Polish Children Research Articles

Air Pollution Increases the Incidence of Upper Respiratory Tract Symptoms among Polish Children.

A substantial proportion of airway disease’s global burden is attributable to exposure to air pollution. This study aimed to investigate the association between air pollution, assessed as concentrations of particulate matter PM2.5 and PM10 on the upper respiratory tract symptoms (URTS) in children. A nation-wide, questionnaire-based study was conducted in Poland in winter 2018/2019 in a population of 1475 children, comparing URTS throughout the study period with publicly available data on airborne particulate matter. A general regression model was used to evaluate the lag effects between daily changes in PM10 and PM2.5 and the number of children reporting URTS and their severity. PM10 and PM2.5 in the single-pollutant models had significant effects on the number of children reporting URTS. The prevalence of URTS: “runny nose”, “sneezing” and “cough” was positively associated with 12-week mean PM2.5 and PM10 concentrations. In the locations with the highest average concentration of PM, the symptoms of runny nose, cough and sneezing were increased by 10%, 9% and 11%, respectively, compared to the cities with the lowest PM concentrations. This study showed that moderate-term exposure (12 week observation period) to air pollution was associated with an increased risk of URTS among children aged 3–12 years in Poland. These findings may influence public debate and future policy at the national and international levels to improve air quality in cities and improve children’s health.

The role of working memory in acquiring new structures and lexicon when learning English as a second language

The following paper discusses working memory as it functions during the acquisition of a second language by children. It analyses the results of a study conducted over a 12 month period on a group of 12 Polish children ages 10 to 14, learning English as a second language. The focus of this longitudinal study was the role that the verbal working memory plays in the acquisition of new structures; namely, the extent to which processing new information in working memory is essential to learning grammar and the possibility of developing strategies of using working memory itself during the learning process. The method adopted was a comparison of several oral tasks, including repetition and postponed repetition. As the conclusion to the discussion, certain didactic implications are presented, such as the need to control and modify the didactic process as to the degree to which it relies on working memory.

Non-specific low back pain: cross-sectional study of 11,423 children and youth and the association with the perception of heaviness in carrying of schoolbags.

BackgroundCarrying a schoolbag is a daily activity for most children and adolescents.The perception of a schoolbag’s weight depends upon the individual and is a relevant theme in schoolchildren. Describing the association between the perception of heaviness in carrying a schoolbag and NLBP can facilitate the planning of preventive programs, quite different from those based on specific weight limits for schoolbags in children and youth.ObjectiveTo determine the prevalence of non-specific low back pain (NLBP) and to analyse the association between the perception of heaviness in carrying of schoolbags and NLBP in Polish children and youth aged 10–19.MethodsThis study included 11,423 children and youth (6,252 girls and 5,171 boys) from Poland. An original questionnaire was used to assess NLBP prevalence.ResultsAmong 11,423 of the respondents, 41.5% of the respondents admitted that they had experienced NLBP in the period of the last 12 months. The percentage of individuals reporting NLBP increased with age of participants, p < 0.001. Girls reported NLBP more often than boys (p < 0.001). Students with NLBP declared that their school backpack was heavy more often than students without LBP. Students who thought that their backpacks weighed too much manifested a 1.44 (95% Cl [1.33–1.55]) times higher probability to experience NLBP.ConclusionIn the examined group of schoolchildren a frequent occurrence of NLBP (41.5%) was noted. Its occurrence was related to female sex and age. Students who thought that their backpacks weighed too much manifested higher probability to develop NLBP.

