ABSTRACT
In most malignancies, response following stem cell transplantation is assessed by the maximal reduction in tumor mass. In multiple myeloma, response is assessed using the surrogate of 50% reduction in M protein level. In AL, the goal of high-dose chemotherapy is eradication of the amyloidogenic protein production. Patients with renal amyloid commonly demonstrate a delay in reduction of urinary protein loss following stem cell transplant. Assessment of organ response in patients with renal amyloidosis should be delayed until one year post-transplant. It is premature to consider patients therapeutic failures and initiate salvage therapies before one year if any downward trend is seen in urinary protein loss. It is difficult to distinguish therapeutic failures from delayed responders. The median time to a 50% reduction in urinary protein is approximately nine months, and the median time to maximal response in urinary protein loss is approximately 27 months.
