Knowledge and Attitudes of Dialysis Patients Toward Kidney Transplantation: Preliminary Report from a Pilot Study Preceding a Cross-Sectional Nationwide Evaluation

BACKGROUND

The knowledge and attitudes of dialyzed patients toward the best method of renal replacement treatment (ie, kidney transplantation [KTx]) may be the main factor motivating them to apply and be put on the national kidney transplant waiting list, resulting in a better prognosis.

OBJECTIVE

Assessment of the knowledge and attitudes of dialyzed patients toward KTx.

METHODS

A pilot study is considered an introductory step before the nationwide project, which will cover dialysis centers in Poland from 2023 to 2024. The authorship 4-part questionnaire, including self-assessment knowledge, attitude dimension, pain and mental evaluation section, was made available to 30 patients with hemodialysis aged 30 to 75 years.

RESULTS

The median age of the patients was 59 years. The primary cause of end-stage renal disease (ESRD) was glomerulonephritis (33%). Most of the patients stayed on hemodialysis for 2 years or less (57%); 43% of the patients declared insufficient knowledge in the field of KTx, 41% of the patients were not informed at the nephrology clinic that KTx remains one of the methods of renal replacement therapy, and 65% did not receive information about the possibility of preemptive or early transplantation from a relative donor. Only 34% of the patients considered KTx to be a much better treatment option than dialysis, but only 20% of those were on the national waiting list for KTx.

CONCLUSIONS

The pilot study showed insufficient knowledge of patients with ESRD regarding kidney transplantation as a method of renal replacement therapy. There is a need to introduce an effective educational program.

Health-related quality of life in children with immunoglobulin A nephropathy - results of a multicentre national study

INTRODUCTION

Immunoglobulin A nephropathy (IgAN) may lead to end stage renal disease and severely affect patient functioning and wellbeing. The aim of the study was to evaluate health-related quality of life (HRQoL) in children and adolescents with IgAN, and compare HRQoL in relation to the disease course, social status and psychological factors, such as expressing anger and perceived personal competence.

MATERIAL AND METHODS

The multicentre cross-sectional study included 51 patients ≥ 8 years from 7 paediatric nephrology centres in Poland. Psychometric analysis was performed using the Kidscreen-52 questionnaire to evaluate HRQoL, the Anger Expression Scale to evaluate the severity of anger and the Personal Competence Scale to measure general perception of personal competence.

RESULTS

Mean age of patients was 14.54 ±3.69 years; duration since the diagnosis of IgAN was 4.98 ±3.9 years. Patients with IgAN rated their psychological wellbeing as significantly worse compared to healthy peers (p < 0.05). The presence of proteinuria was associated with significantly worse physical wellbeing (58.72 ±18.45 vs. 74.44 ±22.97; p < 0.05). Current therapy (steroids/immunosuppressive drugs) had no effect on HRQoL in the study group. Perceived personal competence was rated high by 49% of children in the study group. Children with IgAN were characterized by lower intensity of expressed anger (p < 0.001) and significantly higher intensity of suppressed anger (p < 0.01) compared to reference ranges. Severity of expressed anger correlated positively with the parent relations and school environment dimensions of HRQoL.

CONCLUSIONS

We found lower HRQoL in regard to physical and psychological wellbeing in a group of Polish children with IgAN compared to healthy peers. HRQoL should be monitored in this patient group.

Modification of the Schwartz equations for children increases their accuracy at eGFR > 60 mL/min/1.73 m(2)

AIM

Estimation of eGFR in children with normal kidney function using the Schwartz equations results in underestimating real GFR.

MATERIALS AND METHODS

We propose modification of three Schwartz equations - two based on creatinine concentration (eGFRScrBS bedside) and (eGFRScr) and one 3-marker based on creatinine, urea and cystatin C concentrations (eGFRS3M). The iohexol test (reference method) was performed 417 times in 353 children >2 years with mean GFR: 98 ± 31.6 ml/min/1.73m(2). The assessment included also the Filler and Zappitelli equations. The modification was performed using methods: (1) based on equation, eGFRcor = a [eGFR - T] + T, where T = 50, if eGFR > T, and a equals for: eGFRScrBS 1.4043, for eGFRScr 2.0048, for eGFRS3M 1.2951, and (2) based on correction of all coefficients of the original equation.

RESULTS

For comparison of all the results and for children with GFR< 60, 60-90, 90-135 and > 135 ml/min/1.73m(2) the correlation coefficient, relative error (RE) and root mean square relative error (RMSRE) was employed and revealed improvement of RE from 25.9 to 6.8 and 3.9% (depending on the correction method) for eGFRScr; from 19 to 8.1 and 3.9% for eGFRScrBS and: from 11.6% to 2.0 and 2.3% for eGFRS3M (respectively). The RMSRE values changed from 30 to 21.3 and 19.8% for eGFRScr, from 25.1 to 21.6 and 19.8% for eGFRScrBS and from 19.1 to 15.8 and 15.3 % for eGFRS3M.

CONCLUSIONS

Modifications of Schwartz equations at GFR > 60 ml/min/1.73m(2) significantly improves the accuracy of calculating eGFR. The 3-markers equation is more accurate and should be employed frequently.

Effect of hypertension and antihypertensive medications on residual renal function in children treated with chronic peritoneal dialysis

PURPOSE

To evaluate the effect of hypertension (HTN) and antihypertensive medications (AHM) on residual renal function (RRF) in children on CAPD and APD.

MATERIAL/METHODS

We retrospectively evaluated underlying kidney disease, systolic and diastolic blood pressure (SBP/DBP), presence and control of HTN (SBP/DBP≥95th percentile), AHM, RRF (daily diuresis, residual glomerular filtration rate [rGFR]), biochemical parameters, BMI Z-score, and dialysis parameters during 12-month follow-up in 87 children (38 CAPD, 49 APD) aged 10.22±4.31 years. The rate of RRF loss was expressed as absolute and relative [%] reduction.

RESULTS

At baseline, HTN was found in 74.7% patients (CAPD/APD: 84.2%/67.3%, P=0.06), most commonly in HUS and least frequently in CAKUT. The proportion of CAPD/APD patients with poorly controlled HTN was 70.0%/63.3% (P=0.50). Relative daily diuresis loss in children with uncontrolled HTN was higher (P=0.017) compared to children with SBP/DBP <95th percentile. No effect of AHM on the rate of RRF loss was found. In multivariate analysis, absolute daily diuresis loss was related to baseline diuresis (β=-0.30, P<0.001) and proteinuria (β=-0.31, P=0.004); absolute rGFR loss to baseline rGFR (β=-0.73, P<0.001) and glucose load after 12 months (β=-0.36, P=0.02); relative daily diuresis loss to mean BMI Z-score (β=-0.44, P=0.04); and relative rGFR to baseline rGFR (β=-0.37, P<0.001) and SBP percentile (β=-0.21, P=0.045).

Which equations should and which should not be employed in calculating eGFR in children?

PURPOSE

We assessed the reliability of calculating eGFR in children as compared to the iohexol disappearance test (GFR-I), which was performed 417 times in 353 children aged 2 and more.

MATERIAL/METHODS

eGFR was estimated with equations based on serum creatinine: Schwartz (1: eGFR-Scr), Cockroft-Gault (2: eGFR-CG) and MDRD (3: eGFR-MDRD), and on creatinine clearance (4: eGFR-U), or relying on serum cystatin C: Hoeck (5: eGFR-H), Bokenkamp (6: eGFR-B) and Filler (7: eGFR-F), and on the three Schwartz markers (8: eGFR-S3M). Mean relative error (RE), correlation (R), Bland-Altman analysis and accuracy of GFR-I were studied in all patients and in subgroups: at GFR<60ml/min/1.73m(2); in children aged ≤12 and >12.

RESULTS

The results by eGFR-Scr, eGFR-S3M demonstrated no statistical difference to GFR-I at GFR<60ml/min/1.73m(2), but underestimated eGFR at higher filtration values by 11.6±15.1% and 19.1±16.4, respectively (p<0.0000). The eGFR-B, eGFR-F and eGFR-MDRD equations illustrated important overestimation of reference GFR results (RE: 84±44.2%; 29.5±27.9%, 35.6±62%; p<0.0000 for all). The MDRD and C-G formulas showed statistically better consistency in children aged >12. A good agreement was achieved by the eGFR-H equation (5.1±21.9%; p<0.0000; R=0.78).

