Elena González

Trough tacrolimus concentrations in the first week after kidney transplantation are related to acute rejection.

There is evidence showing the importance of reaching immunosuppressant target concentrations as soon as possible. The aim of this study was to evaluate the relationship between tacrolimus trough concentrations within the first week after transplantation and the rate of acute rejection. In this descriptive-analytic study, we included 57 renal transplant patients receiving tacrolimus as the primary immunosuppressive drug. After univariate analysis, donor age, duration of hospital stay, and creatinine clearance (third month) showed significant differences between rejecters and nonrejecters. In addition, mean tacrolimus trough concentrations on day 5, day 7, mean of days 1-7, and mean of days 5-7 were found to be significantly lower in rejecters (P = 0.009, P = 0.012, P = 0.006, and P = 0.035, respectively). Receiver operating characteristic curve analysis with tacrolimus trough concentrations measured on days 5 and 7 was able to discriminate between patients with and without acute rejection (P = 0.028 and P = 0.048 after Bonferroni correction). The tacrolimus trough concentration with the best sensitivity-specificity balance was 9.3 ng/mL on day 5 and 8.7 ng/mL on day 7. In the Kaplan-Meier analysis, patients with tacrolimus trough concentrations below 9.3 mg/mL on day 5 showed a lower survival time without acute rejection (P = 0.048 after correction) in comparison with patients with tacrolimus trough concentrations above this concentration. After logistic regression, we obtained a model relating rejection with sex, donor age, and tacrolimus trough concentrations on day 5 (P = 0.004). No significant relationship between tacrolimus trough concentrations and delta creatinine clearance from week 1 to month 3 was obtained. These results confirm that tacrolimus trough concentrations during the first week are an important predictor of acute rejection. Therefore, it is critical to reach target blood concentrations of tacrolimus as soon as possible to improve allograft survival.

Ultrasonography in kidney transplantation: values and new developments

Renal transplant is performed on patients with end-stage renal disease. Gray-scale renal sonography combined with color Doppler has become the main noninvasive imaging method for evaluating a kidney transplant, as it provides information about the kidney anatomy and its vascular flow. In this article, we discuss the utility of sonography in renal transplants and describe the ultrasound findings in early and chronic graft pathology. Also, we explain new developments in ultrasound imaging with contrast media and its utility in renal transplantation, proposing that contrast-enhanced sonography be incorporated as a method to evaluate graft status because of its capability to evaluate cortical capillary blood flow.

Association between a common KCNJ11 polymorphism (rs5219) and new-onset posttransplant diabetes in patients treated with Tacrolimus.

KCNJ11 polymorphisms have been linked to the risk of developing type 2 diabetes. Our aim was to define the contribution of KCNJ11 to new-onset diabetes after transplantation (NODAT) among patients treated with Tacrolimus (Tac). A total of 115 NODAT and 205 non-NODAT were genotyped for rs5219 (p.E23K). AA+AG genotypes were significantly associated with NODAT-risk (p=0.004; OR=2.10). The reported effect of this KCNJ11 polymorphism on insulin release by beta cells could explain this association.

Higher daily peritoneal protein clearance when initiating peritoneal dialysis is independently associated with peripheral arterial disease (PAD): A possible new marker of systemic endothelial dysfunction?

