Correlation Between 24-Hour Urine Protein and Random Urine Protein-to-Creatinine Ratio in AL Amyloidosis

Renal Response Criteria for Clinical Trials in Amyloid Light Chain Amyloidosis

Immunoglobin light chain (AL) amyloidosis is a rare disease characterized by organ deposition of amyloid fibrils, most commonly in the heart and kidney. Disease heterogeneity necessitates organ-specific assessment to determine prognosis and response or progression. To facilitate development of new therapies, the Amyloidosis Forum (a public-private partnership between the US Food and Drug Administration and the nonprofit Amyloidosis Research Consortium) held a series of meetings and formed multiple working groups to identify clinical trial end points and analytic strategies. This report summarizes the recommendations of Renal Working Group. Estimated glomerular filtration rate (eGFR) and proteinuria were selected to evaluate eligibility, response, and/or progression in the context of investigational clinical trials for patients with AL amyloidosis. Accurate response assessments at the earliest possible time point were emphasized. The context of use, specific patient population, and the investigational therapeutic mechanism should ultimately drive selection of appropriate end points to evaluate renal response/progression in AL amyloidosis clinical trials.

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.

Amyloidosis and the Kidney: An Update

Various types of systemic amyloidosis can wreak havoc on the architecture and functioning of the kidneys. Amyloidosis should be suspected in patients with worsening kidney function, proteinuria, and multisystem involvement, but isolated kidney involvement also is possible. Confirming the amyloidosis type and specific organ dysfunction is of paramount importance to select the appropriately tailored treatment and aim for better survival while avoiding treatment-associated toxicities. Amyloid renal staging in light chain amyloidosis amyloidosis helps inform prognosis and risk for end-stage kidney disease. Biomarker-based staging systems and response assessment guide the therapeutic strategy and allow the timely identification of refractory or relapsing disease so that patients can be switched to salvage therapy. Kidney transplantation is a viable option for selected patients with amyloidosis. Because of the complex nature of the pathophysiology and treatment of amyloidosis, a multidisciplinary team-based approach should be used in the care of these patients.

Advances in the treatment of light chain amyloidosis

PURPOSE OF REVIEW

After many years, the management of systemic light chain (AL) amyloidosis is entering the era of evidence-based medicine, with three recently published randomized clinical trials, a regimen (daratumumab, cyclophosphamide, bortezomib, and dexamethasone, daratumumab-CyBorD) labeled for upfront therapy, more clinical trials ongoing, and published guidelines. In this review, we discuss how current practice is changing based on this data.

RECENT FINDINGS

Daratumumab-CyBorD grants unprecedentedly high rates of hematologic and organ response and became the novel standard-of-care in AL amyloidosis. The International Society of Amyloidosis and the European Hematology Association issued common guidelines for autologous stem cell transplant (ASCT) in this disease. Improved patient selection and effective induction regimens greatly reduced ASCT-related mortality. Venetoclax is emerging as a very effective option in patients harboring the common t(11;14) abnormality. Rapid and profound reduction of the amyloid free light chain can improve survival also at advanced stages.

SUMMARY

Daratumumab-CyBorD is being integrated into the treatment flow-chart whereas the role of ASCT is being redefined. New approaches are being tested in clinical trials. Treatment of daratumumab-refractory patients and validation of criteria of hematologic progression to be used in clinical trials and in individual patient management are current areas of research.