Initiating renal replacement therapy through incremental haemodialysis: Protocol for a randomized multicentre clinical trial

Background

Thrice-weekly haemodialysis is the usual dose when starting renal replacement therapy; however, this schedule is no longer appropriate since it does not consider residual renal function. Several reports have suggested the potential benefit of beginning haemodialysis less frequently and incrementally increasing the dose as the residual renal function decreases. However, all the data published so far are from observational studies. Thus, this clinical trial avoids any potential selection bias and will assess the possible benefits that have been observed in observational studies.

Methods/design

This report describes the study protocol of a randomized prospective multi-centre open-label clinical trial to evaluate whether starting renal replacement therapy with twice-weekly haemodialysis sessions preserves residual renal function better than the standard thrice-weekly regimen. We also explore other clinical parameters, such as concentrations of uremic toxins, dialysis doses, control of anaemia, removal of medium-weight uremic toxins, nutritional status, quality of life, hospital admissions and mortality. Only incident haemodialysis patients who can maintain a urea clearance rate KrU ≥ 2.5 mL/min/1.73 m² are eligible. Patient recruitment began on 1 January 2017 and will last for 2 years or until the required sample size has been recruited to ensure the established statistical power has been reached. The minimum follow-up period will be 1 year. Anuric patients with acute renal failure and patients who return to haemodialysis after a kidney transplant failure are excluded. It has been calculated that 44 patients should be recruited into each group to achieve a power of 80% in a two-sided comparison of means with a usual significance level of 0.05. A time-to-event analysis will estimate the probability of kidney function survival in both groups using the Kaplan–Meier method. Survival curves will be compared with log-rank tests. This survival analysis will be complemented with a proportional hazard model to estimate the hazard ratio of kidney function survival adjusted for any confounding factors. Analyses will be carried out in accordance with the intention-to-treat principle.

Discussion

The incremental initiation of dialysis may preserve residual renal function better than the conventional treatment, with similar or higher survival rates, as reported by observational studies. To our knowledge, this is the first clinical trial to evaluate whether initiating renal replacement therapy with twice-weekly haemodialysis sessions preserves residual renal function better than beginning with the standard thrice-weekly regimen.

Trial registration

ClinicalTrials.gov, NCT03302546. Registered on 5 October 2017.

[Neurocysticercosis in Murcia (Spain)]

INTRODUCTION

Neurocysticercosis (NC) is the most prevalent parasitic infection in the CNS. Its frequency in our environment has increased with migratory movements. The clinical and demographic characteristics of patients with NC attended in a third level hospital in an area with a high prevalence of immigrant have been analyzed.

PATIENTS AND METHODS

A retrospective study was done of the patients registered by the Coding Service of Virgen de la Arrixaca Hospital (January 2996 to December 2009), analyzing all the clinical histories of patients discharged with the primary or secondary diagnosis of neurocysticercosis. The most relevant epidemiological, diagnostic and therapeutic data were analyzed.

RESULTS

35 patients were included in the study. Of these, 24 were men, all coming from Latin America. The most prevalent onset was seizure episode (27 patients). The number of cases per year began to increase after 2002. Although only 21 of the cases had criteria to begin medical treatment with albendazole, it had been prescribed to 29 patients.

CONCLUSION

In Murcia, NC is mainly an imported disease. An increase in the annual incidence has been observed since 2002, parallel to the rise in the number of immigrants. Approximately 25% of the patients received treatment in spite of not having antiparasitic treatment indication.

Short daily versus conventional hemodialysis quality of life: a cross-sectional multicentric study in Spain

BACKGROUND

End-stage renal disease is a major health problem worldwide nowadays. Although conventional hemodialysis is the most widely used modality, short daily hemodialysis has been proposed as a more physiologic treatment. The objective of this article is to compare the quality of life of patients on each hemodialysis modality.

METHODS

A multicentric cross-sectional study was performed in 9 Spanish hospitals. Patients treated for at least 3 months with conventional or short daily hemodialysis were included and quality of life measured using the Euroqol-5D quality of life questionnaire. Bayesian models were used for analyzing quality of life results.

RESULTS

Ninety-three patients were included, 27 were on daily hemodialysis and 66 on conventional hemodialysis. All models demonstrated a better quality of life for daily hemodialysis versus conventional hemodialysis. Only 14% of the patients on conventional hemodialysis were willing to change to a daily schedule.

CONCLUSIONS

Short daily hemodialysis shows a better quality of life than conventional hemodialysis with all Bayesian approaches considered.

Predictors of mortality in patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia: the role of empiric antibiotic therapy

The objective of this study was to evaluate prognostic factors and the influence of different empiric antibiotic therapies on outcome and mortality in a cohort of 100 inpatients with bacteraemia (84 cases nosocomial) caused by methicillin-resistant Staphylococcus aureus (MRSA). Patients were investigated by means of a standard protocol at a 944-bed hospital in the years 2000-2004. Empiric antibiotic therapies included vancomycin (n = 49), teicoplanin (n = 20), linezolid (n = 17), other antibiotics active in vitro (n = 7), and inactive antibiotics (n = 7). Overall mortality was 40% (12% among linezolid-treated patients; 46.3% among glycopeptide-treated patients). In bivariate analyses, the following factors were statistically associated with higher mortality: rapidly fatal underlying disease, altered mental status, metabolic acidosis, and acute severe clinical condition at the onset of bacteraemia; development of complications (septic shock, renal failure, and disseminated intravascular coagulopathy); empiric monotherapy with glycopeptides (vs combination therapy with an aminoglycoside); and inadequate empiric treatment. Empiric therapy with linezolid was associated with lower mortality. In multivariate analysis, risk factors associated with higher mortality included acute severity of illness (OR 7.49; 95%CI 1.19-25.3) and altered mental status (OR 4.83; 95%CI 1.22-19.15) at onset, complications (OR 3.42; 95%CI 1.02-17.46), and inappropriate empiric treatment (OR 7.6; 95%CI 1.87-31.14). In multivariate analysis limited to patients who received empiric therapy with either linezolid (n = 17) or glycopeptides (n = 69), linezolid was associated with greater rates of survival (OR 7.7; 95%CI 1.1-53) and microbiological eradication (OR 11.76; 95%CI 1.46-90.9) but not with fewer complications (OR 0.71; 95%CI 0.16-3.25). In conclusion, the main prognostic factors associated with mortality in patients with MRSA bacteraemia are complications, acute severe clinical condition at onset, and inappropriate empiric treatment. Empiric therapy with linezolid was associated with greater survival and more successful microbiological eradication but did not reduce complications.

