Establishment of a blood concentration detection system for everolimus in recipients after liver transplantation / 器官移植

Objective To establish a detection system of ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for everolimus concentration in whole blood of liver transplant recipients. Methods The proteins of samples were precipitated with methanol and zinc sulfate, and everolimus-D4 was used as the internal standard. Phenomenex Kinetex PFP column was used. The mobile phase A was water (containing 2 mmol/Lammonium formate and 0.1% formic acid), and the mobile phase B was methanol (containing 2 mmol/L ammonium formate and 0.1% formic acid). The gradient elution was performed with the flow rate of 1 mL/min, the column temperature of 50 ℃ and the injection volume of 1 μL. The multi-reaction monitoring mode was used to quantitatively analyze with electrospray positive ionization. The UPLC-MS/MS detection system required only 100 μL of whole blood, and could achieve a sufficient lower limit of quantification without complicated sample preparation. The total running time was within 4.5 min. Linear regression (1/x2) analysis was performed using peak area of everolimus / peak area of everolimus-D4 (y) and concentration of everolimus/concentration of everolimus-D4 (x) to calculate the calibration function and analyze its accuracy and linear relationship. UPLC-MS/MS was used to detect the trough blood concentration of everolimus in blood samples of 5 recipients after liver transplantation. Results The accuracy of quality control was within 15%, and the linear relationship of everolimus was good in the blood concentration range of 1-100 ng /mL(R2 > 0.990). Trough blood concentration of everolimus measured in blood samples of 5 liver transplant recipients ranged from 3.77 to 9.27 ng/mL. Conclusions The detection system of UPLC-MS/MS in this study is suitable for monitoring the concentration of everolimus in whole blood of liver transplant recipients because of its high accuracy, simple sample processing method and short detection time.

Regulatory control of the Na-Cl co-transporter NCC and its therapeutic potential for hypertension

Hypertension is the largest risk factor for cardiovascular disease, the leading cause of mortality worldwide. As blood pressure regulation is influenced by multiple physiological systems, hypertension cannot be attributed to a single identifiable etiology. Three decades of research into Mendelian forms of hypertension implicated alterations in the renal tubular sodium handling, particularly the distal convoluted tubule (DCT)-native, thiazide-sensitive Na-Cl cotransporter (NCC). Altered functions of the NCC have shown to have profound effects on blood pressure regulation as illustrated by the over activation and inactivation of the NCC in Gordon's and Gitelman syndromes respectively. Substantial progress has uncovered multiple factors that affect the expression and activity of the NCC. In particular, NCC activity is controlled by phosphorylation/dephosphorylation, and NCC expression is facilitated by glycosylation and negatively regulated by ubiquitination. Studies have even found parvalbumin to be an unexpected regulator of the NCC. In recent years, there have been considerable advances in our understanding of NCC control mechanisms, particularly

Etiology of graft dysfunction in renal transplant recipients

Background: Kidney transplantation is the preferred mode of renal replacement therapy for the endstage renal disease, with dramatic improvements in patient and graft survival over the last 50 years. In the modern era of immunosuppression, 1-year patient survival is close to 98%, and 1-year allograft survival rates have improved to 90% for deceased donor kidney transplants and 95 % for living donor kidney transplants with some inter-center variability. The aim of the study: To elucidate the etiology of graft dysfunction among renal transplant recipients. Materials and methods: A retrospective study was conducted among 155 patients who underwent both cadavers and live donor transplant from October 2009 to March 2011 at a tertiary care center in Chennai, South India. All the transplant recipients were regularly followed with serum urea and creatinine, urine routine, calcineurin inhibitor drug levels in the serum, USG Abdomen, urine culture depending on the graft status. Graft dysfunction defined by a rise in the creatinine more than 25% or 0.3 to 0.5 mg per dl from the baseline. Those who developed graft dysfunction were presented for graft biopsy and managed based on the report accordingly. S. Thirumavalavan, Krishna Kumar, S. A. K. Noor Mohamed, R Vijaya Kumar. Etiology of graft dysfunction in renal transplant recipients. IAIM, 2019; 6(3): 313-318. Page 314 Results: Among the 155 transplant recipient patients, 66 (44%) patients developed graft dysfunction and underwent renal biopsy. The graft dysfunction was due to chronic allograft dysfunction (interstitial fibrosis and tubular atrophy) in 24 (15.4%) patients, acute cellular rejection in 13 (8.4%) patients, acute antibody-mediated rejection in 2 (1.3%) patients, acute tubular necrosis in 9 (5.8%) patients, calcineurin toxicity in 6 (3.9%) patients, thrombotic microangiopathy in 6 (3.9%) patients, IgA nephropathy in 3 (1.9%) patients and transplant renal artery stenosis in 1(0.6%) patient. Conclusion: Among the various causes, acute cellular, acute antibody rejection and chronic allograft nephropathy holds nearly 25% of the incidence of graft dysfunction. It indicates appropriate immunological evaluation, appropriate immunosuppression, use of induction agents in high-risk patients and protocol renal biopsy to identify early rejection in high-risk patient and appropriate early intervention is important to improve long-term term graft and patient survival.

