Helio Tedesco Silva Junior

Determination of sirolimus blood concentration using high-performance liquid chromatography with ultraviolet detection.

Background: Different HPLC methods have been developed and used to determined sirolimus blood concentrations. These methods show different performance characteristics, mostly related to peak interference, recovery, assay sensitivity, and turnaround times. Objective: We adapted, improved, and validated an HPLC method with UV detection for measurement of sirolimus in whole blood clinical samples. Methods: The standards, quality controls, or patient samples (0.25 or 0.5 mL) and internal standard (desmethoxysirolimus) were extracted with 1‐chlorobutane. After evaporation, the extract was reconstituted in a 70% acetonitrile/water mixture and analyzed onto a reverse‐phase C18 column at 50°C under a flow rate of 1.0 mL/min in the HPLC system. Ultraviolet detection was performed at 278 nm, with sensitivity setting of 0.010 AUFS. Identification of peaks of interest was by retention time; quantification of sirolimus was based on a peak area ratio. Results: Analytic recovery ranging from 96 to 120% (CV = 3.7 to 16.8%; bias = −4.2 to 16.7%) was observed throughout the assays linear range (2.5‐150.0 ng/mL). The lower limit of quantification for both sample volumes (0.25 or 0.5 mL) was 2.5 ng/mL (CV = 12 and 15%, bias = −1.2 and 4%, respectively). The intra‐and interassay imprecision ranged from 6.2 to 14.4% and from 9.1 to 18.6%, with bias ranging from 1.3 to 12.9% and −1.8% to 7.1, for quality control levels of 3, 10, and 20 ng/mL. Whole blood and extracted samples are stable at room temperature and at 4 and −20°C for 1 week and 3 days, respectively. Chromatograms showed good separation free of interfering peaks. A set of 45 samples can be extracted in 2 h, allowing results within 24 h. Conclusion: This HPLC‐UV method shows good and reproducible performance, satisfying all requirements of an assay designated to be applied in therapeutic drug monitoring strategies after organ transplantation.

Mortality Predictors in Renal Transplant Recipients with Severe Sepsis and Septic Shock

Introduction The growing number of renal transplant recipients in a sustained immunosuppressive state is a factor that can contribute to increased incidence of sepsis. However, relatively little is known about sepsis in this population. The aim of this single-center study was to evaluate the factors associated with hospital mortality in renal transplant patients admitted to the intensive care unit (ICU) with severe sepsis and septic shock. Methods Patient demographics and transplant-related and ICU stay data were retrospectively collected. Multiple logistic regression was conducted to identify the independent risk factors associated with hospital mortality. Results A total of 190 patients were enrolled, 64.2% of whom received kidneys from deceased donors. The mean patient age was 51±13 years (males, 115 [60.5%]), and the median APACHE II was 20 (16–23). The majority of patients developed sepsis late after the renal transplantation (2.1 [0.6–2.3] years). The lung was the most common infection site (59.5%). Upon ICU admission, 16.4% of the patients had ≤1 systemic inflammatory response syndrome criteria. Among the patients, 61.5% presented with ≥2 organ failures at admission, and 27.9% experienced septic shock within the first 24 hours of ICU admission. The overall hospital mortality rate was 38.4%. In the multivariate analysis, the independent determinants of hospital mortality were male gender (OR = 5.9; 95% CI, 1.7–19.6; p = 0.004), delta SOFA 24 h (OR = 1.7; 95% CI, 1.2–2.3; p = 0.001), mechanical ventilation (OR = 30; 95% CI, 8.8–102.2; p<0.0001), hematologic dysfunction (OR = 6.8; 95% CI, 2.0–22.6; p = 0.002), admission from the ward (OR = 3.4; 95% CI, 1.2–9.7; p = 0.02) and acute kidney injury stage 3 (OR = 5.7; 95% CI,1.9–16.6; p = 0.002). Conclusions Hospital mortality in renal transplant patients with severe sepsis and septic shock was associated with male gender, admission from the wards, worse SOFA scores on the first day and the presence of hematologic dysfunction, mechanical ventilation or advanced graft dysfunction.

