Haematological and biochemical profiling combined with HRAMS-based metabolomics reveals the potential biomarkers of Wuchereria bancrofti asymptomatic infections: towards early interventions and diagnostics.

Lymphatic filariasis (LF) encompasses grotesque and irreversible chronic conditions such as lymphedema, hydrocele, and elephantiasis. Asymptomatic or subclinical infections remain largely unnoticed as microscopy, serological tests, and antigen detection typically lack sufficient sensitivity to detect circulating microfilariae. Herein, we utilised high-resolution accurate mass spectrometry (HRAMS)-based metabolomics to thoroughly examine host metabolic responses in 25 patients with active microfilaremic infections compared with 30 healthy controls. Metabolites were annotated using the Compound Discoverer platform and analysed with MetaboAnalyst, confirming significant differential levels of 161 metabolites. The PCA scoring plot showed clear segregation between the two groups (R2X = 0.892 for the positive ESI mode and R2X = 0.904 for the negative ESI mode). The VIP score plots confirmed the top 15 defining metabolites (scores > 1.3), with arachidoyl ethanolamide, retinal, 17-OH pregnenolone sulfate, and N-acetyl-l-cysteine contributing most to the discrimination between the mf and healthy groups in both ionisation modes. The metabolite-gene function network revealed that several metabolites, such as retinal and progesterone, had the maximum number of interacting genes. Retinoids regulate cell differentiation and proliferation, especially in immune cells, like T cell subsets and regulatory T cells. Prostaglandins regulate the type 2 immune response to parasitic helminths. We identified that in individuals with bancroftian microfilaremia, lipid metabolic dysregulation is most crucially affected, with arachidonic acid metabolism being the most affected pathway. The metabolic pathways of alpha-linolenic acid, linoleic acid, and arachidonic acid were considerably enriched (p < 0.05). Overall, the levels of retinal and prostaglandin E2 changed significantly during asymptomatic infection, and therefore, these molecules have emerged as promising biomarkers in this study. Thus, our findings on bancroftian filarial metabolomics will pave the way for the development of an early diagnosis tool and provide a more insightful understanding of the affected metabolic processes in LF infections.