Conversion from Tacrolimus to cyclosporine A in renal transplantation recipients with NODAT / 中华内分泌外科杂志

Objective To discuss the efficiency and safety of conversion from tacrolimus(Tac)to cyclosporine A(CsA) in patients with new onset diabetes after transplantation (NODAT).Methods The glucose metabolism parameters and related clinical indicators in 45 Tac treated renal transplantation recipients who developed NODAT were retrospectively analyzed.The oral immunosuppressive strategy was Tac + mycophenolate mofetil (MMF) + prednisone(Pred).Results 32 cases were converted to CsA whereas 13 patients stuck to Tac.After conversion,fasting plasma glucose (FPG)decreased from(8.2 ± 2.7)mmol/L to(5.9 ± 1.2)mmol/L(P ＜ 0.01)and HbA1c level decreased from (7.0 ± 0.9) ％ to (6.1 ± 0.7) ％ (P ＜ 0.05).The level of FPG and HbA1c was lower in the conversion group than in the control group(P ＜ 0.05).During the 1-year follow-up,the curative rate of NODAT was 53.1％ (17/32) in the conversion group while it was 0％ in the control group.No acute rejection happened after the conversion.There was no obvious change in renal function.The 1-year survival rate of patient and the transplanted kidney was 100％.Blood pressure and lipid levels were stable after the conversion.Conclusion Conversion from Tac to CsA is a simple and effective strategy to improve glucose metabolism in renal transplantation recipients with NODAT.

A single-center retrospective study on calcineurin inhibitors withdraw and conversion to sirolimus for drug adverse reactions / 中华器官移植杂志

Objective To report the results of a single-center, retrospective study on the effect of calcineurin inhibitors (CNI) withdraw for controlling infections and conversion to sirolimus (SRL)for ameliorating renal dysfunction. Methods A total of 947 liver transplant cases from 2002 to 2010were divided into two eras (Jan. 2002 to Dec. 2007 and Jan. 2008 to Dec. 2010). There were 234cases of infections after liver transplantation (LT) in the first era and 101 cases in the second era. And of 329 cases of CNI-related renal dysfunction after LT in two eras, 40 cases (converting group) had converted CNI to SRL, while 289 cases (reducing group) adopted protocol of CNI reducing and mycophenolate mofetil (MMF) raising. Results CNI-based IS took up 95.8 %, 95. 3 %, 97. 5 % of the IS protocols with recipient survival time longer than 1, 3, and 5 years. The primary cause for CNI withdraw was infection (88. 2 %, 15/17) in the second era, and renal dysfunction for conversion to SRL in the two eras (83. 3 %, 40/48). In the second era, 14. 9% (15/101) of the cases of infections after LT experienced CNI withdraw. Of the 15 patients, 11 had effectively controlled the infection (77. 3 %) while rejection rate was 6. 7 % (1/15). The cumulative survival rate of the second era was significantly higher than the first era (P＜0. 05). The glomerular filtration rate (GFR) of converting group at 6th week and 6th month was statistically elevated as compared with that before conversion,respectively (1.28 ± 0. 31, 1.36 ± 0. 32 mL/s vs. 0. 82 ± 0. 24 mL/s, P＜0. 05). Six months after CNI adjustments, survival rate of converting group and reducing group was 85. 0% and 83. 7 %,respectively (P＞0. 05). Conclusion Reducing or even short-term withdraw of CNI may allow the better control of infections after LT, and the conversion from CNI to SRL can ameliorate the CNIrelated nephrotoxicity. These individually tailored IS protocols will benefit the long term survival for LT.