Ambulatory blood pressure parameters and their association with albuminuria in adolescents with type 1 diabetes mellitus.

BACKGROUND: This study aimed to evaluate the blood pressure (BP) status, including arterial stiffness parameters, hemodynamic indicators, circadian profile, and its association with albuminuria in adolescents with type 1 diabetes mellitus (DM1). METHODS: The analysis included 46 patients, with diabetes duration of 7.38 ± 3.48 years. Ambulatory blood pressure monitoring (ABPM) was conducted using an oscillometric device, the Mobil-O-Graph, which is a Pulse Wave Analysis Monitor. RESULTS: Hypertension (HT) was diagnosed in 31 adolescents (67% of patients), primarily due to isolated nocturnal BP (21 cases, 68% of HT cases). The HT group exhibited significantly increased diastolic load (DL). Pulse wave velocity (PWV, a measure of arterial stiffness) values showed a strong correlation with both peripheral systolic BP (r = 0.954) and central systolic BP (r = 0.838). Additionally, non-dipping status was found in 61% of the HT group. Urinary albumin excretion (UAE) was positively correlated with diastolic BP (particularly nocturnal) peripheral and central BP, DL, heart rate, augmentation index (AIx@75), and nocturnal total vascular resistance (TVR). Diastolic non-dippers exhibited a significant increase in UAE. CONCLUSIONS: Hypertension is a common complication in adolescents with type 1 diabetes mellitus, primarily caused by elevated nocturnal diastolic BP. Albuminuria is mainly associated with diastolic BP, especially during the nocturnal period and in cases of diastolic non-dipping status. The association of UAE with AIx@75 and nocturnal TVR suggests the presence of early-stage vascular disease in diabetic adolescents.

Liquid chromatography-tandem mass spectrometry method for mycophenolic acid and its glucuronide determination in saliva samples from children with nephrotic syndrome.

BACKGROUND: Saliva sampling is one of the methods of therapeutic drug monitoring for mycophenolic acid (MPA) and its metabolite, mycophenolic acid glucuronide (MPAG). The study describes the liquid chromatography tandem mass spectrometry (LC-MS/MS) method developed for saliva MPA and MPAG determination in children with nephrotic syndrome. METHODS: The mobile phase consisted of methanol and water at gradient flow, both with 0.1% formic acid. Firstly, 100 µL of saliva was evaporated at 45 °C for 2 h to dryness, secondly, it was reconstituted in the mobile phase, and finally 10 µL was injected into the LC-MS/MS system. Saliva from ten children with nephrotic syndrome treated with mycophenolate mofetil was collected with Salivette®. RESULTS: For MPA and MPAG, within the 2-500 ng/mL range, the method was selective, specific, accurate and precise within-run and between-run. No carry-over and matrix effects were observed. Stability tests showed that MPA and MPAG were stable in saliva samples if stored for 2 h at room temperature, 18 h at 4 °C, and at least 5 months at - 80 °C as well as after three freeze-thaw cycles, in a dry extract for 16 h at 4 °C, and for 8 h at 15 °C in the autosampler. The analytes were not adsorbed onto Salivette® cotton swabs. For concentrations above 500 ng/mL, the samples may be diluted twofold. In children, saliva MPA and MPAG were within the ranges of 4.6-531.8 ng/mL and 10.7-183.7 ng/mL, respectively. CONCLUSIONS: The evaluated LC-MS/MS method has met the validation requirements for saliva MPA and MPAG determination in children with nephrotic syndrome. Further studies are needed to explore plasma-saliva correlations and assess their potential contribution to MPA monitoring.

High-performance liquid chromatography with fluorescence detection for mycophenolic acid determination in saliva samples.