BACKGROUNDnPatients starting peritoneal dialysis (PD) with active cardiovascular disease (CVD) show higher protein and albumin levels in peritoneal effluent. Peripheral arterial disease (PAD) is increasingly recognized as an entity particularly associated with higher mortality.nnnMETHODSnTo explore whether higher daily peritoneal protein clearance (PrC) on starting PD is a cardiovascular risk marker, we have formulated the hypothesis that PAD, as an expression of the highest CVD grade, is specifically related to the amount of PrC.nnnRESULTSnThe average of 24-h effluent peritoneal protein losses (PPL) was 6.88 +/- 3.31 g. The median of PrC was 94.43 ml/day and quartiles 1 and 4 were delimited by 56.25 and 114.18 ml/day, respectively. A significant positive correlation between PrC and peritoneal small solute transport was detected. Patients in the highest quintile of Cr-MTAC (>14.04 ml/min) demonstrated significantly greater PrC than the remainder. An inverse significant correlation with plasma albumin levels was also demonstrated (r = -0.52, P = 0.0001). Eighteen patients with PAD showed significantly higher PrC than patients with no PAD (130.62 +/- 74.89 versus 88.77 +/- 47.56 ml/day; P = 0.033). Other CVDs were not significantly associated with greater PrC. In the univariable logistic regression analysis, PAD was directly and significantly related to PrC, Charlsons index, gender, diabetes and age. Multivariable analysis confirmed that PAD was significantly related to PrC, independent of age (RR: 1.07, IC: 1.02-1.12, P = 0.006) and diabetes (RR: 11.29, IC: 2.9-42.60, P = 0.000).nnnCONCLUSIONnOur study shows that daily peritoneal PrC on initiating PD is significantly and independently related to the presence of PAD. Peritoneal PrC appears to be a possible new marker of systemic endothelial dysfunction.

Reacciones de hipersensibilidad a membranas sintéticas de hemodiálisis

Undergoing a haemodialysis (HD) session poses a certain risk of hypersensitivity adverse reactions as large quantities of blood are in contact with various synthetic materials. Hypersensitivity reactions to ethylene oxide and non-biocompatible membranes, such as cuprophane, have been described in HD. Cases of hypersensitivity with biocompatible membranes, such as polysulfone, and even polysulfone-polyvinylpyrrolidone, have also been reported. In this article we describe six cases of mostly early-stage hypersensitivity reactions to HD occurring in our department, characterised by malaise, desaturation, bronchospasm and arterial hypotension, with good response to the session’s temporary suspension and with reappearance in subsequent sessions that used a synthetic dialyser. No hypersensitivity reactions reappeared in successive observations when the sessions were carried out using a cellulose membrane.

Análisis repetido de la resistencia insulínica estimada mediante índice HOMAIR en pacientes no diabéticos en diálisis peritoneal y su relación con la enfermedad cardiovascular y mortalidad

Terminal chronic renal failure patients show early insulin resistance (IR), characterised by alterations in the hydrocarbon metabolism and hyperinsulinaemia generally associated with dyslipidaemia and a proinflammatory condition. Cardiovascular disease (CVD) is the main cause of mortality in patients on dialysis. There is a strong association between IR, hyperinsulinism and CV disease. The objective of this study was to evaluate the effect of peritoneal dialysis (PD) on IR and its effects on the subsequent CVD morbidity and mortality in nondiabetic uraemic patients. It involved 69 nondiabetic patients on PD, 35 incident patients (≤ 3 months on PD) and 34 prevalent patients (>3 months on PD), with 2 estimated insulin resistance measurements 12 months apart using the insulin resistance index (HOMAIR). The mean HOMAIR value in incident patients was 1.8 ± 1.3 and 2.2 ± 2.1 at baseline situation and at 12 months respectively (not significant [NS]). In prevalent patients these values were 2.3 ± 1.3 and 2.5 ± 2.2 (NS). In our study, the mean glucose, insulin and IR concentrations measured by the HOMAIR and QUICKI indexes (the latter being a quantitative control for insulin sensitivity control) were similar at baseline situation and the following year, in both incident and prevalent patients. We did not find any significant differences in relation to CVD comorbidity, ischaemic heart disease, heart failure or cerebrovascular or peripheral comorbidity neither in the HOMAIR index or insulin levels. To conclude, nondiabetic patients on PD do not display a significant increase in HOMAIR levels and this remains the case over time when on dialysis. This, in turn, suggests that PD is not an IR risk factor. The fact that the IR indexes are not associated with CVD morbidity or mortality seems to suggest that this is a less significant factor in the field of PD.

