Letter to the Editor: Immune-transcriptomic profiles in peripheral blood mononuclear cells highlight early dysregulation in adolescent non-alcoholic fatty liver disease

Abstract

We read with interest the recent study by Zeber-Lubecka et al, published in the World Journal of Hepatology, investigating transcriptome profiles of peripheral blood mononuclear cells (PBMCs) in male adolescents with non-alcoholic fatty liver disease (NAFLD). To maintain consistency with the original publication, we retain the term “NAFLD” throughout this commentary, while recognizing the recent shift toward the MASLD nomenclature. The authors stimulated PBMCs ex vivo with autologous fecal extracts to explore immune-microbiota interactions. Their results revealed distinct transcriptomic and cytokine patterns, including elevated pro-inflammatory mediators indicative of early immune dysregulation. These findings underscore the impact of host-specific gut microbiota on systemic immunity and suggest that PBMC-based immune signatures could serve as minimally invasive biomarkers. This work provides valuable insights into gut-immune crosstalk in pediatric NAFLD and offers a foundation for future research on early diagnosis and therapeutic strategies.

Key Words: Adolescent non-alcoholic fatty liver disease; Peripheral blood mononuclear cells; Immune dysregulation; Gut-liver axis; Transcriptomic profiling

Core Tip: This letter highlights early immune disturbances in adolescents with non-alcoholic fatty liver disease (NAFLD) revealed through transcriptomic and cytokine analysis of peripheral blood mononuclear cells (PBMCs). By exposing PBMCs to autologous fecal extracts, the study recreated gut-liver interactions in vitro, demonstrating how host-specific microbiota shape systemic immune responses. These results suggest that PBMC-derived immune signatures could serve as minimally invasive biomarkers and inform the development of personalized diagnostic and therapeutic strategies in pediatric NAFLD.

TO THE EDITOR

We read with considerable interest the recent publication by Zeber-Lubecka et al[1] in the World Journal of Hepatology. The work is both technically robust and conceptually forward-thinking. The authors employ next-generation sequencing of peripheral blood mononuclear cells (PBMCs) stimulated ex vivo with autologous fecal extracts, an innovative design that directly interrogates immune-microbiota interactions in NAFLD. We commend the authors for their methodological rigor of this strategy. As highlighted in the manuscript’s core tip, the authors demonstrate that “gene activity and immune responses differ” between adolescents with NAFLD and healthy controls, implying that such immune-related alterations may function as early disease indicators[1]. These findings reinforce the importance of immunoprofiling in young populations and suggest earlier diagnostic and therapeutic opportunities in pediatric NAFLD.

We note that the study population was limited to male adolescents; considering established sex-specific differences in immune function and NAFLD progression, extrapolation of these results to females or to other age groups should be undertaken with caution.

A particularly compelling aspect of the study was the integration of PBMC transcriptomics with stimulation by each participant’s own fecal extract. This approach effectively recreated elements of the gut-liver axis in vitro, modeling how microbiota-derived components influence systemic immune behavior. Such an approach is timely considering extensive evidence implicating the gut microbiome in NAFLD pathobiology. For example, Pandey et al[2] suggested that “the gut microbiota plays a critical role in the pathophysiology of NAFLD by influencing liver inflammation through its metabolites” and argued that microbial and metabolic signatures could support early diagnosis and innovative treatment development. By using autologous fecal extracts, Zeber-Lubecka et al[1] directly connected innate immune sensing to host-specific microbial features, an approach not previously applied in NAFLD studies. This approach extends earlier findings of altered immune function in obesity and fatty liver disease[3] by elucidating how specific microbiota-derived cues can modulate circulating immune cells.

In contrast to earlier PBMC transcriptomic analyses that examined unstimulated cells or relied on non-autologous microbial stimuli, Zeber-Lubecka et al[1] employed autologous fecal extracts to preserve host-specific gut-immune interactions, thereby enhancing mechanistic insight into microbiota-driven immune alterations in adolescent NAFLD.

