Urinary tract infections in pediatric renal transplant recipients--a two center risk factors study

UTI are common in renal Tx recipients and may significantly impact on the graft function. The aim of our study was to evaluate the prevalence, risk factors, and significance of UTI in Tx children. We performed a retrospective cross-sectional study of 76 Tx patients, median age at Tx was 13.4 yr. Twenty-one of 76 (28%) patients developed at least one UTI during the mean follow-up time of 3.3 +/- 2.0 yr post-Tx. The first UTI occurred at a median of 160 days post-Tx. The RR of having UTI was significantly higher in patients with the primary diagnosis of obstructive uropathy (RR = 2.6, 95th CI = 1.1-6.0, p = 0.032), history of PN pre Tx (RR = 2.7, 95th CI = 1.3-5.4, p = 0.009) and pre Tx VUR (RR = 2.2, 95th CI = 1.1-4.5, p = 0.045). These three factors also significantly decreased the infection-free survival time to the first UTI. Most UTI caused reversible acute allograft dysfunction, but the long-term graft function could not be reliably assessed with SCr. In conclusion, UTI occurred in 28% of pediatric Tx recipients, mostly during the first year post-Tx despite antibiotic prophylaxis. The diagnosis of obstructive uropathy, history of UTI and VUR prior to Tx were significant risk factors.

Arterial HTN in children with T1DM--frequent and not easy to diagnose

INTRODUCTION

To evaluate the diagnostic efficacy of the office blood pressure (OBP) and ambulatory blood pressure monitoring (ABPM) in the assessment of hypertension (HTN) in children with diabetes mellitus type 1 (T1DM).

METHODS

We analyzed OBP and ABPM measurements in 84 diabetic children (43 boys) obtained at a median age of 14.9 yr and 6.3 +/- 3.5 yr after diagnosis of T1DM. OBP and ABPM results were converted into standard deviation scores (SDS). In addition, we analyzed blood pressure loads and nighttime dipping. The comparison between OBP and ABPM was performed using kappa coefficient and receiver operator curve (ROC).

RESULTS

HTN was diagnosed in 43/84 (51%) patients using OBP (>95th percentile), and in 24/84 (29%) patients using ABPM ( > or = 95th percentile during 24 h, day or night). Both methods were in agreement in 33 ABPM normotensive and 16 ABPM hypertensive patients (most had nighttime HTN); 32% patients had white-coat HTN and 9.5% patients had masked HTN. The kappa coefficient was 0.175 (95% CI from -0.034 to 0.384) suggesting poor agreement between OBP and ABPM. Diastolic OBP was a better predictor of ABPM HTN (ROC area under the curve (AUC) = 0.71 +/- 0.06) than systolic OBP (AUC = 0.58 +/- 0.07). The percentage of non-dippers ranged from 7 to 23% in ABPM normotensive patients, and 21-42% in ABPM hypertensive patients who also had significantly higher BP loads (p < 0.0001).

CONCLUSION

Children with T1DM often suffer from nocturnal, white coat- and masked HTN, which can not be assessed and predicted by the OBP.

Partial remission with cyclosporine A in a patient with nephrotic syndrome due to NPHS2 mutation

Autosomal recessive steroid-resistant nephrotic syndrome (NS) is a rare, genetically determined nephropathy caused mainly by a mutation in the NPHS2 gene. This type of NS is usually resistant to other immunosuppressive therapy as well, but a few cases of cyclosporine A-induced partial remission of inherited NS have been reported. We present a boy that developed NS at the age of 18 months. There was no decrease of proteinuria on standard prednisolone therapy, and a diagnosis of steroid-resistant NS was established. However, the proteinuria decreased significantly following the initiation of cyclosporine A therapy (from 1280 to 380 mg/m(2) per day) without any negative effects on renal function (stable glomerular filtration rate 130-150 ml/min per 1.73 m(2)). The molecular genetic test revealed a homozygous R138Q mutation in the NPHS2 gene. Our case demonstrates that cyclosporine A can induce partial remission in patients with genetic forms of NS without influencing the glomerular filtration rate. However, its long-term effect and safety in children with hereditary forms of nephrotic syndrome have yet to be investigated.