[Irbesartan in hypertensive non-diabetic advanced chronic kidney disease. Comparative study with ACEI]

Angiotensin-converting enzyme inhibitors (ACEI) have proved an antihypertensive and renoprotective effect with reduction of proteinuria in diabetic and non diabetic nephropathy, but not exempt of side effects in advanced chronic kidney disease (ACKD) patients. Angiotensin receptor blockers (ARB) have emerged as antiproteinuric, renoprotective and cardioprotective therapy. Only a few reports have been published studying ARB effects on non-diabetic ACKD patients. Our aim is to study Irbesartan (ARB) on non-diabetic ACKD patients and compare its effects with ACEI.

PATIENTS AND METHODS

Forty three non-diabetic patients at ACKD stage IV NKF-DOQI (CrCl <30 ml/min) were enrolled in a prospective study. Group I: 21 received Irbesartan monodose 150-300 mg/day (63+/-17 y/o, 12 F, 9 M,ClCr 22.1+/-8 ml/m.), Group II: 22 received ACEI (65+/-13 y/o, 8 F, 14 M, CrCl 22.3+/-7 ml/m). Parameters studied: blood pressure (BP), pulse pressure (PP), renal function (CrCl), proteinuria (in patients with proteinuria >or= 0.5 g/d), serum K+ and serum uric acid, at month 0, 3, 6, 9 and 12.

RESULTS

At 12 months, BP was controlled in 57% of Group I vs 39% of Group II. Mean systolic BP was decreased from 154/85 to 138/77 in G I, and from 146/85 to 133/77 in GII, with a decrease in 10.7% of mean BP in GI and 8.5% in GII (NS). Irbesartan reduced PP in 7.2% vs 8.3% with ACEI (NS). CrCl reduction with Irbesartan was 0.23 vs 0.21 ml/min/month with ACEI (NS). The antiproteinuric effect was higher with Irbesartan (from 2.1 to 1.3 g/day) vs. ACEI (from 1.35 to 1.33 gr /day), being statistically significant the reduction percentage between the two groups (p >or= 0.041). Serum K+ level do not change in Irbesartan group and increased 10% in ACEI group (p<0.001). Uric acid was decreased by Irbesartan in 17% and increased in 4% by ACEI (p<0.001).

CONCLUSIONS

Irbesartan in non-diabetics patients with advanced chronic renal disease, compared with ACEI showed similar blood pressure control and similar effect on chronic kidney disease progression, with higher antiproteinuric effect. On the other side, Irbesartan showed a reduction of serum uric acid, and did not increase serum K+ levels.

Early explosive force reduction associated with exercise-induced muscle damage

This study was aimed to analyze the loss of muscle explosive force in the early phase of eccentric exercise-induced damage, and its possible relationships with muscle soreness and blood creatine kinase (CK) levels. Squat jump (SJ) and countermovement jump (CMJ) heights decreased in response to an eccentric exercise (120 eccentric actions of the knee extensors), with reductions that persisted at least for 24 h. The SJ/CMJ ratio was not significantly modified. Blood CK levels changed significantly over time and CK activity was significantly higher at 6 and at 24 h when compared to values obtained immediately after the eccentric exercise. Muscle soreness perceived at 6 h was slightly higher than that experienced just after finalizing the exercise and reached a clearly upper value at 24 h. A highly significant relationship between SJ and CMJ height loss was observed. CK activity at 24 h was significantly related to the SJ height loss at 6 h and to both the SJ height loss and the CMJ height loss immediately after the exercise. In summary, eccentric exercise induced a reduction in the explosive force generating capacity that affected in a similar way the pure concentric jump (SJ) and the jump eliciting the stretch-shortening cycle (CMJ). Results obtained suggest that CK activity is a better predictor of explosive force reduction than soreness, at least when values close to the peak are used.

Bacteriemias por Staphylococcus aureus sensible a meticilina: epidemiología y factores pronósticos. Estudio prospectivo 2000-2003

BACKGROUND

Staphylococcus aureus bacteremia continues to be a major problem in hospitals due to its high prevalence, severity and treatment difficulties. This study aimed to evaluate epidemiological and clinical features, risk factors and influence of antibiotic choice in outcome and mortality in patients with methicillin susceptible S. aureus bacteremia (SAMSB).

PATIENTS AND METHODS

A prospective, observational study of inpatients with SAMSB (2000-3).

RESULTS

A total of 131 with SAMSB were included (mean age 56 years; 58% > or = 60 year-old); 56.5% were due to nosocomial bacteremia; 46% of all patients had an underlying condition (diabetes mellitus being the most frequent [28%]); a risk factor for bacteraemia was identified in 98% (intravenous catheter: 72%). Mortality rate was 16% (21/131). Comparative analysis according to nosocomial or community acquisition showed that the former was more frequent in Surgical Wards, patients with intravenous or urinary catheters, traumatic patients, dialysis and ICU patients. Initial severity and mortality were highest in community-acquired SAMSB. In multivariate analysis, risk factors associated with higher mortality were: presence of an ultimately or rapidly fatal underlying disease, acute severity of illness at onset and inadequate empirical treatment.

