Objective: Few findings are available regarding adult-onset minimal change nephrotic syndrome (MCNS) with respect to the disease course and complications, such as acute kidney injury (AKI). We therefore performed a retrospective review to characterize the clinical presentations, steroid responsiveness and complications of adult-onset MCNS patients in our hospital.
Patients and methods: We retrospectively reviewed 40 cases of idiopathic adult-onset MCNS who had been investigated and treated at a single center. Patients between 18 and 50 years of age (Younger group) at the time of biopsy were compared with those older than 50 years (Older group) with regard to demographic data, clinical features and treatment outcome.
Results: Baseline characteristics of the 40 patients were: median age, 42 years (interquartile range: 28-63 years); male, 70%; mean (+/- standard deviation) systolic and diastolic blood pressures, 125 +/- 17 mmHg and 78 +/- 12 mmHg, respectively; estimated glomerular filtration rate (eGFR), 74 mL/min/1.73 m2 (range: 64-94 mL/min/1.73 m2); serum albumin, 1.8 +/- 0.3 g/dL; and urinary protein, 7.8 g/day (range: 3.9-10.4 g/day). All except for one patient received steroid pulse therapy. Time to complete response (CR) was 12 days (range: 8-21 days). Time to CR was significantly longer in the Older group (p = 0.011). The Late-responder group (time to CR > 2 weeks)was significantly older (p < 0.01), with a low eGFR (p < 0.001) and a higher prevalence of interstitial fibrosis in renal biopsy before the initiation of corticosteroid therapy (p < 0.05), compared with the Early-responder group. AKI was observed in 14 patients. Patients with an episode of AKI were significantly older (p = 0.005), with a lower eGFR (p < 0.002) and a higher prevalence of cellular casts (p < 0.05). At the follow-up, 19 patients (51%) had experienced relapses. The relapse rate was significantly lower in the Older group than in the Younger group (p < 0.05).
Conclusion: The present study revealed that older patients had a longer period to CR and a higher risk of AKI at follow-up.