Impact of estimated glomerular filtration rate after valve and combined valve and coronary surgery

Preoperative renal impairment predicts postoperative mortality in patients undergoing cardiac surgery. We examined the impact of three equations for glomerular filtration rate (GFR) estimation on mortality. This is a retrospective, observational study on patients undergoing valve (n = 594) and combined valve and coronary procedures (n = 412). Glomerular filtration rate was estimated with modification in diet and renal disease (MDRD), Cockcroft-Gault (CG) equation, and Mayo-Clinic (MC) equation. Mean age was 65 ± 11 years and mean logistic EuroSCORE was 9.0 [95% confidence interval (CI): 8.4-9.7]. Preoperative kidney dysfunction (eGFR <60 ml/min/1.73 m2) is associated with increased risk for mortality. Hazard ratios for 30-day mortality differed between eGFR equations [MC 2.6 (95% CI: 1.6-4.1); MDRD 2.9 (95% CI: 1.9-4.4); CG 3.9 (95% CI: 2.2-5.2)]. Discriminatory performance of GFR equations was comparable with logistic EuroSCORE, but CG and MC discriminated significantly better than MDRD. Median intensive care unit stay did not differ, but Bland-Altman plots showed considerable variation between eGFR equations, indicating that they cannot be used interchangeably. Substantial amount of agreement was achieved with CG and MDRD. Only one equation should be used in one institution. The bias between equations varied considerably. Impaired preoperative kidney dysfunction is associated with increased risk for mortality irrespective of the formula used.     

8种肾小球滤过率预测公式对肾细胞癌患者肾功能评价的适用性及相关因素分析

目的 评价8种常用的肾小球滤过率(GFR)预测公式对肾细胞癌患者肾功能评价的适用性,并分析影响预测公式的相关因素。方法 收集蚌埠医学院第一附属医院泌尿外科2017年1月—2018年12月收治的132例肾细胞癌患者的临床资料进行回顾性分析。记录患者术前测得的血清肌酐Scr值、年龄、性别、体质量指数(BMI)、有无合并症、肿瘤T分期等资料。以外源性放射标记物同位素⁹⁹Tc^m-二乙三胺五醋酸 (DTPA) 的肾排泄率所测得的GFR参照值(rGFR)为标准,应用Bland-Altman分析法比较以下8种预测公式计算得出GFR评估值(eGFR)的偏差:改良 MDRD-1、改良MDRD-2,CKD-EPI公式,联合血清肌酐与胱抑素 C的公式,Cockcroft-Gault (C-G) 公式,基于胱抑素 C的公式 1,基于胱抑素C的公式2,简化 MDRD公式。通过单因素分析方法分别观察患者性别、年龄、BMI、T分期及合并症等对不同预测公式的影响。结果 以rGFR为标准比较8种计算公式的95%一致性分析,胱抑素C相关的2种公式均低估了GFR实际水平,其余6种公式均不同程高估了GFR实际水平。eGFR值偏差较小的3种公式依次是CKD-EPI(7.74 mL/min)、血清肌酐与胱抑素 C(7.87 mL/min)以及改良MDRD-1公式(7.98 mL/min),界外百分比最低的3种公式依次为改良MDRD-2(1.98%)、改良MDRD-1(2.48%)、 C-G公式(2.97%);eGFR值偏差最大的公式为:改良MDRD-2(22.22 mL/min)。通过单因素分析显示8种公式计算的eGFR结果在不同性别、BMI及T分期的肾癌患者间差异均无统计学意义(P值均＞0.05)。除胱抑素C-1和胱抑素C-2两种公式计算结果外,其余6种公式计算的eGFR值在不同年龄段结果不同(随年龄的增高均减少),在合并症组较无合并症组低,差异均有统计学意义(P值均<0.05)。结论 CKD-EPI、联合肌酐胱抑素以及改良MDRD-1对于评价肾癌患者适用性较好,影响eGFR准确度的因素是多样的,患者年龄和是否存在合并症对预测公式的一致性影响较大。     