Analysis of frequency and risk factors for complications of enteral nutrition in children in Poland after percutaneous endoscopic gastrostomy placement

ObjectivesThe aim of the study was to assess the complication rate and identify whether age, nutritional status, and history of respiratory aspiration prior to percutaneous endoscopic gastrostomy (PEG) are risk factors for post-PEG placement complications in Polish children. In addition, the safety of two enteral feeding methods (3 h vs. 8 h) after PEG insertion in children was compared. MethodsChildren with clinical indications for PEG placement were recruited from six medical centers in Poland to participate in the study. The patients were centrally randomized to receive the first bolus feed via a feeding tube at 3 h (group 1) or 8 h (group 2) after PEG placement. The preprocedural preparation, postoperative care, and resumption of feeding were performed on all of patients in accordance with the study protocol. Patients were followed for 12 mo. ResultsOf the 97 randomized patients, 49 were assigned to group 1 and 48 to group 2. Full feed after PEG placement was achieved within 24 to 48 h in most cases (74% vs. 82%). There were no differences between the groups regarding the number of early mild (31.3% vs. 31.3%) and serious (2.1% vs 8.3%) complications or the duration of hospitalization after PEG placement (P > 0.05). The most common serious complication after PEG placement was accidental displacement of PEG. Most reported late complications were mild. The results of the regression analysis indicate no statistically significant effect of age, body mass index standard deviation score, white blood cell count, serum albumin level, and respiratory aspiration in the medical history on the occurrence of mild and severe complications. ConclusionsThe early initiation of post-PEG feeding was not associated with an increase in the number of complications. Most complications after the PEG procedure were mild. Age, serum albumin level, white blood cells, body mass index standard deviation score, and a history of aspiration to the respiratory tract were not confirmed as a risk factor for post-PEG complications in children.

Early mindreading scale: From joint attention to false-belief understanding

ABSTRACT The current research aims at constructing a developmentally sensitive mindreading scale (i.e., a battery of tasks measuring different aspects of mindreading ability in children from 1 to 3.5 years of age). Over 300 Polish children were tested at six-month intervals with 48 different tasks designed to measure mindreading ability (for a total of six measurement occasions, T1-T6; NT1 = 357; MageT1 = 52,30 weeks; SD = 1,73; 201 (56%) boys, 156 (44%) girls). Using latent trait modelling, a latent mindreading factor was established. Support was found for satisfactory reliability of the scale that ultimately consisted of 31 tasks. The tasks were age-matched, as the information curves for latent factors for each of the six age ranges and the reliability of the composite constructs were mostly acceptable. The validity was also confirmed using correlational analyses, and the continuous development of mindreading was observed over the tested age ranges: from joint attention, through using gestures in communication and visual perspective taking, to false-belief understanding. The proposed scale is suitable for use in the investigation of the general pattern of the development of, and individual differences in, mindreading ability.

"Adults Control It Better." Health-related Practices, Responsibilities and Bonding in the Narratives of Polish Children

This paper shows how everyday health-related practices are played out in respect to performing parent–children relationships. Based on research with children aged 8–11 years old, conducted in Poland in 2015–18 with the aim of studying their opinions about health, this paper shows that children frame health-related practices in a broader set of social networks. This paper suggests that negotiations concerning healthy lifestyle, common among modern families in Poland, represent rituals through which parent–child relationships are practiced. What is more, children play an active role in this process. Children feel responsible for their own and their family’s health and consider health-related practices as a way of “doing family”.

Association of parental-reported vitamin D supplementation with dental caries of 3-year-old children in Poland: a cross-sectional study

