Outcomes of kidney transplantation in patients with hepatitis B virus infection:A systematic review and meta-analysis

AIM To assess outcomes of kidney transplantation including patient and allograft outcomes in recipients with hepatitis B virus(HBV) infection, and the trends of patient's outcomes overtime.METHODS A literature search was conducted using MEDLINE, EMBASE and Cochrane Database from inception through October 2017. Studies that reported odds ratios(OR) of mortality or renal allograft failure after kidney transplantation in patients with HBV [defined as hepatitis B surface antigen(HBs Ag) positive] were included. The comparison group consisted of HBs Agnegative kidney transplant recipients. Effect estimates from the individual study were extracted and combined using random-effect, generic inverse variance method of Der Simonian and Laird. The protocol for this metaanalysis is registered with PROSPERO(International Prospective Register of Systematic Reviews; no. CRD42017080657).RESULTS Ten observational studies with a total of 87623 kidney transplant patients were enrolled. Compared to HBs Ag-negative recipients, HBs Ag-positive status was significantly associated with increased risk of mortality after kidney transplantation(pooled OR = 2.48; 95%CI: 1.61-3.83). Meta-regression showed significant negative correlations between mortality risk after kidney transplantation in HBs Ag-positive recipients and year of study(slopes =-0.062, P = 0.001). HBs Agpositive status was also associated with increased risk of renal allograft failure with pooled OR of 1.46(95%CI: 1.08-1.96). There was also a significant negative correlation between year of study and risk of allograft failure(slopes =-0.018, P = 0.002). These associations existed in overall analysis as well as in limited cohort of hepatitis C virus-negative patients. We found no publication bias as assessed by the funnel plots and Egger's regression asymmetry test with P = 0.18 and 0.13 for the risks of mortality and allograft failure after kidney transplantation in HBs Ag-positive recipients, respectively.CONCLUSION Among kidney transplant patients, there are significant associations between HBs Ag-positive status and poor outcomes including mortality and allograft failure. However, there are potential improvements in patient and graft survivals in HBs Ag-positive recipients overtime.

Liver transplantation and atrial fibrillation:A meta-analysis

AIM To assess prevalence of pre-existing atrial fibrillation(AF) and/or incidence of AF following liver transplantation, and the trends of patient's outcomes overtime; to evaluate impact of pre-existing AF and post-operative AF on patient outcomes following liver transplantation. METHODS A literature search was conducted utilizing MEDLINE, EMBASE and Cochrane Database from inception throughMarch 2018. We included studies that reported:(1) prevalence of pre-existing AF or incidence of AF following liver transplantation; or(2) outcomes of liver transplant recipients with AF. Effect estimates from the individual study were extracted and combined utilizing randomeffect, generic inverse variance method of DerSimonian and Laird. The protocol for this meta-analysis is registered with PROSPERO(International Prospective Register of Systematic Reviews, No. CRD42018093644). RESULTS Twelve observational studies with a total of 38586 liver transplant patients were enrolled. Overall, the pooled estimated prevalence of pre-existing AF in patients undergoing liver transplantation was 5.4%(95%CI: 4.9%-5.9%) and pooled estimated incidence of AF following liver transplantation was 8.5%(95%CI: 5.2%-13.6%). Meta-regression analyses were performed and showed no significant correlations between year of study and either prevalence of pre-existing AF(P = 0.08) or post-operative AF after liver transplantation(P = 0.54). The pooled OR of mortality among liver transplant recipients with pre-existing AF was 2.34(2 studies; 95%CI: 1.10-5.00). In addition, pre-existing AF is associated with postoperative cardiovascular complications among liver transplant recipients(3 studies; OR: 5.15, 95%CI: 2.67-9.92, I2 = 64%). With limited studies, two studies suggested significant association between new-onset AF and poor clinical outcomes including mortality, cerebrovascular events, post-transplant acute kidney injury, and increased risk of graft failure among liver transplant recipients(P < 0.05).CONCLUSION The overall estimated prevalence of pre-existing AF and incidence of AF following liver transplantation are 5.4% and 8.5%, respectively. Incidence of AF following liver transplant does not seem to decrease overtime. Preexisting AF and new-onset AF are potentially associated with poor clinical outcomes post liver transplantation.

Proton pump inhibitors and adverse effects in kidney transplant recipients: A meta-analysis

BACKGROUND The adverse renal effects of proton pump inhibitors (PPIs) are increasingly recognized in both the general population and patients with chronic kidney disease. Several pharmacokinetic studies have also raised concerns regarding the interaction between PPIs and immunosuppressive drugs in transplant patients. Whether the adverse effects of PPIs have a clinical significance in kidney transplant recipients remains unclear. We performed this meta-analysis to assess the risk of adverse effects in kidney transplant recipients on PPI compared with those without PPI exposure. AIM To investigate the risk of acute rejection, graft loss, hypomagnesemia, renal dysfunction, and overall mortality in kidney transplant recipients on PPI compared with those without PPI exposure. METHODS A systematic review was conducted in MEDLINE, EMBASE, and Cochrane databases from inception through October 2018 to identify studies that evaluated the adverse effects of PPIs in kidney transplant recipients, including biopsyproven acute rejection, graft loss, hypomagnesemia, renal function, and overall mortality. Effect estimates from the individual studies were extracted and combined using random-effect, generic inverse variance method of DerSimonian and Laird. The protocol for this meta-analysis is registered with PROSPERO, No. CRD42018115676. RESULTS Fourteen observational studies with 6786 kidney transplant recipients were enrolled. No significant association was found between PPI exposure and the risk of biopsy-proven acute rejection at ≥ 1 year [pooled odds ratio (OR), 1.25;95% confidence interval (CI), 0.82-1.91, I2 = 55%], graft loss at 1 year (pooled OR = 1.30, 95%CI: 0.75-2.24, I2 = 0%) or 1-year mortality (pooled OR = 1.53, 95%CI: 0.90-2.58, I2 = 34%). However, PPI exposure was significantly associated with hypomagnesemia (pooled OR = 1.56, 95%CI: 1.19-2.05, I2 = 27%). Funnel plots and Egger regression asymmetry test were performed and showed no publication bias. CONCLUSION PPI use was not associated with significant risks of higher acute rejection, graft loss, or 1-year mortality. However, the risk of hypomagnesemia was significantly increased with PPI use. Thus, future studies are needed to assess the impact of PPIs on long-term outcomes.