Introduction to ConvergeR
2026-09-29
Contents
1 Introduction
ConvergeR is an analytical toolkit designed to compute, visualize, and statistically evaluate the convergence of single-cell states, based on the methodology established by Whitfield et al. (2026).
In this vignette, we will demonstrate the package workflow using a full dataset of 3,000 Peripheral Blood Mononuclear Cells (PBMC). We will evaluate cells for their balance between two opposing states: Immune Signaling UP versus Immune Signaling DN from MSigDB.
2 1. Environment Setup and Data Preparation
Let’s load the required packages and the lightweight subset of the PBMC dataset bundled with the package.
library(ConvergeR)
library(Seurat)
#> Le chargement a nécessité le package : SeuratObject
#> Le chargement a nécessité le package : sp
#>
#> Attachement du package : 'SeuratObject'
#> Les objets suivants sont masqués depuis 'package:base':
#>
#> intersect, t
library(ggplot2)
# Load the built-in example dataset
seu_path <- system.file("extdata", "pbmc3k_subset.rds", package = "ConvergeR")
seu <- readRDS(seu_path)
# Normalising
seu <- NormalizeData(seu, verbose = FALSE)
# Inject mock clinical metadata to simulate a multi-patient cohort
set.seed(42)
seu$age <- sample(20:70, ncol(seu), replace = TRUE)
seu$tumor_status <- sample(c("Primary", "Metastatic"), ncol(seu), replace = TRUE)
seu$treatment <- sample(c("Treated", "Untreated"), ncol(seu), replace = TRUE)
seu$SS <- paste0("Patient_", sample(1:5, ncol(seu), replace = TRUE))3 2. Importing MSigDB Signatures and Scoring
Instead of manually importing .gmt files, we use the msigdbr package to directly retrieve the official Hallmark Immune signatures.
library(msigdbr)
# S'assurer que l'on travaille sur l'assay RNA principal
DefaultAssay(seu) <- "RNA"
# Récupérer deux signatures immunitaires/inflammatoires bien exprimées dans les PBMC
hallmark_sets <- msigdbr(species = "Homo sapiens", category = "H")
raw_group1 <- hallmark_sets[hallmark_sets$gs_name == "HALLMARK_INTERFERON_ALPHA_RESPONSE", ]$gene_symbol
raw_group2 <- hallmark_sets[hallmark_sets$gs_name == "HALLMARK_INFLAMMATORY_RESPONSE", ]$gene_symbol
# Intersection stricte avec les gènes réellement présents dans pbmc3k_subset
group1_genes <- intersect(raw_group1, rownames(seu))
group2_genes <- intersect(raw_group2, rownames(seu))
# Calcul des scores de modules Seurat
seu <- AddModuleScore(seu, features = list(group1_genes), name = "Score_IFN_")
seu <- AddModuleScore(seu, features = list(group2_genes), name = "Score_Inflam_")
# Renommer proprement les colonnes pour la suite
seu$Score_IFN <- seu$Score_IFN_1
seu$Score_Inflam <- seu$Score_Inflam_14 3. Computing the Convergence Score
seu <- CalculateConvergedScore(
seurat_obj = seu,
principal_score = "Score_IFN",
other_scores = "Score_Inflam",
principal_name = "Interferon",
other_name = "Inflammatory",
output_colname = "Converged_Immune",
principal_color = "#9b59b6", # Violet pour Interféron
other_color = "#e67e22" # Orange pour Inflammatoire
)5 4. Visualization
ConvergeR automatically reads the color metadata generated in the previous step to produce standardized plots.
5.1 Proportion Barplot
Proportion of cells converging to either Immune state across our 10 mock patients.
PlotConvergenceProportion(
seurat_obj = seu,
x_var = "SS",
fill_var = "Converged_Immune_Direction",
title = "Immune Convergence by Patient"
)
5.2 Crossed Proportion Barplot
Faceted by tumor status to identify subgroup trends.
PlotConvergenceCrossedProportion(
seurat_obj = seu,
x_var = "SS",
fill_var = "Converged_Immune_Direction",
facet_var = "tumor_status",
title = "Immune Convergence split by Tumor Status"
)
5.3 Density Distribution
Continuous relationship of the convergence direction with patient age.
PlotConvergenceDensity(
seurat_obj = seu,
x_var = "age",
fill_var = "Converged_Immune_Direction",
x_label = "Patient Age"
)
6 5. Statistical Testing
We evaluate the statistical significance at the patient level (pseudobulk) to prevent pseudoreplication bias caused by single-cell testing.
6.1 Bivariate Test
TestConvergenceScore(
seurat_obj = seu,
score_var = "Converged_Immune",
test_var = "age",
level = "patient",
patient_id_var = "SS"
)
#> Spearman correlation | level: patient (pseudobulk) | N = 5 | testing 'Converged_Immune' by 'age' | p = 0.517How to read this result: The output message displays the statistical test used (e.g., Spearman correlation for continuous variables), the analysis level (patient pseudobulk to avoid single-cell pseudoreplication), the number of observations (\(N\) patients), and the p-value. A p-value below 0.05 indicates a statistically significant association between the convergence score and the tested variable.
