Chickenpox during pregnancy can lead to life-threatening complications for the mother and various forms of intrauterine infection. The rising incidence of varicella in the Russian Federation, low rates of immunization, lack of pre-pregnancy screening for antibodies to human herpesvirus type 3, and the availability of vaccination only at the pregravid stage contribute to the epidemiological involvement of pregnant women. Low public awareness about the possibility of varicella immunoprophylaxis, along with insufficient caution among healthcare professionals regarding the potential risks of chickenpox during pregnancy, also exacerbate this issue. The solution to this problem is based on an active approach to chickenpox prevention to create a safe environment for pregnant women and to develop unified standards for post-exposure prophylaxis of chickenpox in pregnancy.

Microchimerism is characterized by the presence of circulating cells that are bidirectionally transferred between genetically distinct individuals. This phenomenon occurs physiologically during pregnancy and iatrogenically following blood transfusion and organ transplantation. Migrated cells can persist for extended periods, even decades. Research varies on the role of microchimeric cells in the pathogenesis of different diseases and their significance in tissue repair. Microchimerism has been implicated in the pathogenesis of diseases such as systemic sclerosis, systemic lupus erythematosus, autoimmune thyroid diseases, primary biliary cirrhosis, rheumatoid arthritis, among others. In some cases, microchimerism contributes to the development of autoimmune diseases, while in others, it aids the body in overcoming particular diseases. These findings suggest that foreign cells could serve as a potential target for drugs aimed at treating autoimmune diseases or promoting the regeneration of damaged tissues. The concept of maternal and systemic microchimerism offers insights into certain evolutionary questions and the potential for preventing various pathological conditions.

Sarcopenia is characterized by a decline in skeletal muscle mass and muscle function. Skeletal muscle plays a crucial role in metabolism and overall health throughout the lifespan. Emerging evidence indicates that both prenatal (such as maternal diet during pregnancy and genetic factors) and postnatal factors (including physical activity, hormonal levels, nutrition, and various diseases, such as obesity) influence the development of muscle mass and strength early in life. The presence of sarcopenia is associated with adverse outcomes (such as cardiometabolic disorders, non-alcoholic fatty liver disease, cognitive dysfunction, falls and fractures, reduced physical performance and quality of life, as well as disability and mortality) in both children and later in adults. Despite growing research interest in sarcopenia across different ages, a clear pediatric concept and clinical guidelines are currently lacking. The objective of this review is to examine the latest data on sarcopenia in pediatrics, with a specific focus on myokines and their role. The review includes data from the past 5 years sourced from the Elibrary and PubMed databases. The literature search was conducted using keywords: pediatric sarcopenia, sarcopenia in children, skeletal muscle in childhood, myokines in children.

Marfan syndrome (OMIM #154700) is an autosomal dominantly inherited connective tissue disorder caused by mutations in the FBN1 gene and is marked by significant clinical variability, including cardiovascular manifestations. The causes of this variability remain inadequately studied, and relatively few genotype-phenotype correlations have been identified to date. In this study, we examined 66 children with Marfan syndrome to identify genotype-phenotype correlations. Biochemical, functional, and genetic research methods were employed, confirming a positive correlation between ectopia lentis and missense variants in the FBN1 gene. Additionally, in our cohort, patients with loss-of-function (LoF) mutations, compared to those with missense mutations, statistically showed larger aortic dimensions, earlier onset of foot deformities, marked dolichostenomelia, a higher frequency of elbow contractures, chest deformities, and aortic dilation. Patients with missense variants involving cysteine loss, as opposed to those without cysteine involvement, demonstrated an earlier onset of spinal deformity, higher natriuretic peptide (NT-proBNP) levels, larger aortic sizes, increased prevalence of chest deformities, particularly carinatum, ectopia lentis, and a greater propensity for osteoporosis. Patients with mutations in exons 11 to 20, compared to those with mutations in other exons, were less likely to exhibit pectus carinatum and aortic dilation and had less pronounced dolichostenomelia. Patients with mutations in exons 51 to 66, regardless of mutation type, were less likely to present with ectopia lentis. Thus, based on an analysis of genotype-phenotype correlations in a cohort of 66 children with Marfan syndrome, we identified several statistically significant correlations between phenotypic features of Marfan syndrome and mutation type and location within the FBN1 gene. This study confirmed that stable genotype-phenotype correlations are increasingly important for understanding clinical variability and for predicting disease severity.