Influence of deceased donor hemodynamic factors in transplant recipients renal function

INTRODUCTION The incidence of delayed graft function (DGF) and unsatisfactory creatinine clearance (UCC) after renal transplantation is significantly higher in Brazil, when compared with that observed in United States or Europe. Deceased donor (DD) characteristics should directly influence the occurrence of these two outcomes. OBJECTIVE This study aim to evaluate the influence of DD characteristics on DGF and UCC incidence in Brazil. METHODS DD clinical and laboratory variables were correlated with outcomes incidence. RESULTS We evaluated 787 DD whose organs were transplanted in 1298 patients. We noted a high prevalence of vasoactive drugs use (90.2%), hypernatremia (66.6%) and renal dysfunction (34.8%). The incidence of DGF and UCC was 60.6% and 55.2%, respectively. We observed a progressive increase in DGF risk for age groups over 30 years and for cold ischemia time (CIT) greater than 24 hours. DGF risk was two times higher in recipients of donor kidney final serum creatinine (Cr) over than 1.5 mg/dl. Hypertension and CIT over 36 hours was associated with an increasing of 82% and 99% in UCC risk, respectively. Donor age above 40 years was associated with a progressive increase in UCC risk. CONCLUSION DD age, renal function, hypertension and prolonged CIT were associated with increased risk DGF and UCC.

A Randomized Trial Comparing Dual Axis Rotational Versus Conventional Coronary Angiography in a Population with a High Prevalence of Coronary Artery Disease

OBJECTIVES To compare the safety, radiation dose, and contrast volume between dual axis rotational coronary angiography (DARCA) and conventional coronary angiography (CCA). BACKGROUND CCA is performed in multiple, predefined stationary views, at different angulations around the patient, for both the left and right coronary arteries. DARCA (AlluraXperSwing™, Philips, the Netherlands) involves a pre-set rotation of the C-arm around the patient and allows for the visualization of each coronary artery in different views, using a single automatic pump contrast injection. METHODS From November 2012 to February 2013, 201 patients were randomly assigned to either CCA (n = 100) or DARCA (n = 101). Exclusion criteria included acute coronary syndrome (ACS), prior PCI or CABG. CCAs were performed in 4 acquisition runs for the left coronary artery and 2 to 3 acquisition runs for the right coronary artery, whereas DARCAs were performed in a single run for each coronary artery. RESULTS Baseline demographics and clinical characteristics were similar for both groups. The overall prevalence of CAD was 77.6%. The DARCA group had a significant reduction in the amount of contrast, 60 ml (IQR: 52.5-71.5 ml) versus 76 ml (IQR: 68-87 ml), P < 0.0001; and radiation dose by Air Kerma, 269.5 mGy (IQR: 176-450.5) versus 542.1 mGy (IQR: 370.7-720.8), P < 0.0001. There were fewer patients requiring additional projections in the DARCA group: 54.0% versus 75.0%; P = 0.002. CONCLUSIONS In a population with a high prevalence of CAD, DARCA was safe and resulted in a significant decrease in contrast volume and radiation dose.

Escore de avaliação de risco pré-transplante: metodologia e a importância das características socioeconômicas

INTRODUCTION Kidney transplantation is performed in emergency conditions in a population with high perioperative risk. Instruments for risk assessment before transplantation in this population are scarce. OBJECTIVE To develop a score with pretransplant variables to estimate the probability of success of kidney transplantation, defined as survival of the recipient and the graft with creatinine < 1.5 mg/dl at 6 months. METHODS Analysis of variables of patients from a unique kidney transplantation center in São Paulo. Logistic regression was used to construct an equation with variables able to estimate the probability of success. Integer points were assigned to variables for score construction. RESULTS Of the 305 patients analyzed, 176 (57.7%) achieved success. Of the 23 variables identified by univariate analysis, 21 were included in the logistic regression model and 10 that remained independently associated with success, were used in the score. Four of these 10 variables were socioeconomic. It was great (area under the ROC curve 0.817) the power of discrimination between groups success and not success and adequate (Hosmer and Lemeshow = 0.672) the agreement between frequencies of the probabilities estimated by equation and frequencies of probabilities actual observed. There were correlation (0.982) between the estimated probability via the scoring system and the estimated probabilities via logistic regression. CONCLUSION Point score simplified risk stratification of transplant candidate according to their probability of success. Socioeconomic variables influence the success, demonstrating the need for creation of prognostic tools utilizing clinical and demographic variables of our population.

