Table 5_Single-cell profiling of peripheral immune remodeling in BK polyomavirus–associated nephropathy after kidney transplantation.xlsx

A rare but transcriptionally distinct population, termed Activated Effector Cells (AECs), comprised only 0.60% of cells in BKPyVAN (104 of 17,238 cells) yet accounted for 12.15% of cluster-associated marker calls, the highest among the 17 populations, and displayed marked enrichment of cell cycle and RNA metabolic pathways. Across multiple lineages, AUC-based gene set enrichment analysis revealed convergent activation of RNA processing and intracellular transport pathways.

Pseudobulk differential expression and permutation testing supported condition-associated transcriptional signatures, and leading-edge gene analysis identified candidate transcriptional readouts, including cell cycle regulators, inflammatory mediators, and RNA processing genes, with potential utility for blood-based monitoring. These findings reveal peripheral immune remodeling across the clinical states of BK polyomavirus infection and highlight the value of resolving rare, transcriptionally distinct immune populations, providing a rationale for noninvasive, transcriptomics-informed monitoring and risk stratification strategies.</p>