Fig. 2.

Circulating IgA1-containing immune complexes (cIgA1) from IgA nephropathy (IgAN) patients induced upregulated TREM-1 expression in mesangial cells. a The mRNA expression of TREM-1 in human mesangial cells was significantly upregulated by cIgA1 derived from IgAN patients (2.39 [1.35, 4.24] vs. 1.50 [1.18, 1.85], p = 0.049). b Additionally, the levels of ΔsTREM-1 in the supernatant of mesangial cells were also significantly higher after treatment with cIgA1 derived from IgAN patients, compared to those from healthy controls (18.7 [–36.1, 97.1] vs. −34.5 [–95.8, 9.1] pg/mL, p = 0.003).