Dr Justin Chua1,2,3, Prof Kevan Polkinghorne1,2,4, Dr Samar Ojaimi2,5, A/Prof Jessica Ryan1,2,3, Prof Richard Kitching1,3,6
1Department of Nephrology, Monash Health, Clayton, Australia, 2Monash University Department of Medicine, Clayton, Australia, 3Monash University Centre for Inflammatory Diseases, Department of Medicine, Clayton, Australia, 4School of Public Health and Preventive Medicine, Monash University, Clayton, Australia, 5Department of Immunology, Monash Health, Clayton, Australia, 6Department of Paediatric Nephrology, Monash Children’s Hospital, Clayton, Australia
Biography:
Dr. Justin Chua is a nephrologist and general medicine physician working at Monash Health and Latrobe Regional Health in Victoria. He is completing a PhD through Monash University and Monash Health titled, Defining the Landscape of ANCA-Associated Vasculitides in Australia to Improve Care, under the supervision of Prof. Richard Kitching. He is a recipient of the NHMRC Postgraduate and Monash Graduate Excellence Scholarships.
Aim:
To assess the relationship between ANCA-associated vasculitis (AAV) and autoimmune/inflammatory diseases in first-degree relatives.
Background:
AAV results from interactions between genetic and environmental factors. While genetic polymorphisms associated with AAV involve loci that impact common pathways associated with immune disease, the prevalence of other immune diseases in relatives of AAV patients is unclear.
Methods:
Patients with AAV (cases) from a tertiary hospital were age- and sex-matched one-to-one with patients with kidney disease (controls) but without autoimmune/inflammatory disease. A family history of autoimmune/inflammatory disease was documented after providing participants with a list of conditions. The primary outcome assessed family history of autoimmune/inflammatory disease in ≥1 first-degree relative (FDR) in cases versus controls using conditional logistic regression, adjusted for participant age and number of FDRs. The secondary outcome assessed the risk of FDRs of cases versus controls having autoimmune/inflammatory disease, using Generalised Estimating Equations to account for multiple FDRs within a family.
Results:
145 AAV cases were matched with 145 controls (mean age 62.4, 62.6 years respectively, both 54.5% female), with similar number of known FDRs (median 6, IQR 4,8). A family history of autoimmune/inflammatory disease was present in 67 cases (46.2%) compared to 24 controls (16.6%). Cases were seven times more likely to have a positive family history (OR 7.25, 95% C.I. 3.27,16.09). FDRs of cases were four times more likely to have an autoimmune/inflammatory disease compared with FDRs of a control (OR 4.05, 95% C.I. 2.48,6.64). The most common types of autoimmune/inflammatory disease in FDRs of cases and controls were musculoskeletal/connective tissue (4.2% vs. 0.8% respectively) and endocrine (3.9% vs. 1.0%).
Conclusion:
There is a shared familial susceptibility between AAV and other immune diseases.