Serum apoptosis markers in acute liver failure: a pilot study.

BACKGROUND & AIMS: We sought to determine whether circulating apoptotic markers are altered in acute liver failure (ALF), differ with etiology, or predict clinical outcome in this condition. METHODS: Serum levels of soluble Fas (sFas), tumor necrosis factor-alpha (TNF-alpha), hepatocyte growth factor (HGF), and interleukin-6 (IL-6) were measured in 67 acute liver failure patients, as well as controls. In a subset of the groups, we measured serum M-30 antigen, an exposed neoepitope from caspase cleavage. We also assessed M-30 immunoreactivity in liver tissue of ALF patients and controls. RESULTS: Median levels for TNF-alpha, HGF, IL-6, and M-30 antigen were at least 10-fold greater in ALF than in hepatitis C virus or normal controls (P < .0001). Median day 1 sFas, day 3 sFas, and day 1 HGF levels varied according to etiology of acute liver failure (P = .004, P = .011, and P = .019, respectively), with values for drug-induced liver injury and acetaminophen-related ALF higher than other etiologies. Median M-30 antigen levels were significantly higher in patients who were transplanted and/or died (2183 U/L) than spontaneous survivors (1004 U/L) (P = .026). M-30 immunoreactivity in liver tissue was significantly greater in ALF patients than HCV controls (P = .004). CONCLUSIONS: TNF-alpha, HGF, IL-6, and M-30 antigen were significantly elevated in ALF. High levels of sFas and HGF might help to confirm a diagnosis of drug-induced liver injury or acetaminophen-related ALF. Higher levels of M-30 antigen are associated with poor clinical outcomes in ALF.

Minimization of genetic distances by the consensus, ancestral, and center-of-tree (COT) sequences for HIV-1 variants within an infected individual and the design of reagents to test immune reactivity.

Eliciting maximal immune responses to highly divergent viruses is a challenge and a focus in AIDS vaccine development. Another challenge is to identify the immune correlates of protective immunity. Recent AIDS vaccine design approaches attempt to use reconstructed centralized viral sequences that minimize genetic differences to circulating viruses. Using these approaches, we derive and analyze consensus (CON), ancestral (ANC), and center-of-tree (COT) sequences to represent intra-individual HIV-1 env variants encoding a range of diversities and phylogenetic structures. Each reconstructed sequence significantly minimized genetic distances to extant sequences throughout the first 5 years of infection of an individual. Interestingly, ANC sequences diverged and were not significantly better than extant sequences in minimizing genetic distances at later stages of infection and disease, likely due to the development of a substantially asymmetric phylogeny. COT or CON sequences derived from autologous virus samplings may be useful for increasing the sensitivity of assessments of immune reactivity against HIV.