Marfan syndrome (OMIM #154700) is an autosomal dominantly inherited connective tissue disorder caused by mutations in the FBN1 gene and is marked by significant clinical variability, including cardiovascular manifestations. The causes of this variability remain inadequately studied, and relatively few genotype-phenotype correlations have been identified to date. In this study, we examined 66 children with Marfan syndrome to identify genotype-phenotype correlations. Biochemical, functional, and genetic research methods were employed, confirming a positive correlation between ectopia lentis and missense variants in the FBN1 gene. Additionally, in our cohort, patients with loss-of-function (LoF) mutations, compared to those with missense mutations, statistically showed larger aortic dimensions, earlier onset of foot deformities, marked dolichostenomelia, a higher frequency of elbow contractures, chest deformities, and aortic dilation. Patients with missense variants involving cysteine loss, as opposed to those without cysteine involvement, demonstrated an earlier onset of spinal deformity, higher natriuretic peptide (NT-proBNP) levels, larger aortic sizes, increased prevalence of chest deformities, particularly carinatum, ectopia lentis, and a greater propensity for osteoporosis. Patients with mutations in exons 11 to 20, compared to those with mutations in other exons, were less likely to exhibit pectus carinatum and aortic dilation and had less pronounced dolichostenomelia. Patients with mutations in exons 51 to 66, regardless of mutation type, were less likely to present with ectopia lentis. Thus, based on an analysis of genotype-phenotype correlations in a cohort of 66 children with Marfan syndrome, we identified several statistically significant correlations between phenotypic features of Marfan syndrome and mutation type and location within the FBN1 gene. This study confirmed that stable genotype-phenotype correlations are increasingly important for understanding clinical variability and for predicting disease severity.

Neonatal sepsis remains a pressing issue for healthcare both in Russia and globally due to its high mortality rate and resistance to treatment. Infection generalization in newborns is facilitated by a deficiency in innate immunity, which is particularly evident in impaired neutrophil function.

The aim of this study was to identify phenotypic characteristics of specific neutrophil subsets that could be significant in predicting the development and progression of infection in newborns. Using flow cytometry, we examined CD16 and CD62L expression as well as neutrophil granularity in newborns across three groups: those without infectious complications (n=38), with localized infection (n=32), and with generalized infection (n=21). Neutrophil subsets with high and intermediate levels of CD16 and CD62L expression demonstrated prognostic relevance. Patients with generalized infection exhibited a significant reduction in surface CD16 and granularity in these neutrophil subsets. Cutoff points were calculated, showing that a decrease in these parameters on the first day of illness was significantly associated with extended stays in intensive care units and overall hospitalization duration. The proposed indicators show promise for predicting infectious complications in newborns, facilitating more targeted and proactive care in neonatal practice.

TREC/KREC analysis is utilized in neonatal screening for the detection of primary immunodeficiencies caused by genetic defects in proteins essential for T- and B-lymphocyte development. However, the diagnostic value of this method for the postnatal detection of various primary immunodeficiency forms has not yet been fully established. This study aimed to analyze the TREC/KREC profiles in patients with confirmed inborn errors of immunity. TREC/KREC levels were assessed in 44 patients using real-time PCR at the time of diagnosis. Nine patients were diagnosed with severe combined immunodeficiency (SCID), 25 with syndromic combined immunodeficiency, five with immune dysregulation disorders, and five with antibody production defects. Abnormal TREC/KREC values were observed in 100% of children with classical SCID, 56% with syndromic immunodeficiencies, and 80% with antibody production defects. Sub-threshold TREC/KREC levels were found in 55.6% of children with Louis-Bar syndrome, 40% with DiGeorge syndrome, and both patients with Nijmegen syndrome. Normal TREC levels were observed in two children with Wiskott-Aldrich syndrome, in cases of immune regulation disorders, and in isolated cases of Job syndrome and hyper-IgM syndrome. The lowest TREC values were identified in patients with combined immunodeficiency. These findings support the potential of the TREC/KREC assay as a tool for postnatal screening, including for patients with late-onset inborn errors of immunity.

The non-specific symptoms of impaired tolerance to enteral feeding and the lack of laboratory and instrumental methods for early detection of changes in intestinal permeability make timely assessment of the intestinal barrier in newborns a complex clinical challenge. Identifying reliable and specific markers that differentiate between functional gastrointestinal disorders and early stages of surgical pathology in newborns is an area of significant interest for a wide range of specialists.

Purpose. The study aimed to evaluate the impact of gestational age on the serum levels of Claudin-2, a tight junction protein in enterocytes, in infants during the first months of life.