CONCLUSIONS

(1) Schwartz equations show a good conformity at GFR<60ml/min/1.73m(2), but underestimate the results at higher GFR values. (2) The Bokenkamp equation with original coefficient should not be employed in children. (3) The use of the Hoeck formula in all children and C-G and MDRD formula in children aged >12 is possible. (4) The error of eGFR calculations increases at higher GFR values.

[Do we successfully treat anemia and calcium-phosphate disorders in children with chronic kidney disease at the beginning of the twenty-first century?]

In children with chronic kidney disease (CKD) anemia and calcium-phosphate disturbances are already present at early stages of the disease and require a comprehensive treatment. The aim of this study was to evaluate the efficacy of the treatment of biochemical disturbances, depending on the severity of CKD in children.

MATERIAL AND METHODS

The study included 71 children (44 boys, 27 girls) with CKD stage 1-5. Mean age was 11 ± 5 years, mean height: 135.7 ± 28 cm and mean eGFR 32 ml/min/1.73 m2. The serum hemoglobin, urea, creatinine, cystatin C, calcium, phosphorus and parathyroid hormone (PTH) levels were measured. eGFR was calculated according to Schwartz and Filler formulas, employing creatinine and cystatin C as markers. Patients were divided into groups depending on the stage of CKD [group 1: CKD stage 1+2 (GFR > 60), group 2: CKD stage 3 (GFR = 30-59) Group 3: CKD stage 4 (GFR = 15-29 ml/min/1.73 m2), group 4 - dialyzed children].

RESULTS

The concentration of he- moglobin depending on the stage of CKD (group 1 vs. group 2 vs. group 3 vs group 4) was 12.95 vs. 12.68 vs. 12.47 vs. 11.3 g/dI, respectively. The concentration of total and ionized calcium was significantly lower in children on dialysis compared to patients treated conservatively. With the progression of CKD the concentration of phosphorus (1.39 vs. 1.4 vs. 1.49 vs. 1.82 mmolI) and PTH (21.7 vs 48.6 vs 99.9 vs. 219 pg/ml) significantly increased. Treatment with erythropoietin was used in 48% of children, calcium carbonate in 55% and alphacalcidol in 56% of patients.

CONCLUSIONS

Despite the use of regular treatment, with the progression of CKD a progression of anemia, increased serum phosphate and parathyroid hormone and a decrease in calcium levels in studied children was observed. The severity of metabolic disorders in dialyzed children indicates the need for administration of new and more effective drugs, to prevent early enough complications of CKD in the form of mineral bone disease and cardiovascular complications.

Clinical validity of urinary interleukin 18 and interleukin 6 determinations in preterm newborns

INTRODUCTION

Preterm newborns are at a particular risk of acute kidney injury (AKI) and sepsis.

PURPOSE

Assessment of urinary interleukin 18 (ulL-18) and urinary interleukin 6 (ulL-6) concentrations in association with AKI and sepsis respectively in newborns hospitalized in Neonatal Intensive Care Unit (NICU).

MATERIAL AND METHODS

An evaluation was carried out of the dependence of ulL-18 on neonatal birth weight (BW) and AKI as well as ulL6 on sepsis. In prospective study, the evaluation included 58 children with BW up to 2000 g. Clinical observations spanned the period between the 1st and 28th day of life.

RESULTS

The mean gestational age was 30.3 Hbd, mean BW was 1361.9 g. AKI was diagnosed in 35 (60.3%), sepsis in 22 (39.7%) neonates. For median values of uIL-18 and ulL-18/mgCr, as well as for mean logarithmically transformed values of ulL-18 and ulL-18/mgCr, negative, statistically significant linear correlations were demonstrated for BW. In population, median value of ulL-18 and ulL-18/mgCr decreased respectively by 8.21 pg/ml and 84.8 pg/mgCr per each 100 g increment of BW. A negative, statistically significant linear correlation with an average strength was noted for the dependency of the duration of AKI and BW. No significant differences were observed in uIL-18 and ulL-181 mgCr values between the investigated days of AKI and reference group. There was noted a significant increase of the values of uIL-6 and uIL-6/ mgCr on day 0 of sepsis confirmed by the ROC analysis with AUROC 78% and 74%, respectively.

CONCLUSIONS

ulL-18 and ulL-18/mgCr values might be a reliable marker of renal tubules maturation in newborns; ulL-18 is not a reliable marker in diagnosing AKI in neonatal population; ulL-6 and uIL-6/ mgCr concentration values measured on actual days may be regarded an early marker of sepsis; AKI duration in preterm neonates is negatively correlated with BW.

Acute kidney injury in a single pediatric intensive care unit in Poland: a retrospective study

BACKGROUND/AIMS

The recent improvements of management of patients in pediatric intensive care units (PICU) are associated with improved outcome. However, this decrease in mortality is associated with an increased number of children with acute kidney injury (AKI), especially in patients with multiorgan failure.

METHODS

The report presents a retrospective analysis of 25 cases of AKI (assessed based on the pRIFLE criteria) in PICU within 7 years.

RESULTS

AKI was diagnosed in 1.24% of all hospitalized children. AKI percentage duration (as compared to the total hospitalization time) in the children who died vs. the survivors was 79.55% vs. 46.19%, respectively (p<0.05). The mortality rate of AKI patients was 40% which was 4.4-times higher as compared to the total mortality rate in PICU. The final cumulative survival ratio (FCSR) of patients meeting the oliguria criterion (which was met in 48% of AKI patients) was 37% vs. 49% in non-oliguric children. Averaged urine output values in the first week of hospitalization in the deceased vs. survivors were 1.49 vs. 2.57 ml/kg/h, respectively (p<0.05).

CONCLUSIONS

Oliguria should not be considered as a sensitive parameter for AKI diagnosing in children below one year of age. A decreased mean urine output in the first week of PICU hospitalization (less than 1.4 ml/kg/h) should be considered as a poor prognostic factor. In many cases AKI was diagnosed too infrequently and too late.

[Familial case of oral-facial-digital syndrome type 1 (OFD 1)]

Ciliopathies are phenotypically and genetically heterogeneous disorders that share ciliary dysfunction as a common pathological mechanism. Ciliary dysfunction results in a broad range of malformations including renal, hepatic and pancreatic cysts, visceral abnormalities, retinal degeneration, anosmia, cerebellar or other brain anomalies, polydactyly, bronchiectasis and infertility. The paper presents a familial case of oral-facial-digital syndrome type 1 in 14 year old girl suspected to polycystic kidney disease.

CONCLUSIONS

Molecular testing in daughters of known OFD1 mutation carriers and mothers of affected daughters seems to be reasonable. Not each case of policystic kidney disease which looks like autosomal dominant policystic kiedney disease is actually the above disease. The insight into the pathogenesis of ciliopathies is mandatory for understanding these combined congenital anomaly syndromes of seemingly unrelated symptoms of hepatorenal and pancreatic fibrocystic disease. Close interdisciplinary approach is mandatory in terms of efficient and reliable diagnostic and therapeutic interventions in patients presenting with ciliopathies.

Serum interleukin 6 levels as an early marker of acute kidney injury on children after cardiac surgery

BACKGROUND

Cardiosurgical operations in cardiopulmonary bypass (CPB) constitute a risk of acute kidney injury (AKI).

OBJECTIVES

The aim of the study was an assessment of AKI risk in children within the first 24 hours after CPB cardiac surgery, evaluating serum interleukin 6 (sIL6).

MATERIAL AND METHODS

The study included 47 children with congenital heart disease operated in CPB. Blood samples were taken before the procedure (0 hour) as well as at 2, 6, 12, 18 and 24 hours after the operation.

RESULTS

AKI was confirmed in 19 children. The mean sIL6 concentration in the AKI compared with non-AKI group was: 180.6 vs. 93.7; p = 0.0017. The maximum sIL6 in the AKI group was obtained at 2 hrs after CPB (350.36 pg/ml). Logistic regression analysis for AKI development depending on the value of sIL6 at 2 hrs after CPB proved that every rise of sIL6 by 100 pg/ml increased the chance of AKI development by 70% (p = 0.0161). With every circulatory arrest time prolongation by 10 minutes for a given sIL6 concentration, the chance of AKI development increased by 47% (p = 0.0407). AKI risk at 2 hrs after CPB, for a sIL6 cut-off point amounting to 185 pg/ml, increased more than 3-fold (AUROC - 68%).

