVID-19 infection were higher. These findings might be evidence that infections such as viruses can activate the immune system in an abnormal way to cause disease.
This study aims to try and find out if COVID-19 infection leads to an increased risk of developing GCA. It also aims to see what the time delay between COVID-19 infection and diagnosis with GCA is. It will also look to see if the COVID-19 vaccine rollout has reduced this risk. This knowledge will help to diagnosis of GCA earlier which will lead to improvements in patient care in the future.
We witnessed an increase in the incidence of GCA during the COVID-19 pandemic, with peaks in incidence rates following peaks in COVID-19 prevalence in the local area (Bath, Somerset). The aim of this study is to investigate if COVID-19 infection has increased the incidence of GCA, and to evaluate the temporal relationship between COVID-19 and onset of GCA.
The study population of interest will be all adults aged 50 or over, which is the at-risk population for developing GCA. Primary exposure will be COVID-19 infection and primary outcome will be the development of a new case of GCA as coded in the CPRD Aurum dataset. The design will be a case cohort study which will allow determination odds ratios and hazard ratios of developing GCA after infection with COVID-19. The effect of the covariates age, gender, smoking status, BMI, vaccination status and comorbidity will also be evaluated. The latency period between COVID-19 infection and GCA diagnosis will be estimated from the data.
This study will provide further evidence for the viral hypothesis of GCA to raise public awareness of the disease and may help in future to develop early warning scores to be able to detect GCA sooner to prevent sequelae such as irreversible visual loss.
Incident cases of GCA; Visual loss
Sarah Skeoch - Chief Investigator - University of Bath
Ben Mulhearn - Corresponding Applicant - University of Bath
Anita McGrogan - Collaborator - University of Bath
Jessica Ellis - Collaborator - University of Bath
John Pauling - Collaborator - University of Bath
Julia Snowball - Collaborator - University of Bath
Neil McHugh - Collaborator - University of Bath
Rachel Charlton - Collaborator - University of Bath
Sarah Tansley - Collaborator - University of Bath