In patient group I, apoM concentrations were significantly lower in patients with active renal disease (glomerulonephritis, e.g., urinary casts, proteinuria, hematuria, or pyuria) and skin involvement (rash), compared to patients without these organ manifestations (p < 0.01 and p = 0.01, respectively, Fig. 3). Here, APOM is linked to glomerulonephritis.