CONCLUSIONS

Determining sIL6 in children after cardiosurgical operations at 2 hrs after the procedure constitutes a good, yet not a perfect marker of AKI risk development. Nomograms of the constant risk values of AKI were worked out presenting the ranges of values in relation to serum IL6 concentrations and the child's body mass, age and the time of circulatory arrest.

[Early markers of acute kidney injury in newborns]

The incidence of acute kidney injury (AKI) at neonatal intensive care units (NICU) is estimated as 6-24%. Traditional AKI markers i.e. serum creatinine (SCr) concentration, fractional sodium exertion, urine sodium concentration and renal failure index--are low sensitivity and low specificity markers but beside remain very late ones. Serum creatinine concentration arises 48 hours after renal tissue damage. The paper presents contemporary knowledge concerning concentration reference ranges of some early AKI biomarkers (NGAL, hKIM1, OPN, IL18)--either in term or preterm newborns. The most current reports about chosen AKI biomarkers in newborns with uncomplicated clinical course and in children with AKI within the course of sepsis or after cardiopulmonary bypass surgery--were discussed. Disposing of the reliable clinical data referring to early AKI biomarkers constitutes a valuable aid for clinicians who having got to know about the actual risk possess the time for proper clinical interventions.

Should the Lopot-Plot Be Used in Daily Practice to Optimise Hemodialysis Treatment?

The paper presents an application of the Lopot-plot, which compares the timeaveraged concentration (TAC) and the time-averaged deviation (TAD) of the weekly dialysis cycle, to comprise the results of intensive computational study. The presented case is based on 420 one-week-cycle simulations to verify the consequences implied by the change of the treatments schedule from nonuniformly to uniformly distributed over the week. The concept of steady state is explained and utilized to obtain periodical runs of the urea concentration. The presented graphs encouragingly indicate the potential of such plots in presenting results of multivariable intensive computations that should be advisably performed during the planning process of hemodialysis treatment.

The effect of peritoneal dialysis method on residual renal function in children

We set out to assess the effect of continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) on residual renal function (RRF) in children with end-stage renal disease (ESRD). In 101 children (age: 8.84 +/- 5.25 years; 44 on CAPD, 57 on APD) over 36 months, we evaluated RRF [as daily diuresis (DD) in mL/kg/24 h and mL/m2/24 h], glomerular filtration rate [GFR (in mL/min/1.73 m2)], ESRD cause, presence of arterial hypertension (HTN), biochemical parameters, peritoneal equilibration test (PET), adequacy [as total weekly Kt/V (twKt/V) and creatinine clearance (twCCr)], and infectious complications of PD. Initially, the CAPD and APD groups did not differ significantly in DD, but mean GFR was significantly higher in the APD group (p < 0.05). In the CAPD group, the volume of high osmolarity PD fluid was significantly lower (p < 0.05), and the rates of peritonitis and exit-site infection and of aminoglycoside use were higher (p < 0.001, p < 0.05, and p < 0.005 respectively). Over 36 months, the mean twKt/V and twCCr were within norms in both groups, but were higher in APD, significantly so (p < 0.05) for twKt/V at 24 and 36 months and for twCCr initially. In both groups, RRF decreased systematically, with a significantly lower (p < 0.05) rate of DD (mL/m2/24 h) and GFR decline in the first year in CAPD, but without a difference in the next 2 years. The longest RRF preservation was in children with tubulointerstitial nephropathies, particularly hypoplasia and dysplasia (p < 0.05). Children with hemolytic uremic syndrome (HUS) and hereditary nephropathy were at the highest anuria risk. Compared with the 22 children (7 CAPD, 15 APD) who became anuric, the 20 children (10 CAPD, 10 APD) with RRF preserved for 36 months had a higher DD and GFR before dialysis onset; higher hemoglobin and albumin; and lower HTN prevalence, cholesterol, triglycerides, and proteinuria (p < 0.05). Risk of anuria during 36 months did not differ significantly between the CAPD and APD groups. In children on CAPD or APD, risk factors for RRF loss include HUS, hereditary nephropathy, low diuresis and GFR before dialysis onset, HTN, anemia, hypoalbuminemia, hyperlipidemia, and proteinuria. Compared with children on APD, those on CAPD show better preservation of RRF during year 1, although the risk of anuria seems to be the same for both methods. In children with risk factors for rapid diuresis loss, CAPD might be considered the preferred initial dialysis method.

[Does diagnostic and therapeutic management of urinary tract infections remain still controversial in children?]

The paper presents controversial issues in diagnosis and management of urinary tract infections (UTIs) in children, with respect to diagnosis and so called chronic antibiotic prophylaxis in children with UTI and coexisting vesicoureteral reflux. It should be remembered, that there is a risk of development of chronic kidney disease in adulthood in those who suffered UTIs in childhood.

[Effectiveness of plasmapheresis in adolescent myasthenia gravis treatment]

BACKGROUND

Myasthenia gravis (MG) is a disease with autoimmune background. Impaired neuromuscular transmission is caused by blockage of acetylcholine receptors on postsynaptic membrane by circulating specific antibodies. Recognition of myasthenia gravis in children, especially its ocular type, may be difficult due to occurrence of similar clinical symptoms in other diseases like ecephalomyopathies. MG is characterized by variety of clinical symptoms and their alternations during excercise and rest.

AIM OF THE STUDY

Case report of nearly 18-year-old girl with generalized type of MG.

MATERIAL AND METHODS

Before hospitalization the girl had been treated psychiatrically for 6 months due to suspicion of conversion disorders. After performance of clinical test and electro-neurophysiological examinations mysathenia gravis was diagnosed and conservative treatment was instituted. Additionally, on the ground of low effectiveness of the treatment, sterydotherapy and immunosuppressive treatment were instituted without marked clinical improvement. Thymectomy was also low effective. Thymic inflammation was recognised histopathologically. Only after performance of 5 plasmapheresis was significant clinical improvement achieved.

CONCLUSION

Plasmapheresis may be used not only in the treatment of myasthenic crisis but also in the treatment of drug-resistant mysthenia gravis.

[Non-structural abnormalities of CNS function resulting in coincidence of endocrinopathies, epilepsy and psychoneurologic disorders in children and adolescents]

BACKGROUND

In the population of children and adolescents, epilepsy affects approximately 1% of cases, nonepileptic seizures are seen in approximately 3%, and endocrine disorders are several times more common. For this reason, coincidence of endocrine disorders and epilepsy and psychoneurologic disorders is frequent. Much less common are structural abnormalities (tumors, developmental abnormalities), and especially non-structural CNS abnormalities, resulting in coincidence of both disorders. There are no reports available in the literature that would address the problem.

AIM OF THE STUDY

1) Assessment of the frequency of coincidental epilepsy and endocrine disorders in patients without structural CSN abnormalities treated as outpatients and inpatients of Department of Endocrinology University Children's Hospital of Krakow. 2) Presentation of diagnostic and therapeutic difficulties in these patients, and 3) An attempt at defining the common etiology of both disorders.

MATERIAL AND METHODS

On the basis of ICD code patients with coincidance of endocrine disorders, epilepsy and psychoneurologic disorders were selected from several thousands of children treated between 2000 and 2009 in Pediatric Endocrinology Department. The neurologic disorders were diagnosed and treated in Chair and Department of Children's and Adolescents Neurology or in another pediatric neurology center.

RESULTS

Various forms of epilepsy (symptomatic or idiopathic) and other psychoneurological disorders (disorders of behavior and emotions, obsession-compulsion syndromes, stereotypias, aggression, autoaggression, or hypothalamic obesity) coincident with one or more endocrine disorders, such as growth disorders, disorders of pubertal development, obesity, thyroid diseases, adrenal diseases, hyperprolactinemia, hypoparathyroidism and ion metabolism disorders were diagnosed in 49 patients. The group included: i) children after cranial irradiation and chemotherapy due to medulloblastoma (3 patients), oligodenroglioma (1 patient), ependymoma (1 patient), optic chiasm glioma (2 patients), suprasellar germinal tumor (1 patient), ii) children with Hashimoto encephalopathy (2 patients), iii) children with Prader-Willi syndrome (20 patients), with Klinefelter syndrome (10 patients), with Albright syndrome (9 patients). Of the 49 patients, a group of 6 children representative for individual disorders was selected. In those patients, the etiology of both endocrine disorders, epilepsy and neuropsychiatric disorders was suspected to be common, and the diagnosis was usually delayed.

