ESTIMATION OF THE GLOMERULAR FILTRATION RATE IN CHILDREN WITH HEMOPHILIA.

Estimated glomerular filtration rate (eGFR) is one of the best-performing methods in evaluating kidney function. There are limited data regarding the estimated glomerular filtration rate in children and young adults with hemophilia. The aim of this study was to determine the difference between three commonly used estimated glomerular filtration rate equations in the pediatric population in a cohort of patients with hemophilia. Our prospective study included 36 pediatric patients with moderate or severe hemophilia. eGFR was calculated for each patient using the original creatinine-based "bedside Schwartz" equation, the cystatin C-based equation and the creatinine-cystatin C-based equation. The difference between the equations, calculated using the one-way repeated ANOVA test, was statistically significant (p <0.001), and post hoc analysis found differences between each method. Correlation analysis showed the strongest positive correlation between the bedside Schwartz equation and creatinine-cystatin C-based equation (r=0.866) among the three methods examined. A correlation between the three eGFR methods was present, but with significant differences between them. Due to the observed differences between eGFR in pediatric patients with hemophilia, further research is needed to find the optimal measurement method for eGFR. Nevertheless, we recommend implementing eGFR equations in routine clinical monitoring of pediatric patients with hemophilia.

Geospatial clustering of childhood IgA vasculitis and IgA vasculitis-associated nephritis.

OBJECTIVES: Research on spatial variability of the incidence of IgA vasculitis (IgAV) in children and its potential implications for elucidation of the multifactorial aetiology and pathogenesis is limited. We intended to observe spatial variability of the incidence of IgAV and IgA vasculitis-associated nephritis (IgAVN) using modern geostatistical methods, and hypothesised that their spatial distribution may be spatially clustered. METHODS: Patients' data were retrospectively collected from 2009 to 2019 in five Croatian University Hospital Centres for paediatric rheumatology, and census data were used to calculate the incidence of IgAV. Using spatial empirical Bayesian smoothing, local Morans' I and local indicator of spatial autocorrelation (LISA), we performed spatial statistical analysis. RESULTS: 596 children diagnosed with IgAV were included in this study, of which 313 (52.52%) were male. The average annual incidence proportion was estimated to be 6.79 per 100 000 children, and the prevalence of IgAVN was 19.6%. Existence of spatial autocorrelation was observed in both IgAV and IgAVN; however, clustering distribution differed. While IgAV showed clustering in Mediterranean and west continental part around cities, IgAVN was clustered in the northern Mediterranean and eastern continental part, where a linear cluster following the Drava and Danube river was observed. CONCLUSION: IgAV incidence in Croatia is similar to other European countries. Spatial statistical analysis showed a non-random distribution of IgAV and IgAVN. Although aetiological associations cannot be inferred, spatial analytical techniques may help in investigating and generating new hypotheses in non-communicable diseases considering possible environmental risk factors and identification of potential genetic or epigenetic diversity.

Indoor carbon dioxide concentrations in Croatian elementary school classrooms during the heating season.

Aware that exposure to stuffy indoor air with high levels of carbon dioxide (CO2) is associated with higher absenteeism and reduced academic performance in school pupils, the World Health Organization (WHO) Regional Office for Europe initiated indoor air quality surveys in schools, including CO2 monitoring, to assess ventilation and exposure to stuffy air. Here we report the findings of the first such survey in Croatia. It was conducted in 60 classrooms of 20 urban and rural elementary schools throughout the country during the heating season. Measurements of CO2 levels showed that all 60 classrooms exceeded the international guidelines of 1938 mg/m3. Mean CO2 concentrations ranged from 2771 to 7763 mg/m3. The highest concentration measured in urban schools was 7763 mg/m3 and in rural schools 4771 mg/m3. Average CO2 levels were higher in continental schools (3683 mg/m3) than the coastal ones (3134 mg/m3), but all demonstrate poor ventilation during the heating season all over Croatia.

Multi-lag tone-entropy in neonatal stress.

Heart rate variability (HRV) has been analysed using linear and nonlinear methods. In the framework of a controlled neonatal stress model, we applied tone-entropy (T-E) analysis at multiple lags to understand the influence of external stressors on healthy term neonates. Forty term neonates were included in the study. HRV was analysed using multi-lag T-E at two resting and two stress phases (heel stimulation and a heel stick blood drawing phase). Higher mean entropy values and lower mean tone values when stressed showed a reduction in randomness with increased sympathetic and reduced parasympathetic activity. A ROC analysis was used to estimate the diagnostic performances of tone and entropy and combining both features. Comparing the resting and simulation phase separately, the performance of tone outperformed entropy, but combining the two in a quadratic linear regression model, neonates in resting as compared to stress phases could be distinguished with high accuracy. This raises the possibility that when applied across short time segments, multi-lag T-E becomes an additional tool for more objective assessment of neonatal stress.

Asymmetric detrended fluctuation analysis in neonatal stress.

OBJECTIVE: To detect stress in newborns by observing heart rate (HR) variability utilizing an asymmetric detrended fluctuation analysis (ADFA), we sought to determine the fractal structure of the series of inter-beat intervals, so as to distinguish the periods of acceleration of the HR from decelerations. Thus, two scaling exponents, α + and α -, representing decelerations and accelerations respectively, are obtained. APPROACH: Forty healthy term newborns were included in this study, undergoing two different types of stress stimuli: routine heel lance blood sampling for metabolic screening purposes, and its simulation by applying dull pressure on the heel. MAIN RESULTS: It appears that when newborns face stress, the scaling exponent related to accelerations significantly increases and becomes higher than the deceleration scaling exponent. To test the diagnostic properties of the scaling exponents, an ROC curve analysis was applied; α - showed good diagnostic performance with an AUC between 0.626 and 0.826, depending on the length of the time series. The joint use of α + and α - further increased the diagnostic performance, in particular for shorter series of RR intervals, with an AUC between 0.691 and 0.833. SIGNIFICANCE: ADFA, particularly of the acceleration scaling exponent, may be a useful clinical diagnostic tool for monitoring neonatal stress.