BACKGROUND: For therapeutic drug monitoring (TDM) of mycophenolic acid (MPA), which is frequently proposed, saliva might be a suitable and easy-to-obtain biological matrix. The study aimed to validate an HPLC method with fluorescence detection for determining mycophenolic acid in saliva (sMPA) in children with nephrotic syndrome. METHODS: The mobile phase was composed of methanol and tetrabutylammonium bromide with disodium hydrogen phosphate (pH 8.5) at a 48:52 ratio. To prepare the saliva samples, 100 µL of saliva, 50 µL of calibration standards, and 50 µL of levofloxacin (used as an internal standard) were mixed and evaporated to dryness at 45 °C for 2 h. The resulting dry extract was reconstituted in the mobile phase and injected into the HPLC system after centrifugation. Saliva samples from study participants were collected using Salivette® devices. RESULTS: The method was linear within the range of 5-2000 ng/mL, was selective with no carry-over effect and met the acceptance criteria for within-run and between-run accuracy and precision. Saliva samples can be stored for up to 2 h at room temperature, for up to 4 h at 4 °C, and for up to 6 months at - 80 °C. MPA was stable in saliva after three freeze-thaw cycles, in dry extract for 20 h at 4 °C, and for 4 h in the autosampler at room temperature. MPA recovery from Salivette® cotton swabs was within the range of 94-105%. The sMPA concentrations in the two children with nephrotic syndrome who were treated with mycophenolate mofetil were within 5-112 ng/mL. CONCLUSIONS: The sMPA determination method is specific, selective, and meets the validation requirements for analytic methods. It may be used in children with nephrotic syndrome; however further studies are required to investigate focusing on sMPA and the correlation between sMPA and total MPA and its possible contribution to MPA TDM is required.

Limited sampling strategy to predict free mycophenolic acid area under the concentration-time curve in paediatric patients with nephrotic syndrome.

In paediatric patients, there is no data on the recommended area under the concentration-time curve from 0 to 12 h (AUC0-12 ) for free mycophenolic acid (fMPA), which is the active form of the drug, responsible for the pharmacological effect. We decided to establish the limited sampling strategy (LSS) for fMPA for its use in MPA therapeutic monitoring in children with nephrotic syndrome treated with mycophenolate mofetil (MMF). This study included 23 children (aged 11 ± 4 years) from whom eight blood samples were collected within 12 h after MMF administration. The fMPA was determined using the high-performance liquid chromatography with fluorescence detection method. LSSs were estimated with the use of R software and bootstrap procedure. The best model was chosen based on a number of profiles with AUC predicted within ± 20% of AUC0-12 (good guess), r2 , mean prediction error (%MPE) of ±10% and mean absolute error (%MAE) of less than 25%. The fMPA AUC0-12 was 0.1669 ± 0.0697 µg h/mL and the free fraction was within 0.16%-0.81%. In total, there were 92 equations developed of which five fulfilled the acceptance criteria for %MPE, %MAE, good guess >80% and r2 > 0.900. These equations consisted of three time points: model 1 (C1 , C2 , C6 ), model 2 (C1 , C3 , C6 ), model 3 (C1 , C4 , C6 ), model 5 (C0 , C1 , C2 ), and model 6 (C1 , C2 , C9 ). Although blood sampling up to 9 h after MMF dosing is impractical, it is crucial to include C6 or C9 in LSS to assess fMPA AUCpred correctly. The most practical fMPA LSS, which fulfilled the acceptance criteria in the estimation group, was fMPA AUCpred  = 0.040 + 2.220 × C0 + 1.130 × C1 + 1.742 × C2 . Further studies should define the recommended fMPA AUC0-12 value in children with nephrotic syndrome.

Acute kidney injury and diabetic kidney disease in children with acute complications of diabetes.

