Hemolytic uremic syndrome (HUS) is defined by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury (AKI). Atypical HUS (aHUS), distinguished by its etiology, is caused by uncontrolled overactivation of the alternative complement pathway. The correct diagnosis of aHUS is complex and involves various gene mutations. Severe combined immunodeficiency (SCID), characterized by severe T-cell lymphocytopenia and a lack of antigen-specific T-cell and B-cell immune responses, is of seldom occurrence. In 10–15% of pediatric patients, SCID is caused by adenosine deaminase (ADA) deficiency. The authors describe the case of a boy who suffered from both aHUS and ADA-deficient SCID. At the age of 9 months, the patient presented acute kidney injury with anuria and coagulopathy. The diagnosis of aHUS was established on the basis of alternative complement pathway deregulation and disease-associated gene mutations. Further examination revealed immune system failure and, at the age of 13 months, the ADA deficiency was confirmed by genetic tests and the boy was diagnosed with ADA-SCID. ADA SCID has recently been described as a possible triggering factor of aHUS development and progression. However, more research is required in this field. Nevertheless, it is crucial in clinical practice to be aware of these two co-existing life-threatening diseases.

Idiopathic nephrotic syndrome (INS) is a chronic glomerular disease in children, characterized by severe proteinuria, hypoalbuminemia, and/or presence of edema and hyperlipidemia. The pathogenesis, however, has not been yet established. The clinical course of the disease is characterized by frequent relapses. Interleukin-15 (IL-15) is a pro-inflammatory cytokine, that apart from its involvement in the immune system, was found to be playing a vital role in various cells’ functioning, including renal tissue. It is desirable to look for new predictors of INS. Our study aimed to evaluate IL-15 as a potential marker in the early diagnosis of the disease. The cohort participating in the study consisted of patients hospitalized in Clinical Hospital No. 1 in Zabrze, from December 2019 to December 2021, including study group with INS (n = 30) and control group (n = 44). Results: The concentration of IL-15 in both serum and urine was significantly elevated in patients with INS, compared to healthy controls. The cytokine might serve as a marker of the disease, however, further research on larger study groups is needed.

Idiopathic nephrotic syndrome (INS) is a chronic disease affecting children in early childhood. It is characterized by proteinuria, hypoalbuminemia, edema and hyperlipidemia. To date, the diagnosis is usually established at an advanced stage of proteinuria. Therefore, new methods of early INS detection are desired. This study was designed to assess brain-derived neurotrophic factor (BDNF) as a potential marker in the early diagnosis of INS. The study group included patients with a diagnosis of idiopathic nephrotic syndrome (n = 30) hospitalized in Clinical Hospital No. 1 in Zabrze, from December 2019 to December 2021. Our study shows that serum BDNF concentration decreased and urine BDNF concentration increased in a group of patients with INS, compared with healthy controls. Such outcomes might be related to loss of the BDNF contribution in podocyte structure maintenance. Moreover, we anticipate the role of BDNF in urine protein concentration increase, which could be used as a direct predictor of urine protein fluctuations in clinical practice. Moreover, the ROC curve has also shown that serum BDNF and urine BDNF levels might be useful as an INS marker.

Chronic kidney disease (CKD) is a progressive condition which still leads to significant morbidity and mortality among patients at all ages. Its proper management should be focused on slowing down the disease sequelae, as well as establishing an early diagnosis and treatment of its complications. Eotaxin is a potent, selective eosinophil chemoattractant, which is reported to have an impact on various kidney diseases. Nevertheless, data regarding the potential correlation between eotaxin and CKD in a pediatric population is still scarce. This study aims to assess the concentration of eotaxin in children with CKD and evaluate potential correlations with selected biochemical markers and disease occurrence. Both serum and urine eotaxin concentrations were markedly higher in children with CKD compared to healthy controls. Moreover, Receiver Operating Characteristic (ROC) curves have shown that serum eotaxin and urine eotaxin levels demonstrated high sensitivity and high specificity for the allocation of patients to the study and control groups. The authors advanced a thesis that eotaxin might serve as a marker of CKD occurrence in a pediatric population. Such a research design is innovative, since it has not been analyzed in the literature yet. However, further studies are required.

Idiopathic nephrotic syndrome is the most common chronic glomerular disease in children. Treatment with steroids is usually successful; however, in a small percentage of patients, steroid resistance is observed. The most frequent histologic kidney feature of steroid-resistant nephrotic syndrome (SRNS) is focal segmental glomerulosclerosis (FSGS). Genetic testing has become a valuable diagnostic tool in defining the etiology of SRNS, leading to the identification of a genetic cause. The TRIM8 gene is expressed in various tissues, including kidney cells and the central nervous system (CNS). An association between a mutation in the TRIM8 gene and an early onset of FSGS has been proposed but is not well described. We present a 17-year-old boy with epilepsy, early mild developmental delay, a low IgG serum level, and proteinuria, secondary to FSGS. A Next-Generation Sequencing (NGS)-based analysis revealed a heterozygous de novo pathogenic variant in the TRIM8 gene (c.1200C>G, p.Tyr400Ter). TRIM8 gene sequencing should be considered in individuals with early onset of FSGS, particularly accompanied by symptoms of cortical dysfunction, such as epilepsy and intellectual disability.

Nesfatin-1 is a recently discovered protein with a pleiotropic function on various organs, including kidneys. This molecule presents antiapoptotic, antihyperglycemic, antioxidative, and anorectic features. Available data regarding the role of nesfatin-1 in kidney function and diseases focuses on chronic kidney disease, acute kidney injury, blood pressure, and renal cell carcinoma. Various studies have shown that the levels of nesfatin-1 were increased in patients with diabetic kidney disease (DKD); therefore, it was suggested that nesfatin-1 might act as an early DKD marker. Furthermore, the potential protective function of nesfatin-1 against inflammation, oxidative stress, fibrosis, and apoptosis in kidney tissues was described in several studies. Alternatively, as reported in the literature, a positive correlation between blood pressure elevation and nesfatin-1 levels was noted. Moreover, nesfatin-1 might exert influence on renal cell carcinoma progression and invasion of cancerous cells. Nesfatin-1 shows considerable potential for acting as a prognostic marker or a defensive factor for kidney diseases; however, further investigation, especially in the pediatric population, is still required. Graphical abstract