Figure 1: UMAP graphs for a random subset of 25’000 B cells per group (calculated with 75’000 B cells). Different colors label the clusters that were identified by the FlowSOM algorithm. Clustering was performed with 1.5 million B cells and 7 surface markers. Black dots represent PtC-reactive B cells. pAPS and sAPS patients show higher numbers of PtC-reactive B cells (HD: 217, pAPS: 378, sAPS: 322). PtC-reactive B cells are enriched among different clusters of memory B cells.