A 55-year-old man was admitted to our institute to undergo evaluation for proteinuria (5.4 g/day) with lambda-type Bence-Jones protein (BJP). Primary amyloid light chain (AL) amyloidosis and acquired factor X deficiency were diagnosed. High-dose melphalan combined with autologous stem cell transplantation was performed. After three years, the patient's proteinuria normalized, he was negative for urinary BJP, and his factor X activity improved to 105%. Serial renal biopsy showed no progression of amyloid deposition at a biopsy after 5 years, but showed a slight increase in the amyloid deposition after 11 years. This therapy can improve the prognosis of AL amyloidosis; however, there are limitations to the strategy.
Keywords: AL amyloidosis; autologous stem cell transplantation (SCT); factor X deficiency; high-dose melphalan; vincristine, adriamycin, and dexamethasone (VAD).