CONCLUSIONS

1. Cranial irradiation and chemotherapy, encephalopathy associated with Hashimoto disease and some of the syndromes with the chromosomal and genetic background are the causes of non-structural CNS abnormalities and coincidence of endocrinopathies, epilepsy and psychoneurologic disorders. 2. MR/CT CNS imaging should be performed in any case of central neurological disorders, disorders of behavior, epilepsy or seizures, but also in patients with delayed psycho-motor development, delayed or accelerated growth and pubertal development. All of the above-mentioned manifestations may be symptoms of structural CNS abnormalities and their early treatment determines the child's future. 3. Excluding structural CNS abnormalities allows for forming suspicions associated with diseases resulting in non-structural disorders of the CNS function, predisposing to coincidence of endocrine and neurological disorders. 4. In the diagnosis of Hashimoto's encephalopathy, a decisive factor is exclusion of structural, infectious, traumatic and metabolic causes, intoxications, epilepsy and presence of neuropsychiatric symptoms in patients with high level of against TPO antibodies. In cases of steroids resistance, a good therapeutic effect may be achieved by plasmapheresis, Rituximab therapy and progestagene inhibition of the menstrual cycle.

Correlation between fat mass and blood pressure in healthy children

Obesity is a well-known risk factor for arterial hypertension. The aim of this study was to analyze which surrogate marker of adiposity, i.e., body mass index (BMI) or fat mass (FM), as measured by bioimpedance analysis (BIA), best correlated with blood pressure in healthy children. Body weight, height, and casual blood pressure (BP) were measured in 193 healthy children (103 boys), aged 8-16 years. Body composition was determined by BIA. The correlation between BMI and age was linear, whereas the correlation between percentage of FM and age was nonlinear and it was different in boys and girls. Blood pressure standard deviation scores (SDS) correlated with FM SDS (BIA) over the entire normal range (systolic: r = 0.26, p = 0.002; diastolic: r = 0.33, p < 0.01). An evaluation of the children based on BP (three groups: BP < 50th percentile, 50th < BP > 95th percentile; BP > 95th percentile) revealed that hypertensive children had a higher BMI (17.6 vs. 19.4 vs. 26.2 kg/m(2), respectively) and a greater FM (14.0 vs. 16.8 vs. 30.2%, respectively). In conclusion, the divergence in FM in healthy boys and girls can be determined by BIA but not by BMI. In healthy children, BP within the entire normal range correlated with FM, children with established hypertension presented with a significantly higher FM. The study points to FM as an important determinant of BP pressure in obese and non-obese children.

[Peritonitis in the course of peritoneal dialisis caused by Haemophilus influenzae with BLNAR phenotype]

Most common bacterial species causing peritonitis in the course of peritoneal dialysis (PDP) are coagulase-negative staphylococci, Staphylococcus aureus and streptococci. Haemophilus influenzae is rarely associated with PDP. Hereby we present the first known case of APD-associated peritonitis caused by non-type able H. influenzae (NTHi) presenting the beta-lactamase negative, ampicillin-resistant (BLNAR) phenotype. An 18 year old boy who had been treated with the APD for 12 months due to SLE was admitted in good general condition with diagnosis of PDP. Standard diagnostic and therapeutical procedures were initiated. Dialysis fluid was turbid with cytosis of 435 WBC/ml. From dialysis fluid pure culture of Gram-negative coccobacillus was isolated. The isolate was identified as a BLNAR phenotype. The same bacterium was isolated from nasal swab. Blood cultures were negative. After evaluation of antimicrobial susceptibility the treatment was changed for the oral ciprofloxacin. The treatment was successful. Control tests 2 days later revealed cytosis of 15 WBC/mm3 and control cultures of peritoneal fluid were negative. After two weeks of treatment the patient was discharged in a good condition. Haemophilus influenzae is a bacterium frequently colonizing the nasopharyngeal cavity. A PCR-based method allowed to classify isolates as NTHi. Infection was probably of the respiratory origin as the isolates (from peritoneal fluid and nasal swab) were undistinguishable. There are only few reports describing this species as an ethiologic agent of peritonitis. This case prove that Haemophilus species should be taken into account as a possible aethiologic agent of PDP, especially in patients on immunosupression with carrier state of H. influenzae in the upper respiratory tract. This kind of microorganism requires specific conditions during its growing in vitro. Identification of its sensitivity to antibiotics is essential in order to detect strains of BLNAR phenotype, as it is a crucial part of an effective antibiotic therapy.

[GFR estimation based upon cystatin C concentration as a substance marker--proposal of a new formula]

Glomerular filtration rate (GFR) estimation is very important for evaluation of kidney function. Its calculation is based upon a 24 hour urine collection and serum creatinine concentration values or on the basis of developed for this purpose numerous formulas with special attention dedicated to the abbreviated MDRD formula and Cockcroft-Gault formulas for adults and Schwartz et al. and Counahan et al. formulas for children. Future expectations are related to GFR estimation based on serum cystatin C concentration and formulas specially developed for this cause. The aim of the study was the comparative analysis of GFR results based on Filler's and Lapage's, Grubb's et al. and Schwartz's et al. formulas and reference values obtained in 93 patients after measuring iohexol concentration after its single injection. Significant differences between the results obtained from employed formulas for high, as well as for low values of GFR were shown, respectively. Serial calculations were performed allowing to finding out a new prescription for GFR calculation. A new formula for GFR calculation based on cystatin C concentration: GFR = -7.28+82.29 x C(-1) was proposed.

[Erytrocyte membrane change due to the chemical treatment studied with atomic force microscopy]

The influence of some selected pharmacological compounds on the structure of human erythrocytes (red blood cells, RBCs) has been studied by means of an atomic force microscopy (AFM). The imaging has been done both in the air environment on the fixed cells, and in the liquid (physiological conditions). It was shown that RBCs are very sensitive to osmotic changes in the solution. Increased NaCl concentration in the solution to a value higher than 0.9% leads to the characteristic changes of the erythrocyte from a discoid-like shape to a very irregular one, the so-called "echinocyte", with a lot of ledges. After exposition on nifedipin the modification of the erythrocyte surface morphology was observed. Based on the contact and non-contact AFMs study the consecutive stages of RBCs surface modification were observed. Scanning electron microscopy pictures of erythrocytes were presented for comparison.

Residual renal function in children treated with continuous ambulatory peritoneal dialysis or automated peritoneal dialysis--a preliminary study

Our study assessed the influence of mode of dialysis [continuous ambulatory peritoneal dialysis (CAPD) or automated peritoneal dialysis (APD)] on residual renal function (RRF). The study retrospectively examined 30 children [15 on CAPD, mean age: 8.85 +/- 5.15 years; and 15 on APD, mean age: 10.17 +/- 3.63 years (nonsignificant)], followed for at least 12 months, for whom these methods were initial mode of treatment. Arterial hypertension was found in 80% of the children on CAPD and in 67% on APD. Parameters that were analyzed included 24-hour urine output; residual glomerular filtration rate (GFR); adequacy based on total weekly Kt/V urea and creatinine clearance; and hemoglobin, total protein, serum albumin, daily proteinuria, medications used, and causes of end-stage renal disease. After 12 months of decline in urine output, residual GFR was higher in children on APD (p = 0.06, nonsignificant). The difference in adequacy between CAPD and APD was nonsignificant, but a higher volume of dialysate was used in APD (p < 0.01). Proteinuria was present in 9 children on CAPD and in 6 on APD. In CAPD, we observed a negative correlation between the volume of dialysate and duration of treatment (p < 0.01, r = -0.79); in APD, a positive correlation (p < 0.0001, r = 0.89) was observed. In APD, we observed negative correlations between residual diuresis and duration of treatment (p < 0.0001, r = -0.9), serum albumin (p < 0.05, r = -0.6), and volume of dialysate (p < 0.001, r = -0.83). Residual renal function was better preserved in children with a glomerulopathy or a familial or hereditary renal disease than in those with pyelonephritis. Our results suggest that RRF is better preserved in children with a glomerulopathy or a familial or hereditary renal disease, especially in those treated with CAPD. Further studies are needed in larger groups of patients.

