ABSTRACT
Intermediate CAG expansions in the gene ataxin-2 (ATXN2) are a known risk factor for ALS, but little is known about their role in FTD risk. Moreover, their contribution to the risk and phenotype of patients might vary in populations with different genetic backgrounds. The aim of this study was to assess the relationship of intermediate CAG expansions in ATXN2 with the risk and phenotype of ALS and FTD in the Spanish population. Repeat-primed PCR was performed in 620 ALS and 137 FTD patients in three referral centers in Spain to determine the exact number of CAG repeats. In our cohort, ≥27 CAG repeats in ATXN2 were associated with a higher risk of developing ALS (odds ratio [OR] = 2.666 [1.471-4.882]; p = 0.0013) but not FTD (odds ratio [OR] = 1.446 [0.558-3.574]; p = 0.44). Moreover, ALS patients with ≥27 CAG repeats in ATXN2 showed a shorter survival rate compared to those with <27 repeats (hazard ratio [HR] 1.74 [1.18, 2.56], p = 0.005), more frequent limb onset (odds ratio [OR] = 2.34 [1.093-4.936]; p = 0.028) and a family history of ALS (odds ratio [OR] = 2.538 [1.375-4.634]; p = 0.002). Intermediate CAG expansions of ≥27 repeats in ATXN2 are associated with ALS risk but not with FTD in the Spanish population. ALS patients carrying an intermediate expansion in ATXN2 show more frequent limb onset but a worse prognosis than those without expansions. In patients carrying C9orf72 expansions, the intermediate ATXN2 expansion might increase the penetrance and modify the phenotype.
ABSTRACT
INTRODUCTION AND AIM: Liver transplantation (LT) for acute liver failure (ALF) still has a high early mortality. We aimed to evaluate changes occurring in recent years and identify risk factors for poor outcomes. MATERIAL AND METHODS: Data were retrospectively obtained from the Argentinean Transplant Registry from two time periods (1998-2005 and 2006-2016). We used survival analysis to evaluate risk of death. RESULTS: A total of 561 patients were listed for LT (69% female, mean age 39.5±16.4 years). Between early and later periods there was a reduction in wait-list mortality from 27% to 19% (p<0.02) and 1-month post-LT survival rates improved from 70% to 82% (p<0.01). Overall, 61% of the patients underwent LT and 22% died on the waiting list. Among those undergoing LT, Cox regression analysis identified prolonged cold ischemia time (HR 1.18 [1.02-1.36] and serum creatinine (HR 1.31 [1.01-1.71]) as independent risk factors of death post-LT. Etiologies of ALF were only available in the later period (N=363) with indeterminate and autoimmune hepatitis accounting for 28% and 26% of the cases, respectively. After adjusting for age, gender, private/public hospital, INR, creatinine and bilirubin, and considering LT as the competing event, indeterminate etiology was significantly associated with death (SHR 1.63 [1.06-2.51] and autoimmune hepatitis presented a trend to improved survival (SHR 0.61 [0.36-1.05]). CONCLUSIONS: Survival of patients with ALF on the waiting list and after LT has significantly improved in recent years. Indeterminate cause and autoimmune hepatitis were the most frequent etiologies of ALF in Argentina and were associated with mortality.
