Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of rare but potentially life-threatening autoimmune diseases that affect small to medium-sized blood vessels. Recent evidence highlights the critical role of neutrophil extracellular traps (NETs) in the pathophysiology of AAV. NETs, which are web-like structures composed of DNA and antimicrobial proteins, contribute to vascular damage and immune activation. In patients with AAV, excessive or impaired clearance of NETs can trigger autoantibody production and exacerbate inflammation. This literature review demonstrates the association between NETs and disease activity in AAV. Biomarkers such as MPO-DNA complexes and circulating free DNA can be used to assess disease activity and the response to treatment. Understanding NETosis in the clinical context could improve risk stratification, guide treatment decisions, enable the development of new targeted therapies, and support the development of more precise monitoring tools for AAV treatment.

Smith–Lemli–Opitz syndrome (SLOS) is a rare, autosomal recessive genetic disorder caused by mutations in the DHCR7 gene, which encodes the enzyme responsible for the final step in cholesterol biosynthesis. Impaired enzyme function leads to cholesterol deficiency, affecting the development and function of the entire organism. The accumulation of cholesterol precursors enhances the formation of oxysterols, which are involved in the pathomechanism of neurological, ophthalmological, and vascular changes in patients. This review analyzes 53 studies published between 2020 and 2025 on the molecular mechanisms underlying the clinical features of SLOS, including cholesterol deficiency, oxysterol accumulation, and the latest diagnostic methods, including LC-MS/MS chromatography and biomarkers such as GFAP for monitoring disease progression. MRI is discussed as a supportive tool for neuroimaging, along with advances in prenatal diagnostics, such as the detection of cholesterol precursors in neonatal hair. Therapeutic options are also reviewed, with particular emphasis on cholesterol supplementation, cholic acid, and experimental treatments such as vitamin E supplementation, statin therapy, gene therapy, and liver transplantation. Current research indicates that expanding knowledge in this area not only improves patient prognosis but also provides hope for the development of effective therapies in the future.

Background/Objectives: Patients receiving maintenance hemodialysis (HD) commonly exhibit malnutrition, chronic low-grade inflammation, and metabolic disturbances. Gut dysbiosis may contribute to these abnormalities through the gut-kidney axis. This study aimed to characterize gut microbiota composition in HD patients and examine its associations with demographic, clinical, and body composition parameters. Methods: This cross-sectional study included 96 patients with end-stage kidney disease on maintenance HD. Clinical, laboratory, inflammatory, nutritional, and bioimpedance-derived body composition data were collected, including Malnutrition-Inflammation Score (MIS). Stool samples were analyzed for gut microbiota composition. Associations with host-related variables were assessed using alpha- and beta-diversity analyses, subgroup comparisons, and Mantel testing. Results: Gut microbiota showed marked inter-individual heterogeneity at the genus level, with dominant taxa including Blautia, Faecalibacterium, Streptococcus, Gemmiger, Ruminococcus, Escherichia-Shigella, and Enterococcus. Chao1 richness was higher in men than in women. Shannon entropy and Chao1 richness were positively associated with age and visceral adipose tissue (VAT), while Faith’s phylogenetic diversity increased with age. In contrast, the Gini index was negatively associated with age and VAT, indicating a more even microbial structure in older individuals and those with higher visceral adiposity. Beta-diversity differed between men and women and across categories within the female subgroup. Mantel testing showed a modest but significant correlation between microbiota and metadata distances. Conclusions: Gut microbiota in maintenance HD patients is highly heterogeneous and associated mainly with sex, age, visceral adiposity, and overall host phenotype. These findings suggest that microbiota variation in HD reflects multidimensional host-related factors rather than a single clinical feature.

Background/Objectives: Patients receiving maintenance hemodialysis (HD) commonly exhibit chronic low-grade inflammation, nutritional disturbances, altered body composition, and metabolic imbalance. Gut dysbiosis may contribute to these abnormalities through the gut–kidney axis; however, the relationship between the gut microbiota composition and host phenotype in HD patients remains incompletely characterized. This study aimed to characterize the gut microbiota composition in maintenance HD patients and assess its cross-sectional associations with demographic, inflammatory, nutritional, dialysis-related, and bioimpedance-derived body composition parameters. Methods: This single-center cross-sectional study included 96 patients with end-stage kidney disease undergoing maintenance HD. The primary objective was to characterize the gut microbiota composition in maintenance HD patients. Secondary objectives were to assess cross-sectional associations with demographic factors (sex, age) and bioimpedance-derived body composition (specifically VAT). Clinical and laboratory data, inflammatory markers, nutritional indicators, malnutrition–inflammation score (MIS), dialysis-related variables, and bioimpedance-derived body composition parameters were collected. Stool samples were analyzed using full-length 16S rRNA sequencing. The gut microbiota composition was assessed using taxonomic profiling, alpha-diversity and beta-diversity analyses, subgroup comparisons, and exploratory distance-based analyses. Associations were interpreted within a descriptive and hypothesis-generating framework. Results: The gut microbiota composition showed marked inter-individual heterogeneity at the genus level, with dominant taxa including Blautia, Faecalibacterium, Streptococcus, Gemmiger, Ruminococcus, Escherichia-Shigella, and Enterococcus. Chao1 richness was higher in men than in women. Shannon entropy and Chao1 richness were positively associated with age and visceral adipose tissue (VAT), while Faith’s phylogenetic diversity increased with age. In contrast, the Gini index was negatively associated with age and VAT, indicating a more even microbial community structure in older individuals and in those with higher visceral adiposity. Beta-diversity analyses suggested modest differences in microbial community structure according to sex and selected body composition-related categories, particularly in sex-stratified analyses. Exploratory distance-based analysis showed a modest association between overall microbiota dissimilarity and host phenotype dissimilarity, although this finding was limited by reduced sample overlap. Conclusions: The gut microbiota composition in maintenance HD patients was highly heterogeneous and showed cross-sectional associations, mainly with sex, age, visceral adiposity, and broader host phenotype. These findings suggest that microbiota variation in HD reflects multidimensional demographic, inflammatory, nutritional, metabolic, and body composition-related factors rather than a single clinical determinant. Larger longitudinal studies integrating standardized dietary, medication, metabolic, and clinical outcome data are needed to determine the prognostic relevance of these microbiota patterns.