[The assessment of heart function in children with chronic kidney disease (CKD)]

THE AIM OF THE STUDY

The echocardiography evaluation of cardiac function in children with CKD.

PATIENTS AND METHODS

30 children (17 males, 13 females), aged 2-20 yrs with CKD 2-5. Left ventricular (LV) dimensions, LV ejection fraction (EF) and LV mass index (LVMI), as well mitral inflow velocity (E/A waves) and isovolumetric relaxation time (IRT) were evaluated.

RESULTS

Impaired diastolic heart function were ascertained in 12 patients (in 2 from 5 with CKD 3, in 3 from 10 with 4 and 7 from 14 with 5). Left ventricular hypertrophy was observed in 13 children with CDD 3-5 (4, 4, 5), and decreased ejection fraction in 2.

CONCLUSIONS

The vast majority of children with chronic kidney disease demonstrate an impairment of diastolic cardiac function.

[24-hour pulse pressure in children with chronic kidney disease]

The aim of the study was to assess 24-h pulse pressure (PP) and to determine relationships between PP and echocardiographic parameters of left ventricle in children with chronic kidney disease (CKD). The study population included 47 children (mean age: 13.11 yrs) with CKD treated conservatively (n=14), with hemodialysis (HD) (n=13) and automated peritoneal dialysis (APD) (n=20). Retrospectively, antropometrical data, office blood pressure, ambulatory blood pressure monitoring (ABPM) variables and LV parameters in echocardiogaphy were analyzed. In study subjects, hypertension (HTN) was present in 25 (53.19%) and in 29 (61.7%) when based on office blood pressure and ABPM respectively. The prevalence of HTN was the highest in predialysis patients. 21 (44.6%) of children had left ventricular hypertrophy (LVH), which was the most frequently found in HD group. The mean PP value was 45.26 +/- 7.56 mmHg and was similar in all groups. Positive correlations were found between PP and weight (p < 0.001), height (p < 0.05), body surface area (p < 0.01) and LV measures (LV mass, LV posterior wall thickness and diastolic diameter of LV, all p < 0.05). Children with PP above median had tendency for greater LV mass (p = 0.06). There was no difference in severity of blood pressure and PP in children with/without LVH. However, in 45% of patients LVH was noted in whom the value of PP was greater than calculated normative value of PP (95 centile). HTN and LVH is common in children with CKD. A mean PP in children with CKD is lower when compared to adult population with CKD. The results confirm that PP increases with the age and an increasing PP has an influence on the changes of LV geometry. Assessment of PP in ABPM might help in identifying those with abnormal LV geometry.

[Shall we recognize chronic renal insufficiency as a pediatric controversy?]

Introduction in 2002 the new, 5 - degree classification of chronic renal disease which has been based upon calculation of glomerularfiltration rate (eGFR)--on the one hand took note of the problem of kidney injury and decrease of active nephrons' number which may accompany various renal diseases--on the other--allowed to define the risk factors, which include first of all--hypertension and persistent proteinuria. Chronic renal disease is diagnosed in each clinical case, where a decrease of glomerular filtration rate below 90 ml/min/1.73m2 had occurred with or without kidney injury or when a decrease of glomerular filtration rate maintains for at least 3 months on the level < 60 ml/min/1.73 m2. Delayed diagnosis of chronic kidney disease leads to manifestation of chronic renal failure symptoms and excludes an effective nephroprotective treatment. In the face of a large number of potential causes of chronic renal disease which may be encountered by a pediatrician, all children which are numbered among the high risk group--should have eGFR calculated--initially according to the simplest Schwartz formula. Setting of a diagnosis of chronic renal failure only on the basis of serum creatinine concentration doesn't allow to notice hyper-filtration phenomenon and should not be a daily clinical practice. Fundamental approach of therapeutical management in in children with chronic renal disease is slowing down the disease progression and/or elimination or modification of some risk factors. Each child with diagnosed chronic renal disease should be referred to specialist outpatient pediatric nephrology clinic.

[Body mass index (BMI) or bioimpedance analysis (BIA) --which method enables a better assessment of fat mass in children?]

A comparison of accuracy between electrical bioimpedance analysis (BIA) and body mass index (BMI) for fat mass evaluation in children was the aim of the study. One-hundred and ninety three healthy children (90 females, 103 males) were enrolled. The mean age of the studied population was 11.8 years (+/- 2.2), mean weight equalled to 42.6 (+/- 12.8) kg and mean height-151.1 (+/- 13.5) cm. BIA measurments were performed by multifrequency (1; 5; 50; 100 kHz) BIA 2000M analyzer using BIANOSTIC electrods. Calculations of free fat mass and fat mass were performed using Nutri 4 Data Input Software (Germany). The LMS method for percentile charts of FFM and FM acording to height has been applied and results for boys and girls were drawn separatelly. Percentile charts of FM and BMI were compared. Different shape of curves of FM content and BMI for boys during puberty was noticed. BIA allows for precise fat mass content evaluation in children and its use should be disseminated.

[Are permanent catheters a safe vascular access in chronically hemodialysed children?]

The paper's aim is an analysis of the complications related to permanent catheters used as a vascular access in chronically hemodialysed (HD) children. From 1998 to 2005. 34 surgically implanted permanent catheters were used as a vascular access for HD in 21 patients at average age of 13,6 (range 5-26) yrs. The catheters were placed mainly into right internal jugular vein or less often into left i.j.v., left subclavian v. and femoral veins. In 12 patients only one catheter was used for HD, in the others--the catheters had to be replaced. The average patient's observation period was 17 (range 3-73) months and the average catheter's usage period was 10,6 (range 0.5-40) months. In 9 children the catheter function period was shorter than 12 months. No complications were observed only in 2 patients with short observation's period (< 6 months). The complication frequency rate amounted to 0,7 epizode/observation month (range 0.0-5.0), the thrombotic complications rate was 0,3 and the infectious complications index was 0.2 episode/month, respectively. The rare mechanical dysfunctions were noted in 2 patients (the catheter's rupture and falling out). The serious thrombotic complications were noted in 2 cases (carotic veins bilateral severe stenosis with marked collateral circulation accompanied and extensive thrombosis of the femoral and iliac veins). The diagnostic and therapeutic angio-graphic investigation of carotic venous system and catheter placement were performed in 2 patients. The Urokinase was used in 13 children (repeatedly in 8 HD subjects). In the follow up, among 34 analyzed catheters--the function of 11 (32%) was appropriate, 13 (38%) were exchanged, 6 (18%)--surgically replaced, in 6 cases the catheters were removed with subsequent changing the vascular access or dialysis modatlity (in 1 case on patient's demand).

CONCLUSIONS

The use of permanent catheter as a chronic vascular access for HD in children is associated with high rate of complications. However, this type of vascular access should be considered as a last resort when creation of the other vascular access is unlikely.

[Early laboratory markers of acute renal failure]

Acute renal failure is a sudden clinical condition caused by loss of renal ability to maintain homeostasis. Despite significant advances in renal replacement therapy--the mortality rate in ARF patients is still very high--ranging from 20% to 50%. Differential diagnostics, especially between acute prerenal and intrinsic acute renal failure is an extremly important stage in patient evaluation process. In the article--the authors present a short and concise profile of novel, more and less promising for future diagnostic ARF biomarkers: neutrophil gelatinase associated lipocalin (NGAL), sodium/hydrogen exchanger isoform 3 (NHE3), human kidney injury molecule-1 (hKIM-1), interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 18 (IL-18), urinary cysteine-rich protein (Cyr 61), urinary glutathione-S-transferase (GST), cystatin C, spermidine/spermine N-acetyl transferase (SSAT) and actin) which are recently either in the animal model research stage or during preliminary clinical studies. Extension of research and wideninig of knowledge about the discussed novel, early markers of ARF--would permit for quicker introduction of specifically guided therapy and might improve the prognosis of ARF patients in the near future.