BACKGROUND: Diabetic ketoacidosis (DKA) and hyperglycaemia without ketoacidosis are common acute complications of diabetes. Their association with acute kidney injury (AKI) and diabetic kidney disease (DKD) was studied. METHODS: The study group consisted of 197 children with type 1 diabetes with average diabetes duration of 8.08 ± 2.32 years. The medical history of the patients was retrospectively reviewed. The number of children with severe hyperglycaemia, DKA and AKI was assessed. The association with the risk of chronic kidney disease (CKD) was analysed. RESULTS: AKI was found in 14% of cases hospitalised for DKA and 8% of cases hospitalised for hyperglycaemia. Patients with AKI showed a significantly increased corrected sodium (141.23 ± 5.09 mmol/L, p = 0.035). Patients with AKI in DKA showed a significant increase in WBC (20.73 ± 8.71 × 103/µL, p = 0.0009). Follow-up analysis after a minimum of 5 years of diabetes revealed that a single episode of DKA was found in 63 patients and a single episode of AKI in 18 patients. Two or more episodes of DKA were found in 18 patients, and nine cases were complicated by AKI. These patients showed a significant increase in urinary albumin excretion (44.20 ± 64.21 mg/24 h), the highest values of eGFR and the worst glycaemic control. CONCLUSIONS: Diabetic children can develop AKI in the course of DKA and hyperglycaemia without ketoacidosis, which is associated with volume depletion and reflected by corrected sodium concentration. AKI in DKA seems to be complicated by stress and inflammation activation. AKI and poor glycaemic control with repeated DKA episodes can magnify the risk of progression to DKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Inosine monophosphate dehydrogenase activity and mycophenolate pharmacokinetics in children with nephrotic syndrome treated with mycophenolate mofetil.

Some studies have shown that the area under the concentration-time curve (AUC) of mycophenolic acid (MPA) should be higher for children with nephrotic syndrome (NS) than after renal transplantation. The pharmacodynamic aspect of MPA, the activity of inosine monophosphate dehydrogenase (IMPDH), has not been studied in children with NS. The study included 21 children (4-16 years old) with NS treated with mycophenolate mofetil. MPA and its glucuronide plasma concentrations were determined using validated high-performance liquid chromatography-ultraviolet (HPLC-UV). The separate HPLC-UV method was applied for IMPDH activity determination. The variability was expressed by the coefficient of variation (CV). IMPDH activity and MPA concentration (Ctrough ) before the morning dose amounted to 29.95 µmol s-1  mol-1 adenosine monophosphate (AMP) (range, 6.71-98.60 µmol s-1  mol-1 AMP) and 1.72 µg/mL (range, 0.39-4.34 µg/mL), respectively, whereas the area under the effect-time curve from 0 to 4 h and MPA AUC0-4 were 130.36 µmol s-1  mol-1 AMP × h (range, 23.58-306.57 µmol s-1  mol-1 AMP × h) and 24.63 µg h/mL (range, 12.21-67.48 µg h/mL), respectively. IMPDH activity decreased concomitantly with MPA concentration increase, however, the variability of the pharmacodynamic parameters was greater than of the pharmacokinetics. The median degree of maximum IMPDH inhibition was 61%. MPA Ctrough and predicted AUC were lower than in our previous study. Only a few MPA pharmacokinetic parameters correlated with the pharmacodynamics. IMPDH activity did not correlate with the children's age and did not differ between boys and girls. MPA clearance was the highest in younger children (median, 10.54 L/m2 /h) and cholesterol correlated negatively with the children's age (r = -0.659, P = 0.003). IMPDH minimum activity and the degree of maximum IMPDH inhibition were similar to those obtained in renal transplant recipients. IMPDH activity does not undergo developmental or gender-specific regulation in children with NS. MPA underexposure might be more frequent in younger children, especially with high cholesterol and triglycerides levels because of high MPA clearance.

Chronic kidney disease predictors in obese adolescents.

