SPONTANEOUS RESOLUTION OF ACQUIRED FACTOR-X DEFICIENCY IN AMYLOIDOSIS

We describe the case of a 51-year-old man with systemic amyloidosis in whom factor X activity was initially 6% of the normal. Amyloidosis wa s responsible for congestive heart failure and a nephrotic syndrome bu t there was no bleeding diathesis. A 12-month trial of melphalan and p rednisone failed to improve cardiac and renal dysfunction; factor X le vels remained low. Eighteen months after this treatment was stopped, f actor X spontaneously normalized although renal insufficiency persiste d. We suggest that the possibility of a spontaneous factor X recovery must be considered when evaluating efficacy of therapeutic agents in a myloidosis.