Genotype-phenotype correlation in children with autosomal dominant polycystic kidney disease

Adults with autosomal dominant polycystic kidney disease (ADPKD) and PKD1 mutations have a more severe disease than do patients with PKD2 mutations. The aim of this study was to compare phenotypes between children with mutations in the PKD1/PKD2 genes. Fifty PKD1 children and ten PKD2 children were investigated. Their mean age was similar (8.6 +/- 5.4 years and 8.9 +/- 5.6 years). Renal ultrasound was performed, and office blood pressure (BP), ambulatory BP, creatinine clearance and proteinuria were measured. The PKD1 children had, in comparison with those with PKD2, significantly greater total of renal cysts (13.3 +/- 12.5 vs 3.0 +/- 2.1, P = 0.004), larger kidneys [right/left kidney length 0.89 +/- 1.22 standard deviation score (SDS) vs 0.17 +/- 1.03 SDS, P = 0.045, and 1.19 +/- 1.42 SDS vs 0.12 +/- 1.09 SDS, P = 0.014, successively] and higher ambulatory day-time and night-time systolic BP (day-time/night-time BP index 0.93 +/- 0.10 vs 0.86 +/- 0.05, P = 0.021 and 0.94 +/- 0.07 vs 0.89 +/- 0.04, P = 0.037, successively). There were no significant differences in office BP, creatinine clearance or proteinuria. Prenatal renal cysts (14%), hypertension defined by ambulatory BP (27%) and enlarged kidneys (32%) were observed only in the PKD1 children. This is the first study on genotype-phenotype correlation in children with ADPKD. PKD1 children have more and larger renal cysts, larger kidneys and higher ambulatory BP than do PKD2 children. Renal cysts and enlarged kidneys detected prenatally are highly specific for children with PKD1.

Demography of adolescent health care delivery and training in Europe

BACKGROUND

We aimed to determine the status of and factors associated with adolescent health care delivery and training in Europe on behalf of the European Paediatric Association-UNEPSA.

MATERIALS AND METHODS

A questionnaire was mailed to the presidents of 48 national paediatric societies in Europe. For statistical analyses, non-parametric tests were used as appropriate.

RESULTS

Six of the countries had a paediatric (PSPCA), 14 had a combined and nine had a general practitioner/family doctor system for the primary care of adolescents (GP/FDSA). Paediatricians served children 17 years of age or older in 15 and 17, up to 16 years of age in three and six, and up to 14 years of age in six and six countries in outpatient and inpatient settings, respectively. Fifteen and 18 of the countries had some kind of special inpatient wards and outpatient clinics for adolescents, respectively. Twenty-eight of the countries had some kind of national/governmental screening or/and preventive health programmes for adolescents. In countries with a PSPCA, the gross national income (GNI) per capita was significantly lower than in those with a GP/FDSA, and the mean upper age limit of adolescents was significantly higher than in those with the other systems. In the eastern part of Europe, the mortality rate of 10-14 year olds was significantly higher than that in the western part (p=0.008). Training in adolescent medicine was offered in pre-graduate education in 14 countries in the paediatric curriculum and in the context of paediatric residency and GP/family physician residency programmes in 18 and nine countries, respectively. Adolescent medicine was reported as a recognised subspecialty in 15 countries and as a certified subspecialty of paediatrics in one country. In countries with a PSPCA, paediatric residents were more likely to be educated in adolescent medicine than paediatric residents in countries with a GP/FDSA.

CONCLUSION

The results of the present study show that there is a need for the reconstruction and standardisation of adolescent health care delivery and training in European countries. The European Paediatric Association-UNEPSA could play a key role in the implementation of the proposals suggested in this paper.