核素^99mTc—DTPA测定GFR与公式估算GFR的相关性研究

目的：探讨核素^99mTc—DTPA测定GFR与MDRD公式、简化MDRD公式估算GFR的相关性。方法：178例CKD患者，用核素^99mTc—DTPA测定GFR，同时测定血清肌酐、尿素氮和白蛋白，根据年龄和性别分别用MDRD和简化MDRD公式估算GFR。结果：核素^99mTc—DTPA测定的GFR与MDRD公式估算的GFR有显著性差异，P=0．0001，MDRD公式高估了GFR；核素^99mTc—DTPA测定的GFR与简化MDRD公式估算的GFR亦有显著性差异，P=0．0001，简化MDRD公式低估了GFR；MDRD公式估算的GFR与核素^99mTc—DTPA测定的GFR呈正相关，r=0．8292，P〈0．01；简化MDRD公式估算的GFR与核素^99mTc—DTPA测定的GFR值呈正相关，r=0．8277，P〈0．01。结论：MDRD公式、简化MDRD公式估算的GFR与核素^99mTc—DTPA测得的GFR有差异，需进一步校正后用于估算GFR。     

A Comparison of Measured Creatinine Clearance versus Calculated Glomerular Filtration Rate for Assessment of Renal Function before Autologous and Allogeneic BMT

Common blood and marrow transplantation (BMT) eligibility criteria include a minimum glomerular filtration rate (GFR) that may vary by regimen intensity. GFR is often estimated by measurement of creatinine clearance in a 24-hour urine collection (24-hr CrCl), an inconvenient and error-prone method that overestimates GFR. The study objectives were to determine which of 6 GFR calculations: Cockroft-Gault (CG), modified CG (mCG), Modification of Diet in Renal Disease 1 (MDRD1), MDRD2, Jelliffe, and Wright, consistently underestimated measured 24-hr CrCl pre-BMT. We retrospectively analyzed 98 consecutive allogeneic (n = 48) or autologous (n = 50) adult BMT patients from January 2006 to April 2007. All 6 formulas were significantly (P < .001) correlated with 24-hr CrCl with R = 0.64 (Wright), 0.63 (CG), 0.61 (mCG), 0.61 (Jelliffe), 0.54 (MDRD2), and 0.50 (MDRD1). When compared to the measured 24-hr CrCl, MDRD2 consistently underestimated it in the highest proportion of patients (66%, P < .001), compared with MDRD1 (65%, P < .001), Jelliffe (61%, P = NS), mCG (55%, P = NS), Wright (34%, P < .001), and CG (34%, P = .001). Measured 24-hr CrCl, pre-BMT serum Cr, and all 6 equations were not predictive of renal regimen-related toxicity (RRT) post-BMT. The Wright and CG formulas are closest to, but overestimate 24-hr CrCl in 66% of patients. In comparison, MDRD2 consistently underestimates 24-hr CrCl in 66%. Although MDRD2 is the most conservative formula, all 6 formulas gave reasonable estimates of GFR and any of the 6 equations can replace the measured 24-hr CrCl. Larger analyses and transplantation of patients with GFR <50 mL/min may better define subgroups at risk for renal RRT.     

Measurement of glomerular filtration rate in obese patients: pitfalls and potential consequences on drug therapy

Epidemiological studies have shown that obesity is associated with chronic kidney disease and end stage renal disease. These studies have used creatinine derived equations to estimate glomerular filtration rate (GFR) and have indexed GFR to body surface area (BSA). However, the use of equations using creatinine as a surrogate marker of glomerular filtration and the indexation of GFR for BSA can be questioned in the obese population. First, these equations lack precision when they are compared to gold standard GFR measurements such as inulin clearances; secondly, the indexation of GFR for 1.73 m(2) of BSA leads to a systematic underestimation of GFR compared to absolute GFR in obese patients who have BSA that usually exceed 1.73 m(2). Obesity is also associated with pathophysiological changes that can affect the pharmacokinetics of drugs. The effect of obesity on both renal function and drug pharmacokinetics raises the issue of correct drug dosage in obese individuals. This may be particularly relevant for drugs known to have a narrow therapeutic range or excreted by the kidney.     