The authors report several notable observations with significant biological and clinical implications. PBMC transcriptomes from adolescents with NAFLD displayed distinct gene-expression alterations compared with healthy counterparts, consistent with systemic immune activation. This interpretation is well aligned with established inflammatory markers in NAFLD. Shirakawa et al[3] observed markedly elevated tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and high-sensitivity C-reactive protein levels in obese young adults with fatty liver, and numerous studies have linked these cytokines to disease severity. A recent meta-analysis further confirmed the strong associations of interleukin-1β, IL-6, TNF-α and C-reactive protein with NAFLD, supporting their potential utility as biomarkers[4]. Similarly, Zeber-Lubecka et al[1] reported enhanced cytokine secretion in PBMCs from adolescents with NAFLD, reflecting the characteristic pro-inflammatory milieu of the disease. This is consistent with the well-established roles of IL-6 and TNF-α in the pathogenesis of NAFLD[4]. Moreover, the study’s use of fecal extracts provides mechanistic context for signals such as interleukin-8 (IL-8), as gut-derived lipopolysaccharide can activate hepatic TLR4 pathways and induce IL-8 production, propagating inflammation in NAFLD[2]. Collectively, the demonstration of altered transcriptional pathways and heightened cytokine responses supports the concept that immune dysregulation manifests early in NAFLD, even in adolescents.

Increased levels of IL-6, TNF-α, and interleukin-17 (IL-17) indicate a shift toward T helper 17 cells (Th17)-dominated immune responses accompanied by relative regulatory T (Treg) deficiency, a dysregulation that may promote hepatic inflammation and activate fibrogenic pathways.

These insights carry important translational promise. The unique PBMC transcriptomic and cytokine patterns identified by the authors may constitute a foundation for developing minimally invasive biomarkers suitable for early detection, especially in pediatric populations where biopsy and imaging have limitations. Pandey et al[2] specifically highlighted the need for “microbial and metabolic signatures” to facilitate early diagnosis. Similarly, immune signatures linked to microbial dysbiosis represent a complementary and potentially powerful biomarker domain. In addition, delineating these immune perturbations may reveal new therapeutic targets. If pathways such as IL-17-IL-6-TNF are indeed upregulated, interventions aimed at modulating the balance between Th17 and Tregs or selectively blocking key cytokines may hold therapeutic promise. The observed heightened PBMC responsiveness to autologous microbiota suggests that repairing gut barrier function or reshaping microbiome composition could mitigate aberrant immune activation. In this context, therapeutic strategies acting on the gut-liver axis, such as probiotics, prebiotics, or fecal microbiota transplantation, discussed by Pandey et al[2], may synergize with immunomodulatory treatments. Broadly, Zeber-Lubecka et al[1] provide an important new perspective on NAFLD pathogenesis centered on gut-immune interactions, with potential to inform composite biomarkers and personalized therapeutic strategies.

The development of PBMC-derived signatures as clinical biomarkers will require ensuring reproducibility across different platforms, standardizing stimulation protocols and assay conditions, accounting for inter-individual variability, and evaluating cost-effectiveness for routine clinical implementation.

Given the cross-sectional design and reliance on ex vivo experiments, the observed associations reflect correlated processes rather than definitive causal relationships within the gut-immune-liver axis; longitudinal analyses and in vivo investigations are therefore necessary to establish directionality and causality.

Further work should extend these findings through longitudinal designs to determine whether the identified PBMC transcriptional patterns can predict disease progression or treatment responses. Integrating untargeted metabolomic profiling would help identify specific microbial metabolites responsible for inducing immune activation. Parallel microbiome analyses (16S rRNA sequencing or shotgun metagenomics) of the fecal samples could reveal bacterial taxa or functional pathways associated with PBMC transcriptional and cytokine responses. Such analyses would help address causality within gut dysbiosis-immunity interactions. Additionally, resolving PBMC heterogeneity by examining specific immune subsets and their epigenetic regulation could highlight discrete pathways amenable to targeted intervention. These directions are feasible and would enable translation of the study’s cross-sectional observations into dynamic, clinically actionable frameworks.

CONCLUSION

In conclusion, Zeber-Lubecka et al[1] provide a significant contribution to the field by comprehensively characterizing immune-microbiota interactions in adolescent NAFLD. Their inventive experimental design and detailed analyses are commendable, and their findings illuminate early immunological disturbances in the disease. We anticipate that future investigations will validate and build upon this work, ultimately advancing diagnostic and therapeutic strategies for pediatric NAFLD.