Cooccurrence of Alport syndrome and poststreptococcal acute glomerulonephritis with improvement after steroid administration

It is clinically possible for patients with Alport syndrome (AS) to suffer from poststreptococcal acute glomerulonephritis (PSAGN). However, there is only one report of such a patient, and he had end-stage kidney disease. Here, we describe an 8-year-old male with X-linked AS and chronic kidney disease (CKD) stage G2. He presented with diffuse edema, gross hematuria, proteinuria, and body weight gain after streptococcal pharyngitis. Blood examination showed kidney dysfunction, hypocomplementemia, and increased anti-streptolysin-O levels. His kidney function did not improve with symptomatic treatment. Therefore, we started steroid administration on the 12th day of hospitalization. Then, his kidney function improved before he was discharged. We confirmed that his complement function had recovered at a later date. Pathological evaluation showed findings of AS and PSAGN, including cellular crescents in 3/30 glomeruli on light microscopy. In addition, electron dense deposits (EDDs) were seen in not only the visceral subepithelium but also the glomerular basement intramembrane and subendothelium, some of which were hump-like. Although AS and CKD are indicated to have a poor prognosis in PSAGN, our patient recovered after administration of steroids. Our case suggests that we can consider the administration of steroids, including pulse therapy for PSAGN, when patients have, for example, crescents on pathology, severe renal dysfunction, nephrotic proteinuria, or AS with CKD, as in our case. Kidney pathology suggested that a typical hump is not seen in patients with cooccurring AS and PSAGN. After the patient's kidney function recovered, we continued to follow him.