PMC10189804_01
Serum creatinine of patient 1 during hospitalization. Timing of plasma exchange (TPE) and eculizumab treatments are indicated.
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F1
After eculizumab, there was a rapid improvement in his creatinine (Figure 1), and his hemodialysis treatment was stopped.
PMC10189804_02
Renal histology and lab results of patient 2 during hospitalization. (A) (Left) Hematoxylin and eosin stain (100x magnification) shows a glomerulus with a segmented appearance and prominent endocapillary hypercellularity with frequent neutrophils. Background parenchyma shows occasional injured tubules and scattered interstitial and peritubular neutrophils. (Right) Electron microscopy (4,800x magnification) demonstrates a capillary loop with swollen endothelial cells and endocapillary neutrophils. Several subepithelial hump-like immune complex deposits are present, not associated with significant glomerular basement membrane remodeling. Immunofluorescence microscopy showed IgG (2+), C3 (3+), kappa (2+), and lambda (2+) granular staining along the glomerular capillary loops (not shown). (B) Platelet count and serum creatinine during the hospital course. Timing of plasma exchange (TPE) and eculizumab treatments are indicated.
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F2
Day 9. Although he had anemia (7.7 g/dl) and thrombocytopenia (53 x 109/L) at that time, his haptoglobin was normal with no hemolysis findings in the peripheral smear. Due to diagnostic uncertainty, a renal biopsy was performed on Day 12 which showed no signs of TMA but diffuse endocapillary proliferative glomerulonephritis with subepithelial hump-like immune complex deposits consistent with PIGN (Figure 2A). Although his peripheral smear did not show schistocytes, in the presence of low haptoglobin, anemia, thrombocytopenia, and acute kidney injury, he was considered to have possible aHUS and started on eculizumab on Day 31 (Figure 2B).