[Mycophenolate mofetil in treatment of childhood nephrotic syndrome--preliminary report]

The management of nephrotic syndrome (NS) in children remains a clinical challenge for pediatricians and pediatric nephrologists. Especially, the treatment of patients with steroid-resistant (SR) and steroid-dependent (SD) nephrotic syndrome, because they are at risk for developing complications from prolonged exposure to steroids, CsA and alkylating agents. Mycophenolate mofetil (MMF) is a selective and reversible inhibitor of inosine monophosphate dehydrogenase used above all in transplantology and recently also in patients with nephrotic syndrome. The aim of this study was to tentatively assess the usefulness and the safety of MMF as an immunosuppressive agent in children with steroid-resistant NS, in whom remission was not obtained with previous treatment regimens, and those with steroid-dependent NS, in whom severe adverse reactions were observed in steroid and cyclosporine therapy. The study included 19 children with NS (11 girls, 8 boys) aged 7 to 19.5 years (a mean of 13.5), treated at the Deptartment of Pediatric Nephrology. The duration of disease was from 1 to 16 years (a mean of 9.3). The patients were divided into 3 groups: I--9 children with steroid-dependent NS; II--6 children with steroid-dependent NS and episodes of steroid-resistance; III--4 children with steroid-resistant NS. All patients in groups II and III required multi-drug therapy (prednisone, cyclosporine A, methylprednisolone, chlorambucil, cyclophosphamide) before MMF was introduced. MMF was administered orally: 180-600 mg/m2 body surface/dose, twice daily. The follow-up period lasted for 4 to 16 months (a mean of 7.7). The clinical outcome analysis included decrease or disappearance of proteinuria, clinical improvement and/or possibility of tapering therapy intensity, especially the dosage of steroids and/or CsA. Also, renal function was monitored with serum cystatine C concentration. Particular attention was paid to adverse effects of MMF upon the gastro- intestinal tract and/or opportunistic infections. All medication (apart from MMF) could be discontinued in 4 patients; in 15 cases, prednizone dose was reduced and in 9 cases CsA dose was reduced or discontinued. In group I (SD) steroid treatment could be reduced from a mean prednisone dose of 22.8 to 3.6 mg/m2/48 hours (p=0.018), in groups II and III, in spite of 50 % reduction of a mean prednisone dose, the difference did not reach statistical significance. During MMF therapy Csa treatment could be reduced from a mean CsA dose 4.3 to 2.9 mg/kg/24 hours (p=0.008). Improvement or preservation of stable renal function was observed in all patients--cystatin C levels decreased significantly from a mean 1.35 to 0.96 mg/l (p=0.007). Adverse reaction to MMF (abdominal pain) was observed in 2 patients (nausea, vomiting, diarrhoea in 1, CMV infection in 1). The initial clinical observation of MMF treatment in nephrotic patients shows its best effect in the group of patients with steroid-dependent NS. MMF can safely be used in children with NS. The introduction of MMF allows for reduction of other chronically used medications, especially CsA and steroids.

[Preliminary assessment of heart function in chronically dialysed children]

Renal replacement therapy has become a recognized treatment modality of children with chronic renal failure (CRF). Despite of unquestionable progress in heamodialysis treatment quite high morbidity and mortality still remain a serious problem among pediatric patients. The most common cause of death in haemodialyzed and transplanted patients are cardiovascular complications. The main aim of the study was an echocardiographic (ECHO) assessment of selected cardiac parameters in heamodialyzed children.

METHODOLOGY

16 chronically dialyzed (6 HD, 10 PD) children participated in the study (10 M, 6 F), aged 5-18,5 yrs (x=12.2 +/- 3.8 yrs). Echocardiography examinations were carried out with HP 5500 device and S4 ultrasound probe of variable frequency. Diastolic and systolic LV dimension, ejection fraction (EF) and LV mass index (LVMI) were evaluated. By means of pulsating Doppler method mitral flow peak E and A velocity and isovolumetric relaxation time (IRT) were assessed.

RESULTS

On the basis of ECHO examinations 3 groups were singled out: A (n=3) of normal heart function, B (n=3) of impaired systolic and diastolic heart function and C (n=10) of normal systolic and impaired diastolic heart function. In group of children with severe cardiac lesion (B group) a higher LV mass (A vs B vs C: 74.7 vs 119.9 vs 73.5 g/m2) and statistically significant lower ejection fraction (68.1 vs. 33.7 vs. 65.9%) were ascertained. These children were anuric (996 vs. 0 vs. 1112 mild), their systolic (102.1 vs. 118.4 vs. 117,9) and diastolic (64,4 vs. 84.8 vs. 77.9) blood pressure were significantly higher, so was the number or hipotensive medications (0.33 vs. 1.72 vs. 1,44).

CONCLUSIONS

The great majority of chronically dialyzed children demonstrates an impairment of cardiac function mainly of diastolic parameters. Anuria and hypertension stand for a significant risk factor of cardiac lesion.

[Chronic peritoneal dialysis in infants--preliminary results of the multicenter survey]

We retrospectively analysed peritoneal dialysis treatment in 29 infants dialysed in 9 paediatric centres in Poland in the years 1993-2004. The mean age at the start of dialysis was 4.9 +/- 3.5 months (range 2 days to 11 months), mean body mass 5.6 +/- 2.5 kg (range 2.5 to 11 kg). The mean duration of PD was 6.8 +/- 3.9 in the first year of life and total duration of the therapy 34 +/- 27 months. Of the 29 infants 4 died (2 in infancy), 11 underwent renal transplantation, in 2 children PD was stopped (they received a conventional treatment) and 12 were still dialysed at the date of data collection. The peritonitis rate was 1/9.5 patient-month and exit site infection rate 1/16 patient-month up to 1 year of life. 9 children (31%) required hernia repairs and in 9 catheters were replaced. Chronic peritoneal dialysis in infants is associated with high risk of infections and surgical complications and remains a challenge for paediatric nephrologists.

[Does daily hemodialysis influence urea kinetic modeling (UKM) coefficients?--Preliminary report]

Large number of data shows beneficial effects of implementing daily hemodialysis (DH) upon the outcome in patients dialysed previously in 3 times a week hemodialysis (3H) schedule. The mechanisms responsible for this phenomenon are still unclear, despite the time of low-flux DH sessions is shortened almost by half. Evaluation of the effect of doubling the number of hemodialyses per week upon so called cellular clearance (intercompartmental diffusion coefficient, Kc) computed in 2 pool-model was main aim of this study. 6 chronically dialysed patients (previously 3x per week) were subjected to DH. Based upon output data from UKM and weekly KT/V, the time for each DH session was computed, with no change in Kd (dialyser clearance). Kc was estimated from double-pool volume variable model equations and rebound. By the use of almost similar dialyser clearances in 16 conventional and 29 DH modeling sessions, estimated Kc values had been found non significantly higher in DH: (323.16; S.D. 187.86 vs. 268.80; S.D. 104.09 ml/min; p=0,68). Mean ultrafiltration/pre-dialysis body weight ratio (UFR/BW1) was 4,97 (S.D. 2.27)% in conventional hemodialysis and 3.66 (S.D. 1.46)% in DH. Mean dialysis index Kt/V values had decreased in DH (0.79; S.D. 0.17, vs. 1,34 (S.D. 0.26). Mean UFR/W1 ratio correlated negatively with Kc either in conventional or in DH (r=-0.653; p = 0.006 and r=-0.552; p=0.0036, respectively). Statistically significant negative correlation between Kt/V and Kc was found only in DH subjects (r=-0.466, p =0.010). The authors concluded, that increased Kc observed in patients subjected to DH may be responsible for better dialysis efficacy in patients switched into this treatment modality.