ObjectiveThe study aimed to assess the association between parental-reported vitamin D supplementation and caries in a national sample of 3-year-olds in Poland.Materials and methodsA total of 1900 children, representing all provinces of Poland, were invited. The questionnaires concerned vitamin D supplementation, socio-demographics, and oral health behaviours. Based on dental examination, caries scores (dmft/dmfs), prevalence of early childhood caries (ECC) and severe ECC (S-ECC) were calculated. The Spearman’s correlation, linear regression and logistic regression were used to assess the association between various factors and caries (p < 0.05).ResultsA total of 1638 children were tested. Of this number, 99.1% infants were supplemented with vitamin D. Supplementation had been continued seasonally in 55.2% children. ECC/S-ECC prevalence were significantly lower in children receiving vitamin D (ECC 38.3% vs. 44.7%, OR = 0.77; S-ECC 20.5% vs. 27.1%, OR = 0.69; p < 0.05). Mean dmft/dmfs were lower in those with supplementation (1.54 ± 2.72 vs. 2.24 ± 3.55; 2.40 ± 5.56 vs. 3.72 ± 7.56, respectively; p < 0.001). After controlling for confounding factors, supplementation was not significantly associated with caries; only dt/ds were still associated. Maternal education, sweetened beverages before bedtime, bottle use were significantly associated with S-ECC.ConclusionsLower caries prevalence was observed in those with vitamin D supplementation. The association between parental-reported vitamin D and ECC/S-ECC was not significant in Polish children. Decayed teeth and supplementation were still associated. Dietary habits can modify the association with caries.Clinical relevanceThere may be an association between vitamin D supplementation and lower caries in children. Parents should supplement their children during periods of significant growth and development.

Physical fitness percentiles of Polish children aged 4\u20137 years

The purpose of this study was to report sex- and age-specific physical fitness level in Polish children aged 4 to 7. 11.709 children participated in the study, including 5.684 girls and 6.025 boys aged 4 to 7 who attended kindergarten institutions throughout Poland. Physical fitness was assessed using four tests developed by Sekita including shuttle run 4 × 5 m with moving the block, standing long jump, throwing 1 kg medicine ball with two hands above the head and 20 m run. Percentile charts were developed separately for males and females using the LMS method. Boys showed higher physical fitness values than girls. In addition, an increase in the level of physical fitness was observed along with the age of the subjects. The developed reference values by age and sex in the field of physical fitness can be used for diagnostic purposes and assessing the level of physical fitness of preschool children. In addition, they can be helpful for healthcare professionals, parents and teachers to develop children’s motor activation programs and monitor their physical fitness.

Associations between second to fourth digit ratio, cortisol, vitamin D, and body composition among Polish children

Associations between body characteristics (body composition: fat mass, muscle mass, cell, and water mass as well as body proportion—BMI), the 2D:4D digit ratio, and the concentrations of cortisol and vitamin (25-OH)D among Polish children have not been studied before. A total of 133 (73 girls and 60 boys) healthy Polish children aged 7–11 years were examined. The investigation was divided into three parts: measuring (the length of the second and fourth fingers in both hands, body composition, and body height and mass), questionnaires (socioeconomic status), and laboratory investigations (25-OH vitamin D and cortisol concentrations in saliva measured with ELISA methods). Boys with digit ratios below 1 had lower vitamin D concentration than those with digit ratios equal to or higher than 1 (Z = − 2.33; p = 0.019). Only boys with the male-typical pattern of 2D:4D digit ratio tended to have a lower 25-OH vitamin D concentration in saliva. Thus, it might indicate an effect of prenatal programming on the concentrations of steroid hormones in later life. Neither vitamin D, 2D:4D digit ratio nor the cortisol level was associated with the body components or proportions. More studies are needed to evaluate the molecular and genetic background of this phenomenon.

Prediction of Early Childhood Caries Based on Single Nucleotide Polymorphisms Using Neural Networks.

Background: Several genes and single nucleotide polymorphisms (SNPs) have been associated with early childhood caries. However, they are highly age- and population-dependent and the majority of existing caries prediction models are based on environmental and behavioral factors only and are scarce in infants. Methods: We examined 6 novel and previously analyzed 22 SNPs in the cohort of 95 Polish children (48 caries, 47 caries-free) aged 2–3 years. All polymorphisms were genotyped from DNA extracted from oral epithelium samples. We used Fisher’s exact test, receiver operator characteristic (ROC) curve and uni-/multi-variable logistic regression to test the association of SNPs with the disease, followed by the neural network (NN) analysis. Results: The logistic regression (LogReg) model showed 90% sensitivity and 96% specificity, overall accuracy of 93% (p < 0.0001), and the area under the curve (AUC) was 0.970 (95% CI: 0.912–0.994; p < 0.0001). We found 90.9–98.4% and 73.6–87.2% prediction accuracy in the test and validation predictions, respectively. The strongest predictors were: AMELX_rs17878486 and TUFT1_rs2337360 (in both LogReg and NN), MMP16_rs1042937 (in NN) and ENAM_rs12640848 (in LogReg). Conclusions: Neural network prediction model might be a substantial tool for screening/early preventive treatment of patients at high risk of caries development in the early childhood. The knowledge of potential risk status could allow early targeted training in oral hygiene and modifications of eating habits.