Tubulointerstitial nephritis and uveitis syndrome in a mother and her son

A mother and her son, both with tubulointerstitial nephritis and uveitis syndrome (TINU) are reported. The nephritis presented itself at 13 years in the mother and at 10 years in her son. Glomerular filtration (GFR) decreased in both, and renal biopsies confirmed the diagnosis. Nephritis preceded the onset of uveitis in both. Clinical course and renal function improved quickly on oral steroids in the boy. The mother's hyperazotemia decreased spontaneously (without steroids), but not to normal range, and remained stable for 35 years of follow-up. Local steroids due to recurrences of uveitis were repeatedly needed in both. We believe this is the first report on familial occurrence of inherited TINU syndrome in two generations.

Recurrence of nephrotic proteinuria in children with focal segmental glomerulosclerosis after renal transplantation treated with plasmapheresis and immunoadsorption: case reports

Idiopathic focal segmental glomerulosclerosis (FSGS) is believed to be caused by a circulating permeability factor. FSGS recurrence is common after transplantation. The treatment is still a matter of debate; plasmapheresis (PE) and immunoadsorption (IA) are often used. We report on PE and IA in the treatment of two children with recurrent nephrotic proteinuria. Patient 1 was a 16-year-old girl who had recurrence of nephrotic proteinuria on the first day after transplantation (proteinuria-19 g/d). Primary immunosuppressive therapy was changed to high-dose cyclosporine and cyclophosphamide; plasmapheresis was started on day 4. Altogether we performed 53 PE and 38 IA procedures. During the first month, PE procedures were performed with no more than a 2-day interval between sessions, and the girl achieved partial remission (proteinuria 3 g/d). PE was then stopped. After 2 months, a relapse of heavy proteinuria occurred. This relapse was successfully treated again with intensified PE treatment. After achieving remission, a chronic PE regimen was started (PE once a week), similar to the previous series. The child remained in partial remission. Seven months after renal transplantation, she was switched from PE to IA, because of severe hypoproteinemia. Graft biopsy performed at 4 months showed effacement of the foot processes. At the present time she has a good graft function and 3 g/d proteinuria. Patient 2 was a 13-year-old girl with FSGS since 9 years. On the second day after renal transplantation she developed nephrotic proteinuria (proteinuria-14 g/d), which was treated with 39 PE and 16 IA treatments. She went into complete remission on the intensified PE regimen, had one relapse, and was switched to chronic IA. Graft biopsy performed at 2 weeks after transplantation showed effacement of the foot processes. At the present time she has good graft function and low proteinuria (0.3 g/d). In conclusion, intensified PE or IA treatments induced remission of recurrent nephrotic range proteinuria. Chronic PE or IA can maintain patients with frequent relapses in long-term remission.

Regression of left-ventricular hypertrophy in children and adolescents with hypertension during ramipril monotherapy

BACKGROUND

Left-ventricular hypertrophy (LVH) is a risk factor for cardiovascular morbidity. Antihypertensive treatment with angiotensin-converting enzyme inhibitors (ACEI) is able to induce the regression of LVH in adults. However, there has been no study of the ability of ACEI to induce the regression of LVH in children. Our aim was to investigate the effect of ramipril on left-ventricular mass and blood pressure (BP) in hypertensive children.

METHODS

Twenty-one children (median age, 15 years) with renal (76%) or primary (24%) hypertension were prospectively treated with ramipril monotherapy for 6 months. Blood pressure was evaluated using ambulatory BP monitoring, with hypertension defined as mean BP >or=95th percentile. Left-ventricular hypertrophy was defined either as left-ventricular mass index (LVMI) >38.6 g/m(2.7) (pediatric definition) or as LVMI >51.0 g/m(2.7) (adult definition).