Ethnic coefficients for glomerular filtration rate estimation by the Modification of Diet in Renal Disease study equations in the Korean population

Race and ethnicity are influential in estimating glomerular filtration rate (GFR). We aimed to find the Korean coefficients for the Modification of Diet in Renal Disease (MDRD) study equations and to obtain novel proper estimation equations. Reference GFR was measured by systemic inulin clearance. Serum creatinine (SCr) values were measured by the alkaline picrate Jaffé kinetic method, then, recalibrated to CX3 analyzer and to isotope dilution mass spectrometry (IDMS). The Korean coefficients for the 4 and 6 variable MDRD and IDMS MDRD study equations based on the SCr recalibrated to CX3 and to IDMS were 0.73989/0.74254 and 0.99096/0.9554, respectively. Coefficients for the 4 and 6 variable MDRD equations based on the SCr measured by Jaffé method were 1.09825 and 1.04334, respectively. The modified equations showed better performances than the original equations. The novel 4 variable equations for Korean based on the SCr measured and recalibrated to IDMS were 107.904×SCr(-1.009)×age(-0.02) (×0.667, if woman) and 87.832×SCr(-0.882)×age(0.01) (×0.653, if woman), respectively. Modified estimations of the MDRD and IDMS MDRD study equations with ethnic coefficients and the novel equations improve the performance of GFR estimation for the overall renal function.     

Assessment of accuracy of Cockcroft-Gault and MDRD formulae in critically ill Indian patients

Background:

Cockroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) formulae have not been validated in critically ill Indian patients. We sought to quantify the discrepancy, if any, in Glomerular Filteration Rate (GFR) estimated by CG and MDRD formulae with 24 hrs urine Creatinine Clearance (Cr Cl).

Materials and Methods:

Prospective cohort study in 50 adult patients in a mixed medical-surgical intensive care unit. Inclusion criteria: Intensive Therapy Unit (ITU) stay >48 hrs and indwelling urinary catheter. Exclusion criteria: Age <18 years, pregnancy, dialysis, urine output <400 ml/day and patients receiving ranitidine, cefoxitin, trimethoprim or diuretics. We estimated Creatinine Clearance by CG and MDRD formula and measured GFR by 24 hrs urine creatinine clearance. Bland Altman plot was used to find the difference between the paired observations. The association between the methods was measured by the product moment correlation coefficient.

Result:

The mean GFR as calculated by Creatinine Clearance was 79.76 ml/min/1.73 m² [95% Confidence Interval (CI) 65.79 to 93.72], that by CG formula was 90.05 ml/min/1.73 m² [95% CI: 74.50 to 105.60], by MDRD was 85.92 ml/min/1.73 m² [95% CI: 71.25 to 100.59]. The Bias and Precision between CG and Cr Cl were −4.5 and 140.24 respectively, between MDRD and Cr Cl was −6.1 and 122.52. The Correlation coefficient of CG formula as a measure of GFR was 0.65 (P < 0.0001), that of MDRD was 0.70 (P < 0.0001).

Conclusion:

We conclude that CG and MDRD formulae have a strong correlation with measured GFR but are not a reliable measure and overestimate GFR in critically ill Indian patients.     

半胱氨酸蛋白酶抑制剂C联合肌酐评估慢性肾脏病肾小球滤过率的准确性

目的 验证2008年美国CKD-EPI基于半胱氨酸蛋白酶抑制剂C(cystatinc)开发的肾小球滤过率(GFR)评估方程在中国慢性肾脏病(CKD)患者的适用性.方法 选择2008年12月至2009年4月中山大学附属第二医院68例非透析CKD患者,用体表面积标准化Cockcroft-Ganh方程、简化MDRD方程、改良后简化MDRD方程、肾动态显像以及2008年美同CKD-EPI基于eystatin C开发的3条GFR评估方程计算的GFR(分别为cGFR、aGFR、mGFR、gGFR、CyslGFR、Cys2GFR、Cys3GFR),与双血浆法99mTc-DTPA血浆清除率测定的GFR(即tGFR)进行比较分析.结果 Pearson相关分析显示,7种方法GFR估计值与tGFR明显相关,相关系数从大到小依次为Cys3GFR(0.93)、gGFR(0.91)、mGFR(0.89)、Cys2GFR(0.88)、CyslGFR(0.85)、cGFR(0.85)、aGFR(0.83).在准确性比较中,Cys3GFR较aGFR、CysIGFR准确性高.Bland.Altman分析显示Cys3GFR估计值与tGFR的一致性最好,其一致性限度未超过事先规定的专业界值.线性同归结果显示mGFR偏差最小,精确度最高.结论 cystatin C联合肌酐并包括人口统计学参数的方程(Cys3GFR)应用于中国CKD患者准确性较高,与tGFR相关性和一致性最好.且优于仅包括cystatin C GFR估评方程(CyslGFR)、Cockcrofi-Gauh方程、简化MDRD方程.     