Material and methods. The study included 115 newborns with gestational ages (GA) ranging from 33 to 41 weeks (median GA 38.0 [36.0–39.0] weeks). The infants were divided into two groups based on GA: Group 1 (term infants, median GA 39.0 [38.0–40.0] weeks, n=80) and Group 2 (preterm infants, median GA 35.0 [34.5–36.0] weeks, n=35). Serum Claudin-2 levels were measured during the first months of life using a Human CLDN2 enzyme immunoassay kit. Results. Serum Claudin-2 concentrations increased from 3.434 [1.198; 7.866] ng/ml in the first 10 days of life to 5.147 [3.529; 8.211] ng/ml (p=0.02) by 1–1.5 months, with the most pronounced increase observed in term infants (from 1.508 [1.004; 4.33] ng ml to 4.302 [3.188; 5.776] ng/ml, p<0.001). An inverse correlation was noted between GA and Claudin-2 concentration in the first days of life (–0.507, p<0.001), which weakened by 1–1.5 months (–0.342, p<0.001). Additionally, higher Claudin-2 concentrations were observed in preterm infants at a postmenstrual age of 40–41 weeks compared to full-term infants at birth (p<0.001).

Conclusion. The findings demonstrate the influence of GA on Claudin-2 levels in the first months of life, suggesting increased intestinal permeability in infants with lower gestational maturity, mediated by variable Claudin-2 expression.

Preventing respiratory diseases in young children remains a primary focus in pediatric healthcare.

Purpose. To evaluate the impact of passive immunization against respiratory syncytial virus (RSV) in children at high risk of severe RSV infection on the incidence of respiratory illnesses and the levels of proteolytic enzyme biomarkers in children aged 1–3 years.

Material and methods. The study included 216 children aged 0–3 years, divided into three groups: Main Group 1 (children who received RSV immunization), Main Group 2 (children without immunization), and a control group (health groups I and II). Health assessments were conducted during the newborn period and at ages 1–3 years. Biomarkers of pulmonary proteolytic enzymes were measured, including matrix metalloproteinases 2 (MMP-2) and 9 (MMP-9), tissue inhibitor of matrix metalloproteinase-2 (TIMMP-2), and vascular endothelial growth factor (VEGF-D).

Results. The absence of RSV immunoprophylaxis in the first year of life significantly contributed to the development of recurrent obstructive bronchitis (AP = 46%) and pneumonia (AP = 49.7%) in early childhood. An association was identified between MMP-9 and TIMMP-2 levels in serum and the frequency of recurrent obstructive bronchitis at ages 1–3 years. The lack of passive RSV immunization during the first year of life increased the likelihood of VEGF-D levels reaching very high values (≥97‰) by a factor of 10. An increased risk of recurrent obstructive bronchitis was also observed at elevated VEGF-D levels (≥90‰). Completing the RSV immunization cycle was associated with a significant reduction in respiratory disease cases and decreased VEGF-D levels.

Conclusion. Passive immunization against RSV in children at risk for severe RSV infection is associated with a reduction in respiratory disease incidence, recurrent obstructive bronchitis, and pneumonia, as well as an impact on fibrosis markers in children aged 1–3 years.

Currently, there are no standardized guidelines on the need for and frequency of anti-relapse therapy in children with chronic secondary pyelonephritis.

Purpose. To assess the diagnostic value of urinary neutrophil gelatinase-associated lipocalin (NGAL) measured as a ratio to urinary creatinine (NGAL/Cr), in predicting recurrence rates of chronic secondary pyelonephritis in children.

Material and methods. The study included 158 children aged 2 to 14 years with chronic secondary pyelonephritis, comprising 130 girls (82.3%) and 28 boys (17.7%). Children were divided into groups based on the presence and scheme of anti-relapse therapy (furazidine and/or phytopreparation BNO 1045). This article continues the authors’ research previously published in 2019, 2020, and 2023.

Results. A pre-treatment urinary NGAL/Cr level above 12 ng/mg in patients with recurrent secondary pyelonephritis allowed prediction of disease recurrence and supported the need for anti-relapse therapy. Adding the phytopreparation BNO 1045 to anti-relapse therapy for one month following a two-week furazidine course extended the relapse-free period from 13 to 16 months and reduced the recurrence risk by 1.9 times with therapy administered annually. Implementing this anti-relapse therapy every six months increased the median relapse-free period to 22 months, reducing recurrence risk by over fourfold.

Conclusion. The study demonstrates the predictive value of urinary NGAL/Cr levels before the initiation of antibacterial therapy, allowing assessment of relapse risk in secondary pyelonephritis. The findings support the necessity of anti-relapse therapy in children with chronic secondary pyelonephritis. Optimal remission extension was achieved with a combination therapy of furazidine and phytopreparation BNO 1045.

Orofaciodigital syndrome type I is a rare (orphan) disease with a prevalence of 1:50,000 to 1:250,000, characterized by craniofacial, oral, and digital anomalies, as well as involvement of internal organs, including the kidneys. Orofaciodigital syndrome type I is inherited in an X-linked dominant manner, primarily affecting females, and arises from defects in the formation of primary cilia. This article presents a clinical case of a 12-year-old patient diagnosed with orofaciodigital syndrome type I, along with a review of the pathogenic mechanisms and clinical manifestations of the syndrome based on literature data. The article demonstrates the significant genetic heterogeneity and clinical variability among patients with mutations in the OFD1 gene.