RESULTS

Nineteen children completed the study. The median LVMI decreased from 36.8 g/m(2.7) (range, 18.9 to 55.8 g/m(2.7)) to 32.6 g/m(2.7) (range, 19.0 to 52.1 g/m(2.7); P < .05) after 6 months. The prevalence of LVH decreased from 42% to 11% using the pediatric definition (P < .05) and did not change using the adult definition (ie, it remained at 5%). The median ambulatory BP decreased by 11, 7, 8, and 7 mm Hg for daytime systolic, daytime diastolic, nighttime systolic, and nighttime diastolic BP (P < .05), respectively. A positive correlation was found between LVMI and nighttime systolic BP at the start of the study (r = 0.46, P < .05).

CONCLUSIONS

Ramipril is an effective drug in children with hypertension, for its ability to reduce not only BP but also left-ventricular mass and induce regression of LVH.

Improved control of hypertension in children after renal transplantation: results of a two-yr interventional trial

Hypertension is a frequent complication in children after renal transplantation and the control of post-transplant hypertension is unsatisfactorily low. The aim of this prospective interventional study was to improve the control of hypertension in children after renal transplantation. Thirty-six children fulfilled the inclusion criteria (> or =6 months after transplantation and no acute rejection in the last three months). BP was measured using ABPM. Hypertension was defined as mean ambulatory BP > or =95th-centile for healthy children and/or using antihypertensive drugs. The study intervention consisted of using intensified antihypertensive drug therapy - in children with uncontrolled hypertension (i.e., mean ambulatory BP was > or =95th centile in treated children), antihypertensive therapy was intensified by adding new antihypertensive drugs to reach goal BP <95th centile. ABPM was repeated after 12 and 24 months. Daytime BP did not change significantly after 12 or 24 months. Night-time BP decreased from 1.57 +/- 1.33 to 0.88 +/- 0.84 SDS for systolic and from 1.10 +/- 1.51 to 0.35 +/- 1.18 SDS for diastolic BP after 24 months (p < 0.05). The number of antihypertensive drugs increased from 2.1 +/- 0.9 to 2.7 +/- 0.8 drugs per patient (p < 0.05), this was especially seen with the use of ACE-inhibitors (increase from 19% to 40% of children, p < 0.05). In conclusion, this interventional trial demonstrated that, in children after renal transplantation, the control of hypertension, especially at night-time, can be improved by increasing the number of antihypertensive drugs, especially ACE-inhibitors.

Thirty years of the Union of National European Paediatric Societies and Associations (UNEPSA)

BACKGROUND

The Union of National European Paediatric Societies and Associations was founded in 1976 in Rotterdam. Thirty years later, the authors--former presidents and secretaries general--present a retrospective on the activities and achievements of UNEPSA. In 2006, 36 of 46 (78%) European countries, including some countries of the former Soviet Union, were members of UNEPSA. UNEPSA has created a forum for the mutual discussion of matters concerning paediatrics. UNEPSA is closely linked with the International Pediatric Association (IPA). It was never UNEPSA's ambition to promote a uniform European paediatrics. In the 30 years of its existence, it became clear that the diversity of paediatric care in different countries in Europe is extreme. During the "cold war", UNEPSA was able to cross boundaries between socialist and capitalist countries in Europe, and it was due to the activity of individual members of the UNEPSA council that clinical co-operation and research activities were initiated crossing many political borders. Annual meetings of national paediatric presidents focus on the most urgent problems of paediatric health care. "Europaediatrics" became the tri-annual congress for all general paediatricians and paediatric sub-specialists in Europe. The main research activities of UNEPSA concentrated on identifying the demography of primary, secondary and tertiary care paediatrics in Europe.

CONCLUSION

UNEPSA is an active paediatric association representing more than three quarters of all European countries. After 30 years, it is still an expanding and vital instrument in improving the medical care of all children and the co-operation of their carers in Europe.