Home Artificial Nutrition in Polish Children: An Analysis of 9-Year National Healthcare Provider Data.

Background: Home artificial nutrition (HAN) is a developing method of treatment that reduces the need for hospitalizations. The epidemiology of pediatric HAN in Poland has not yet been covered in detail. This study is a longitudinal nationwide analysis of incidence, prevalence, and patients’ profile for HAN in Polish children. Methods: Assessment of National Health Fund (NFZ) data covering all pediatric patients treated with HAN in Poland between 2010 and 2018. Results: HAN was received by 4426 children, 65 patients were on home enteral nutrition (HEN) or home parenteral nutrition (HPN) at different times (HEN n = 3865, HPN n = 626). HAN was most frequently started before the child was 3 years old and long-term HAN programs (5–9 years) were reported. The most common principal diagnosis in HEN was food-related symptoms and signs. In HPN, it was postoperative gastrointestinal disorders. A regionally differentiated prevalence of HAN patients and centers was demonstrated. Mortality among patients was 24.9% for HEN, and 9.6% for HPN, and the main in-hospital cause of death was cardiac arrest. Conclusions: HAN’s use is increasing and evolving in Poland. Uneven distribution of patients and centers results in difficult access to the nutritional procedure which, together with the increasing number of patients, highlights the need for data analysis and development of nutrition centers.

Development of central auditory processes in Polish children and adolescents at the age from 7 to 16 years

There are discrepancies in the literature regarding the course of central auditory processes (CAP) maturation in typically developing children and adolescents. The purpose of the study was to provide an overview of age – related improvement in CAP in Polish primary and secondary school students aged 7–16 years. 180 children/adolescents, subdivided into 9 age categories, and 20 adults (aged 18–24 years) performed the Dichotic Digit Test (DDT), Duration Pattern Test (DPT), Frequency Pattern Test (FPT), Gap Detection Test (GDT) and adaptive Speech-in-Noise (aSpN). The 12-year-olds was retested after w week. We found the age effects only for the DDT, DPT and FPT. In the right ear DDT the 7-year-olds performed more poorly than all groups ≥12. In the left ear DDT both 7- and 8-year-olds achieved less correct responses compared with the 13-, 14-, 15-year-olds and with the adults. The right ear advantage was greater in the 7-year-olds than in the 15-year-olds and adult group. At the age of 7 there was lower DPT and FPT scores than in all participants ≥13 whereas the 8-year-olds obtained less correct responses in the FPT than all age categories ≥12. Almost all groups (except for the 7-year-olds) performed better in the DPT than FPT. The test-retest reliability for all tests was satisfactory. The study demonstrated that different CAP have their own patterns of improvement with age and some of them are specific for the Polish population. The psychoacoustic battery may be useful in screening for CAP disorders in Poland.

