Hematologic response criteria in light chain (AL) amyloidosis require the difference in involved and uninvolved free light chains (dFLC) to be at least 5 mg/dl. We describe the clinical presentation and outcomes of newly diagnosed amyloidosis patients with dFLC <5 mg/dl (non-evaluable dFLC; 14%, n=165) compared with patients with dFLC ⩾5 mg/dl (evaluable dFLC; 86%, n=975). Patients with non-evaluable dFLC had less cardiac involvement (40% vs 80%, P<0.001), less liver involvement (11% vs 17%, P=0.04) and a trend toward less gastrointestinal involvement (18% vs 25%, P=0.08). However, significantly higher renal involvement (72% vs 56%, P=0.0002) was observed in the non-evaluable dFLC cohort. Differences in treatment patterns were observed, with 51% of treated patients undergoing upfront stem cell transplantation in the non-evaluable cohort compared with 28% in the evaluable dFLC group (P<0.001). Progression-free survival (61 vs 13 months, P<0.001) and overall survival (OS; 101 vs 29 months, P<0.001) were significantly longer in the non-evaluable dFLC cohort. Normalization of involved light chain levels and decrease in dFLC <1 mg/dl (baseline at least 2 mg/dl) were predictive of OS and associated with better dialysis-free survival and may be used for response assessment in patients with non-evaluable FLC levels.

中文翻译：

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具有不可评估的血清游离轻链的轻链淀粉样变性患者的临床表现和结果。

轻链 (AL) 淀粉样变性的血液学反应标准要求受累和未受累的游离轻链 (dFLC) 的差异至少为 5 mg/dl。我们描述了新诊断的 dFLC <5 mg/dl（不可评估 dFLC；14%，n=165）与 dFLC ≤5 mg/dl（可评估 dFLC；86%，n =975）。不可评估的 dFLC 患者心脏受累较少（40% vs 80%，P<0.001），肝脏受累较少（11% vs 17%，P=0.04），胃肠道受累较少（18% vs 25%， P = 0.08）。然而，在不可评估的 dFLC 队列中观察到显着更高的肾脏受累（72% vs 56%，P=0.0002）。观察到治疗模式的差异，在不可评估的队列中，51% 的治疗患者接受了前期干细胞移植，而在可评估的 dFLC 组中这一比例为 28%（P<0.001）。在不可评估的 dFLC 队列中，无进展生存期（61 对 13 个月，P<0.001）和总生存期（OS；101 对 29 个月，P<0.001）显着更长。相关轻链水平的正常化和 dFLC <1 mg/dl（基线至少 2 mg/dl）的降低可预测 OS，并与更好的无透析生存期相关，并可用于不可评估 FLC 患者的反应评估水平。