Mild course of Puumala nephropathy in children in an area with sporadic occurrence Hantavirus infection

The first three children with Puumala virus nephropathy diagnosis in the Czech Republic are reported on. A boy and two girls were admitted with symptoms of interstitial nephritis. The medical history in all children revealed flu-like symptoms. All patients were mildly pyrexial and had elevated erythrocytes sedimentation rate, C-reactive protein and low hemoglobin levels. Serum creatinine levels were elevated and proteinuria exceeded 700 mg/L in all children. Tubular proteinuria, glycosuria, high urinary N-acetyl-beta-D-glucosaminidase levels and alpha-1-microglobulin levels confirmed the tubular lesion. Renal biopsies revealed a uniform pattern and showed non-purulent interstitial nephritis in all patients. Puumala virus antigen antibodies were detected in the plasma. All patients were treated with steroids and urine abnormalities and renal function returned to normal within 4 weeks. Hantavirus infection should be considered as one of possible causes of interstitial nephritis with decreased GFR in children even in areas with a low incidence of this infection.

Blood pressure, renal function, and proteinuria in children with unilateral renal agenesis

BACKGROUND/AIM

Unilateral renal agenesis (URA) is a model for a reduced nephron number that is believed to be a risk factor for blood pressure (BP) elevation and reduced renal function. The aim of the study was to investigate BP and renal function in children with URA.

METHODS

Data on children with URA from two pediatric nephrology centers were firstly retrospectively reviewed (renal ultrasound and scintigraphy, clinical BP, creatinine clearance, urinalysis). Children with normal renal ultrasound and scintigraphy were thereafter investigated using ambulatory BP monitoring.

RESULTS

Twenty-nine children with URA were investigated--14 children with an abnormal kidney (mostly scarring) and 15 children with healthy kidneys. Hypertension was diagnosed on the basis of clinical BP in 57% of the children with abnormal kidneys and on the basis of ambulatory BP monitoring in 1 child (7%) with healthy kidneys. The mean ambulatory BP in children with normal kidneys was not significantly different from that in controls. Forty-three percent of the children with abnormal kidneys had a reduced renal function, but none of children with normal kidneys.

CONCLUSIONS

Children with abnormalities of a solitary kidney have often hypertension, proteinuria, or a reduced renal function. In contrast, children with healthy solitary kidneys have BP and renal function similar to those of healthy children.

Control of hypertension in children after renal transplantation

The aim of this cross-sectional single-center study was to investigate the efficacy of hypertension control in children who underwent transplantation using ambulatory blood pressure (BP) monitoring, and to determine the risk factors associated with poor control of hypertension. Thirty-six children fulfilled the inclusion criteria. The mean age was 13.9+/-4.4 yr; the mean time after renal transplantation was 2.7+/-2.4 yr (0.5-10.1). Hypertension was defined as a mean ambulatory BP > or =95th centile for healthy children and/or requiring antihypertensive drugs. Hypertension was regarded as controlled if the mean ambulatory BP was <95th centile in children already on antihypertensive drugs, or uncontrolled if the mean ambulatory BP was > or =95th centile in treated children. Hypertension was present in 89% of children. Seventeen children (47%) had controlled hypertension, and 14 (39%) had uncontrolled hypertension. One child (3%) had untreated hypertension, and only four children (11%) showed normal BP without antihypertensive drugs. The efficacy of hypertensive control was 55% (17 of 31 children on antihypertensive drugs had a BP<95th centile), i.e. 45% of treated children still had hypertension. Children with uncontrolled hypertension had significantly higher cyclosporine doses (6.1 vs. 4.3 mg/kg/day, p=0.01) and tacrolimus levels (9.2 vs. 6.1 microg/L, p<0.05), and there was a tendency toward use of lower number of antihypertensive drugs (2.0 vs. 1.5 drugs/patient, p=0.06) and lower use of angiotensin-converting enzyme (ACE) inhibitors (7 vs. 35%, p=0.09) and diuretics (29 vs. 59%, p=0.14) than in children with controlled hypertension. In conclusion, nearly 90% of our children after renal transplantation are hypertensive and the control of hypertension is unsatisfactorily low. The control of hypertension could be improved by increasing the number of prescribed antihypertensive drugs, especially ACE inhibitors, and diuretics, or by using higher doses of currently used antihypertensives.