6.2 Multivariate Linear Model
TestMultivariateConvergence(
seurat_obj = seu,
score_var = "Converged_Immune",
test_vars = c("age", "tumor_status", "treatment"),
level = "patient",
patient_id_var = "SS"
)
#> ======================================================
#> Multivariate Linear Model | level: patient (pseudobulk) | N = 5
#> Formula: Converged_Immune ~ age + tumor_status + treatment
#> Global Model R-squared: 0.77 | Global p-value: 0.586
#> ------------------------------------------------------
#> Independent Variable Effects:
#> - age : p = 0.563 (Estimate = 0.002)
#> - tumor_statusPrimary : p = 0.599 (Estimate = -0.079)
#> - treatmentUntreated : p = 0.551 (Estimate = 0.078)
#> ======================================================How to read this result: This model fits a multivariable linear regression on pseudobulk data. It details the global model performance (\(R^2\) and global p-value) and breaks down the independent effect (Estimate) and significance (p-value accompanied by conventional significance stars) for each covariate, allowing you to assess the effect of a variable while controlling for potential confounders.
7 Session Information
sessionInfo()
#> R version 4.4.3 (2025-02-28)
#> Platform: x86_64-pc-linux-gnu
#> Running under: Ubuntu 22.04.5 LTS
#>
#> Matrix products: default
#> BLAS: /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3
#> LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/libopenblasp-r0.3.20.so; LAPACK version 3.10.0
#>
#> locale:
#> [1] LC_CTYPE=fr_FR.UTF-8 LC_NUMERIC=C
#> [3] LC_TIME=fr_FR.UTF-8 LC_COLLATE=C
#> [5] LC_MONETARY=fr_FR.UTF-8 LC_MESSAGES=fr_FR.UTF-8
#> [7] LC_PAPER=fr_FR.UTF-8 LC_NAME=C
#> [9] LC_ADDRESS=C LC_TELEPHONE=C
#> [11] LC_MEASUREMENT=fr_FR.UTF-8 LC_IDENTIFICATION=C
#>
#> time zone: Europe/Paris
#> tzcode source: system (glibc)
#>
#> attached base packages:
#> [1] stats graphics grDevices utils datasets methods base
#>
#> other attached packages:
#> [1] msigdbr_26.1.1 ggplot2_4.0.3 Seurat_5.1.0 SeuratObject_5.1.0
#> [5] sp_2.2-3 ConvergeR_0.99.1 BiocStyle_2.32.1
#>
#> loaded via a namespace (and not attached):
#> [1] deldir_2.0-4 pbapply_1.7-5 gridExtra_2.3.1
#> [4] rlang_1.3.0 magrittr_2.0.5 RcppAnnoy_0.0.23
#> [7] otel_0.2.0 spatstat.geom_3.8-2 matrixStats_1.5.0
#> [10] ggridges_0.5.7 compiler_4.4.3 png_0.1-9
#> [13] vctrs_0.7.3 reshape2_1.4.5 stringr_1.6.0
#> [16] pkgconfig_2.0.3 fastmap_1.2.0 magick_2.9.1
#> [19] labeling_0.4.3 promises_1.5.0 rmarkdown_2.32
#> [22] tinytex_0.60 purrr_1.2.2 xfun_0.60
#> [25] cachem_1.1.0 jsonlite_2.0.0 goftest_1.2-3
#> [28] later_1.4.8 spatstat.utils_3.2-4 irlba_2.3.7
#> [31] parallel_4.4.3 cluster_2.1.8.3 R6_2.6.1
#> [34] ica_1.0-3 spatstat.data_3.1-9 stringi_1.8.9
#> [37] bslib_0.12.0 RColorBrewer_1.1-3 reticulate_1.47.0
#> [40] spatstat.univar_3.2-0 parallelly_1.48.0 lmtest_0.9-40
#> [43] jquerylib_0.1.4 scattermore_1.2 assertthat_0.2.1
#> [46] Rcpp_1.1.2 bookdown_0.48 knitr_1.52
#> [49] tensor_1.5.1 future.apply_1.20.2 zoo_1.9-0
#> [52] sctransform_0.4.3 httpuv_1.6.17 Matrix_1.7-3
#> [55] splines_4.4.3 igraph_2.3.3 tidyselect_1.2.1
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#> [64] codetools_0.2-19 miniUI_0.1.2 listenv_1.0.0
#> [67] plyr_1.8.9 lattice_0.22-5 tibble_3.3.1
#> [70] withr_3.0.3 shiny_1.14.0 S7_0.2.2
#> [73] ROCR_1.0-12 evaluate_1.0.5 Rtsne_0.17
#> [76] future_1.75.0 fastDummies_1.7.6 survival_3.8-3
#> [79] polyclip_1.10-7 fitdistrplus_1.2-6 pillar_1.11.1
#> [82] BiocManager_1.30.27 KernSmooth_2.23-26 plotly_4.12.1
#> [85] generics_0.1.4 RcppHNSW_0.7.0 scales_1.4.0
#> [88] globals_0.19.1 xtable_1.8-8 glue_1.8.1
#> [91] tools_4.4.3 data.table_1.18.6.1 RSpectra_0.16-2
#> [94] RANN_2.6.3 leiden_0.4.3.1 dotCall64_1.2
#> [97] cowplot_1.2.0 grid_4.4.3 tidyr_1.3.2
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#> [115] htmltools_0.5.9 lifecycle_1.0.5 httr_1.4.9
#> [118] mime_0.13 MASS_7.3-65