Self-reported food safety knowledge and practices of early-school-aged children – a result of analysis in towns near the Warsaw city

PurposeThe purpose of this study is to evaluate the knowledge and practices of selected group of Polish children in early school age in terms of issues such as: (1) the principles of food preparation, storage and eating meals; (2) personal hygiene; and (3) basic information about microorganisms.Design/methodology/approachThe auditorium survey method was used. The questionnaire consisted of 15 questions related to the children's knowledge of personal hygiene, the principles of food preparation and storage and the physiology of microorganisms and 13 questions related to the children's personal and food hygiene practice. In total, 169 questionnaires were collected. The study group of children had incomplete knowledge and often reported inappropriate food hygiene practices.FindingsThe subjects of food preparation and storage and knowledge of microbes were particular problem areas. By contrast, aspects related to handwashing, the appropriate practices while coughing or sneezing and washing fruit before consumption were positively evaluated. The children demonstrated the most knowledge in the field of personal hygiene. However, a very low percentage of correct answers was noted for the question about handwashing at school. None of the 13 questions related to this practice received more than 90% correct answers. The boys and girls demonstrated a comparable level of knowledge and practice in the area of food safety. It was showed that the place of school influenced answers to a greater extent compared to gender.Originality/valueThe results of the study play an important role in the prevention of food poisoning and are useful for the teachers, staff of training institutions and parents. They can also inspire institutions in countries with a high incidence of food poisoning to search for the causes in the inappropriate hygienic practices of young children.

FCN1 polymorphisms are not the markers of dental caries susceptibility in Polish children: A case-control study.

To examine the association of four FCN1 SNPs: -542G>A (rs10120023), -144C>A (rs10117466), +6658C>T (rs148649884), and +7895A>G (rs150625869) with dental caries in Polish children. The study group consisted of 261 15-year-old Polish teenagers: 82 children with "higher" caries experience (having Decayed Missing Filled Teeth, DMFT >5) and 179 children with "lower" caries experience (having DMFT ≤5). Moreover, in additional comparison, a group of 229 children with caries experience (DMFT ≥1) was compared to a caries-free (DMFT =0) group of 32 children. Extraction of genomic DNA was performed from buccal swabs, and genotyping was performed by Real-Time PCR. FCN1 SNPs +6658C>T and +7895A>G appeared to be monomorphic in our sample. The genotype, allele, or haplotype distributions in FCN1 SNPs -542G>A and -144C>A in children with "higher" caries experience did not differ significantly from those in "lower" caries experience group. Similar results with no significant differences were demonstrated for subjects with DMFT ≥1 compared to subjects with DMFT =0. FCN1 SNPs are not the markers of dental caries susceptibility in Polish children.

Current status and achievements of Polish haemato-oncology

The number of newly diagnosed haematological malignancies in Polish adults and children is about 9,000 a year, which constitutes about 5.5% of all malignancies in the country. Adult patients with haematological malignancies are diagnosed and treated in 42 institutions in Poland. The scientific and educational support for this activity is provided under the umbrella of the Polish Society of Haematologists and Transfusiologists (PTHiT, Polskie Towarzystwo Hematologów i Transfuzjologów ), the Polish Adult Leukemia Group (PALG), the Polish Lymphoma Research Group (PLRG), the Polish Myeloma Study Group (PMSG), the Polish Myeloma Consortium (PMC), and consultants in haematology. The aim of this position paper is to present the current status and progress in therapy of haematological malignancies in Polish haematology adult centres, focusing on the activity of PALG, PLRG, and PMSG. The achievements of Polish haemato-oncology at the beginning of the third decade of the 21 st century are set out in this paper. Polish haemato-oncology today has an important international position based on contributions to the development of knowledge, international cooperation, and a high quality of patient care. In many instances, clinical trials run by Polish collaborative groups have influenced international standards. Polish haematologists have been the authors of treatment recommendations, and their research has indicated areas for further research.

Association Between rs12037447, rs146732504, rs151078858, rs55723436, and rs6094136 Polymorphisms and Kawasaki Disease in the Population of Polish Children.

