D Kioroglou, J L Cabriada, U Martinez Marigorta, I Rodriguez-Lago. Journal of Crohn’s and Colitis, Volume 18, Issue Supplement_1, January 2024, Page i389,doi.org=10.1093/ecco-jcc/jjad212.0236

Background
Granulocyte-monocyte apheresis (GMA) is a non-pharmacological treatment approved for the management of ulcerative colitis (UC), particularly steroid-dependent cases. The exact mechanism of action and immunological changes associated with GMA remain undescribed. Gene expression analysis at the single-cell level (through scRNA-Seq) has emerged as a key tool of choice to characterize drug response at the molecular level. We used scRNA-Seq to characterize the transcriptomic effects and immune cell population alterations in GMA.

Methods
We generated scRNA-Seq from peripheral blood mononuclear cells (PBMC) of two ulcerative colitis (UC) patients undergoing GMA treatment. We compared the gene expression profile before and after 5 sessions of GMA treatment. The analytical pipeline included quality control and classical filtering steps, cell-type annotation, differential gene expression analysis and pathway enrichment profiling.

Results
We report three main results. First, we observed significant reductions of cell types directly affected by GMA treatment in UC patients. This includes classical CD14+ monocytes and Natural killers, which are central components of the innate system. Of note, we observed a remarkable increase in Double-negative T cells (dnT) after 5 sessions of GMA treatment, suggesting potential expansion of protective populations involved in decreased inflammation. Second, we observe a variety of genes and regulatory pathways altered by GMA treatment. In total, we detect 86 differentially expressed genes (DEGs), which overall are biased towards downregulation (63%). Of note, we detected dnT-s exhibiting upregulation of NEFL that is associated with the MAPK cascade and downregulation of genes related to immune response and signaling pathways. Finally, the effects of GMA treatment extend beyond the above mentioned populations, with particular alterations in CD4+ T cell populations such as CD4+ central memory and CD4+ Naive (7 and 13 DEGs, respectively).

Conclusion
For the first time, we generated single-cell transcriptomic profiles to characterize the effects of GMA treatment in peripheral blood of UC patients. Our preliminary analysis detects important alterations in the gene regulation and cell type composition in samples obtained after 5 sessions of GMA. Through expansion of this dataset to include more time points and profiles for more individuals, we will discuss the longitudinal changes and molecular mechanisms involved in response to GMA treatment.

Esteban Sáez-González MD, Inés Moret-Tatay PhD, Guillermo Bastida MD, PhD, Mariam Aguas MD, PhD, Marisa Iborra MD, PhD, Pilar Nos MD, PhD, Belén Beltrán MD, PhD  J Clin Apher. 2023 38(6); 1-10. doi:10.1002/jca.22101

Background

Ulcerative colitis (UC) is an inflammatory bowel disease characterized by chronic inflammation of the gastrointestinal tract, affecting millions of individuals throughout the world, and producing an impaired health-related quality of life. Granulocyte and monocyte apheresis (GMA) is a therapeutic option for UC management to induce remission by selective removal of activated leukocytes from bloodstream. Despite the knowledge of the important role of epigenetics in UC pathogenesis, and in the response to different treatments, nothing is known about the role of microRNAs in GMA therapy in UC patients.

Methods

7 consecutively UC patients who started GMA in combo therapy with infliximab were recruited. Peripheral blood samples were taken before the apheresis session, at the start of the induction (S0) and at the end (S10). They were follow-up during the induction phase (10 sessions: 2 sessions for a week during 3 wk and 1 session for a week during 4 wk) of the treatment at a tertiary hospital (Hospital la Fe) and 6 mo after finishing the GMA induction therapy. MiRNA was extracted and analyzed by RT-PCR. R software and GraphPad were used.

Results

Clinical disease activity significantly decreased after induction therapy with GMA (median partial Mayo score 2 (IQR, 1-6) (P < .05). Fecal calprotectin value and CRP value significantly decreased after induction therapy. Five microRNAs modified their expression during GMA (unsupervised analysis): miR-342-3p, miR-215-5p, miR-376c-3p, miR-139-5p, and miR-150-5p. When a sub-analysis was performed in those patients who showed good response to apheresis treatment (n = 5), two microRNAs showed to be implicated: miR-215-5p and miR-365a-3p. These are preliminary but promising and novel results, as it is the first time, to our knowledge that microRNA profiles have been studied in the context of GMA treatment for IBD.

MicroRNA and granulocyte-monocyte adsorption apheresis combotherapy after inadequate response to anti-TNF agents in ulcerative colitis – PubMed (nih.gov)

MicroRNA and granulocyte‐monocyte adsorption apheresis combotherapy after inadequate response to anti‐TNF agents in ulcerative colitis – Sáez‐González – Journal of Clinical Apheresis – Wiley Online Library