CONCLUSIONS

SAMSB is a clinically severe infection that occurs in patients with baseline disease, especially diabetics, that is almost always related to predisposing risk factors (mainly intravenous catheters). In the presence of a serious baseline disease, the initial critical clinical condition and inadequate empirical treatment are the main prognostic factors associated to greater mortality.

Electromyostimulation and plyometric training effects on jumping and sprint time

This study compared the effects of four-week training periods of electromyostimulation (EMS), plyometric training (P), or combined EMS and P training of the knee extensor muscles on 20 m sprint time (ST), jumping ability (Squat jump [SJ] and Countermovement jump [CMJ]), maximal isometric strength (MVC), and muscle cross-sectional area (CSA). Forty subjects were randomly assigned to one of the four treatment groups: electromyostimulation (EG), plyometric (PG), combined EMG, and P (EPG), that took place 4 times per week, and a control group (CG). Subjects were tested before and after the training program, as well as once more after 2 wk of detraining. A significant improvement (p < 0.05) in ST was observed after training (2.4 %) in EG while a significant slowing (p < 0.05) was observed (- 2.3 %) in EPG. Significant increases in EPG (p < 0.05) were observed in SJ (7.5 %) and CMJ (7.3 %) after training, while no significant changes in both jumps were observed after training and detraining for EG. A significant increase (p < 0.05) in MVC was observed after training (9.1 %) and after detraining (8.1 %) in EG. A significant increase (p < 0.05) in MVC was observed after training (16.3 %) in EPG. A significant increase (p < 0.01) in CSA was observed after training in EG (9.0 %) and in EPG (7.1 %). EMS combined with plyometric training increased the jumping height and sprint run in physically active men. In addition, EMS alone or EMS combined with plyometric training leads to increase maximal strength and to some hypertrophy of trained muscles. However, EMS training alone did not result in any improvement in jumping explosive strength development or even interfered in sprint run.

The validation of a new method that measures contact and flight times during vertical jump

The aim of this study was to design and validate a vertical jump assessing system based on flight time measurements. Hence, the first phase of this study consisted of programming the software SportJumpv-1.0 and adapting a contact mat and a computer mouse in order to record the flight and contact times of a jump test. In the second phase, 9 subjects made 12 maximal and submaximal vertical single and rebound jumps. Thus 108 flight times and 36 contact times were simultaneously obtained with five different systems: ErgoJump Bosco System (PS), SportJump-v1.0 (SJ), Force Plate (FP), High-speed camera (HSC), and a Led (LED) filmed with a high-speed camera; FP was considered as the reference system. No significant differences were found either between SJ and LED, or between FP and HSC systems. SJ and LED overestimate flight time (9 ms and p < 0.001) and underestimate contact time in respect to FP values. PS underestimates flight time regarding FP values (4 ms and p < 0.01). In spite of the differences obtained between the systems, the errors found are constant. Those slightly depend on the subject's body mass for the systems that are connected to a contact mat. A high correlation between all of them was obtained (r approximately 1 and p < 0.001). The SJ system was validated for an accuracy of 500 Hz, and it was shown to be a useful tool in measuring flight and contact times during jumping. The differences and correlations found between the five systems show that it is necessary to take into account which system is being used when analyzing vertical jump performance.

[Vascular access guidelines for hemodialysis]

Quality of vascular access (VA) has a remarkable influence in hemodialysis patients outcomes. Dysfunction of VA represents a capital cause of morbi-mortality of these patients as well an increase in economical. Spanish Society of Neprhology, aware of the problem, has decided to carry out a revision of the issue with the aim of providing help in comprehensión and treatment related with VA problems, and achieving an homogenization of practices in three mayor aspects: to increase arteriovenous fistula utilization as first vascular access, to increment vascular access monitoring practice and rationalise central catheters use. We present a consensus document elaborated by a multidisciplinar group composed by nephrologists, vascular surgeons, interventional radiologysts, infectious diseases specialists and nephrological nurses. Along six chapters that cover patient education, creation of VA, care, monitoring, complications and central catheters, we present the state of the art and propose guidelines for the best practice, according different evidence based degrees, with the intention to provide help at the professionals in order to make aproppiate decissions. Several quality standars are also included.

Pulmonary diffusing capacity in chronic dialysis patients

Patients with end-stage renal disease treated by hemodialysis with bioincompatible membranes are exposed during the dialysis period to acute effects on lung microcirculation, which may result in pulmonary fibrosis and diffusion defects in long-standing dialysis. To investigate the occurrence of these possible chronic pulmonary alterations, we determined lung function in patients with chronic renal failure not undergoing hemodialysis and in patients who had been receiving regular hemodialysis both for short and long periods of time. Forty-three patients divided into three groups were studied: 17 patients before dialysis with a mean (SD) creatinine clearance of 14.1 (6.8) ml/min 11.73 m2, 10 patients receiving regular hemodialysis for a period of less than 12 months (mean 6.4 +/- 3.5 months), and 16 patients receiving regular hemodialysis for more than 5 years (mean 8.3 +/- 3.6 years). First-use bioincompatible cellulosic dialysis membranes were used in all the cases. The following parameters were recorded: forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), total lung capacity (TLC), residual volume (RV), carbon monoxide transfer factor (TLCO), accessible lung volume (VA), carbon monoxide transfer factor/accessible lung volume (KCO- that is, TLCO/VA), and arterial blood gases. Patients receiving regular hemodialysis for more than 5 years showed significantly lower values of TLCO and KCO than patients before dialysis and patients receiving regular hemodialysis for less than 12 months. Seventy-five percent of patients on long-term hemodialysis had markedly reduced TLCO or KCO values (below 80% of the reference value) as compared with 17% of patients before dialysis and 10% of patients dialyzed for less than 12 months (P < 0.001). Differences among groups for the remaining parameters were not observed. In conclusion, patients undergoing long-term regular hemodialysis with a bioincompatible membrane showed a selective reduction in pulmonary diffusing capacity possibly due to chronic pulmonary fibrosis.