Background: Kawasaki disease (KD) is an acute self-limited febrile vasculitis that mainly affects young children. Coronary artery involvement is the most serious complication in children with KD. It is currently the leading cause of acquired cardiac disease in children from developed countries. Literature data indicate a significant role of genetic susceptibility to KD.Objective: The aim of this study was to perform the first Genome-Wide Association Study (GWAS) in a population of Polish children with KD and identify susceptible genes involved in the pathogenesis of KD.Materials and Methods: The blood samples of Kawasaki disease patients (n = 119) were collected between 2016 and 2020, isolated and stored at the Department of Pediatrics, Nutrition and Metabolic Diseases, Children's Memorial Health Institute in Warsaw. The control group was based on Polish donors (n = 6,071) registered as the POPULOUS collection at the Biobank Lab of The Department of Molecular Biophysics in University of Lodz. DNA samples were genotyped for 558,231 Single Nucleotide Polymorphisms (SNPs) using the 24 × 1 Infinium HTS Human Core Exome microarrays according to the protocol provided by the manufacturer. In order to discover and verify genetic risk-factors for KD, association analysis was carried out using PLINK 1.9.Results: Of all 164,395 variants, 5 were shown to occur statistically (padjusted < 0.05) more frequent in Kawasaki disease patients than in controls. Those are: rs12037447 in non-coding sequence (padjusted = 8.329 × 10−4, OR = 8.697, 95% CI; 3.629–20.84) and rs146732504 in KIF25 (padjusted = 0.007354, OR = 11.42, 95% CI; 3.79–34.43), rs151078858 in PTPRJ (padjusted = 0.04513, OR = 8.116, 95% CI; 3.134–21.01), rs55723436 in SPECC1L (padjusted = 0.04596, OR = 5.596, 95% CI; 2.669–11.74), rs6094136 in RPN2 (padjusted = 0.04755, OR = 10.08, 95% CI; 3.385–30.01) genes.Conclusion: Polymorphisms of genes KIF25, PTRPJ, SPECC1L, RNP2 may be linked with the incidence of Kawasaki disease in Polish children.

The Diagnostic-Measurement Method-Resting Energy Expenditure Assessment of Polish Children Practicing Football.

Establishing the amount of energy needed to cover the energy demand of children doing sport training and thus ensuring they achieve an even energy balance requires the resting energy expenditure (REE) to be estimated. One of the methods that measures REE is the indirect calorimetry method, which may be influenced by many factors, including body composition, gender, age, height or blood pressure. The aim of the study was to assess the correlation between the resting energy expenditure of children regularly playing football and selected factors that influence the REE in this group. The study was conducted among 219 children aged 9 to 17 using a calorimeter, a device used to assess body composition by the electrical bioimpedance method by means of segment analyzer and a blood pressure monitor. The results of REE obtained by indirect calorimetry were compared with the results calculated using the ready-to-use formula, the Harris Benedict formula. The results showed a significant correlation of girls’ resting energy expenditure with muscle mass and body height, while boys’ resting energy expenditure was correlated with muscle mass and body water content. The value of the REE was significantly higher (p ≤ 0.001) than the value of the basal metabolic rate calculated by means of Harris Benedict formula. The obtained results can be a worthwhile suggestion for specialists dealing with energy demand planning in children, especially among those who are physically active to achieve optimal sporting successes ensuring proper functioning of their body.

Prevalence of Overweight, Obesity, Abdominal Obesity, and Obesity-Related Risk Factors in Polish Preschool Children: A Cross-Sectional Study.

