Targeted LC-MS/MS validation of unsaturated fatty acid dysregulation and PI3K-Akt-related metabolic signatures in immune thrombocytopenia.

BACKGROUND

Immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder characterized by immune dysregulation and thrombocytopenia. Metabolic reprogramming has been implicated in the pathogenesis of immune-mediated diseases, while the PI3K-Akt signaling pathway acts as a critical link between immune response and metabolic regulation.Based on our previously published untargeted metabolomics findings, this study aimed to validate selected lipid metabolites in ITP and explore their potential association with PI3K-Akt-related metabolic signatures.

METHODS

Twenty adults with newly diagnosed active ITP and 17 healthy controls were enrolled. Candidate metabolites were selected from our previously published untargeted metabolomics dataset and prioritized through metabolite annotation and KEGG pathway enrichment analysis. Serum oleic acid, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Statistical analyses were conducted to compare metabolite levels between the two groups, with P values adjusted for multiple comparisons using the Benjamini-Hochberg false discovery rate (FDR) method. Exploratory receiver operating characteristic (ROC) analyses were performed for individual metabolites, and a multivariable logistic regression model incorporating oleic acid, DHA, and EPA was constructed to evaluate their combined discriminative performance.

RESULTS

Untargeted metabolomics showed clear metabolic separation between the ITP and control groups. KEGG analysis indicated enrichment in the PI3K-Akt signaling pathway and multiple lipid metabolism-related pathways. Targeted LC-MS/MS further confirmed that serum oleic acid, DHA, and EPA levels were all significantly higher in patients with ITP than in healthy controls (all FDR-adjusted P = 0.0008). Exploratory ROC analysis showed that oleic acid, EPA, and DHA individually yielded AUC values of 0.841, 0.829, and 0.826, respectively, while the combined logistic regression model incorporating all three metabolites achieved an AUC of 0.879.

CONCLUSIONS

Patients with ITP exhibit measurable lipid metabolic abnormalities characterized by elevated oleic acid, DHA, and EPA levels. These findings provide targeted quantitative support for lipid metabolic dysregulation in ITP and suggest that these alterations may be associated with PI3K-Akt-related metabolic signatures inferred from pathway enrichment analysis.