Long-term experience with the Thomas shunt, the forgotten permanent vascular access for haemodialysis

BACKGROUND

Vascular access complications are the main cause of hospitalization in dialysis patients. The difficulty in creating and maintaining vascular access after several years on haemodialysis (HD) remains the primary problem in these patients. The femoro-femoral Thomas shunt is a permanent vascular access that was used in the 1970s and is all but forgotten at present. We analysed our experience with the Thomas shunt since 1979 in patients with no other possibility of regular vascular access.

METHODS

We retrospectively studied 27 Thomas shunts implanted in 10 patients, aged 27-75 years at the time of first shunt implantation. Prior to implantation of the Thomas shunt, these patients had experienced 80 failed vascular accesses (plus four patients on CAPD), with an average of 8.6 accesses per patient. All Thomas shunts were implanted in femoral vessels. Clinical data were extracted from hospital and dialysis unit records and were analysed for efficacy, complications, and duration of patency.

RESULTS

Total follow-up was 1176 months, with an average shunt duration of 43.7 months (range 3-151 months). One-, 2-, 3- and 6-year survival rates were 85, 57, 49 and 25% respectively. Five patients spent more than 10 years on HD using the Thomas shunt, and one patient had the same unit for 12.5 years. A high blood flow (450 ml/min) was obtained, without recirculation, due to the characteristics of this shunt. Efficacy, measured as percentage urea reduction (PRU), was high (on average 77.8+/-1.5%). The infection incidence was one episode every 37.5 patient-months, Staphylococcus species being the most commonly isolated. There were no shunt removals because of infection. The most important cause of shunt withdrawal was thrombosis, with an incidence of one episode every 7 patient-months. Percutaneous angioplasty was successful in the majority of stenosis episodes.

CONCLUSIONS

This study indicates that the Thomas shunt provides a good permanent vascular access for HD patients who have no other possibility of a regular vascular access. This shunt offers high dialysis efficacy without recirculation and an access duration comparable to AV fistulae. For these reasons the Thomas shunt should continue to be used as a vascular access in HD.

Incidence of renal artery stenosis in pediatric en bloc and adult single kidney transplants

BACKGROUND

The incidence, time of onset, and outcome of transplant renal artery stenosis (TRAS) in pediatric en bloc (PT) and adult single-kidney (AT) transplants were reviewed.

METHODS

Forty-three cases (7 PT and 36 AT) of suspected TRAS were selected out of 367 functioning grafts (35 of them PT). Diagnosis was performed by digital subtraction arteriography. Percutaneous transluminal angioplasty (PTA) was performed when needed.

RESULTS

Seven (20%) PT and 24 (7.1%) AT presented TRAS. Time of onset was 7+/-1 months in PT and 18+/-17 months in AT (P<0.05). PTA was performed in all cases of TRAS in PT and in 19 AT. One PT and 7 AT had re-stenosis. There was no significant difference in renal function after treatment. Control of blood pressure improved in both groups.

CONCLUSIONS

Recipients of PT grafts showed a higher incidence and earlier onset of TRAS. Re-stenosis was more frequent in AT.

[Invasive fungal infections in liver transplant recipients: analysis of 21 cases]

BACKGROUND

Invasive fungal infections (IFI) are one of the most important causes of mortality in liver transplant (LT) recipients. The aim of this study was to describe the characteristics of IFI in the LT program of our institution with an special emphasis in the differences between Candida infections (CI) and that caused by other fungi (NCI).

PATIENTS AND METHODS

Retrospective analysis of the hospital charts of 21 patients who underwent a LT from February 1987 to December 1995. The diagnosis of IFI required the histological evidence of tissue invasion or a positive culture in a tissue sample or in an usually sterile fluid. Esophageal candidiasis was not considered as IFI. Antifungal prophylaxis was performed either with nystatin or fluconazole.

RESULTS

Twenty-one of 356 patients (6%) developed a total of 23 episodes of IFI. Pathogens were Candida spp. (n = 10), Aspergillus (n = 8), Zygomicetes (n = 4) and Cryptococcus (n = 1). Fifty-seven percent of the episodes of IFI (80% of those caused by Candida and 38% of those produced by other fungi; p < 0.05) developed in the first 3 months after transplantation and only 5 episodes appeared after the sixth month. The diagnosis of IFI was done at autopsy in 6 patients (29%). Overall, NCI (13 episodes) predominated over CI (10 episodes), being the later the cause of the 54% of the episodes in the first 178 recipients but only the 30% in the last 178 patients (p = 0.09). No differences were found in the distribution of the risk factors amongst those patients with CI or NCI. Seventeen of the 21 patients (71%) died and 15 of these deaths (72%) were attributable to fungi; 15 patients who died either did not receive amphotericin (n = 6) or received a cumulative dose lower than 500 mg. Six patients received a cumulative dose of more than 1.5 g (mean, 3.2 g) and four of them were cured. Mortality in the nonfungal infection group was 26% (p < 0.001).

CONCLUSIONS

IFI was a rare but severe complication in our LT recipients. The relative frequency of CI was progressively decreasing during the study period, being NCI the predominant infections. Amphotericin therapy was effective only when a high cumulative dose could be administered.

Functional glomerular reserve in recipients of en bloc pediatric transplant kidneys

BACKGROUND

The transplantation of an adequate renal mass is increasingly recognized to be of importance. The improved graft survival is probably due to a lesser risk of developing hyperfiltration-associated lesions.

METHODS

We have reviewed the glomerular reserve in our recipients of en bloc pediatric transplant kidneys after an intravenous amino acid overload and compared them to single adult kidney transplant recipients.

