Higher human T-cell leukaemia virus type 1 (HTLV-1) proviral load is associated with end-stage kidney disease in Indigenous Australians: Results of a case-control study in central Australia

Case series suggest that human T-cell leukaemia virus type 1 (HTLV-1) is associated with kidney disease; however, little is known about the impact of proviral load (PVL). The present study was commenced to determine whether higher HTLV-1 PVL is associated with end stage kidney disease (ESKD) in Indigenous Australians. A case-control study was conducted in Alice Springs Hospital (ASH), 1 July 2007 to 30 November 2015. Cases included all 80 Indigenous adults (>17 years) with HTLV-1c and ESKD, matched 1:1 by sex to controls with HTLV-1 who had no renal disease or other recognised disease associations of HTLV-1, and were recruited during the same period. The association between PVL and ESKD was assessed using logistic regression. Median (IQR) HTLV-1c PVL for subjects with ESKD (6.86, IQR (3.35, 8.23) log copies per 10⁵ peripheral blood leukocytes (PBL) (ie, 0.95; IQR, 0.03; 3.70% PBL) was significantly higher than that of the asymptomatic group (3.47; IQR (−0.04, 6.61) log copies per 10 ⁵ PBL (ie, 0.01; IQR, 0.00; 0.52% PBL) (asymptomatic vs ESKD, P (ranksum) <.001). Major factors associated with ESKD were diabetes (adjusted odds ratio [aOR], 21.80; 95% CI, 4.84, 98.22; P <.001), hypertension (aOR, 4.16; 1.11, 15.64; P =.03), remote residence (aOR, 5.34; 95% CI, 1.17, 27.29; P =.03) and HTLV-1c PVL greater than or equal to 100 copies per 10 ⁵ PBL (aOR, 3.67; 95% CI, 1.36, 9.92; P =.01). Higher HTLV-1c PVL are strongly associated with inflammatory diseases. The high HTLV-1c PVL reported here may have clinical implications for people with HTLV-1 who require haemodialysis. Longitudinal studies are required to determine whether this association is causal.