BACKGROUND: Glomerular hyperfiltration, initiating development of obesity-related glomerulopathy, results in an enlargement of the glomeruli and unsealing of the filtration barrier. It can be followed by adaptive focal segmental glomerulosclerosis and chronic kidney disease (CKD). The aim of the study was to determine the expression pattern of lipid metabolism and selected kidney damage markers in obese adolescents and to identify potential factors which can predict CKD. METHODS: The study group consisted of 142 adolescents with a BMI z-score > 2. Sixty-two healthy and normal-weight individuals served as controls. The factors associated with the rate of glomerular filtration in obese adolescents were assessed by linear regression methods using univariate and multivariate analyses. The risk of developing CKD was estimated using the Fisher's exact test. RESULTS: The study group was divided into "elevated," "normal," and "decreased" glomerular filtration rate (GFR) patients. Increased urine galectin-3 (Gal-3) concentration was diagnosed in all patients. "Decreased GFR" subjects expressed increased urine concentration of neutrophil gelatinase-associated lipocalin (NGAL) and daily megalin excretion. Thirty-nine study participants developed CKD. Increased uric acid (UA) concentration was associated with CKD development both in "normal" and "decreased GFR" patients. Additionally, in "normal" GFR patients, increased concentrations of cholesterol (Ch), triglycerides (TG), and NGAL were associated with CKD. CONCLUSIONS: Increased serum concentrations of Ch, TG, and UA and increased urine concentration of NGAL might predict CKD development in obese adolescents with normal and decreased GFR. A higher resolution version of the Graphical abstract is available as Supplementary information.

Differences between Obese and Non-Obese Children and Adolescents Regarding Their Oral Status and Blood Markers of Kidney Diseases.

(1) Background: A rarely discussed effect of obesity-related glomerulopathy (ORG) may slowly lead to irreversible glomerular damage and the development of chronic kidney disease. These patients need to undertake medical care, but whether they should be included in intensive oral care is still not mandatory. The study aimed to assess a relationship between renal, metabolic, and oral health indicators among pediatric patients affected by simple obesity. (2) Methods: 45 children and adolescents with simple obesity hospitalized (BMI 34.1 ± 4.8 kg/m2, age 15.4 ± 2.3) and compared with 41 aged-matched healthy controls (BMI 16.4 ± 2.4 kg/m2, age 15.4 ± 2.7). Echocardiography, 24-h ambulatory blood pressure monitoring, ultrasound exam with Doppler, and laboratory tests including kidney and metabolic markers were performed. Oral status was examined regarding the occurrence of carious lesions using decay missing filling teeth (DMFT), gingivitis as bleeding on probing (BOP), and bacterial colonization as plaque control record (PCR). (3) Results: The strongest correlation was revealed between BMI and concentration of uric acid, cystatin C, GFR estimated by the Filler formula (r = 0.74; r = 0.48; r = -0.52), and between oral variables such as PCR and BOP (r = 0.54; r = 0.58). Children and adolescents with obesity demonstrated untreated dental caries, less efficient in plaque control and gingivitis. (4) Conclusions: No specific relation to markers of kidney disease were found; however, more frequent gingivitis/bacterial colonization and significant differences in oral status between obese and non-obese patients were revealed. Susceptibility to inflammation may be conducive to developing metabolic syndrome and kidney damage in the form of obesity-related glomerulopathy and contribute to future dental caries. Uric acid seems to indicate metabolic syndrome and cardiovascular complications (LVMI > 95 percentiles). Cystatin C and uric acid might aspire to be early markers of kidney damage leading to obesity-related glomerulopathy.

The Evaluation of Multiple Linear Regression-Based Limited Sampling Strategies for Mycophenolic Acid in Children with Nephrotic Syndrome.

We evaluated mycophenolic acid (MPA) limited sampling strategies (LSSs) established using multiple linear regression (MLR) in children with nephrotic syndrome treated with mycophenolate mofetil (MMF). MLR-LSS is an easy-to-determine approach of therapeutic drug monitoring (TDM). We assessed the practicability of different LSSs for the estimation of MPA exposure as well as the optimal time points for MPA TDM. The literature search returned 29 studies dated 1998-2020. We applied 53 LSSs (n = 48 for MPA, n = 5 for free MPA [fMPA]) to predict the area under the time-concentration curve (AUCpred) in 24 children with nephrotic syndrome, for whom we previously determined MPA and fMPA concentrations, and compare the results with the determined AUC (AUCtotal). Nine equations met the requirements for bias and precision ±15%. The MPA AUC in children with nephrotic syndrome was predicted the best by four time-point LSSs developed for renal transplant recipients. Out of five LSSs evaluated for fMPA, none fulfilled the ±15% criteria for bias and precision probably due to very high percentage of bound MPA (99.64%). MPA LSS for children with nephrotic syndrome should include blood samples collected 1 h, 2 h and near the second MPA maximum concentration. MPA concentrations determined with the high performance liquid chromatography after multiplying by 1.175 may be used in LSSs based on MPA concentrations determined with the immunoassay technique. MPA LSS may facilitate TDM in the case of MMF, however, more studies on fMPA LSS are required for children with nephrotic syndrome.