The incidence of malignant neoplasms associated with solitary thyroid nodules is higher in children than in adults. The diagnosis of nodular thyroid pathology in pediatric practice clearly requires particular attention. Clinical history should include an assessment of risk factors for malignant tumors and a family history. Thyroid tumors are observed in certain syndromes, such as Carney complex, familial adenomatous polyposis, and Cowden, DICER1, Werner, McCune–Albright, and Li–Fraumeni syndromes. This article presents a case of a highly differentiated thyroid tumor diagnosed in a 15-year-old boy. The distinct morphological features of the postoperative tissue indicated the need for molecular genetic testing in this patient. Genetic analysis revealed a mutation in a gene responsible for regulating cellular apoptosis, suggesting a diagnosis of Cowden syndrome in the patient. Cowden syndrome is a rare disorder associated with a mutation in the PTEN gene, characterized by multiple hamartomas in various organs. PTEN gene mutations lead to lesions in the skin, mucous membranes, thyroid gland, and fibrocystic mastopathy.

Pathogenic nucleotide variants in the MORC2 gene have recently been linked to axonal peripheral neuropathy (Charcot–Marie–Tooth disease, axonal type 2Z) and the syndrome of developmental and growth disorders, facial dysmorphia, and axonal neuropathy (DIGFAN syndrome). DIGFAN syndrome is marked by early onset and multisystem symptoms, particularly affecting the visual and auditory organs. In approximately 30% of cases, mitochondrial encephalomyopathy is initially considered a possible diagnosis. In a girl with a heterozygous MORC2 gene mutation, the presence of DIGFAN syndrome was confirmed. Her clinical profile included motor, speech, and physical developmental delays, along with visual and auditory impairments, peripheral neuropathy, facial dysmorphia, Lee-like changes on MRI, and moderate lactic acidemia. Following metabolic therapy targeting intracellular energy exchange processes, alongside a rehabilitation program, some improvement in her condition and normalization of blood lactate levels were observed. The importance of early diagnosis is highlighted, as it supports the timely initiation of metabolic therapy and other therapeutic interventions under specialist supervision. Confirming the diagnosis is critical for anticipating disease progression and providing genetic counseling for the proband and their family.

The article provides current information on the clinical forms of hypophosphatasia. The OMIM catalog lists 5 forms of hypophosphatasia: perinatal (lethal), infantile, childhood, adult, and odontohypophosphatasia. The ORPHA portal identifies 6 subtypes of the disorder, including adult, childhood, infantile, perinatal (lethal), and prenatal (benign) hypophosphatasia. M.E. Nunes (2023) identifies 7 forms of hypophosphatasia. International studies have established the pathogenesis, phenotypic variability, and severity of hypophosphatasia. A global consortium provides information on 446 mutation variants of the ALPL gene and 797 genotypes in pediatric and adult patients. The review presents updated diagnostic criteria for hypophosphatasia in children and adults with low alkaline phosphatase activity in the blood. Ten years of experience in 40 countries have proven the safety and efficacy of enzyme replacement therapy with Asfotase Alfa in children with perinatal, infantile, childhood hypophosphatasia, and odontohypophosphatasia. In the Russian Federation, enzyme replacement therapy with Asfotase Alfa for children with hypophosphatasia has been funded by the Circle of Kindness Foundation, established by the Ministry of Health, since 2021.

Urolithiasis in young children is a rare condition requiring particular attention due to its potential complexity and the necessity of an individualized treatment approach. This article presents a case study of a 5-year-old child treated for urolithiasis following acute lymphoblastic leukemia therapy.

 Case report. A 5-year-old boy presented at Ilyinskaya Hospital with right ureteral obstruction. Ultrasound performed due to abdominal pain revealed dilation of the kidney’s collecting system (calyces up to 12 mm, renal pelvis up to 16 mm) and the proximal ureter (up to 6 mm) on the right side. A solitary calculus obstructing the right ureter was identified via computed tomography. The child underwent emergency surgery, including cystoureteroscopy, lithoextraction from the right ureter, and placement of an internal stent. The postoperative period was marked by infectious complications, which were effectively managed. The internal stent was removed on the 6th postoperative day. The patient remained under hematology and nephrology follow-up, with no recurrence of urolithiasis reported.

Conclusion: This study emphasizes the necessity of a comprehensive approach in managing pediatric urolithiasis, including careful monitoring and appropriate treatment, particularly in the presence of underlying conditions that may exacerbate or contribute to the disease. Special attention is given to adequate postoperative care and prevention of recurrence, which are essential for a favorable outcome and minimizing the risk of stone reformation.