[Heterozygotic mutation in NPHS2 gene as a cause of familial steroid resistant nephrotic syndrome in two siblings--case report]

Within recent years the number of children with focal segmental glomerulonephritis (FSGS) has increased. A significant progress in defining of molecular basis of the disease has been made. Gene mutations for nephrin, podocin, WT1, alpha-actinin 4 cause the damage of filtration barrier of glomerulus and proteinuria in consequence. A girl (S.G.) became ill at the age of 3.5, suffering form steroid-resistant nephritic syndrome (SRNS) with microscopic hematuria. The renal biopsy showed FSGS accompanied by a complete diffuse effacement of podocyte food processes. Despite intensive and regular immunosuppressive therapy, remission was not achieved. In the control renal biopsy performed a year after cyclosporin A had been applied, 50% of globally sclerosed glomeruli as well as some features of post-cyclosporin damage were found. The girl required renal replacement therapy at the age of 10.5. Dialyzed at the adult dialysis centre she died at the age of 11.5. A boy S.P. was diagnosed with SRNS when he was 11.5 years old. The renal biopsy was performed after one month of treatment and showed mesangial proliferation and diffuse effacement of podocyte food processes. After chlorambucil treatment remission was not achieved, and after methylprednisolon pulse therapy only the reduction of proteinuria was achieved. In a control renal biopsy 10 out of 13 glomeruli were globally sclerosed. At the age of 17 the patient showed chronic renal failure with a fast progression of the disease. In September 2000 the boy started renal replacement therapy, an in June 2001 he received a renal transplant without the recurrence of FGS. In 2001 a heterozygous mutation (A284V) in gene NPHS2 was found in both of the siblings. Within the confines of the clinical project ESCAPE Trial another genetic examination was performed. In the boy one missense mutation on one allele (A284V) and the R229Q polymorphism on the other allele were found. In this family the father is bear. ing the A284V mutation and the mother the R229Q variant. These results prove that this disease is due to alterations of the podocin gene in the described family.

Does a late referral to a nephrologist constitute a problem in children starting renal replacement therapy in Poland? – a nationwide study

BACKGROUND

It is estimated that 20-50% of adult patients start chronic dialysis therapy without prior contact with a nephrologist. The aim of this nationwide study was to assess clinical and metabolic status of children at the start of chronic dialysis in Poland with regard to the timing of the referral to a nephrologist.

METHODS

We studied data of 180 children (mean age 14+/-6 years) undergoing chronic dialysis in 13 (out of 14) dialysis pediatric centres in Poland. Patients were classified as early referrals (ERs) when they entered the dialysis programme at least 1 month after the first referral to a nephrologist or late referrals (LRs) when the dialysis was introduced within 1 month from the first visit.

RESULTS

Seventy-nine percent of pediatric patients were referred early (ER) to the dialysis centre and 21% were referred late (LR) and had to start dialysis within a month. When starting dialysis, LR patients had significantly higher levels of urea and phosphate as well as lower calcium and haemoglobin in comparison with ERs. Hypertension, pulmonary oedema, fluid overload, treatment in the intensive care unit (ICU) and body mass index (BMI) below 10th percentile turned out to be more frequent in the LR group. Peritoneal dialysis (PD) was used as the first method of dialysis in 59% of ERs and 46% of LRs. The majority of ER patients was treated in the predialysis period with calcitriol, phosphate binders and low protein diet (84%, 89%, 92% of all children, respectively), and 20% of them received epoetin. In the up to 3 years observation of our initial cohort, we also found that the patients who were referred late were less likely to receive kidney transplant (P = 0.02).

CONCLUSION

The results of the study indicate that the LR to a pediatric nephrologist was associated with poorer clinical and metabolic status of children entering chronic dialysis programmes.

Hypertension in dialysed children: the prevalence and therapeutic approach in Poland--a nationwide survey

BACKGROUND

The aim of this nationwide analysis was to assess the incidence and current treatment profile of arterial hypertension in children undergoing chronic haemodialysis or peritoneal dialysis and attitudes of paediatric nephrologists towards the choice of antihypertensive drugs in their patients.

METHODS

The study group consisted of 134 children (89 males, 45 females, mean age 10.7+/-5 years) from all 13 paediatric dialysis centres in Poland. The data were gathered through a questionnaire for each patient dialysed in November 2004.

RESULTS

The overall incidence of hypertension in the study group was 55% (74 of 134 patients; 47 males, 27 females). The incidence rate was similar in boys and girls (53 vs 60%) and in those on haemodialysis and peritoneal dialysis (56 vs 54%). Chronic glomerulonephritis as an underlying renal disease was significantly more frequent in the hypertensive than in the normotensive subjects (37 vs 10%, P = 0.004). Residual urine output was higher in normotensives (41 vs 10 ml/kg body weight; P < 0.001). Among those treated with antihypertensives: 32% were treated by monotherapy, 36% received two drugs, 22% received three drugs, while 7% received > or = 4 drugs. The therapy was effective in only 57% of subjects. We observed no differences in biochemical and clinical parameters between those who responded to the therapy and those who failed to do so. Calcium channel blockers constituted the most frequently administered class of drugs [73% of children; in 43 out of 48 (90%) combined with other drugs, but in 11 out of 24 (46%) as a monotherapy]. In monotherapy, angiotensin-converting enzyme inhibitors and calcium channel blockers were administered most frequently.

CONCLUSION

We conclude that the incidence of hypertension in dialysis children in Poland is high (55%). The effectiveness of antihypertensive treatment is rather low (58%) and the choice of drugs is limited.

[Consequences of thallium poisoning in adolescent]

INTRODUCTION

Thallium poisoning appears very rare in developmental age and its consequences are quite different. The aim of this study was to characterised the course of thallium poisoning in adolescent and especially electroneurophysiological consequences of it.

PATIENT AND METHODS

In a 15 year old boy with sensory-motor polyneuropathy thallium poisoning was recognised in the third week duration of the symptoms. Hemodialysis and hemodiaperfusion were used in the therapy. Data of the repeated electroneurographic and videoEEG examinations were collected.

RESULTS

First electroneurographic data showed axonal motor polyneuropathy. Control after 1 year presented the largest form of the motor-sensory polyneuropathy. On videoEEG tape rejestered in the 5th month of clinical symptoms of poisoning, present were tonic seizures (although EEG pattern was flat with short low voltage theta activity). After next the 3 months of encephalopathy and phenobarbital therapy, voltage of the EEG pattern was slightly higher without any background and seizure activity.

CONCLUSIONS

Thallium poisoning may result with catastrophic clinical consequences of polyneuropathy and encephalopathy. Electroneurographic and electroencephalographic changes 1 year after indicate that clinical consequences of the poisoning are un-remediable.

[New measurement techniques in biology and medicine: atomic force microscopy (part III)]

Biological samples can be investigated with atomic force microscopy (AFM) in either of two imaging modes: contact mode or tapping mode. Applications of fluid tapping mode AFM in biology and medical sciences are constantly growing and the data obtained with this technique are improving, especially in terms of resolution. Even dynamic processes can be observed almost as they would occur in vivo. AFM is a proven imaging technique that has recently gained attention in biomaterials due to its ability to analyze surface properties, non-destructively at nanometer-level resolution in ambient air or in fluid environments.

[New measurement technics in biology and medicine: atomic force microscopy (part II)]

At present, there are a lot of biological and medical research fields, where atomic force microscopy (AFM) is being successfully used. AFM has contributed to research in the investigation of DNA, RNA structure, nucleic acid--protein complexes, chromosomes, ligand-receptor binding, cell membranes, proteins, lipids, carbohydrates, living cells (yeasts, bacteria, neurons, erythrocytes, endothelial cells); it enables to monitor drug interactions with cells and tissues, to visualize changes in protein molecular structure and crystal growth. Unlike electron microscopes, samples do not need to be stained, coated or frozen. Recent work indicates that, in the near future, AFM may be employed in ultra-sensitive immunoassay detection without any kind of labeling for both qualitative and quantitative work. AFM is more than a surface--imaging tool in that force measurements can be used to probe the physical properties of the specimen, such as molecular interactions, surface hydrophobicity, surface charges, and mechanical properties.

[The new measurement technics in biology and medicine--atomic force microscopy]

Scanning probe microscopy (SPM) has recently become the most dynamically developing technique employed in research investigations. Atomic force microscopy (AFM) that uses a digitally-controlled scanner and a cantilever system with a measurement tip shaped as a cone with the apex radius of 2-50 nm and the application force of 10(-10) N, as well as a system of recording detectors, has allowed for identification of numerous biological structures in a nanometer scale. The paper presents a review of measurement methods that employ the atomic force microscopy and are being used in medicine and biology, along with major achievements accomplished owing to this technique by various investigators, including the authors themselves.