Prediction of steroid resistance and steroid dependence in nephrotic syndrome children.

BACKGROUND: Steroid resistant (SR) nephrotic syndrome (NS) affects up to 30% of children and is responsible for fast progression to end stage renal disease. Currently there is no early prognostic marker of SR and studied candidate variants and parameters differ highly between distinct ethnic cohorts. METHODS: Here, we analyzed 11polymorphic variants, 6 mutations, SOCS3 promoter methylation and biochemical parameters as prognostic markers in a group of 124 Polish NS children (53 steroid resistant, 71 steroid sensitive including 31 steroid dependent) and 55 controls. We used single marker and multiple logistic regression analysis, accompanied by prediction modeling using neural network approach. RESULTS: We achieved 92% (AUC = 0.778) SR prediction for binomial and 63% for multinomial calculations, with the strongest predictors ABCB1 rs1922240, rs1045642 and rs2235048, CD73 rs9444348 and rs4431401, serum creatinine and unmethylated SOCS3 promoter region. Next, we achieved 80% (AUC = 0.720) in binomial and 63% in multinomial prediction of SD, with the strongest predictors ABCB1 rs1045642 and rs2235048. Haplotype analysis revealed CD73_AG to be associated with SR while ABCB1_AGT was associated with SR, SD and membranoproliferative pattern of kidney injury regardless the steroid response. CONCLUSIONS: We achieved prediction of steroid resistance and, as a novelty, steroid dependence, based on early markers in NS children. Such predictions, prior to drug administration, could facilitate decision on a proper treatment and avoid diverse effects of high steroid doses.

Mild X-linked Alport syndrome due to the COL4A5 G624D variant originating in the Middle Ages is predominant in Central/East Europe and causes kidney failure in midlife.

A study of 269 children enrolled into a National Registry for children with persistent glomerular hematuria identified 131 individuals with genetically confirmed X-linked Alport Syndrome. A single variant c.1871G>A p.Gly624Asp (G624D) in COL4A5 was predominant and accounted for 39% of X-linked Alport Syndrome in unrelated Polish families (44 of 113). To evaluate its origins, the genetic variation in a 2.79 Mb segment encompassing the COL4A5 locus on chromosome X was assessed. All G624D alleles were found on the same rare haplotype background, indicating a founder effect dating back to the 12-13th century. The phenotypic data of 131 children with X-linked Alport Syndrome and their 195 affected adult relatives revealed that the G624D variant was associated with a significantly milder clinical course in comparison to other pathogenic COL4A5 variants. Furthermore the clinical course of this genetically uniform cohort was milder than that observed in individuals with other COL4A5 missense mutations. In spite of the benign clinical manifestation throughout childhood and early adulthood, the G624D variant confers significant risk for both kidney failure and deafness in males, albeit 20-30 years later than that observed in individuals with other COL4A5 pathogenic variants (50% cumulative risk of starting dialysis at 54 years (95% confidence interval: 50-62) v. 26 years (95% confidence interval: 22-30)). Thus, males with G624D are candidates for existing and emerging therapies for Alport Syndrome.

Dental caries-related primary hypertension in children and adolescents: Cross-sectional study.