The aim of this study was to assess the prevalence of overweight, obesity, abdominal obesity (AO), and obesity-related risk factors in children aged 5–6 years from Poland. The study was conducted at 22 randomly selected kindergartens representing each city district. A cross-sectional study of 1172 children aged 5–6 years was conducted using questionnaire forms and physical measurements. The physical measurements included body height, weight, waist circumference (WC), and body fat percentage (BFP). A univariate and multivariate logistic regressions were performed to evaluate the risk factors for excess weight, excess adiposity, and abdominal obesity (AO). The prevalence of excess weight (BMI ≥ 85th percentile) was 11.0%. The prevalence of excess adiposity (BFP ≥ 85th percentile) was 42.3%. Prevalence of AO (WC ≥ 90th percentile) was higher in girls compared to boys (14.9% vs. 10.7%, respectively). Multivariate logistic regression analysis indicated that children whose both parents were obese had significantly higher risk of excess weight, excess adiposity, and AO. Lower education level of fathers was associated with higher risk of excess weight and excess adiposity in children, while a lower level of maternal education was associated with higher risk of AO in children. Screen time over 120 min per day, participating less than once a week in at least 60 min of moderate-to-vigorous physical activity (MVPA) and birth weight over 4000 g were associated with excess weight, excess adiposity and AO. Moreover, cesarean delivery was associated with higher risk of excess weight and excess adiposity, and lower socio-economic status with higher risk of AO. This study revealed that excess adiposity and AO differed by gender. Parental obesity, screen time, MVPA, and birth weight could be significant determinants of excess weight, excess adiposity and AO in Polish preschool children.

Children’s Astronomy. Development of the Shape of the Earth Concept in Polish Children between 5 and 10 Years of Age

The Earth’s shape concept develops as consecutive cognitive problems (e.g., the location of people and trees on the spherical Earth) are gradually resolved. Establishing the order of problem solving may be important for the organisation of teaching situations. This study attempted to determine the sequence of problems to be resolved based on tasks included in the EARTH2 test. The study covered a group of 444 children between 5 and 10 years of age. It captured the order in which children solve cognitive problems on the way to constructing a science-like concept. The test results were compared with previous studies. The importance of cultural influences connected to significant differences (24%) in test results was emphasised. Attention was drawn to the problem of the consistency of the mental model approach highlighted in the literature. The analysis of the individual sets of answers provided a high level of consistency of indications referring to the same model (36%), emphasising the importance of the concept of mental models.

Retrospective analysis of clinical and pathomorphological features of lupus nephritis in children

PurposeThe aim of the study was to evaluate the clinical course and pathomorphological correlations in Polish children with the diagnosis of lupus nephritis (LN). MethodsWe retrospectively analyzed the medical records of 39 children hospitalized due to LN in 7 pediatric nephrology units in Poland between 2010 and 2019. Demographic data, clinical symptoms at the onset of LN and laboratory parameters were reviewed. We analyzed Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), histological LN findings with the activity (IA) and chronicity index (IC). ResultsWe examined 32 girls and 7 boys, median age at LN onset was 14.75 (IQR 13.0–16.0) years, SLEDAI of 22.0 (IQR 18.0–27.0) points; LN histological class: IV (59.4%), III (18.9%), III/V (10.8%), IV/V (8.1%), VI (2.7%); IA 8.0 (IQR 6.0–11.0) points, IC 1.05 (IQR 0–2.0) points.Children with nephrotic (n ​= ​22) and non-nephrotic (n ​= ​17) proteinuria differed in median Hb level (9.55, IQR 8.3–11.2 vs 10.9, IQR 10.1–11.6 ​g/L; P ​< ​0.05), albumin level (2.5, IQR 2.1–3.19 vs 3.6, IQR 3.4–4.1 ​g/dL; P ​< ​0.001), proteinuria (5.76, IQR 3.0–7.5 vs 1.08, IQR 0.53–1.50 ​g/day; P ​< ​0.0001), eGFR (53.9, IQR 27.0–68.8 vs 96.7, IQR 73.8–106.2 ​mL/min/1.73 ​m2; P ​< ​0.01) and occurrence of hypertension (77% vs 23%; P ​< ​0.01).In multivariate analysis Hb level (β ​= ​8.0; 95%CI, 1.90–14.11) was the significant predictor of eGFR<90 ​mL/min/1.73 ​m2. ConclusionsProliferative forms of LN in children may have a varying clinical presentation.Children with LN with nephrotic range proteinuria have lower Hb level, lower eGFR and higher occurrence of hypertension. Hb level is the significant predictor of eGFR<90 ​mL/min/1.73 ​m2 in children with LN.