Azithromycin treatment is associated with enrichment of energy metabolism, cell cycle, and immune response pathways. (A) Frozen peripheral mononuclear blood cells (PBMCs) from patients (placebo, n = 14; and azithromycin, n = 17) were thawed and analyzed by means of cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq). Cells were clustered according to cell surface antigen expression. (B) Uniform manifold approximation and projection (UMAP) describing cell clustering. (C) Heatmap depicting scaled cell surface antigen expression in cell subsets. (D) Dot plot depicting enrichment analysis within each subset of cells with the use of hallmark gene sets. Only immune cells with at least 1 enriched pathway are depicted. P values were computed with adaptive multilevel split Monte-Carlo and adjusted with false discovery rate. (E) Cell cycle analysis from CITE-Seq with cell cycle score. P values were computed by means of 2-sided matched-pair Wilcoxon rank test. Clas., classical; DN, double negative; EM, effector memory; EMRA, effector memory CD45RA⁺; Int., intermediate; MAIT, mucosal associated invariant T cells; NK, natural killer.