Determination of tacrolimus in human whole blood in kidney transplant recipients using a rapid and specific LC-MS/MS method.

OBJECTIVE: To develop and validate an LC-M/SMS method for the determination of tacrolimus in human whole blood. METHOD: The LC-MS/MS method for the determination of tacrolimus in whole blood was developed and validated according to the guidelines. Concentrations of TAC in 100 kidney transplant patients measured by LC-MS/MS were compared with CMIA using correlation analysis and Bland-Altman plots. RESULTS: The method had a total chromatographic run time of 5 min. The calibration curves were linear over the range of 0.5-100.0 ng/mL with a lower limit of quantification of 1 ng/mL. The intra- and interday accuracy was within the range of 93.3%-109.2% and 96.0%-108.4%, respectively, with precision ranging from 0.8 to 9.4%. The mean extraction recoveries of TAC ranged from 102.6 to 107.8%. The mean concentrations of TAC in whole blood of kidney transplant patients measured by the two assays were different at 1, 3 months and all time points (p < 0.001), but no significant difference was observed at 6 months (p = 0.094). The correlation of data was good with the correlation coefficients (r2 ) of 0.7581, 0.8811, 0.8777, and 0.8077, respectively. Passing-Bablok regression analysis demonstrated good correlations with r2 values higher than 0.88 between TAC levels measured by LC-MS/MS and CMIA. Using Bland-Altman plots yielded average biases of 1.29, 0.79, 0.11, and 0.65 ng/mL at 1, 3, and 6 months and all time points. CONCLUSION: The LC-MS/MS method was validated for the accurate determination of TAC in human whole blood. The comparison of tacrolimus concentrations measured by the LC-MS/MS with CMIA showed a good correlation and agreement of two methods, suggesting LC-MS/MS should be used routinely to monitor TAC concentrations in kidney transplant patients.

Serum total iron-binding capacity and iron status in patients with non-dialysis-dependent chronic kidney disease: A cross-sectional study in Vietnam.

BACKGROUND AND OBJECTIVES: We performed this study to evaluate serum iron and ferritin concentrations, serum total iron-binding capacity (TIBC), and proportion of overall iron deficiency among patients with non-dialysisdependent chronic kidney disease (ND-CKD). METHODS AND STUDY DESIGN: A hospital-based cross-sectional observational study was conducted on 175 adult patients with stage 3-5 chronic kidney disease (CKD) by using 51 healthy age-sex-matched Vietnamese adults as the control group. We next examined the prevalence of anemia and determined the serum iron and ferritin concentrations and TIBC. Anemia in CKD was defined as hemoglobin levels <13 g/dL in men and <12 g/dL in women. Transferrin saturation (TSAT, %) was calculated as (serum iron x 100)/TIBC. Functional iron deficiency was defined as serum ferritin >100 ng/mL and TSAT <20%, and absolute iron deficiency was defined as serum ferritin <100 ng/mL and TSAT <20%. Overall iron deficiency was defined as the presence of either absolute or functional iron deficiency. RESULTS: Anemia prevalence in our study was approximately 88.6% with a mean hemoglobin concentration of 9.71±2.26 g/dL. The median serum TIBC was lower in the CKD group (50.4 µmol/L) than in the control group (66.0 µmol/L; p<0.001). The proportion of overall iron deficiency was 44.0%. TIBC had a diagnostic value for overall iron deficiency (area under the ROC curve=0.81; p<0.001). CONCLUSIONS: Anemia and iron deficiency are common in Vietnamese patients with NDCKD. TIBC had diagnostic value for overall iron deficiency.

Neutrophil: Lymphocyte and Platelet: Lymphocyte ratios measured before transplantation and their correlation with new-onset diabetes post-transplantation in renal transplant recipients.