半胱氨酸蛋白酶抑制剂C联合肌酐评估慢性肾脏病肾小球滤过率的准确性

目的 验证2008年美国CKD-EPI基于半胱氨酸蛋白酶抑制剂C(cystatinc)开发的肾小球滤过率(GFR)评估方程在中国慢性肾脏病(CKD)患者的适用性.方法 选择2008年12月至2009年4月中山大学附属第二医院68例非透析CKD患者,用体表面积标准化Cockcroft-Ganh方程、简化MDRD方程、改良后简化MDRD方程、肾动态显像以及2008年美同CKD-EPI基于eystatin C开发的3条GFR评估方程计算的GFR(分别为cGFR、aGFR、mGFR、gGFR、CyslGFR、Cys2GFR、Cys3GFR),与双血浆法99mTc-DTPA血浆清除率测定的GFR(即tGFR)进行比较分析.结果 Pearson相关分析显示,7种方法GFR估计值与tGFR明显相关,相关系数从大到小依次为Cys3GFR(0.93)、gGFR(0.91)、mGFR(0.89)、Cys2GFR(0.88)、CyslGFR(0.85)、cGFR(0.85)、aGFR(0.83).在准确性比较中,Cys3GFR较aGFR、CysIGFR准确性高.Bland.Altman分析显示Cys3GFR估计值与tGFR的一致性最好,其一致性限度未超过事先规定的专业界值.线性同归结果显示mGFR偏差最小,精确度最高.结论 cystatin C联合肌酐并包括人口统计学参数的方程(Cys3GFR)应用于中国CKD患者准确性较高,与tGFR相关性和一致性最好.且优于仅包括cystatin C GFR估评方程(CyslGFR)、Cockcrofi-Gauh方程、简化MDRD方程.     

Gender differences in post-exercise sagittal knee translation: a comparison between elite volleyball players and swimmers

BACKGROUND: There is an increased risk for anterior cruciate ligament injury during the last part of a match or training session and one reason for that could be a post-exercise increase in tibial translation. PURPOSE: To investigate if sagittal tibial translation is affected after a workout session in volleyball or swimming in elite athletes. In addition, gender differences in sagittal tibial translation after the workout session were investigated. METHOD: Thirty-one elite volleyball players (16 male) and 33 elite swimmers (15 male) participated in this study. Measurements of total tibial translation were taken before and after a workout session in either volleyball or swimming with the use of a KT-1000 arthrometer. RESULTS: Total tibial translation increased by 1.1 mm (SD 1.9) in the group consisting of both male and female volleyball players (p=0.003) and remained unchanged in the swimmers. Male athletes increased their tibial translation with 1.8 mm (SD 1.8) and 0.6 mm (SD 1.1) in the two sports, respectively, while the tibial translation did not increase in the female athletes. CONCLUSION: Impact sports such as volleyball training leads to a post-exercise increase in tibial translation in male athletes. The increase in tibial translation in swimmers, that is a non-impact sport, was small and may not be clinically significant for the functional stability of the joint. It has been shown that female athletes have an increased risk for injury. Our results show no support for an increase in tibial translation being an important factor for this increased risk, and suggest that the difference between males and females in this regard should be sought elsewhere.     

