Poster Presentation 15th Lorne Infection and Immunity 2025

Tracing the plasma proteomic and metatranscriptomic response to cladribine treatment in multiple sclerosis. (#349)

Sam WZ Olechnowicz 1 2 , Marilou H Barrios 1 2 , Allan Motyer 1 2 , Tanya Golubchik 3 , Felix Marsh-Wakefield 3 , Simon Hawke 3 , Georges Grau 3 , Rory Bowden 1 2 , David Tscharke 4
  1. Advanced Technology and Biology Division, WEHI, Parkville, Victoria, Australia
  2. Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
  3. School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
  4. John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia

Cladribine is a cytotoxic agent used in relapsing-remitting Multiple Sclerosis (MS) to reduce nervous system inflammation by killing immune cells, specifically B cells. We hypothesized that the immunosuppressive effect of cladribine may influence the control of infections, and that multiomics profiling of circulating host protein markers and pathogen sequences may be informative in monitoring treatment and disease progression. A cohort of 15 MS patients undergoing cladribine treatment and 15 matched healthy controls were screened across a 36-month longitudinal study, alongside baseline measurements for 14 additional MS patients. Pathogen RNA and DNA from platelet-free plasma was sequenced after CaptureSeq enrichment with a comprehensive human pathogen panel using the CASTANET framework (Mayne et al. 2024). The same plasma samples were also screened for 272 unique neuroinflammation-related circulating proteins using the Olink Proteomics Proximity Extension Assay. 

B and T cell counts declined substantially in MS patients after Cladribine treatment. Notably, Epstein-Barr virus (EBV) levels were significantly reduced within 2–4 months, gradually rebounding to peak levels 30- and 36-months post-treatment. Cladribine-induced B-cell depletion exerts a substantial impact on EBV dynamics in MS patients, highlighting a potentially important secondary effect of therapeutic immune modulation. 

Baseline (pre-treatment) MS plasma contained several disease-specific protein markers, including significantly increased Hepatocyte Growth Factor (HGF), N-Alpha-Acetyltransferase 10 (NAA10) and Oncostatin M (p<0.05 after adjustment for multiple testing). However, known MS biomarkers including NEFL were not significantly altered in MS patients, perhaps distinguishing inflammation pathways from markers of neurological damage. Accounting for individual differences at baseline enables us to distinguish the dynamics of responses to cladribine treatment, such as the dramatic and sustained increase in Flt3L, a cytokine that stimulates haemopoietic progenitors to effect blood cell homeostasis. 

Our study underlines the feasibility of monitoring immunosuppressive therapy, with potential benefits in optimising treatment and managing patient-specific side effects.  

  1. Mayne R, Secret S, Geoghegan C, Trebes A, Kean K, Reid K, Lin GL, Ansari MA, de Cesare M, Bonsall D, Elliott I, Piazza P, Brown A, Bray J, Knight JC, Harvala H, Breuer J, Simmonds P, Bowden RJ, Golubchik T. Castanet: a pipeline for rapid analysis of targeted multi-pathogen genomic data. Bioinformatics. 2024 Oct 1;40(10):btae591. doi: 10.1093/bioinformatics/btae591.