Valores de cistatina C sérica en recién nacidos pretérmino en nuestro medio. Relación con valores de creatinina sérica y patologías de la prematuridad

Background nCystatin C (CysC) is a renal function marker that is not as influenced as creatinine (Cr) by endogenous or exogenous agents, so it is therefore proposed as a marker in preterm infants.BACKGROUNDnCystatin C (CysC) is a renal function marker that is not as influenced as creatinine (Cr) by endogenous or exogenous agents, so it is therefore proposed as a marker in preterm infants.nnnOBJECTIVESnTo determine serum CysC values in preterm infants during the first week of life, compared to Cr. To analyze alterations caused by prematurity diseases.nnnMETHODnThe design involved a longitudinal, observational study of prospective cohorts. Groups were based on gestational age (GA): Group A (24-27 weeks), Group B (28-33 weeks), Group C (34-36 weeks). Blood samples were collected at birth, within 48-72hours and after 7 days of life.nnnSTATISTICSnSPSS v.20 software was used. The statistical methods applied included chi-squared test and ANOVA.nnnRESULTSnA total of 109 preterm infants were included in the study. CysC levels were: 1.54mg/L (±0.28) at birth; 1.38mg/L (±0.36) within 48-72hours of life; 1.50mg/L (±0.31) after 7 days (p<0.05). Cr levels were: 0.64mg/dL (±0.17) at birth; 0.64mg/dL (±0.28) within 48-72hours; 0.56mg/dL (±0.19) after 7 days (P<.05). CysC values were lower in hypotensive patients and those with a respiratory disease (P<.05), and no alterations associated with other diseases were observed. There were no differences in Cr levels associated with any disease. Creatinine levels were higher in patients ≤1.500g (P<.05).nnnCONCLUSIONSnSerum CysC decreased within 48-72hours of life, and this decline showed significance (P<.05). The levels increased after 7 days in all 3 GA groups, and there was no difference in CysC levels among the groups. More studies in preterm infants with hypotension and respiratory disease are required. CysC is a better glomerular filtration (GF) marker in ≤1.500g preterm infants.

Original breveValores de cistatina C sérica en recién nacidos pretérmino en nuestro medio. Relación con valores de creatinina sérica y patologías de la prematuridadSerum cystatin C levels in preterm newborns in our setting: Correlation with serum creatinine and preterm pathologies

Background nCystatin C (CysC) is a renal function marker that is not as influenced as creatinine (Cr) by endogenous or exogenous agents, so it is therefore proposed as a marker in preterm infants.BACKGROUNDnCystatin C (CysC) is a renal function marker that is not as influenced as creatinine (Cr) by endogenous or exogenous agents, so it is therefore proposed as a marker in preterm infants.nnnOBJECTIVESnTo determine serum CysC values in preterm infants during the first week of life, compared to Cr. To analyze alterations caused by prematurity diseases.nnnMETHODnThe design involved a longitudinal, observational study of prospective cohorts. Groups were based on gestational age (GA): Group A (24-27 weeks), Group B (28-33 weeks), Group C (34-36 weeks). Blood samples were collected at birth, within 48-72hours and after 7 days of life.nnnSTATISTICSnSPSS v.20 software was used. The statistical methods applied included chi-squared test and ANOVA.nnnRESULTSnA total of 109 preterm infants were included in the study. CysC levels were: 1.54mg/L (±0.28) at birth; 1.38mg/L (±0.36) within 48-72hours of life; 1.50mg/L (±0.31) after 7 days (p<0.05). Cr levels were: 0.64mg/dL (±0.17) at birth; 0.64mg/dL (±0.28) within 48-72hours; 0.56mg/dL (±0.19) after 7 days (P<.05). CysC values were lower in hypotensive patients and those with a respiratory disease (P<.05), and no alterations associated with other diseases were observed. There were no differences in Cr levels associated with any disease. Creatinine levels were higher in patients ≤1.500g (P<.05).nnnCONCLUSIONSnSerum CysC decreased within 48-72hours of life, and this decline showed significance (P<.05). The levels increased after 7 days in all 3 GA groups, and there was no difference in CysC levels among the groups. More studies in preterm infants with hypotension and respiratory disease are required. CysC is a better glomerular filtration (GF) marker in ≤1.500g preterm infants.