Implications of method specific creatinine adjustments on General Medical Services chronic kidney disease classification

AIMS: To evaluate the impact of different equations for calculation of estimated glomerular filtration rate (eGFR) on general practitioner (GP) workload. METHODS: Retrospective evaluation of routine workload data from a district general hospital chemical pathology laboratory serving a GP patient population of approximately 250 000. The most recent serum creatinine result from 80 583 patients was identified and used for the evaluation. eGFR was calculated using one of three different variants of the four-parameter Modification of Diet in Renal Disease (MDRD) equation. RESULTS: The original MDRD equation (eGFR(186)) and the modified equation with assay-specific data (eGFR(175corrected)) both identified similar numbers of patients with stage 4 and stage 5 chronic kidney disease (ChKD), but the modified equation without assay specific data (eGFR(175)) resulted in a significant increase in stage 4 ChKD. For stage 3 ChKD the eGFR(175) identified 28.69% of the population, the eGFR(186) identified 21.35% of the population and the eGFR(175corrected) identified 13.6% of the population. CONCLUSIONS: Depending on the choice of equation there can be very large changes in the proportions of patients identified with the different stages of ChKD. Given that according to the General Medical Services Quality Framework, all patients with ChKD stages 3-5 should be included on a practice renal registry, and receive relevant drug therapy, this could have significant impacts on practice workload and drug budgets. It is essential that practices work with their local laboratories.     

Consequences for clinical biochemists of the modifications of the creatinine-based evaluation of glomerular filtration rate between 2005 and 2008

Since 2005, international guidelines propose a stadification for chronic renal failure based on the glomerular filtration rate (GFR) value. The performance of the creatinine-based equations allowing the estimation of GFR and the bias of the creatinine measurements is, more than ever, a crucial issue. The consequences for the clinical biologists are of importance. First, the Cockcroft-Gault formula must be replaced by the four variable-MDRD equation. Second, the biologists must chose from the "175" and the "186" versions of the MDRD equation. The first one fits the creatinine methods which are traceable to the reference method (liquid or gas chromatography coupled to mass spectrometry). The second equation must be used for creatinine methods, which are not traceable to the reference method. Today, only some enzymatic methods can prove that they are traceable to the reference method. For the colorimetric methods, future is inclear.     

Creatinine or cystatin C – which is a better index of renal function in morbid obesity?

PurposeThe most important index of renal function is estimated glomerular filtration rate (eGFR) which can be calculated from creatinine or cystatin C concentration in serum. There is uncertainty, which formula is best suited to assess renal function in morbidly obese patients. The aim of this study was to evaluate eGFR in patients with morbid obesity using formulas: Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Grubb, Le Bricon, Hoek, Larsson, and to compare the obtained results.Material and MethodsIn 40 morbidly obese patients, serum concentration of cystatin C and creatinine were assayed. Values of eGFR were calculated using the above-mentioned formulas.ResultsThe mean value of eGFR ranged from 85.9 to 111.1 ml/min/1.73m², depending on the formula. The biggest difference between the obtained values was 29% (Grubb vs. Hoek p<0.01). After calculation of eGFR from creatinine concentration (MDRD), 7 patients were qualified to the 2^nd and 3^rd stage of chronic renal disease, while application of Hoek's formula, based on cystatin C concentration, allotted 27 patients to 2nd and 3rd stage of chronic renal disease. Le Bricon formula gave eGFR values, that correlated best with albuminuria.ConclusioneGFR calculated using Le Bricon formula based on the cystatin C concentration was significantly lower than eGFR calculated from creatinine concentration and was more closely associated with albuminuria. Relying only on creatinine concentration to estimate glomerular filtration rate can lead to underestimation of renal malfunction in obese patients.     

The upper limit of physiological cardiac hypertrophy in elite male and female athletes: the British experience

Establishment of upper normal limits of physiological hypertrophy in response to physical training is important in the differentiation of physiological and pathological left ventricular hypertrophy. The genetic differences that exist in the adaptive response of the heart to physical training and the causes of sudden cardiac death in young athletes indicate the need for population-specific normal values. Between September 1994 and December 2001, 442 (306 male, 136 female) elite British athletes from 13 sports were profiled. Standard two-dimensional guided M-mode and Doppler echocardiography were employed to evaluate left ventricular morphology and function. Eleven (2.5%) athletes, competing in a range of sports including judo, skiing, cycling, triathlon, rugby and tennis, presented with a wall thickness >13 mm, commensurate with a diagnosis of hypertrophic cardiomyopathy. Eighteen (5.8%) male athletes presented with a left ventricular internal diameter during diastole (LVIDd) >60 mm, with an upper limit of 65 mm. Of the 136 female athletes, none where found to have a maximum wall thickness >11 mm. Left ventricular internal diameter was <60 mm in all female athletes. Systolic and diastolic function were within normal limits for all athletes. Upper normal limits for left ventricular wall thickness and LVIDd are 14 mm and 65 mm for elite male British athletes, and 11 mm and 60 mm for elite female British athletes. Values in excess of these should be viewed with caution and should prompt further investigation to identify the underlying mechanism.     