PURPOSE: Our goal was to evaluate the neutrophil:lymphocyte (NLR) and platelet:lymphocyte (PLR) ratios measured before transplantation and their correlation with new-onset diabetes after transplantation (NODAT) in renal transplant recipients. PATIENTS AND METHODS: We conducted our study in 324 adult patients consecutively admitted to Military Hospital 103, Ha Noi, Viet Nam, who received kidney allografts from living donors. These patients were followed-up during the first 2 years post-transplantation for NODAT. We examined the association between NLR and PLR measured prior to transplantation in patients with NODAT: NLR and PLR were calculated based on the results of the complete blood count. The criteria for diagnosis of a fully symptomatic NODAT case were based on the guidelines established by the American Diabetes Association and included fasting venous blood glucose and glycosylated hemoglobin A1c (HbA1c) levels, with or without an oral glucose tolerance test. RESULTS: The overall rate of NODAT during the two years after kidney transplantation was 13.6%. We found mean values of age and body mass index (BMI), and median values of NLR, PLR, high sensitivity C-reactive protein (hs-CRP) levels, and the arteriosclerosis ratio in the NODAT group to be significantly higher than those of the non-NODAT group (all p < 0.05). Furthermore, an adjusted multivariate regression analysis showed that age (area under the curve [AUC] = 0.727, p < 0.001), BMI (AUC = 0.846, p < 0.001), serum hs-CRP levels (AUC = 0.884, p < 0.001), NLR (AUC = 0.888; p < 0.001), and PLR (AUC = 0.818; p < 0.001) had predictive value for NODAT. CONCLUSION: NLR and PLR measured before transplantation were good predictors for NODAT in the first 2 years post-renal transplantation.

Genomic Mutations of BK Polyomavirus in Patients after Kidney Transplantation: A Cross-Sectional Study in Vietnam.

OBJECTIVES: The purpose of this study was to identify the SNP sites and determine the BKV genotype circulating in kidney-transplant Vietnamese recipients based on the VP1 gene region. METHODS: 344 samples were collected from post-kidney-transplant recipients at the 103 Vietnam Military Hospital to investigate the number of BKV infections. Positive samples with a sufficient virus concentration were analyzed by nested PCR in the VP1 region, sequencing detected genotyping and single-nucleotide polymorphism. RESULTS: BKV infection was determined in 214 patients (62.2%), of whom 11 (5.1%) were diagnosed with BKV-associated nephropathy. Among the 90 BKV-I strains sequenced, 89 (98.88%) were strains of I/b-1 and 1 (1.12%) was strain I/b-2. The 60 BKV-IV strains had a greater diversity of subgroups, including 40% IV/a-1, 1.66% IV/a-2, 56.68% IV/c-1, and 1.16% IV/c-2. Additionally, of 11 cases diagnosed with BKVN, seven belonged to subgroup I/b-1 (63.6%) and four to subgroup IV/c-1 (36.4%). Moreover, 22 specific SNPs that were genotype I or IV were determined in this Vietnamese population. Specifically, at position 1745, for the Vietnamese BKV-IV strains, the SNP position (A→G) appeared in 57/60 samples (95%). This causes transformation of the amino acid N→S. This SNP site can enable detection of genotype IV in Vietnam. It represents a unique evolution pattern and mutation that has not been found in other international strains. CONCLUSION: The BKV-I genotype was more common than BKV-IV; however, mutations that occur on the VP1 typing region of BKV-IV strains were more frequent than in BKV-I strains.

Frequencies and Association of CYP3A5 Polymorphism With Tacrolimus Concentration Among Renal Transplant Recipients in Vietnam.