[The effect of recombinant human growth hormone on urea and creatinine kinetics and selected dialysis adequacy parameters in children with end-stage renal failure treated with peritoneal dialysis]

The aim of this work was to assess the effect of recombinant human growth hormone (rhGH) on the kinetics of urea and creatinine and selected indices of dialysis adequacy in children with end-stage renal failure treated with peritoneal dialysis. We studied 24 children on peritoneal dialysis, including 10 children aged 9-15.7 years (mean age 12.5 years) treated with 1-1.1 IU/kg/week of rhGH administered daily for 6 months. The control group included 14 patients aged 5.4-18.3 years (mean age 12.6 years). Kinetic modelling of urea and creatinine using Adequest was performed in all patients at baseline and after 3 and 6 months of follow-up. Total dialysate and urinary excretion of urea and creatinine (tUE and tCE, mg/min), total urea and creatinine clearance (tUC and tCC, L/week), weekly Kt/V, normalized total weekly creatinine clearance (ntCC, L/week/1.73 m2), total body water (TBW, kg), and absolute and percent change of TBW (DTBW, kg, and D%TBW, respectively) were calculated. Albumin level was measured and diet composition was analysed in all patients. Insignificant decrease in Kt/V was found after 3 and 6 months of rhGH treatment despite stable values of tUC (45.3 +/- 15 L/week vs 45.6 +/- 15 L/week, p = NS). Serum creatinine increased from 7.38 +/- 1.52 to 9.26 +/- 2.98 mg/dL after 6 months of rhGH treatment. Significantly higher values of delta %TBW were found among treated patients compared to the control group (1.23 +/- 0.7 kh vs 0.57 +/- 0.7 kg, P < 0.05). delta TBW in patients treated with rhGH was significantly higher during months 0-3 compared to months 3-6 (0.85 +/- 0.6 kg and 0.38 +/- 0.17 kg, respectively, p < 0.05). No significant changes in ntCC, albumin concentration and diet composition were found.

CONCLUSIONS

1. A trend to lower urea values in children treated with peritoneal dialysis was found after 3 months of rhGH treatment. Concomitant decrease in Kt/V may have resulted from increased TBW. 2. An increase in creatinine level was observed during rhGH treatment in children treated with peritoneal dialysis. Decrease in normalized total creatinine clearance (ntCC) and normalized dialysate creatinine clearance (ndCC) during rhGH treatment may have resulted from increased serum creatinine and not from decreased creatinine excretion. 3. Treatment with rhGH in children on peritoneal dialysis makes it difficult to interpret commonly used indices of dialysis adequacy such as Kt/V and ntCC.

[Use of modern microscopic techniques for examining dialysis membrane properties]

The aim of the study was the microscopic evaluation of internal structure of cuprophane and polysulfone membrane and their surface analysis before and after reprocessing. The investigations were performed using an optical measurement system (Digital Instruments), a scanning electron microscope (SEM) and an atomic force microscope (AFM). We confirmed by SEM that reprocessing completely removed biofilm from both membranes surface. The analysis based on AFM visualized channels in the examined membrane. The diameter of the channels varied from 150 nm for cuprophane to 380 nm for polysulfone. The roughness expressed as root mean square (RMS) was higher for cuprophane than for polysulfone membrane. The physical differences between nanostrucure of the examined membranes might be responsible for lower biocompatibility of cuprophane.

[Results of treatment with recombinant human growth hormone in children with growth retardation in end-stage renal disease]

The aim of the study was to estimate the results of recombinant human growth hormone (rhGH) treatment in children with end-stage renal disease (ESRD). 60 growth retarded children with ESRD (mean age 11.2 +/- 7.2 years) were treated with rhGH at a dose of 1-1.1 IU/kg/week. The time of observation was 24 months. Thirty children completed first year, 18--second year of treatment. The mean growth velocity prior to the treatment was 3.03 +/- 1.9, during first year of the study--7.52 +/- 2.42, during second year 6.68 +/- 2.87 cm/year. The negative correlation between growth velocity and patient's age (r = -0.39; p < 0.05) suggest the better growth results in younger children during rhGH treatment. The rhGH therapy is effective method of treatment in growth retarded children with ESRD. Side effects are rare.

[Bone metabolism markers and bone histomorphometry in children with chronic renal failure in predialysis period during growth hormone treatment]

The aim of the study was to estimate biochemical bone metabolism markers and bone histomorphometric parameters in children with chronic renal failure (CRF) treated with recombinant human growth hormone (rhGH). Twelve children with CRF aged 2-13.4 years were treated with rhGH 1-1.1 IU/kg per week and alfacalcidol. Bone biopsies were performed before and after 12 months of therapy. An increase in the biochemical markers of bone formation and bone resorption were noted. A statistically significant increase in mineral apposition rate (MAR) was observed in bone histomorphometry. The administration of active vitamin D metabolites enable proper bone mineralization in fast growing children with CRF during rhGH treatment.

Accuracy of hemodialysis modeling

BACKGROUND

One- and two-compartmental models of hemodialysis (HD) are well known. These models make it possible to analyze the course of treatment and to predict the effect of dialysis procedures. Mathematical modeling helps physicians to match dialysis therapy to the individual needs of the patient; however, the efficiency of the models depends on the accuracy of the coefficients. How to select coefficients in the case of one-compartmental models is known for urea and creatinine. Less information is available for two-compartmental models. Results on modeling of uric acid concentrations have not been published.

METHODS

The identification of the mathematical model coefficients was based on the concentration measurements of three markers of uremic toxicity (urea, creatinine, and uric acid) in both patients' blood and dialysate. Blood samples were taken from the arterial line several times throughout the dialysis period. Simultaneously, dialysate samples were taken from a test port in the dialyzer outflow line. The mathematical model parameters were determined so as to minimize the deviations between the measured points and the calculated curves. In this way, distribution volumes, cellular clearances, and dialyzer mass transfer coefficients were estimated.

RESULTS

For a one-compartmental model, the median value of distribution volume V = 0.56 DW was obtained, where DW is the patient's dry weight. For a two-compartmental model, intercompartment volume Vi = 0.36 DW and extracompartment volume Ve = 0.21 DW. The following median values for cellular clearances were established: urea 415 (mL/min), creatinine 207 (mL/min), and uric acid 257 (mL/min).

CONCLUSIONS

One- and two-compartmental models describe the concentration of the urea, creatinine, and uric acid very effectively, in contrast with phosphorus, in which modeling results are not satisfactory. Although two-compartmental models are more effective, they are much more complicated than one-compartmental models, which justifies using the one-compartmental model for hemodialysis modeling. A two-compartmental model must be used in the case of rebound phenomenon modeling. The total body water values we have obtained are similar to the anthropometrically based values for urea and creatinine and to a lesser degree for uric acid. Distribution volumes for one- and two-compartmental models obtained from patient weight are the simplest coefficients for mathematical models and have sufficient precision as well. The global value of both compartments is slightly greater than the corresponding value for a one-compartmental model. The effectiveness of dialyzers is in practice lower than might be expected on the basis of the data provided by their manufacturers. Urea cellular clearance is two times greater than creatinine and uric acid cellular clearances. The clearance differences are more prominent for the cellular membrane than for artificial semipermeable membranes.

Severe polyneuropathy in a 3-year-old child after dichlorophenoxyacetic herbicide--chwastox intoxication, treated successfully with plasmapheresis (PF)

The clinical picture of intoxication with dichlorophenoxy acetic herbicides is well recognised in adults and some treatment recommendations are established. To the best of our knowledge there is scarcity of well documented cases of intoxication with this substance in children. Our report describes the clinical picture of Chwastox intoxication in a 3-year-old child. Some similarities and differences between adults and children are discussed, as well as the indications for plasmapheresis, which could be a valuable mode of treatment in such cases.

[Clinical and metabolic effects of erythropoietin administration in hemodialyzed children]

The study aimed at the evaluation of metabolic effect of recombinant human erythropoietin (EPO) in children treated with repeated hemodialyses. The research included 16 patients aged 7-17 years of life. The observations were carried out for 6 months prior to and during EPO administration programme. In that time there were monitored changes in peripheral blood count, lean body mass, protein catabolic rate- pcr, urea time averaged concentration TAC and dialysis index KT/V. The results obtained in both phases of the investigation revealed that correction of anemia by means of EPO evokes in children a significant increase of lean body mass, while TAC decreases. The two factors combined speak for anabolic effect of EPO in these patients. The results of peripheral blood count obtained in the groups with high and acceptable exposure to uremic toxemia did not differ significantly, this proves that uremic toxemia does not exert inhibitory effect on erythropoiesis stimulated by EPO administration.