BACKGROUND: Hypertension is a growing clinical problem in pediatric population. Also, the cause of hypertension is usually unknown and it may result from systemic inflammation related to tooth decay. AIM: To estimate the potential association in cross-sectional study between tooth decay and hypertension in children and adolescents. PATIENTS AND METHODS: Study group-65 children diagnosed with primary arterial hypertension; control subjects-44 normotensive children. Blood pressure, dental examination, measurement of salivary cortisol, alpha-amylase, secretory IgA, and lysozyme concentrations were performed in all of the children. RESULTS: Hyper- and normotensive children had similar peripheral blood morphology and serum biochemical parameters, except of uric acid concentration, which was significantly higher in the study group (p = .047). Salivary evening concentrations of cortisol and alpha-amylase were significantly higher in hypertensive children (p = .002 and p = .004, respectively). Although 24-hr systolic blood pressure (SBP), including daytime and nighttime SBP, correlated with "decay," "microalbuminuria," "BMI," and "glomerular filtration rate" (r > .75, r > .7, r < .68, and r < .43, respectively), in multivariate analysis only "decay" was associated with hypertension both in children and in adolescents (p < .0001). CONCLUSION: Tooth decay in children/adolescents might be regarded as a potent trigger factor of hypertension in individuals in whom all other causes of secondary arterial hypertension have been excluded.

Association of Oral Status and Early Primary Hypertension Biomarkers among Children and Adolescents.

The aim of this case-control study was the evaluation of the association between biomarkers of early primary arterial hypertension (HA) and oral diseases among children and adolescents. Material and methods. Subjects suspected of primary HA (n = 180) underwent a complex evaluation of their vascular status: blood pressure, heart rate, vascular stiffness, sympathetic activity in a 24 h ambulatory examination, followed by measurement of serum uric acid (UA), cystatin C, and creatinine. This procedure allowed the identification of children with primary (n = 58) and secondary HA (n = 74), as well as of children with normal arterial blood pressure, who served as a control group (n = 48). All subjects with secondary HA were excluded from further investigation. Oral examination included the measurement of caries intensity (using the decayed, missing, filled index for permanent teeth DMFT /primary teeth dmft), bacterial plaque (by the plaque control record index, PCR%), and gingivitis (by the bleeding on probing index, BOP%). For statistical analysis, a linear regression model and Spearman rank correlation were used. Results. UA, cystatin C, and creatinine were not altered in the HA group. However, the number of decayed permanent teeth (DT) and the DMFT, PCR%, and BOP% indexes were significantly higher in the primary HA group compared to the control group (p = 0.0006; p = 0.02; p = 0.0009; p = 0.003). Our results are not sufficient to prove the important role of caries and gingival inflammation in the modulation of HA symptoms, although they prove the association of oral diseases with primary HA symptoms. This may indicate future strategies for preventive measures for hypertensive children and adolescents.

Early kidney damage in diabetic adolescents with increased blood pressure and glomerular hyperfiltration.

BACKGROUND: The early impact of type-1 diabetes mellitus (DM1), increased blood pressure and glomerular hyperfiltration (GHF) on kidney damage in adolescents using two urinary markers of kidney injury - neutrophil gelatinase-associated lipocalin (uNGAL) and transferrin (uTransf) was assessed. METHODS: The study group consisted of 80 adolescents with DM1, of whom 42 were patients with increased blood pressure (IBP), and 38 were patients with normal blood pressure (NBP). Blood pressure was assessed by 24-hour ambulatory bloodpressure monitoring. All patients showed estimated glomerular-filtration rates (eGFRs) above 90 ml/min/1.73m2. The control group consisted of 19 healthy, age and gender-matched adolescents. RESULTS: All diabetic children showed a significant increase in uNGAL (p<0.001). This increase was not related to blood pressure. The uNGAL was elevated in all patients with normal albuminuria, normal eGFR and NBP. The concentration of uTransf was not increased in the entire studied group and was not related to blood pressure. Children with GHF had significantly higher levels of both uTransf (p=0.010) and uNGAL (p<0.001). In patients with GHF, blood pressure was normal. Patients with IBP showed a significantly higher value for triglycerides (r=0.247; p=0.032) and a longer duration of diabetes (r=0.264; p=0.019). CONCLUSIONS: Diabetes is the leading risk factor for early kidney injury. However, increased blood pressure does not lead to kidney damage, at least in the early stage of DM1. The uNGAL is the early indicator of kidney injury and increases in patients with normal albuminuria, normal glomerular filtration and normal blood pressure. Glomerular hyperfiltration seems to be a marker of diabetic-kidney involvement.

