A case of Alport syndrome with pregnancy-related atypical hemolytic uremic syndrome and crescentic glomerulonephritis.

Kidney function may be impaired during pregnancy due to various reasons, and the physiological changes of pregnancy may unmask or worsen pre-existing kidney disease. Herein, we report a pregnant patient presenting with nephrotic-range proteinuria. She later developed acute kidney injury and pre-eclampsia. However, hemolytic anemia and thrombocytopenia persisted after delivery, and she was diagnosed with atypical hemolytic uremic syndrome (aHUS). Although hematological abnormalities resolved with eculizumab treatment, her renal functions did not improve. Kidney biopsy showed crescentic glomerulonephritis without thrombotic microangiopathy features. Concurrently, she was evaluated for hearing impairment, and a diagnosis of Alport syndrome was confirmed with genetic testing. Kidney function may worsen in patients with Alport syndrome during pregnancy. However, crescentic glomerulonephritis (GN) is a rare finding in Alport disease. Pauci-immune crescentic GN has been shown to be related to dysregulated activation of the alternative complement pathway, which is also the underlying pathophysiological mechanism in aHUS.