Time to Redefine Risk-Stratification and Response Criteria in Immunoglobulin Light Chain Amyloidosis?

Assessment of renal outcome following therapy in monoclonal immunoglobulin deposition disease: Emphasizing the need for a consensus approach

“…The standardized amyloid response criteria, predominantly based on proteinuria and widely adopted by consensus and validated in the context of amyloidosis, [27][28][29] are often used in MGRS, including MIDD, to assess renal response. However, renal dysfunction caused by MIDD is distinct from that caused by amyloid deposition, such that these criteria may have limited applicability.…”

“…IMWG renal response criteria include the following: complete response (Renal CR), if eGFR <50 ml/min/1.73 m 2 prior to treatment improves to eGFR ≥60 ml/min/1.73 m 2 ; partial response (Renal PR), if eGFR <15 ml/min/1.73 m 2 prior to treatment improves to 30–59 ml/min/1.73 m 2 ; minor response (Renal MR), if eGFR <15 ml/min/1.73 m 2 prior to treatment improves to 15–29 ml/min/1.73 m 2 or if eGFR 15–29 ml/min/1.73 m 2 prior to treatment improves to 30–59 ml/min/1.73 m 2 ; or renal progression, if there is a >25% decrease in eGFR or > 50% increase in 24‐hour urine protein (to >1 g/24 h) 26 . Amyloid renal response was defined as either reduced proteinuria by ≥50% or a drop in proteinuria to <0.5 g/24 h in those with >0.5 g/24 h at baseline and stable renal function (i.e., ≤ 25% increase in eGFR) 27–29 . For patients with eGFR <50 ml/min/1.73 m 2 and proteinuria (>1 g/24 h) as the main presentation of the disease, both sets of criteria defined above were used for response evaluation.…”

“…26 Amyloid renal response was defined as either reduced proteinuria by ≥50% or a drop in proteinuria to <0.5 g/24 h in those with >0.5 g/24 h at baseline and stable renal function (i.e., ≤ 25% increase in eGFR). [27][28][29] For patients with eGFR <50 ml/min/1.73 m 2 and proteinuria (>1 g/24 h) as the main presentation of the disease, both sets of criteria defined above were used for response evaluation.…”