The Application of Inosine 5'-Monophosphate Dehydrogenase Activity Determination in Peripheral Blood Mononuclear Cells for Monitoring Mycophenolate Mofetil Therapy in Children with Nephrotic Syndrome.

In pediatric nephrotic syndrome, recommended mycophenolic acid (MPA) pharmacokinetics are higher than those for transplant recipients. In MPA therapeutic monitoring, inosine-5'-monophosphate dehydrogenase (IMPDH) activity may be useful. We modified the method established for renal transplant recipients and determined IMPDH activity in peripheral blood mononuclear cells (PBMCs) from healthy volunteers and children (4-16 years) with nephrotic syndrome treated with mycophenolate mofetil (MMF). From children, four blood samples were collected, and MPA concentrations were also determined. IMPDH activity was calculated using xanthosine monophosphate (XMP) normalized with adenosine monophosphate (AMP), both determined with the HPLC-UV method. The modified method was accurate, precise, and linear for AMP and XMP within 0.50-50.0 µmoL/L. Mean IMPDH activity in volunteers was 45.97 ± 6.24 µmoL·s-1·moL-1 AMP, whereas for children, the values were variable and amounted to 39.23 ± 27.40 µmoL·s-1·moL-1 AMP and 17.97 ± 15.24 µmoL·s-1·moL-1 AMP before the next MMF dose and 1 h afterward, respectively. The modified method may be applied to IMPDH activity determination in children with nephrotic syndrome treated with MMF. IMPDH activity should be determined after one thawing of PBMCs due to the change in AMP and XMP concentrations after subsequent thawing. For children, the lowest IMPDH activity was observed concomitantly with the highest MPA concentration.

Comparison of cuff-based and cuffless continuous blood pressure measurements in children and adolescents.

OBJECTIVE: In recent times, new methods of blood pressure measurements have been introduced, including cuffless blood pressure (BP) measurement device using pulse transit time (PTT) for calculation of BP values. However, it is still unknown how values obtained with a new cuffless device compare with standard ambulatory measurements in children. The main aim of the study was to investigate whether BP values measured by a cuffless PTT device are comparable with measurements by a standard upper arm cuff-based BP device. METHODS: Thirty children were prospectively included. Blood pressure measurements using the cuffless device (Somnotouch-NIBP) and cuff-based standard device (Omron 907) were performed simultaneously on the left and right arm. RESULTS: Mean systolic BP of the standard measurements was 123,47 ± 14,91 mmHg and 127,48 ± 15,98 mmHg (p < .001) measured by cuffless method. Mean diastolic BP of the standard ABPM measurements was 66,88 ± 11,86 mmHg and 68,52 ± 12,36 mmHg (p < .001). There were significant positive correlations between standard and cuffless measurements. CONCLUSION: The results show that the created PWV-BP function produces a significant correlation between BP derived from the PWV and the SBP measured by sphygmomanometry. When applying this device in clinical practice, one may keep in mind that the reported mean values over 24 hours, awake and asleep time are not directly interchangeable with cuff-based standard 24-hour BP values. The measured BP values were higher by the new technique. Although differences in SBP between both methods reached values up to 20 mmHg, we think that the development of a cuffless BP monitoring system will provide novel solutions in various medical situations.

Phakomatoses and cutaneous manifestations associated with moyamoya disease and syndrome.

