PTX3 and lupus nephritis: The average level of serum PTX3 in active lupus nephritis patients was significantly higher than that in SLE without renal involvement (3.207 (0.399–56.376) ng/ml versus 1.065 (0.040–9.098) ng/ml, p < .001) and normal controls (3.207 (0.399–56.376) ng/ml versus 0.993 (0.007–2.655) ng/ml, p < .001).