Long-term follow-up of survival of liver transplant recipients with familial amyloid polyneuropathy (Portuguese type)

Portuguese type familial amyloid polyneuropathy is a dominantly inherited neuropathic amyloidosis caused by a mutant transthyretin (TTR). Because TTR is produced mainly by the liver, liver transplantation (LT) abolishes production of the amyloidogenic variant TTR. To date, the procedure appears to halt the progress of the disease. However, long-term outcome is unknown. The aim of the present study is to evaluate the survival of our initial group of unselected liver transplant recipients with FAP. Seventy patients, 51 transplant recipients and a control group of 19 nontransplantation patients, with disease onset before the age of 55 years were included on the study. Transplant recipients were divided into two categories: (1) early series, with patients followed up for 5 years or longer, and (2) new series, with patients followed up for I to 5 years. Nonparametric statistical methods were used. Binary regression analyses were performed by stepwise logistic regression and Cox proportional hazard regression. Survival analysis was performed using Kaplan-Meier analysis, the Cox-Mantel test. Survival analyses and Cox proportional hazard regression analysis were performed from disease onset, not from LT. Significantly decreased survival was noted for transplant recipients with a modified body mass index (mBMI) less than 600 compared with the control group (P < .05). A significant difference in survival also was observed between transplant recipients with an mBMI greater than 600 at the time of LT compared with those with an mBMI less than 600 (P < .02). mBMI and age at LT had a significant impact on survival; whereas late deaths were related to age at LT, early deaths were related to mBMI. The cumulative 10-year survival rate after disease onset was 94% in the new series, with one early death (<6 months) after LT, compared with a 78% survival rate and eight early deaths in the early series (P = .1).