Fig. 1

PLD4 expression in immune cells in HDs and patients with SLE. A RT-qPCR demonstrated PLD4 expression among immune cells (n = 1). B Representative flow cytometry plots showing PLD4 + cells in pDCs and B cells from an HD and a lupus patient. C Boxplots showing the ratios of PLD4 + B cells in HDs (n = 19) and lupus patients (n = 40). D FSC-A was analyzed among the populations denoted below the plots. E CD19 + B cells were compartmentalized based on the PLD4 expression and FSC-A. F A boxplot showing the ratios of PLD4 + blasts in the patients. G, H The patients were divided by the ratios of PLD4 + blasts (G) or PLD4 + B cell (H). SLEDAI scores were compared between the two groups. I, J In lupus patients, the correlation between the ratios of plasmablasts and PLD4 + blasts (I) and PLD4 + B cells (J) were assessed. *P < 0.05, **P < 0.01, ***P < 0.005, by the Mann–Whitney U test in C, G, and H. In I and J, Spearman rank correlation coefficient (ρ) and P values are shown, and the gray shade areas represent the 95% confidence interval of the regression line. Mono, monocytes; NK, natural killer cells