RESULTS

En bloc transplants evidenced increased glomerular filtration rate as compared with baseline as from the second hour of amino acid infusion (from 71+/-14 to 84.9+/-17 ml/min, 1.73 m2, P<0.05) and increased renal plasma flow as from the third hour (from 335+/-116 to 402+/-155 ml/min, 1.73 m2, P<0.05). In the single adult kidney recipient group, no change was seen either in the glomerular filtration rate (from 62.5+/-13 to 58.1+/-13 ml/min, 1.73 m2, P=NS) nor in renal plasma flow (from 354+/-125 to 304+/-98 ml/min, 1.73 m2, P=NS).

CONCLUSIONS

These results show that patients receiving en bloc pediatric kidney transplantations have a greater renal functional reserve and show a lesser risk of hyperfiltration.

Calcium salts of keto-amino acids, a phosphate binder alternative for patients on CAPD

Control of hyperphosphoremia is crucial to the prevention of secondary hyperparathyroidism. Calcium salts of keto-amino acids (KAA) were employed as phosphate binders in hemodialysis patients. We wanted to assess the efficacy of these substances as quelating agents in patients under continuous ambulatory peritoneal dialysis (CAPD). Also, as an amino acid supplement, we determined their possible effect on some parameters related to nutritional status. We studied 13 patients (7 M; 6 F) with a mean age of 45.2 +/- 17 years and a mean time on CAPD of 18.4 +/- 11.4 months. None had severe secondary hyperparathyroidism and/or clinically relevant aluminium intoxication. They were not receiving calcitriol and none were using low-calcium peritoneal dialysis fluids. All were under aluminum hydroxide (AlOH3) treatment and 8 patients also received calcium carbonate. These quelating agents were withdrawn and after 21 days (wash-out period) KAA were initiated. We analyzed serum levels of bone metabolism parameters (calcium, phosphate, osteocalcin [OC], intact parathyroid hormone [iPTH], alkaline phosphatase [AP]) and nutritional parameters (total protein, albumin, pre-albumin, transferrin) in four periods: (A) during AlOH3; (B) immediately after the washout period; (C) after 1.5 months; and (D) after 3 months of KAA therapy. In 5 patients serum aluminum level was also measured in periods (A) and (D). The serum phosphate level at period (B) was significantly higher than in other periods. After 3 months of treatment phosphate levels decreased significantly (A = 1.77 +/- 0.3 mmol/l vs D = 1.48 +/- 0.2; p < 0.05). Serum calcium levels increased, while iPTH and OC decreased (p = ns). AP remained stable during the study. All nutritional parameters increased at the end of the study (p = ns). Calcium salts of keto-amino acids showed to be an effective alternative to aluminum-containing phosphate binders. They were well tolerated, without relevant side-effects. These compounds could also represent an additional source of oral amino acid supplementation with improvement of nutritional status.

Reduced aminolevulinate dehydrase activity in rats with functional renal failure induced by cyclosporin A

Patients with chronic failure evidence various abnormalities in heme metabolism, primarily erythrocyte aminolevulinate dehydrase hypoactivity and increased plasma and erythrocyte porphyrin levels. Such abnormalities have also been observed in animals with both acute and chronic experimental renal failure. The aim of this work was to study these parameters of porphyrin metabolism in an experimental model of functional renal failure. A group of 11 male Wistar rats received 13 doses (25 mg/kg body weight/day) of cyclosporin A. Serum creatinine did not vary, but the blood urea nitrogen levels increased and a significant decrease in the creatinine clearance was observed. The drug also caused a marked decrease in the erythrocyte aminolevulinate dehydrase activity, a slight reduction of the hematocrit value, and increased levels of blood porphyrins. The plasma of treated rats showed capacity to inhibit aminolevulinate dehydrase activity when incubated in vitro with erythrocytes from control rats. Porphyrin metabolism remained unchanged in the liver. The daily diuresis was significantly decreased in the cyclosporin as compared to the control group; however, the porphyrinuria showed no changes. The derangements in the erythrocyte heme biosynthesis pathway observed in patients with chronic renal failure are reproducible in an experimental model of cyclosporin A-induced functional renal failure.

Clinical presentation and outcome of tuberculosis in kidney, liver, and heart transplant recipients in Spain. Spanish Transplantation Infection Study Group, GESITRA

BACKGROUND

Tuberculosis is unusual in transplant recipients. The incidence, clinical manifestations, and optimal treatment of this disease in this population has not been adequately defined. The present study was undertaken to assess the incidence, clinical features, and response to therapy of Mycobacterium tuberculosis infection in solid-organ transplant recipients.

METHODS

We evaluated retrospectively the incidence, clinical characteristics, diagnostic procedures, antituberculous treatment, clinical course, and factors influencing mortality in 51 solid-organ transplant recipients who developed tuberculosis after transplantation. We also reviewed the world literature on tuberculosis in solid-organ transplantation.

RESULTS

The overall incidence of tuberculosis was 0.8%. The localization was pulmonary in 63% of the cases, disseminated in 25%, and extrapulmonary in 12%. Tuberculosis developed from 15 days to 13 years after surgery (mean, 23 months). In one third of the cases, diagnosis was not suspected initially, and in three cases, diagnosis was made at necropsy. Fever was the most frequent symptom, followed by constitutional symptoms, cough, respiratory insufficiency, and pleuritic pain. Fifteen patients (33%) developed hepatotoxicity during treatment; hepatotoxicity was severe in seven cases. Hepatotoxicity was higher in patients receiving four or more antituberculous drugs (50%) than in patients receiving three drugs (21%; P=0.03). Serum levels of cyclosporine decreased in the 26 patients under the simultaneous use of rifampin. Nine of them (35%) developed acute rejection, and five (56%) died, in comparison with 3 of 17 patients (18%) who did not develop rejection after the use of cyclosporine and rifampin (P=0.03). Although microbiological response was favorable in 94% of the 35 patients who completed 6 or more months of treatment, 16 other patients (31%) died before diagnosis or in the course of treatment. None of the patients treated for more than 9 months died as a consequence of tuberculosis, whereas the mortality rate was 33% among those treated for 6 to 9 months (P=0.03). Use of antilymphocyte antibodies or high doses of steroids for acute rejection before tuberculosis was associated with a higher mortality rate.

