20.500.12556/DiRROS-28996 Faecal inflammatory protein markers in children with autism spectrum disorder are comparable to their healthy siblings Background: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition often accompanied by gastrointestinal (GI) symptoms. Inflammatory proteins in stool have been proposed as potential biomarkers, but evidence remains inconsistent. We compared fecal levels of a1-antitrypsin (A1AT), immunoglobulin A (IgA), and calprotectin (Cal) in 57 children with ASD and 57 biological siblings without ASD. Sibling designs are now preferred to disentangle ASD-specific biology from shared environmental and microbiome factors. Participants were carefully screened to exclude recent antibiotic use, digestive problems, gastrointestinal infections, and abnormal dietary patterns, thereby controlling for major factors known to influence gut inflammatory markers. Methods: Stool samples were thawed, freeze-dried, and proteins extracted using ammonium bicarbonate buffer with sodium deoxycholate. After BCA quantification, samples were reduced, alkylated, spiked with stable isotope– labelled peptides, and digested with trypsin. Peptides were purified and analyzed by UHPLC–MS/MS (Agilent 6495A) in dynamic SRM mode. Quantification used internal standards and normalization to total protein. Ratios of IgA1/IgA2 and S100A8/S100A9 were calculated. ASD severity was evaluated using the Childhood Autism Rating Scale (CARS). Results: Children with ASD showed trends toward higher IgA and calprotectin and lower a1-antitrypsin compared with siblings, but differences were not statistically significant. Subgroup analysis suggested different distribution patterns in moderate versus severe ASD, including higher IgA in the moderate group and altered S100A8/S100A9 ratio in the severe group. These subgroup findings were exploratory, derived from critically underpowered post-hoc analyses (severe subgroup: n = 11 pairs, ~18% power for medium effects), and should be considered hypothesis-generating only, pending validation in adequately powered pre-registered studies. Conclusions: The results are consistent with recent meta-analyses reporting no consistent evidence of gut inflammation in ASD. Larger, sex-matched studies with full assay validation are needed to clarify the role of stool proteins in ASD. autism inflammation protein biomarkers avtizem vnetje proteinski biološki označevalci true false true Angleški jezik Slovenski jezik Neznano 2026-04-16 08:42:15 2026-04-16 08:42:16 2026-04-17 03:55:03 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Opis vira z dne 16. 4. 2026; str. 1-17 [article no.] 1792801 Vol. 17 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 616.896 1664-0640 10.3389/fpsyt.2026.1792801 275381251 RAZ_Osredkar_Josko_2026.pdf RAZ_Osredkar_Josko_2026.pdf 1 74755D58C9DF23760DDAC91D10B3BA0A c94b1e5402ada714c061712d9847a187e16ff7f2ef7ce27f5ae4dcc21346e9cf 81da58b1-395f-11f1-9cc3-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=43281 https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2026.1792801/full 1 6a940b45-395f-11f1-9cc3-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=43280 Univerzitetni klinični center Ljubljana 0 0 0