The Health Economic Impact of Nephrotic Syndrome in the United States

Comparison of three spot proteinuria measurements for pediatric nephrotic syndrome: based on the International pediatric Nephrology Association 2022 Guidelines

BACKGROUND

Pediatric nephrotic syndrome (NS) requires routine proteinuria monitoring, which is costly and affects patients' quality of life. The gold-standard 24-h urine protein (UP) measurement is challenging in children, and first-morning urine collection requires specific conditions, making it difficult in outpatient settings. Studies have reported comparability of second or random morning urine sample to the first-morning specimen. This study aimed to compare outcomes of random morning proteinuria measurements to 24-h UP and the roles of the urinary protein creatinine ratio (UPCR) and dipstick tests in pediatric NS, based on International Pediatric Nephrology Association (IPNA) 2022 Guidelines.

METHOD

Twenty-four-hour and morning urine samples were collected from 92 pediatric NS patients. These were subjected to automated analyses for 24-h UP, UPCR, and semi-automated dipstick analysis. A blinded doctor performed manual dipstick analysis.

RESULTS

UPCR had a stronger correlation with 24-h UP than with automated and manual urine dipstick tests. UPCR had the highest sensitivity and specificity for predicting no remission/relapse and high sensitivity but low specificity for complete remission. The optimal UPCR cutoff for remission was 0.44 mg/mg and for no remission/relapse was 2.08 mg/mg. Automated and manual dipstick tests demonstrated limited sensitivity but high specificity and similar AUC values for remission/relapse.

CONCLUSION

UPCR was sensitive and specific for diagnosing no remission/relapse and sensitive but not specific for detecting remission. Manual and automated urine dipstick tests were comparable for remission and no remission/relapse detection. This study supports the IPNA 2022 Guidelines, as 2 mg/mg was the optimal UPCR cutoff for no remission/relapse, while for remission the optimal cutoff was 0.4 mg/mg.

Immunosuppressive Agent Options for Primary Nephrotic Syndrome: A Review of Network Meta-Analyses and Cost-Effectiveness Analysis

Therapeutic options with immunosuppressive agents for glomerular diseases have widened with refinements to the Kidney Disease Improving Global Outcomes (KDIGO) guidelines from 2012 to 2021. However, international guidelines do not necessarily match the reality in each country. Expensive therapies such as rituximab and calcineurin inhibitors are sometimes inaccessible to patients with refractory nephrotic syndrome due to cost or regulations. Under the Japanese medical insurance system, rituximab is accessible but still limited to steroid-dependent patients who developed idiopathic nephrotic syndrome in childhood. Based on international KDIGO guidelines and other national guidelines, possible applications of immunosuppressive agents for nephrotic syndrome are comprehensively examined in this review. While rituximab has become the mainstay of immunosuppressive therapy for nephrotic syndrome, clinical trials have indicated that options such as cyclophosphamide, calcineurin inhibitors, and mycophenolate mofetil would be preferable. Given the rising number of patients with nephrotic syndrome worldwide, KDIGO guidelines mention the need for further consideration of cost-effectiveness. If the new option of rituximab is to be the first choice in combination with steroids for nephrotic syndrome, its cost-effectiveness should also be verified. Among the few studies examining the cost-effectiveness of treatments for nephrotic syndrome, administration of rituximab to young adults has been shown to be cost-beneficial, at least in Japan. However, further large-scale studies involving multiple facilities are needed to verify such findings. Network meta-analyses have concluded that the efficacy of rituximab remains controversial and confirmation through high-quality studies of large cohorts is needed. To this end, the mechanisms of action underlying immunosuppressive agents, both old and new, need to be understood and experience must be accumulated to evaluate possible effects and side effects.