Growth and development of male gymnasts,swimmers, soccer and tennis players: A longitudinal study

Élite adult athletes are known to have physical and physiological characteristics specifically suited to their sport. However, it is not clear whether the observed adult differences arise because of training or whether the sport selects the individual with the appropriate characteristics. The purpose of this prospective study was to compare and contrast the physical development of young athletes (8–19 years), and in so doing provide a possible response to this question. Development of anthropometric characteristics and sexual maturation were assessed in a group of 232 male athletes for three consecutive years. Parental heights were used to predict target heights. The subjects were a randomly selected group of young British athletes, from four sports: soccer, gymnastics, swimming and tennis. Using a linked longitudinal cohort study design (age cohorts 8, 10, 12, 14 and 16 years) it was possible to estimate a consecutive 11-year development pattern, over the 3-year testing period. The adjusted mean (ANCOVA) height, accounting for age and pubertal status, of male swimmers (161·6 ± 0·6 cm) was found to be significantly greater (p < 0·01) than gymnasts (150·7 ± 0·8 cm) and soccer players (158·7 ± 0·6 cm), and their adjusted mean body mass (51·3 ± 0·6 kg) significantly greater (p < 0·01) than the other groups. When testicular volumes were compared, it was found that swimmers had significantly larger volumes than gymnasts and tennis players from 14 to 16 years of age (p < 0·05). Gymnasts' growth curve of testis size was characteristic of late maturers, the swimmers' curve was characteristic of early maturers. As all the young athletes started training prior to puberty the observed late sexual maturation of gymnasts and early maturation of swimmers suggests some form of sports-specific selection. Training did not appear to have affected these young athletes's growth and development; rather their continued success in sport appeared to be related to inherited traits.     

Cystatin C as an early biomarker of nephropathy in patients with type 2 diabetes

This study was done to evaluate clinical usefulness of cystatin C levels of serum and urine in predicting renal impairment in normoalbuminuric patients with type 2 diabetes and to evaluate the association between albuminuria and serum/urine cystatin C. Type 2 diabetic patients (n = 332) with normoalbuminuria (n = 210), microalbuminuria (n = 83) and macroalbuminuria (n = 42) were enrolled. Creatinine, urinary albumin levels, serum/urine cystatin C and estimated glomerular filtration rate (eGFR by MDRD [Modification of Diet in Renal Disease] and CKD-EPI [Chronic Kidney Disease Epidemiology Collaboration] equations) were determined. The cystatin C levels of serum and urine increased with increasing degree of albuminuria, reaching higher levels in macroalbuminuric patients (P < 0.001). In multiple regression analysis, serum cystatin C was affected by C-reactive protein (CRP), sex, albumin-creatinine ratio (ACR) and eGFR. Urine cystatin C was affected by triglyceride, age, eGFR and ACR. In multivariate logistic analysis, cystatin C levels of serum and urine were identified as independent factors associated with eGFR < 60 mL/min/1.73 m(2) estimated by MDRD equation in patients with normoalbuminuria. On the other hand, eGFR < 60 mL/min/1.73 m(2) estimated by CKD-EPI equation was independently associated with low level of high-density lipoprotein in normoalbuminuric patients. The cystatin C levels of serum and urine could be useful markers for renal dysfunction in type 2 diabetic patients with normoalbuminuria.     