BACKGROUND: This study aims to investigate the frequencies and association of CYP3A5 polymorphism with tacrolimus concentration among renal transplant recipients in Vietnam. METHODS: Sixty-eight kidney transplant recipients were included in this study from the department of nephrology and dialysis, Military Hospital 103. Blood samples were collected for monitoring of tacrolimus levels and determination of CYP3A5 genetic polymorphism. RESULTS: A total of 68 patients studied. The CYP3A5*3*3, CYP3A5*1*3, and CYP3A5*1*1 genotypes were detected in 48 (70.6%), 16 (23.5%), and 4 (5.9%), respectively. Tacrolimus concentrations were much lower in CYP3A5 expressors than in CYP3A5 nonexpressors on the first day, month 1, 3, 6, and 12 (5.98 ± 1.05 vs 6.57 ± 1.03, P = .03; 5.79 ± 1.13 vs 6.82 ± 1.05, P < .001; 4.76 ± 1.48 vs 6.73 ± 1.09, P < .001; 4.29 ± 1.64 vs 6.46 ± 1.23, P < .001; 4.20 ± 1.36 vs 6.04 ± 1.26, P < .001), respectively. Notably, the concentration/dose ratio in the CYP3A5 expressors was lower than in CYP3A5 nonexpressors at time points of follow up (P < .001). However, there were no significant differences in the age, sex, HLA mismatch, type of donors, acute rejection, and creatinine levels at time points between group of CYP3A5 expressors and those of CYP3A5 nonexpressors. CONCLUSION: In conclusion, this research indicated the significant association of CYP3A5 genetic polymorphism with daily dose and tacrolimus concentrations in renal transplant recipients. This study provided a closer step to individualize the dose of tacrolimus in renal transplant patients in Vietnam.

Stepwise Reduction of Mycophenolate Mofetil with Conversion to Everolimus for the Treatment of Active BKV in Kidney Transplant Recipients: A Single-Center Experience in Vietnam.

Background: No specific antiviral drug can effectively treat BKV reactivation after kidney transplantation. Thus, we evaluated stepwise-reduced immunosuppression to treat BKV reactivation. Methods: 341 kidney-transplant recipients were monitored for BKV infection (BKV-viremia, BKV-viruria). Positive samples with a significant virus load were nested PCR-genotyped in the VP1 region. In 97/211 patients presenting BKV viremia ≥104 copies/mL and/or BKV viruria ≥107 copies/mL, or BKV-nephropathy immunosuppression (i.e., mycophenolate mofetil [MMF]) was reduced by 50%. If viral load did not decrease within 28 days, MMF dose was further reduced by 25%, although calcineurin-inhibitor (CNI) therapy remained unchanged. If BKV viral load did not decrease within another 28 days, MMF was withdrawn and replaced by everolimus combined with reduced CNIs. Results: Only 41/97 BKV (+) cases completed the 6-month follow-up. Among these, 29 (71%) were in the BKV-I group and 12 (29%) were in BKV-IV. BKV viruria and BKV viremia were significantly decreased from 9.32 to 6.09 log10 copies/mL, and from 3.59 to 2.45 log10 copies/mL (p < 0.001 and p = 0.024, respectively). 11/32 (34.4%) patients were cleared of BKV viremia; 2/32 (6.3%) patients were cleared of BKV in both serum and urine, and 9/9 (100%) only had BKV viruria but did not develop BKV viremia. eGFR remained stable. No patient with BKV-related nephropathy had graft loss. There was a significant inverse relationship between changes in eGFR and serum BKV load (r = −0.314, p = 0.04). Conclusions: This stepwise immunosuppressive strategy proved effective at reducing BKV viral load in kidney transplant recipients that had high BKV loads in serum and/or urine. Renal function remained stable without rejection.

Long Hemodialysis Duration Predicts Delayed Graft Function in Renal Transplant Recipients From Living Donor: A Single-Center Study.

BACKGROUND: This study aims to determine the ratio of delayed graft function in renal transplant recipients from living donors and the predictive value of hemodialysis time before transplant for delayed graft function. METHODS: We conducted a study on 116 adult patients who were diagnosed with end-stage kidney disease and were treated with hemodialysis and transplanted kidneys from living donors for 2 years (from June 2018 to June 2020). Delayed graft function event was collected for each patient. RESULTS: The recipients had a median age of 36.5 years old, in which 55.2% of them were men, 4.3% of them had the diabetic mellitus, and the median hemodialysis duration was 6 months. The ratio of positive panel-reactive antibody was 33.6% and vascular reconstruction of the donor's kidney was 16.4%. The ratio of delayed graft function was 12.2% (14 of 116 patients). Delayed graft function significantly related to positive panel-reactive antibody, long duration of hemodialysis before transplant, and vascular reconstruction of donor's kidney with P < .001. Duration of hemodialysis before kidney transplant had a predictive value for delayed graft function (area under the curve, 0.83; P < .001). CONCLUSION: Delayed graft function was not rare in renal transplant recipients from living donors. Duration of hemodialysis before kidney transplant was a good predictor for delayed graft function.

