Prevention, Diagnosis, Evaluation, and Treatment of Hepatitis C in Chronic Kidney Disease: Synopsis of the Kidney Disease: Improving Global Outcomes 2022 Clinical Practice Guideline

Mendelian Randomization Analysis of Systemic Iron Status and Risk of Different Types of Kidney Disease

With rapid increases in incidence, diverse subtypes, and complicated etiologies, kidney disease remains a global public health problem. Iron, as an essential trace element, has pleiotropic effects on renal function and the progression of kidney diseases. A two-sample Mendelian randomization (MR) analysis was implemented to determine the potential causal effects between systemic iron status on different kidney diseases. Systemic iron status was represented by four iron-related biomarkers: serum iron, ferritin, transferrin saturation (TfSat), and total iron binding capacity (TIBC). For systemic iron status, 163,511, 246,139, 131,471, and 135,430 individuals were included in the genome-wide association study (GWAS) of serum iron, ferritin, TfSat, and TIBC, respectively. For kidney diseases, 653,143 individuals (15,658 cases and 637,485 controls), 657,076 individuals (8160 cases and 648,916 controls), and 659,320 individuals (10,404 cases and 648,916 controls) were included for immunoglobulin A nephropathy (IgAN), acute kidney disease (AKD), and chronic kidney disease (CKD), respectively. Our MR results showed that increased serum iron [odds ratio (OR): 1.10; 95% confidence interval (95% CI): 1.04, 1.16; p < 0.0042], ferritin (OR: 1.30; 95% CI: 1.14, 1.48; p < 0.0042), and TfSat (OR: 1.07; 95% CI: 1.04, 1.11; p < 0.0042)] and decreased TIBC (OR: 0.92; 95% CI: 0.88, 0.97; p < 0.0042) were associated with elevated IgAN risk. However, no significant associations were found between systemic iron status and AKD or CKD. In our MR study, the genetic evidence supports elevated systemic iron status as a causal effect on IgAN, which suggests a potential protective effect of iron chelation on IgAN patients.

The impact of hepatitis B and C positive serologies on the outcomes of non-hepatic solid organ transplantation in the United States

Chronic viral hepatitis B (HBV) and C (HCV) infection could negatively affect outcomes of non-hepatic solid organ transplantations due to the risk of viral reactivation in the presence of immunosuppression. This study aimed to determine post-transplant outcomes in patients with HBV or HCV positivity receiving non-hepatic solid-state organ transplant. Data was collected from the Scientific Registry of Transplant Recipients (SRTR) 2006-2021 for patients (≥18) who received a lung, heart, or kidney single organ transplant in the U.S. Hepatitis C positivity (HCV+) was determined as positive HCV Ab and hepatitis B positivity (HBV+) as positive HBsAg. We included N = 30,872 lung, N = 36,990 heart and N = 280,162 kidney transplant recipients. The prevalence of HBV+ was 1.3% in lung, 1.5% in heart and 1.7% in kidney patients, HCV+ was 2.2%, 2.2% and 5.0%, respectively. Post-transplant survival of patients with vs. without HBV+ was similar in all solid organ transplants (all p > .05). Similarly, there was no difference in post-transplant survival between lung transplant recipients with vs. without anti-HCV (all p > .05). Heart transplant recipients with HCV+ had higher crude post-transplant mortality (all p < .01). Similarly, there was higher post-transplant mortality in kidney transplant recipients with HCV+ (1-year: 6% vs. 3%; 5-year: 21% vs. 13%; 10-year: 47% vs. 31%; all p < .0001). In multivariate analysis controlling for confounders, only the association of HCV+ with higher post-kidney transplant mortality remained significant: adjusted hazard ratio (aHR) (95% CI) = 1.16 (1.12-1.20), p < .0001. There was no association of viral hepatitis seropositivity with the risk of graft failure in all groups (p > .05). In most cases, the presence of HBV or HCV serologies is not associated with adverse post-transplant outcomes in non-hepatic solid organ transplants. However, kidney transplant recipients who are positive for HCV serology have an increased risk for post-transplant mortality.