Renal concentrating capacity is linked to blood pressure in children with autosomal dominant polycystic kidney disease

Impaired glomerular filtration rate (GFR) is a risk factor for the development of hypertension in patients with autosomal dominant polycystic kidney disease (ADPKD). However, markers of tubular function were not tested whether they are linked to hypertension or blood pressure (BP) level. The aim of our study was to investigate the relationship between renal concentrating capacity and BP in children with ADPKD. Fifty-three children (mean age 11.8+/-4.4 years) were investigated. Standardized renal concentrating capacity test was performed after nasal drop application of desmopressin, BP was measured by ambulatory BP monitoring (ABPM). Renal concentrating capacity was decreased in 58 % of children. The prevalence of hypertension was significantly higher in children with decreased renal concentrating capacity (35 %) than in children with normal renal concentrating capacity (5 %) (p<0.05). Significant negative correlations were found between renal concentrating capacity, ambulatory BP and number of renal cysts (r = -0.29 to -0.39, p<0.05 to p<0.01). In conclusion, the concentrating capacity is decreased in about half of the patients and is linked to BP. Decreased renal concentrating capacity should be considered.

[Mutations in tumor suppressor gene NBS1 in adult patients with malignancies]

BACKGROUND

Mutations 657del5 and R215W in exon 6 of tumor suppressor gene NBS I are found in 1% Slavic populations. Increased occurrence of cancer was repeatedly reported in adult relatives of patients with Nijmegen breakage syndrome. Among children with oncological problematic, nonsignificantly increased frequency of NBS1 heterozygotes was found, which seems not to play any important role in cancerogenesis in childhood. However, the proportion of NBS heterozygotes among adult patients with malignancies could be significant and their therapy and follow up should respect their hyperradiosensitivity.

METHODS AND RESULTS

Mutations in exon were studied in 706 adult patients with malignancies. We found 5 NBS heterozygotes, which not more than the population prevalence (1:129-165). Increased frequency of NBS heterozygotes was found among patients with colon and rectal cancer (2/101), breast cancer (1/60), skin malignancies (1/98).

CONCLUSIONS

Surprisingly only one NBS heterozygote was found among 228 patients with nonHodgkin lymphoma, the malignancy which is a common complication in NBS homozygotes. Other types of malignancies were uncommon and only one R215W heterozygote was found. Comparison frequency of NBS heterozygotes with incidence NBS among person older than 70 years shows significant difference. Prevention of malignancies by avoidance from ionisation could be realized also in relatives of patients after identification of their genotype.

Chronic endothelin receptor blockade reduces end-organ damage independently of blood pressure effects in salt-loaded heterozygous Ren-2 transgenic rats

The present study was performed to evaluate the role of an interaction between the endothelin (ET) and the renin-angiotensin systems (RAS) in the development and maintenance of hypertension and in hypertension-associated end-organ damage in heterozygous male and female transgenic rats harboring the mouse Ren-2 renin gene (TGR). Twenty-eight days old heterozygous TGR and age-matched transgene-negative normotensive Hannover Sprague-Dawley rats (HanSD) were randomly assigned to groups with normal-salt (NS) or high-salt (HS) intake. Nonselective ET(A)/ET(B) receptor blockade was achieved with bosentan (100 mg.kg(-1).day(-1)). All male and female HanSD as well as heterozygous TGR on NS exhibited 100 % survival rate until 180 days of age (end of experiment). HS diet in heterozygous TGR induced a transition from benign to malignant phase hypertension. The survival rates in male and in female heterozygous TGR on the HS diet were 46 % and 80 %, respectively, and were significantly improved by administration of bosentan to 76 % and 97 %, respectively. Treatment with bosentan did not influence either the course of hypertension (measured by plethysmography in conscious animals) or the final levels of blood pressure (measured by a direct method in anesthetized rats) in any of the experimental groups of HanSD or TGR. Administration of bosentan in heterozygous TGR fed the HS diet markedly reduced proteinuria, glomerulosclerosis and attenuated the development of cardiac hypertrophy compared with untreated TGR. Our data show that the ET receptor blockade markedly improves the survival rate and ameliorates end-organ damage in heterozygous TGR exposed to HS diet. These findings indicate that the interaction between the RAS and ET systems plays an important role in the development of hypertension-associated end-organ damage in TGR exposed to salt-loading.

