C XU 1, K GOH 1, A ABEYARATNE 1,2, M MORGULLA 1, S MAJONI 1,2,3, K PRIYADARSHANA 1
1Department of Nephrology, Royal Darwin Hospital, Darwin, Australia, 2Menzies School of Health Research, Darwin, Australia, 3Flinders University and Northern Territory Medical Program, Darwin, Australia
Lupus nephritis (LN) is common feature of Systemic Lupus Erythematosus (SLE) and affects 50% of patients with SLE. Racial differences in incidence and prevalence have been well documented worldwide. In Australia, higher incidence and prevalence of SLE had been previously reported in Aboriginal and Torres Strait Islander Australians compared to non-Indigenous Australians. We aimed to describe the differences in clinical features and lupus biomarkers between Aboriginal and Torres Strait Islander Australian and non-Indigenous Australian LN patients in the Top End of Australia. We retrospectively identified all consecutive biopsy-proven LN patients in our institution and compared the clinical features and lupus biomarkers between Aboriginal and Torres Strait Islander Australians and non-indigenous Australians. Of the thirty-three consecutive biopsy proven LN patients, twenty-six self-identified as of Aboriginal and Torres Strait Islander descent. The estimated incidence of lupus nephritis in Aboriginal and Torres Strait Islander Australian and non-Indigenous Australians were 5.08 and 0.47 per 100,000 patient years respectively. Neurological manifestations (23.08% vs 0%), haematological manifestations (46.50 % vs 16.67) and right heart catheter proven pulmonary arterial hypertension (23.08% vs 0%) were more frequently observed amongst Indigenous Australian patients compared to non-Indigenous Australian patients. The incidence of positive Extractable Nuclear Antigen (84.62% vs 57.14%), anti-ribosomal P antibodies (57.69% vs 14.29%), anti-Smith antibodies (34.62% vs 28.57%), anti-RNP antibodies (42.31% vs 28.57%), anti-Ro60 antibodies (61.54% vs 42.86%), anti-cardiolipin antibodies (29.17% vs 0%), anti-b2 glycoprotein antibodies (16.67% vs 0%) were also higher among Indigenous Australian patients. Our study further supports the observation that lupus in Aboriginal and Torres Strait Islander Australians were of a ‘distinct phenotype’ compared to non-Indigenous Australians. Future research should be aimed at delineating the reason for this observed difference.
Chris is a renal trainee who recently completed 1st year training at the Royal Darwin Hospital.