Interleukin 6 is a better predictor of 5-year cardiovascular mortality than high-sensitivity C-reactive protein in hemodialysis patients using reused low-flux dialyzers.

PURPOSE: In this study, we focused on the role of elevated serum interleukin 6 (IL-6) concentration in predicting 5-year cardiovascular mortality in hemodialysis patients using low-flux dialyzer reuse. MATERIALS AND METHODS: We measured serum IL-6 concentrations in 236 hemodialysis patients (138 males and 98 females) to predict 5-year cardiovascular mortality. We assessed the baseline demographics of all patients who had a mean age of 44 years and a median hemodialysis duration of 38.5 months. We divided all patients into two equal groups based on the serum IL-6 concentration: G1 (n = 118) with serum IL-6 concentration < 6.78 pg/L and G2 (n = 118) with serum IL-6 concentration ≥ 6.78 pg/L. RESULTS: After the 5-year follow-up, 45 patients died due to cardiovascular causes (19.1%). Lipid disorder, hemoglobin, serum albumin, ß2-M, and IL-6 concentration were independent risk factors for predicting cardiovascular mortality during the 60-month follow-up in hemodialysis patients. Based on the Kaplan-Meier analysis, we realized that patients with a higher interleukin 6 concentration (G2) had a significantly higher cardiovascular mortality rate than patients in G1 (log-rank test p < 0.001). Serum IL-6 concentration was a better predictor of 5-year cardiovascular mortality than high-sensitivity C-reactive protein in hemodialysis patients using low-flux dialyzer reuse (AUC = 0.818; p < 0.001; cut-off value: 8.055 pg/mL, Se = 77.8%, Sp = 78.5%). CONCLUSION: Serum IL-6 concentration was a better predictor of 5-year cardiovascular mortality than high-sensitivity C-reactive protein in maintenance hemodialysis patients using low-flux dialysis reuse.

Correction to: Interleukin 6 is a better predictor of 5-year cardiovascular mortality than high-sensitivity C-reactive protein in hemodialysis patients using reused low-flux dialyzers.

The article "Interleukin 6 is a better predictor of 5-year cardiovascular mortality than high-sensitivity C-reactive protein in hemodialysis patients using reused low-fux dialyzers".

Measuring serum beta2-microglobulin to predict long-term mortality in hemodialysis patients using low-flux dialyzer reuse.

PURPOSE: Beta2-microglobulin (ß2-M) is recognized as a surrogate marker relating to the mechanisms of dialysis-associated amyloidosis. Few studies have evaluated the association of serum ß2-M with clinical outcome in hemodialysis patients using high-flux type. However, study on patients using low-flux dialyzer reuse has not been done yet. PATIENTS AND METHODS: Using serum ß2-M level on predicting long-term mortality of hemodialysis patients was examined in 326 prevalent hemodialysis patients (45.59±14.46 years, hemodialysis duration of 47.5 (26-79) months, 186 males and 140 females). The patients were divided into 3 groups with equal number of patients, according to their serum ß2-M levels: group A (n=109, serum ß2-M concentration ≤55.7 mg/L), group B (n=109, serum ß2-M level from 55.8 mg/L to 75.4 mg/L) and group C (n=108, serum ß2-M concentration >75.4 mg/L). RESULTS: During the follow-up period of 5 years, there were 75 all-cause deaths (23.0%). Kaplan-Meier analysis revealed that all-cause mortality in the higher ß2-M group was significantly higher compared to that in the lower ß2-M groups (p<0.001). Serum ß2-M level was a significant predictor for all-cause mortality (AUC =0.898; p<0.001; Cut-off value: 74.9 mg/L, Se=93.3%, Sp=92.9%). CONCLUSION: Serum ß2-M levels were a significant predictor of long-term mortality in hemodialysis patients, who use only low-flux dialyzers and reuse 6 times.