Phakomatoses are a group of neurocutaneous disorders whose origin is derived from the embryonic ectoderm. These disorders affect the central nervous system, the eyes, and the skin. This article presents phakomatoses and cutaneous manifestations associated with moyamoya disease and syndrome. Moyamoya disease is a progressive and occlusive disorder of the cerebral vasculature often presenting with particular phakomatoses. This article aims to reveal why patients with phakomatoses qualify for detailed neuroimaging.

Infiltration of CD68+ cells correlates positively with matrix metalloproteinase 2 expression in the arteries used as aortocoronary bypass grafts. Possible clinical implications.

BACKGROUND: Late failure of arterial aortocoronary conduits may result from abnormal activity of cells found in the vessel wall, including macrophages. The purpose of this study was to assess if there are any associations between the number of macrophages and overexpression of matrix metalloproteinases (MMPs) in the wall of arterial grafts, as well as their clinical significance. METHODS: This study involved 128 consecutive patients with a mean age of 64.9 ± 9.7 years who underwent elective surgery for coronary artery disease (CAD). The surplus segments of internal thoracic artery (ITA) and radial arteries (RA) were taken for immunohistochemical analysis of macrophage numbers and MMPs expression. The participants who reached the clinical primary end-point (cardiacrelated death, acute coronary syndrome or progression of CAD) had a follow-up angiography. RESULTS: The mean numbers of macrophages were higher on RA (70 [24; 112]) than ITA cross-sections (44 [24; 59]; p < 0.001). Median expression of both MMP2 and MMP9 were stronger in the ITA than RA cross-sections (p < 0.001). A significant positive correlation of MMP2 expression and a number of macrophages infiltrating the tunica media of arterial segments were noted on both ITA and RA cross-sections. In addition, the arterial segments of the 6 patients who reached clinical end-point had higher numbers of macrophages and stronger MMP2 expression when compared to the rest of the participants. CONCLUSIONS: Macrophage infiltration of arterial wall grafts prior to harvesting may be associated with higher risk of late occlusion and MMP2 might be facilitating this process.

Limited sampling strategy to predict mycophenolic acid area under the curve in pediatric patients with nephrotic syndrome: a retrospective cohort study.

PURPOSE: Limited sampling strategy (LSS) is a precise and relatively convenient therapeutic drug monitoring method. We evaluated LSSs for mycophenolic acid (MPA) in children with nephrotic syndrome treated with mycophenolic mofetil (MMF) and validated the LSSs using two different approaches. METHODS: We measured MPA plasma concentrations in 31 children using HPLC-UV method and received 37 MPA pharmacokinetic profiles (0-12 h). For six children, MPA profiles were estimated twice after two MMF doses. LSSs were developed using multilinear regression with STATISTICA and R software and validated using validation group and bootstrap method, respectively. RESULTS: The best three time point equations included C1, C3, C6 (good guess 83%, bias - 2.78%; 95% confidence interval (CI) - 9.85-0.46); C1, C2, C6 (good guess 72%, bias 0.72%; 95% CI - 5.33-7.69); and C1, C2, C4 (good guess 72%, bias 2.05%; 95% CI - 4.92-13.01) for STATISTICA software. For R software, the best equations consisted of C1, C3, C6 (good guess 92%, bias - 2.69%; 95% CI - 27.18-33.75); C0, C1, C3 (good guess 84%, bias - 2.11%; 95% CI - 24.19-22.29); and C0, C1, C2 (good guess 84%, bias - 0.48%; 95% CI - 30.77-54.07). During validation, better results were obtained for R evaluations, i.e., bootstrap method. CONCLUSIONS: The most useful equations included C0, C1, C3 and C0, C1, C2 time points; however, the most precise included C1, C3, C6 time points because of MPA enterohepatic recirculation. Better results were obtained for bootstrap validation due to greater number of patients. Validated LSS should be used only in the population for which it was developed. As there is growing evidence that underexposure of MPA is associated with insufficient treatment response, we recommend the introduction of therapeutic drug monitoring for MPA in children with nephrotic syndrome.