CONCLUSIONS

M tuberculosis causes serious and potentially life-threatening disease in solid-organ transplant recipients. Treatment with at least three drugs during 9 months or more, avoiding the use of rifampin, appears to be appropriate.

Cardiovascular effects of recombinant human erythropoietin in predialysis patients

Treatment with recombinant human erythropoietin (rHuEPO) has solved the problem of anemia in patients on dialysis. However, its application to predialysis patients has raised some doubts about its effects on the progression of renal disease and on blood pressure (BP) and hemodynamic regulation. We have prospectively studied over at least 6 months a group of 11 predialysis patients receiving rHuEPO treatment (initial dose, 1,000 U subcutaneously three times a week). Clinical assessment and biochemical and hematologic measurements were made once every 2 weeks. Twenty-four-hour ambulatory BP monitoring, echocardiography, and determination of neurohumoral mediators of hemodynamics were performed once every 3 months. An adequate hematologic response was found (hemoglobin, 11.7 +/- 0.4 g/dL v 9 +/- 0.3 g/dL) without changes in the progression of renal disease. A decrease in cardiac output and an increase in total peripheral resistance was seen as anemia improved. A trend toward decreased left ventricular (LV) thickness and a significant decrease in LV mass index (from 178.2 +/- 20.6 g/m2 to 147.3 +/- 20.6 g/m2) were observed. Blood pressure control did not improve; moreover, in some patients an increase in systolic values was detected by ambulatory BP. Casual BP remained seemingly stable. Sequential determinations of neurohumoral mediators of hemodynamic substances (endothelin, renin, norepinephrine, epinephrine, dopamine) failed to explain these results. Ambulatory BP reveals a worse control in some patients who were previously hypertensive and confirms the utility of this technique in the assessment of patients under erythropoietin treatment. The trend toward LV hypertrophy regression without improved BP control confirms the role of anemia among the multiple factors leading to LV hypertrophy in end-stage renal disease (ESRD), and opens therapeutic possibilities. Better control of BP may avoid a potential offsetting of beneficial effects that correcting anemia would have on the cardiovascular system.

Effects of recombinant human erythropoietin on porphyrin metabolism in uremic patients on hemodialysis

Recombinant human erythropoietin (r-HuEPO) is being successfully used for the treatment of uremic anemia. Several abnormalities of heme biosynthetic pathway have been described in patients with end-stage renal failure. In this condition, the activity of erythrocyte porphobilinogen deaminase has been found to be slightly increased. If this enzyme were to be the key enzyme in erythroid heme regulation, its activity would be increased to an even greater degree during the correction of uremic anemia. To assess this hypothesis, this study followed the variations of this and other parameters of porphyrin metabolism over 12 months of erythropoietin therapy in eight patients with nephrogenic anemia who underwent hemodialysis. By the first month of therapy, an increase of the previously depressed erythrocyte activity of aminolevulinate dehydratase was already evident, in coincidence with a nonsignificant increase of the reticulocyte count. The activity of this enzyme reached its maximal level by Month 3, and did not change up to Month 10. The porphobilinogen deaminase hyperactivity normalized at Month 4. By Month 12, in coincidence with the reduction of erythropoietin doses, the maximal levels of erythrocyte protoporphyrin, and the decrease in aminolevulinate dehydratase activity, the porphobilinogen deaminase values started to increase once again. In conclusion, the administration of r-HuEPO to hemodialyzed patients induced transient normalization of the previously observed porphyrin metabolism abnormalities. However, erythrocyte porphobilinogen deaminase activity did not rise concomitantly with the increase in hematocrit or hemoglobin values, but it did diminish during treatment. Therefore, porphobilinogen deaminase did not behave as a controlling enzyme in heme synthesis during the r-HuEPO-induced correction of uremic anemia.

Abnormalities of heme biosynthesis in experimental acute renal failure

Several abnormalities of porphyrin metabolism have been described in patients with end-stage renal failure. Because the heme biosynthetic pathway in acute renal failure has not been studied hitherto, an experimental model was therefore induced in 30 dogs by ligation and transection of both ureters. Forty-eight h after this procedure, anemia and uremia developed, erythrocyte aminolevulinate dehydratase activity decreased, and plasma porphyrins increased in these 30 dogs, whereas seven sham-operated animals did not exhibit any alteration of these parameters. Uremic plasma showed a capacity to inhibit aminolevulinate dehydratase activity (mean, 11.1 +/- 5.8%) when incubated in vitro with erythrocytes from healthy dogs. Such findings are similar to those reported in uremic patients on hemodialysis or on continuous ambulatory peritoneal dialysis. Twenty-three of the 30 animals underwent a hemodialysis session (180 min) 48 h after ureteral ligation, using a polyacrylonitrile membrane dialyzer. In addition to reducing serum creatinine and urea levels, this procedure significantly reduced plasma porphyrin values. However, the activity of erythrocyte aminolevulinate dehydratase and the plasma capacity to inhibit this enzyme were not modified after the hemodialysis session. This results described here show that some of the abnormalities of heme biosynthesis described in chronic renal failure are detected early in an experimental model of acute renal failure. This study also confirms that, although most plasma porphyrins circulate bound to proteins, hemodialysis may reduce levels of plasma porphyrins when a high permeability membrane is used.

Double renal transplant from infant donors. A good alternative for adult recipients

Several groups have reported technical complications and poor graft survival rates in kidney transplants from pediatric donors to adult recipients. Increased incidences of acute rejections, vascular thrombosis, and early glomerulosclerotic lesions have led many groups to abandon this graft combination. Over the last 4 years, we have set up a program of two-kidney transplantation from cadaveric infant donors under age 3 years, which to date includes 15 adult recipients. Thirteen of these grafts are currently functioning at least as well as those from adult donors, after a mean follow-up of 1.5 years. Our surgical and therapeutic procedures have led to a minimization of the early complications reported by other groups. With this transplantation procedure, the patients receive double the number of nephrons, which will probably give them better long-term function. The encouraging results achieved by our group may help change the current consideration of pediatric donors as "suboptimal" ones.

