Association of immigration background with kidney graft function in a publicly funded health system: a nationwide retrospective cohort study in Italy

The impact of immigration background on kidney graft function (eGFR) is unknown. Italy has a publicly funded health system with universal coverage. Since immigration from non-European Union (EU) countries beyond Eastern Europe is a recent and extensive phenomenon, Italy is a rather unique setting for studying the effect of immigration status as a socioeconomic and cultural condition. We retrospectively identified all adult deceased donor kidney transplant recipients (KTRs) in Italy (2010–2015) and followed them until death, dialysis or 5-years post-transplantation; 6346 were EU-born, 161 Eastern European-born, and 490 non-European-born. We examined changes in eGFR after 1-year post-transplant using multivariable-adjusted joint longitudinal survival random-intercept Cox regression. Compared to EU-born KTRs, in non-European-born KTRs the adjusted average yearly eGFR decline was −0.96 ml/min/year (95% confidence interval: −1.48 to −0.45; P < 0.001), whereas it was similar in Eastern European-born KTRs [+0.02 ml/min/year (−0.77 to +0.81; P = 0.96)]. Adjusted 5-year transplant survival did not statistically differ between non-European-born, Eastern European-born, and EU-born. In those surviving beyond 1-year, it was 91.8% in EU-born (87.1–96.8), 92.5% in Eastern European-born (86.1–99.4), and 89.3% in non-European-born KTRs (83.0–96.0). This study provides evidence that among EU KTRs, non-European immigration background is associated with eGFR decline.