Longitudinal observation of Epstein-Barr virus antibodies in athletes during a competitive season

Epstein–Barr virus (EBV) serology continues to be the first diagnostic test when infectious mononucleosis is suspected. Due to possible mild immunosuppression in competitive athletes, EBV reactivation determined by increases in salivary viral load have been identified as one possible cause in recurrent respiratory infections. The long‐term variation in EBV antibody levels in athletes compared to a control group remains unclear. The purpose of the study was to investigate the time course of changes in concentration of EBV antibodies in athletes with special emphasis on antibodies against early antigens (EAs) and avidity determination. During a competition season of approximately 12 months, the serological status of 15 biathletes (age 27 ± 3 years, 7 female, 8 male, international to Olympic level) was compared with 11 controls (age 23 ± 1 years; 1 female 10 male) at multiple time points. In addition, 43 healthy swimmers (age 22 ± 4 years, 18 female, 25 male, national to international level) were tested to validate the results with only two time points interspersed by approximately 6 months of intensive physical exercise. Analysis of quantitative antibody intensity bands revealed stable values during a competition season. In particular, IgG‐antibodies against EAs may persist and were found in 15% of past infections in swimmers exhibiting fluctuations in concentration after 6 months. These results provide evidence that positive Anti‐EA‐IgG may persist in healthy athletes and thus, should not be used to diagnose EBV reactivations or to identify a compromised immune function. J. Med. Virol. 84:1415–1422, 2012. © 2012 Wiley Periodicals, Inc.     

Comparison of renal function markers in Kuwaiti patients with sickle cell disease

BACKGROUND: Proteinuria is a common manifestation of renal disease which is a significant cause of morbidity in patients with sickle cell disease (SCD). OBJECTIVE: To evaluate and compare cystatin C, beta(2)-microglobulin, and creatinine as markers of renal disease in relation to the degree of proteinuria and other complications of SCD. METHODS: 24 h urine collections were used for estimation of urine protein and creatinine clearance in 59 patients with SCD. Results were correlated with plasma cystatin C, beta(2)-microglobulin, creatinine, glomerular filtration rate (GFR; derived from plasma creatinine by Cockcroft-Gault, MDRD formulae, and calculated cystatin C clearance), and clinical and haematological variables. RESULTS: Comparing the different methods of GFR, the proportion of patients with hyperfiltration (GFR >140 ml/min) were 30.5% (MDRD), 44.1% (Cockcroft-Gault), and 10.2 % (calculated cystatin C clearance). Cystatin C was the most consistent marker of hyperfiltration. The endogenous markers of GFR showed an increasing trend with increasing proteinuria, but haematological variables were not correlated with cystatin C, beta(2)-microglobulin, or plasma creatinine. Urine protein excretion was correlated with age (r = 0.33) and significant proteinuria was present in 13.6% of patients. Patients with proteinuria had lower haemoglobin concentration (p = 0.027) than those without proteinuria but HbF was not related to the degree of proteinuria or to markers of GFR. CONCLUSIONS: Markers of GFR show variable ability to identify hyperfiltration in patients with SCD, but cystatin C is the best endogenous marker. Proteinuria is associated with age, haemoglobin, and abnormalities of GFR. Routine screening is recommended to allow for early detection and intervention.     

The upper limit of physiological cardiac hypertrophy in elite male and female athletes in China

Physiological hypertrophy in response to physical training is important in the differentiation of physiological and pathological left ventricular hypertrophy. The goal of our study was to define the structural characteristics of the heart in Chinese athletes. Between June 2005 and August 2005, 339 (165 male, 174 female) elite Chinese athletes from 19 sports were profiled. Standard two-dimensional guided M-mode and Doppler echocardiography were employed to evaluate left ventricular morphology and function. Of the 165 male athletes, 19 (11.5%) male athletes presented with an LVIDd ≥ 60 mm, with an upper limit of 65 mm. Only three male athletes presented with wall thickness values ≥13 mm. Eighteen (10.3%) female athletes presented with an LVIDd ≥ 50 mm, and seven (4.2%) female athletes presented with an LVIDd ≥ 55 mm, with an upper limit of 62 mm. None were found to have a maximum wall thickness greater than 11 mm. Systolic and diastolic functions were within normal limits for all athletes. Results from the present study suggest that upper normal limits for left ventricular wall thickness and LVIDd are 14 and 65 mm for elite male Chinese athletes, and 11 mm and 62 mm for elite female Chinese athletes. Values in excess of these should be viewed with caution and should prompt further investigation to identify the underlying mechanism for the observed left ventricular hypertrophy.