[Improved control of hypertension and its effect on graft function in children after renal transplantation]

BACKGROUND

Hypertension in patients after renal transplantation (RTx) is associated with impaired graft functions and graft survival. Control of hypertension in children after RTx is low--only 20-50 % of children have well controlled hypertension. The aim of this interventional study is to improve blood pressure control and to investigate whether the improved control will improve the graft survival.

METHODS AND RESULTS

36 children after RTx (mean age 13.9 +/- 4.4 years, time after RTx 2.7 +/- 2.4) fulfilled the inclusion criteria. Ambulatory blood pressure monitoring (ABPM) and graft function were examined. In children with uncontrolled hypertension, the dose and number of antihypertensive drugs were increased to reach BP <95th centile. ABPM was repeated after 12 months. After 12 months day-time and night-time BP dropped non-significantly, however prevalence of uncontrolled hypertension improved significantly from 42 % to 34 % (p<0.05). Number of antihypertensive drugs increased from 2.1 +/- 0.9 to 2.4 +/- 0.8 drugs per patient (p<0.05), namely that of ACE-inhibitors (from 19% to 27%, p<0.05). Graft function decreased by 3.6 ml/min/1.73m2/year (p<0.05).

CONCLUSIONS

This 12 months interventional trial demonstrated that control of hypertension in children after RTx can be improved by increasing number of prescribed antihypertensive drugs. The decline of graft function was lower comparing with previous trials.

Proteinuria in Children After Renal Transplantation

Proteinuria is associated with poor long-term allograft as well as patient survival among adults after renal transplantation. In children, there are no studies focusing primarily on posttransplant proteinuria. The aim of this cross-sectional study was to investigate the prevalence of and possible risk factors associated with proteinuria. Thirty-three children (mean age of 13.7 +/- 4.3 years; mean time after renal transplantation = 2.3 +/- 2.2 years) were eligible for the study. There was an 82% prevalence of proteinuria (> or =96 mg/m2/d) with nephrotic range proteinuria (> or =960 mg/m2/d) in 12% of children. The mean urinary protein excretion was 256 +/- 299 mg/m2/d (range = 47 to 1264). Children with hypertension, as defined by ambulatory blood pressure monitoring, showed significantly higher proteinuria than normotensive children (382 +/- 435 vs 163 +/- 79 mg/m2/d, P < .05). Children with a history of a previous acute rejection episode showed significantly higher proteinuria than children who never had an episode (416 +/- 445 vs 165 +/- 91 mg/m2/d, P < .05). Children with proteinuria did not show statistically different graft function than children without proteinuria. No statistically significant correlation was observed between proteinuria and ambulatory blood pressure values or graft function. In conclusion, proteinuria is a frequent finding also in children after renal transplantation; it is associated with hypertension and a history of rejection episodes.

Reduced nocturnal blood pressure dip and sustained nighttime hypertension are specific markers of secondary hypertension

OBJECTIVE

To investigate with the use of ambulatory blood pressure (BP) monitoring whether nocturnal BP dip and nighttime BP values are different in children with untreated primary and secondary hypertension.

STUDY DESIGN

Ambulatory BP monitoring studies from 145 children with untreated hypertension were retrospectively analyzed. Forty-five children had primary hypertension and 100 children had secondary hypertension.

RESULTS

Children with secondary hypertension had lower nocturnal BP dip for systolic and diastolic BP in comparison to children with primary hypertension (8% +/- 5% vs 14% +/- 4% for systolic and 14% +/- 7% vs 22% +/- 5% for diastolic BP, P < .0001 for both). Eleven percent of children with primary hypertension were classified as nondipper (BP dip <10%) for systolic BP and no child for diastolic BP; on the contrary, in children with secondary hypertension, 65% were nondippers for systolic and 21% for diastolic BP. Nocturnal systolic and diastolic BP loads were significantly greater in children with secondary hypertension than in those with primary hypertension.