Evolução clínica pós-stent coronariano em pacientes submetidos a transplante de rim

OBJECTIVE: To assess the clinical outcome of renal transplant patients who developed coronary artery disease and were treated with coronary stenting (TCA-ST). METHODS: A total of 3,334 renal transplants were performed in our service - Hospital do Rim e Hipertensao - HRH (Kidney and Hypertension Hospital) from July, 1998 to November, 2004. During this period, 33 of the renal transplant patients underwent TCA-ST to treat 62 severe stenoses in 54 coronary arteries. A retrospective analysis was performed with renal transplant patients undergoing TCA-ST at HRH. The clinical events were registered using medical charts, medical visits and phone calls. RESULTS: During the 30-month clinical follow-up after TCA-ST, 67% of the patients remained asymptomatic, 18% presented stable angina, 6% presented acute coronary syndrome without ST-segment elevation (ACSWSTE), and 3% presented acute coronary syndrome with ST-segment elevation (ACSSTE). No strokes, CHF or cardiac deaths were observed. Three non-cardiac deaths occurred. A restenosis rate of 9% was observed, which is comparable to those found in studies on drug-eluting stents. CONCLUSION: In conclusion, renal transplant patients who developed CAD and were treated with coronary stenting had a low rate of in-stent restenosis, probably related to the immunosuppressive regimen given to prevent kidney rejection.

Sirolimus quantification by high-performance liquid chromatography with ultraviolet detection

The need to adapt optimal conditions of sirolimus blood level monitoring in laboratories led us to optimize an high‐performance liquid chromatography–ultraviolet method and compare the elution performances using the mobile phase A, 68% MeOH/2% acetonitrile (ACN)/30% H2O and mobile phase B, 30% MeOH/42% ACN/28% H2O. Samples were assayed with 1‐chlorobutane, redissolved in MeOH/water and injected onto a C‐18 column at 50 °C. The assay achieved sensitivity of 2.5–150 ng/ml (CV = 10.6%) and recovery of 92–103.6%. The intra‐ and interassay precisions ranged from 3.3% to 13% and from 5.9% to 15% for quality controls of 7.5, 60 and 120 ng/ml. The mobile phase A was unable to elute and recover sirolimus and internal standard in the expected retention time and concentration. Under our working conditions, the assay was precise, accurate and sensible, stressing the importance of establishing for the best working conditions according to the staff and demands of the laboratory.

Terapia de indução com alentuzumabe em receptores de transplante renal

INTRODUCAO: Terapias de inducao sao usualmente utilizadas em receptores sensibilizados contra antigenos HLA, retransplantes e pacientes com risco de apresentar funcao tardia do enxerto (FTE). METODO: Estudo retrospectivo com objetivo de avaliar os desfechos do transplante renal com doador falecido em pacientes que receberam inducao com alentuzumabe (n = 9). Os pacientes do grupo controle, pareados conforme idade do receptor, tempo em dialise e tempo de isquemia fria, receberam timoglobulina (n = 18). RESULTADOS: Nao houve diferenca nas caracteristicas demograficas [...]

Use of Thymoglobulin® (antithymocyte immunoglobulin) in renal transplantation: practical guide

The combination of immunosuppressive drugs is part of the treatment regimen of patients undergoing kidney transplantation (RT). Thymoglobulin®, a rabbit immunoglobulin directed against human thymocytes, is the most commonly agent used for induction therapy in RT in the US. In Brazil, Thymoglobulin® is approved by ANVISA for the use in patients who underwent kidney transplantation and despite being widely used, there are controversies regarding the drug administration. We prepared a systematic review of the literature, evaluating studies that used Thymoglobulin® for induction and for acute rejection treatment in patients undergoing RT. The review used the computadorized databases of EMBASE, LILACS and MedLine. Data were extracted from the studies concerning general features, methodological characteristics and variables analyzed in each study. From the results, a practical guide was prepared analyzing various aspects on the use of Thymoglobulin® in patients submitted to RT.

Long-term outcomes of elderly kidney transplant recipients

INTRODUCTION The number of elderly patients with chronic kidney disease increases progressively, challenging the allocation algorithms in a scenario of organ shortage for transplantation. OBJECTIVE To evaluate the impact of age on patient and graft survival. METHODS Evolution of all 366 patients greater than 60 years transplanted between 1998 and 2010 was analyzed versus a control group of 366 younger patients matched for gender, type of donor (living or deceased) and year of transplantation. RESULTS Diabetes mellitus (HR 1.8; IC 1.2-2.6; p = 0,003) and prioritization (HR 2.9; IC 1.2-2.6; p < 0,001), but not age, were independent factors for kidney graft loss. CONCLUSION Advanced age was not related to negative outcomes after kidney transplantation, after excluding recipient death as a cause of allograft loss. Higher mortality rate in this group was associated to a higher frequency of comorbidities, especially diabetes mellitus.