Long-term erythropoietin in rats with reduced renal mass

Hematocrit increase with recombinant erythropoietin (rEPO) has been associated with increased progression of renal insufficiency in experimental models of renal mass reduction. The aim of the present study was to assess the effects of therapy with rEPO and various antihypertensives on the progression of chronic renal insufficiency and on arterial hypertension in an experimental model of renal mass reduction. Rats subjected to a two-thirds nephrectomy were randomly assigned to an untreated control group or to therapy with rEPO (subcutaneously, at an initial dose of 40 U/kg thrice weekly), rEPO plus verapamil (subcutaneously, 0.5 mg/kg/day), or rEPO plus enalapril (orally, 50 mg/l in the drinking water). Combining enalapril and rEPO therapy controlled systemic blood pressure (BP) and the increase in proteinuria. Glomerular injury, as assessed 16 weeks after renal ablation, was more marked in the animals treated with rEPO with or without either antihypertensive. The morphometric analyses showed greater glomerular tuft areas in the three groups receiving rEPO than in the controls. The glomerular tuft area was directly correlated with the rate of glomerulosclerosis. In about 11% of the rEPO-treated hypertensive rats, the lesions showed severe hypertensive vasculopathy; in the animals treated with rEPO plus enalapril, the lesions were less severe. We conclude that therapy with rEPO was associated to renal damage which could not be attenuated by enalapril despite controlling BP and proteinuria, and may have a nonhemodynamic cause. Therapy with rEPO might trigger lesions usually associated with severe arterial hypertension; concomitant therapy with enalapril attenuates hypertensive vasculopathy.

Alterations in renal endothelin production in rats with reduced renal mass

Renal endothelin-1 (ET-1) production is diminished in spontaneously hypertensive rats. An increase has been reported of renal ET-1 production associated with progression of renal disease in rats with reduced renal mass. The purpose of the present study was to investigate the evolution over time of the urinary ET-1 excretion in an experimental model of renal mass reduction not caused by renal infarction. Rats were subjected to 2/3 nephrectomy (right nephrectomy and resection of the lower left renal pole) and thereafter randomly assigned to a no-treatment control group or to treatment with recombinant erythropoietin, recombinant erythropoietin plus verapamil, or recombinant erythropoietin plus enalapril. The urinary ET-1 excretion was decreased by week 16 after nephrectomy as compared with healthy animals and with the levels 6 weeks after nephrectomy. The temporal evolution of urinary ET-1 excretion in the various groups of rats showed a trend toward decrease in all groups except the one receiving enalapril. The urinary ET-1 excretion correlated directly with creatinine clearance and inversely with tubulointerstitial damage. We observed an inverse correlation between urinary ET-1 excretion and arterial blood pressure 16 weeks after nephrectomy. These results indicate that renal ET-1 production decreases with the progression of renal disease and in relation with the severity of tubulointerstitial damage. The decrease in renal ET-1 production might contribute to the development and perpetuation of renal disease-associated arterial hypertension; this situation may be favorably modified by the use of enalapril.

LMP-1 activates NF-kappa B by targeting the inhibitory molecule I kappa B alpha

LMP-1, an Epstein-Barr virus membrane protein expressed during latent infection, has oncogenic properties, as judged from its ability to transform B lymphocytes and rodent fibroblasts. LMP-1 induces the expression of bcl2, an oncogene which protects cells from apoptosis, as well as of genes encoding other proteins involved in cell regulation and growth control. The mechanisms by which LMP-1 upregulates these proteins is unknown, but it is plausible that LMP-1 modifies signal transduction pathways that result in the activation of one or more transcription factors that ultimately regulate transcription of oncogenic genes. NF-kappa B, a transcription factor controlling the expression of genes involved in cell activation and growth control, has been shown to be activated by LMP-1. The mechanism(s) regulating this activation remains unknown. Our data indicate that increased NF-kappa B DNA binding and functional activity are present in B-lymphoid cells stably or transiently expressing LMP-1. I kappa B alpha is selectively modified in LMP-1-expressing B cells. A phosphorylated form of I kappa B alpha and increased protein turnover-degradation correlate with increased NF-kappa B nuclear translocation. This results in increased transcription of NF-kappa B-dependent-genes, including those encoding p105 and I kappa B alpha (MAD3). These results indicate that LMP-1 activates NF-kappa B in B-cell lines by targeting I kappa B alpha. Identification of the pathways activated by LMP-1 to result in posttranslational modifications of I kappa B alpha will aid in determining the role of this virus-host cell protein interaction in Epstein-Barr virus-mediated oncogenesis.

Efficiency of three different hemodialysis membranes for plasma porphyrin removal

To assess the capability of three different membranes to remove porphyrins, plasma and dialysate porphyrin levels were fluorometrically measured in 10 patients with end-stage renal failure who were on hemodialysis. Three different hemodialysis membranes were used: cuprophan, polyacrylonitrile, and cellulose triacetate. Total plasma porphyrin concentrations decreased after dialysis, but to a lesser extent when using the cuprophan membrane (19%) than with the polyacrylonitrile (26%) or cellulose triacetate (30%) membranes (P < 0.01). However, since the free plasma porphyrin fraction remained unchanged, it can be assumed that the equilibrium between protein-bound and non-protein-bound (free) porphyrins is displaced toward the latter fraction. Dialysate porphyrin levels were lower (P < 0.01) when using the cuprophan membrane (10.1 micrograms/session) than when using polyacrylonitrile (17.8 micrograms/session) and cellulose triacetate (21.9 micrograms/session). Although most of the plasma porphyrins are protein bound, our results show that hemodialysis can remove significant amounts of non-protein-bound (free) porphyrins. The polyacrylonitrile and cellulose triacetate membranes had a greater capacity for porphyrin removal than cuprophan. Thus, two high-permeability membranes (polyacrylonitrile and cellulose triacetate) should be used whenever a reduction of plasma porphyrin levels is desired.

