Outcome in XXXX in relation to changes in concentration of circulating free immunoglobulin light chains following chemotherapy.

@entity1 @entity527 @entity1581 @entity2783 @entity1582 @entity2015
Monoclonal immunoglobulin light chains are deposited as amyloid fibrils in systemic @entity1582 (primary) @entity2783 , but the underlying @entity1581 are often difficult to detect or unquantifiable. The relationships between circulating monoclonal light chains, amyloid load and clinical outcome, and the relative efficacies of chemotherapy regimens aimed at suppressing monoclonal immunoglobulin production, have not been determined. Circulating @entity2015 ( @entity2015 ) concentration was measured with a sensitive nephelometric immunoassay in 262 @entity1 with @entity1582 , and followed serially in 137 @entity1 who received either high-dose chemotherapy or one of two intermediate-dose cytotoxic regimens. Amyloid load was quantified by serum amyloid P component scintigraphy. A monoclonal excess of @entity2015 was identified at diagnosis in 98% of @entity1 . Among 86 @entity1 whose abnormal @entity2015 concentration fell by more than 50% following chemotherapy, 5-year survival was 88% compared with only 39% among those whose @entity2015 did not fall by half (P < 0.0001). @entity527 regressed in 58 @entity1 . The magnitude and duration of the @entity2015 responses to intermediate- and high-dose chemotherapy regimens were similar. The @entity2015 assay enabled the circulating fibril precursor protein in @entity1582 to be quantified and monitored in most @entity1 . Reduction of the amyloidogenic @entity2015 by more than 50% was associated with substantial survival benefit, regardless of the type of chemotherapy used. Clinical improvement following chemotherapy in @entity1582 is delayed, but treatment strategies can be guided by their early effect on serum @entity2015 concentration.
