Vitamin D deficiency is associated with increased risk of bacterial infections after kidney transplantation

BACKGROUND/AIMS: There may be an association between vitamin D levels and allograft outcomes in kidney transplant recipients (KTRs). However, few studies have been conducted to determine the association between vitamin D levels and post-transplant infections. This study investigated the impact of vitamin D deficiency on the risk of infection after kidney transplantation. METHODS: We measured 25-hydroxyvitamin D (25(OH)D) levels prior to kidney transplantation. Vitamin D deficiency was defined as a serum 25(OH)D level < 20 ng/mL. We examined the incidence of various post-transplant infections during follow-up period. We used Cox proportional hazards regression analysis to determine factors associated with increased risk of post-transplant infections during the follow-up period. RESULTS: A total of 164 KTRs were followed up for a mean of 24.8 ± 10.7 months. Among them, 135 patients (82.3%) had vitamin D deficiency. Patients with vitamin D deficiency had a significantly higher incidence of urinary tract infection (p = 0.027) and any bacterial infection (p = 0.010) compared to those without vitamin D deficiency. Vitamin D deficiency was not significantly associated with incidence of viral or fungal infections. Cox proportional hazards regression analysis revealed that vitamin D deficiency (hazard ratio, 11.07; 95% confidence interval, 1.46 to 84.03; p = 0.020) was independent risk factor for post-transplant bacterial infections. CONCLUSIONS: Pre-transplant vitamin D deficiency was a significant risk factor for bacterial infections after kidney transplantation. Further studies are needed on possible benefits of vitamin D supplementation for preventing post-transplant bacterial infection.

Vitamin D deficiency is associated with increased risk of bacterial infections after kidney transplantation

BACKGROUND/AIMS: There may be an association between vitamin D levels and allograft outcomes in kidney transplant recipients (KTRs). However, few studies have been conducted to determine the association between vitamin D levels and post-transplant infections. This study investigated the impact of vitamin D deficiency on the risk of infection after kidney transplantation. METHODS: We measured 25-hydroxyvitamin D (25(OH)D) levels prior to kidney transplantation. Vitamin D deficiency was defined as a serum 25(OH)D level < 20 ng/mL. We examined the incidence of various post-transplant infections during follow-up period. We used Cox proportional hazards regression analysis to determine factors associated with increased risk of post-transplant infections during the follow-up period. RESULTS: A total of 164 KTRs were followed up for a mean of 24.8 ± 10.7 months. Among them, 135 patients (82.3%) had vitamin D deficiency. Patients with vitamin D deficiency had a significantly higher incidence of urinary tract infection (p = 0.027) and any bacterial infection (p = 0.010) compared to those without vitamin D deficiency. Vitamin D deficiency was not significantly associated with incidence of viral or fungal infections. Cox proportional hazards regression analysis revealed that vitamin D deficiency (hazard ratio, 11.07; 95% confidence interval, 1.46 to 84.03; p = 0.020) was independent risk factor for post-transplant bacterial infections. CONCLUSIONS: Pre-transplant vitamin D deficiency was a significant risk factor for bacterial infections after kidney transplantation. Further studies are needed on possible benefits of vitamin D supplementation for preventing post-transplant bacterial infection.

Central Transposition of the Cephalic Vein in Patients with Brachiocephalic Arteriovenous Fistula and Cephalic Arch Stenosis

PURPOSE: Our study aims to evaluate to evaluate clinical outcomes after cephalic vein transposition (CVT) to the axilla in patients with brachiocephalic arteriovenous fistula (BC-AVF) and cephalic arch stenosis (CAS). MATERIALS AND METHODS: Hospital records of 13 patients (median age, 61 years; males, 54%) who received CVT to the proximal basilic/axillary vein due to either dysfunction (n=2) or thrombosis (n=11) between January 2010 and February 2014 were retrospectively reviewed. RESULTS: Operation was performed under local anesthesia in all cases. There was no technical failure. Concomitant inflow procedure (banding or aneurysmorrhaphy) was performed in 5 patients (38%). During follow-up (1 to 50 months, median 17 months), 3 patients died with functioning AVF and one was successfully transplanted. Two patients suffered from recurrent symptomatic stenosis of AVF and received percutaneous balloon angioplasty. Another 2 patients experienced AVF occlusion treated with interposition graft and manual fragmentation. Overall primary, assisted primary, and secondary patency rates were 77.5%, 92.3%, and 100% at 6 months and 66.1%, 92.3%, and 100% at 1 year, respectively. CONCLUSION: Although most patients presented with BC-AVF occlusion, technical success and access patency rates after CVT were favorable compared with historical data for interventional treatment. CVT should be considered as an appropriate option in selected patients with CAS.

Effect of High-Dose Intravenous N-acetylcysteine on the Concentration of Plasma Sulfur-Containing Amino Acids

BACKGROUND: The purpose of this study was to determine the adequate loading and maintenance doses of N-acetylcyseteine (NAC) for patients suffering from acute ROS-induced injury. METHODS: Concentrations of extra cellular NAC, cysteine (Cys), cystine (Cyst2), and methionine (Met) were measured in vitro, at which more than 50% of the intracellular ROS raised by paraquat were suppressed using Swiss 3T3 fibroblasts. An in vivo pharmacokinetic study followed on a healthy subject to determine the proper loading and maintenance doses of reduced NAC following intravenous administration of 25 mg/kg NAC. RESULTS: In vivo, NAC suppressed ROS in a dose dependant manner. 10 mM of NAC suppressed about 50% of ROS, and was comparable to 10 micro M of Cys and Met and 400 micro M of Cys2. In vitro, the elimination of half-life was achieved at 2.88+/-1.14 h for NAC and at 3.68+/-1.84 h for total NAC. The body clearances were 1.23+/-0.77 L h (-1) kg (-1) and 0.56+/-0.27 L h (-1) kg (-1) and the volumes of distribution were 3.07+/-0.10 L kg (-1) and 3.00+/-0.11 L kg (-1), respectively. The loading and maintenance NAC doses used to reach the target concentration of 10 mM, were 5010 mg. kg (-1) and 2250 mg min (-1) kg (-1), respectively. CONCLUSION: NAC provides an antioxidant effect on ROS produced by paraquat in vivo. However, in vitro, our results showed that the intravenous NAC dose could not be estimated from NAC plasma concentration or its metabolites.