Excessive fluid accumulation during stem cell mobilization: a novel prognostic factor of first-year survival after stem cell transplantation in AL amyloidosis patients.

High-dose melphalan followed by stem cell transplantation (HDM-SCT) has become the treatment of choice for patients with immunoglobulin light chain amyloidosis (AL). Unfortunately, treatment mortality can be excessive in certain subpopulations. We have noted that patients who gained more than 2% body weight during mobilization had a poorer outcome following HDM-SCT. Excluding 2 patients for lack of weight record and denial of consent, 126 patients between July 1997 and June 2003 were retrospectively studied. Weight increased more than 2.0% during mobilization in 51.6% of the patients. Patients who accumulated more than 2.0% tended to have more proteinuria, more organs involved, lower serum albumin, more diuretic use, and dosage adjustment during mobilization. First-year mortality was significantly higher in those with more than 2% weight gain (33.9% versus 9.8%, P = .002). Multivariate analysis showed weight gain, glomerular filtration rate, and septal thickness to be independent predictors of first-year mortality. The increase in mortality was noted even after the excess weight was diuresed prior to conditioning. The impact on mortality dissipated after the first year. Weight gain during mobilization appears to be a new marker of adverse outcome following HDM-SCT. Better prognostication may improve the treatment mortality rate of these patients.