CONCLUSIONS

Reduced nocturnal BP dip and sustained nighttime BP elevation are specific markers of secondary hypertension in children with untreated hypertension. Children with blunted nocturnal BP dip or sustained nighttime hypertension should be thoroughly investigated searching for the underlying cause of hypertension.

Ambulatory blood pressure monitoring in children after renal transplantation

Arterial hypertension is a common complication in children after renal transplantation and the control of hypertension is often difficult. This retrospective investigates the prevalence and rate of control of hypertension using ambulatory blood pressure monitoring (ABPM) in 45 children (mean age 14.1 +/- 4.3 years, mean time after renal transplantation 2.2 +/- 2.7 years), all on cyclosporine or tacrolimus, azathioprine or mycophenolate mofetil plus daily steroids. The overall prevalence of hypertension was 82%. None of the transplanted children had normal blood pressure without antihypertensive therapy (ie, spontaneous normotension). Twenty percent of children had untreated hypertension, 18% had controlled hypertension, and 62% had uncontrolled hypertension. Prevalence of the nondipping phenomenon was 53%. The mean number of antihypertensive drugs (without diuretic monotherapy) in treated patients was 1.9 drugs per patient. The prevalence of arterial hypertension in children after renal transplantation is high and the control of hypertension is often unsatisfactorily low.

Blockade of Endothelin Receptors Attenuates End-Organ Damage in Homozygous Hypertensive Ren-2 Transgenic Rats

BACKGROUND/AIMS

A growing body of evidence suggests that the interplay between the endothelin (ET) and the renin-angiotensin systems (RAS) plays an important role in the development of the malignant phase of hypertension. The present study was performed to evaluate the role of an interaction between ET and RAS in the development of hypertension and hypertension-associated end-organ damage in homozygous male transgenic rats harboring the mouse Ren-2 renin gene (TGRs) under conditions of normal-salt (NS, 0.45% NaCl) and high-salt (HS, 2% NaCl) intake.

METHODS

Twenty-eight-day-old homozygous male TGRs and age-matched transgene-negative male normotensive Hannover Sprague-Dawley (HanSD) rats were randomly assigned to groups with NS or HS intake. Nonselective ET(A/B) receptor blockade was achieved with bosentan (100 mg/kg/day). Systolic blood pressure (BP) was measured in conscious animals by tail plethysmography. Rats were placed into metabolic cages to determine proteinuria and clearance of endogenous creatinine. At the end of the experiment the final arterial BP was measured directly in anesthetized rats. Kidneys were taken for morphological examination.

RESULTS

All male HanSD fed either the NS or HS diet exhibited a 100% survival rate until 180 days of age (end of experiment). The survival rate in untreated homozygous male TGRs fed the NS diet was 41%, which was markedly improved by treatment with bosentan to 88%. The HS diet reduced the survival rate in homozygous male TGRs to 10%. The survival rate in homozygous male TGRs on the HS diet was significantly improved by bosentan to 69%. Treatment with bosentan did not influence either the course of hypertension or the final levels of BP in any of the experimental groups of HanSD rats or TGRs. Although the ET-1 content in the renal cortex did not differ between HanSD rats and TGRs, ET-1 in the left heart ventricle of TGRs fed the HS diet was significantly higher compared with all other groups. Administration of bosentan to homozygous male TGRs fed either the NS or HS diet markedly reduced proteinuria, glomerulosclerosis and attenuated the development of cardiac hypertrophy compared with untreated TGR.

CONCLUSIONS

Our data show that nonselective ET(A/B) receptor blockade markedly improves the survival rate and ameliorates end-organ damage in homozygous male TGRs without significantly lowering BP.