Hemodialysis with acetate, DL-lactate and bicarbonate: a hemodynamic and gasometric study

Using invasive techniques we have studied various hemodynamic and gasometric parameters in the course of hemodialysis (HD) with different buffers in an animal model. HD sessions of 180 minutes at zero ultrafiltration were carried out on three groups of eight uremic dogs each, under anesthesia and constant mechanical ventilation. The three groups differed only in the buffer used: acetate (Group AC), equal proportions of DL-lactate and acetate (Group AC+LA), and bicarbonate (Group BC). No hemodynamic changes were seen in Group BC. In the AC and AC+LA groups we observed on minute 1 a decrease of the mean blood pressure (MBP) and of the systemic vascular resistances (SVR). These parameters returned to baseline values within the first 30 minutes in Group AC+LA. In Group AC the SVR also returned to baseline values after the minute 30, but the MBP remained below baseline throughout the study period, together with cardiac index and left ventricular stroke work index decreases. Only in Group AC did we see a flattening of the ventricular function curves. Only in this Group was there a decrease of the arterial oxygen pressure (PaO2) with an associated increase of the alveolo-arterial and arterio-venous O2 differences. The O2 consumption was not modified in any of the groups. Acetate as a single buffer induces hemodynamic instability through peripheral vasodilation and reduction of myocardial contractility. The myocardial depression induced by acetate, in its turn, causes a reduction in PaO2. The mixed acetate+lactate buffer is hemodynamically better tolerated than acetate as single buffer, as it induces only vasodilation.

Alveolar hemorrhage associated with antineutrophil cytoplasmic antibodies in rheumatoid arthritis

A 65-year-old woman with previously known rheumatoid arthritis and chronic renal failure of possible glomerular origin was admitted to the hospital because of hemoptysis and respiratory insufficiency. Antineutrophil cytoplasmic antibodies (ANCAs) with antimyeloperoxidase activity were detected in her serum. The lung biopsy specimen evidenced alveolar hemorrhage. Under immunosuppressive therapy with steroids and cyclophosphamide, the patient's condition improved both clinically and radiologically, and the ANCA became negative after 6 months' therapy.

Heme biosynthesis in uremic patients on CAPD or hemodialysis

We have analyzed some parameters of porphyrin metabolism in 60 patients with end-stage renal failure, 20 of them on CAPD and the remaining on HD. In comparison with 56 control subjects, both groups of patients showed the three following findings: low erythrocyte aminolevulinate dehydrase activity, inhibition ability for the activity of this enzyme when their plasma was incubated in vitro with normal erythrocytes, and increased plasma porphyrin levels. Like anemia, these abnormalities were more remarkable in patients on HD who also exhibited increased erythrocyte protoporphyrin levels and compensatory porphobilinogen deaminase activities. Mean weekly porphyrin removal through dialysate was higher in CAPD (90.8 micrograms) than in HD patients (30.4 micrograms). Dialysate and plasma porphyrins were correlated in both circumstances (r = 0.714, P < 0.01 and r = 0.637, P < 0.05, respectively). The less pronounced porphyrin abnormalities found in CAPD patients with respect to HD patients may be due to the more efficient capability of peritoneal dialysis for removing from plasma protein-bound substances, as porphyrins and inhibitors of aminolevulinate dehydrase or other enzymes involved in erythropoiesis. Since no close relationship was found between these abnormalities of porphyrin metabolism and hematocrit values, the anemia of uremia cannot be merely considered as a direct consequence of altered heme biosynthetic pathway.

Ganciclovir prophylaxis decreases frequency and severity of cytomegalovirus disease in seropositive liver transplant recipients treated with OKT3 monoclonal antibodies

The efficacy of ganciclovir, given prophylactically, to prevent cytomegalovirus-related disease was evaluated in liver transplant recipients, mostly seropositive, under treatment with OKT3 monoclonal antibodies. The incidence of cytomegalovirus disease and visceral involvement was reduced, respectively, from 52 and 36% in the control group to 12 and 8% in the ganciclovir-treated patients. Leukopenia was a frequent (32%) side effect of ganciclovir administration.

[Nosocomial fungemia caused by Candida parapsilosis]

We review 27 episodes of nosocomial fungemia due to Candida parapsilosis over a 6 year period, compared to a control group of 27 episodes of nosocomial fungemia due to Candida albicans. During the study period, C. parapsilosis accounts for 23% of all yeast isolated from blood-cultures. Fungemia due to C. parapsilosis was more frequently seen in males (23/4). More than half of the cases (15/27) presented in the postoperative period. In 89% of cases the patients were under total parenteral nutrition and 81% had received broad-spectrum antibiotics. In 41% of cases, the source of the fungemia was unknown, and in another 41% of cases was related to an iv line infection. Direct attributable mortality to C. parapsilosis infection was 11%. When compared to the control group, nosocomial fungemia due to C. parapsilosis occurs in patient with more prolonged courses of total parenteral nutrition, and also was related with less frequent development of septic shock and lower attributable mortality.

Isolated primary aldosteronism in a patient with adrenal carcinoma and XY/XXY mosaic Klinefelter's syndrome

Although breast cancer, germ cell tumors and other neoplasms are known to occur in patients with Klinefelter's syndrome, adrenal carcinoma has not yet been reported in such patients. We describe a rare case of severe primary aldosteronism as the unique manifestation of a large adrenocortical carcinoma in a patient with Klinefelter's syndrome. Complete biological and hormonal evaluation was performed. Surgical treatment was successful and the patient remained asymptomatic with normal biological and hormonal values after 1 year of followup.