Changes in Serum Electrolytes during Treatment of Patients in Liver Failure with Molecular Adsorbent Recirculating System

PURPOSE

To study the effect of MARS on serum electrolytes during liver failure.

DESIGN

Twenty-three patients admitted to a quaternary health care facility from September 2000 to May 2002, 22 adults and 1 child, 11 males (48%) and 12 females (52%), age 15-70 (median 53), treated with MARS for: 12 acute-on-chronic liver failure (52%); 4 fulminant hepatic failure (17%); 3 intractable pruritus (13%); 2 primary-non-function (9%); 2 following major liver resection (9%).

PROCEDURES

Sodium, potassium, chloride, phosphorus, calcium, and magnesium were measured in the serum, ultrafiltrate and albumin circuit before and after MARS.

STATISTICAL METHODS

A comparison of electrolyte concentrations, before and after MARS, was performed using a paired t test.

MAIN FINDINGS

Serum electrolyte concentrations before and after MARS, while statistically significant in some cases, were very small, and of no clinical relevance.

CONCLUSION

MARS exchanges potassium, chloride, calcium, and magnesium by ultrafiltration; sodium by the albumin dialysis.

Primary and reactivated HHV8 infection and disease after liver transplantation: a prospective study

Human herpesvirus 8 (HHV8) is pathogenic in humans, especially in cases of immunosuppression. We evaluated the risk of HHV8 transmission from liver donors, and its clinical impact in southern Italy, where its seroprevalence in the general population is reported to be as high as 18.3%. We tested 179 liver transplant recipients and their donors for HHV8 antibodies at the time of transplantation, and implemented in all recipients a 12-month posttransplant surveillance program for HHV8 infection. Of the 179 liver transplant recipients enrolled, 10.6% were HHV8 seropositive before transplantation, whereas the organ donor's seroprevalence was 4.4%. Eight seronegative patients received a liver from a seropositive donor, and four of them developed primary HHV8 infection. Two of these patients had lethal nonmalignant illness with systemic involvement and multiorgan failure. Among the 19 HHV8 seropositive recipients, two had viral reactivation after liver transplantation. In addition, an HHV8 seronegative recipient of a seronegative donor developed primary HHV8 infection and multicentric Castleman's disease. In conclusion, primary HHV8 infection transmitted from a seropositive donor to a seronegative liver transplant recipient can cause a severe nonmalignant illness associated with high mortality. Donor screening for HHV8 should be considered in geographic areas with a high prevalence of such infection.

Role of basiliximab in the prevention of acute cellular rejection in adult to adult living-related liver transplantation: a single center experience

We report our single center experience with the use of basiliximab, a chimeric monoclonal antibody directed against the alpha chain of the interleukin-2 (IL-2) receptor (CD25), in combination with a steroid- and tacrolimus-based regimen in adult to adult living-related liver transplantation (ALRLT). Sixty consecutive ALRLTs were analyzed. All patients received two 20-mg doses of basiliximab (days 0 and 4 after transplantation) followed by tacrolimus (0.15 mg/kg/day; 10-15 ng/mL target trough levels) and a dose regimen of steroids (starting with 20 mg iv, switched to po as soon as the patient was able to eat, and weaned off within 1-2 months). Follow-up ranged from 6 to 1699.4 days after transplantation (mean 517.5 days, SD +/- 413.4; median 424 days). Of the recipients, 95% remained rejection-free during follow-up, with an actuarial rejection-free probability of 96.61% within 3 months. Three patients had episodes of biopsy-proven acute cellular rejection (ACR). Actuarial patient and graft survival rates at 3 years were 82.09% and 75.61%. Six patients (10%) experienced sepsis. There was no evidence of cytomegalovirus infections or side-effects related to the basiliximab. We found zero de novo malignancy, although we observed 5 patients with metastatic spread of their primary malignancy during the follow-up. Basiliximab in association with tacrolimus and steroids is effective in reducing episodes of ACR and increasing ACR-free survival after ALRLT.

Conserved hepatitis C virus sequences are highly immunogenic for CD4(+) T cells: implications for vaccine development

The HLA class II-restricted T-cell response to hepatitis C virus (HCV) antigens is believed to influence the final outcome of hepatitis C, because it is vigorous in patients who recover from acute hepatitis C, but it is weak in those who develop a chronic infection. For this reason, exogenous stimulation of T-cell responses in chronic HCV infection may represent a strategy to cure patients with chronic hepatitis C by approximating the vigor of their T-cell reactivity to that of patients who succeed in recovering from hepatitis. It may also be a preventive approach to avoid spread of the virus by facilitating the development of a vigorous protective response at the very early stages of infection. T-cell-based vaccines composed of immunodominant, promiscuous, and conserved T-cell epitopes may represent a powerful tool to achieve optimal stimulation of the T-cell reactivity. To identify HLA class II-restricted T-cell epitopes useful for this purpose, 22 subjects with acute HCV infection were studied and followed for an average time of 29 months. Eight of them recovered from hepatitis, and 14 developed a chronic infection. Overlapping 20-mer peptides covering the entire core and NS4 antigens and a panel of peptides representing highly conserved regions of core, NS3, NS4, and NS5 were used. By direct peripheral blood T-cell stimulation and by fine-specificity analysis of HCV-specific T-cell lines and clones, highly immunogenic T-cell epitopes were identified within core, NS3, and NS4. All these epitopes are immunodominant and highly conserved among the known HCV isolates. Moreover, they are promiscuous, because they can be presented to T cells by different HLA class II molecules. Immunodominance, sequence conservation, and promiscuity make these epitopes ideal components of preventive or therapeutic T-cell-based vaccines against HCV.

Antiviral cell-mediated immune responses during hepatitis B and hepatitis C virus infections

Cell-mediated immune responses to hepatitis B (HBV) and hepatitis C virus (HCV) antigens are vigorous and multispecific in acute, self-limited infections. Moreover, the prevalent cytokine pattern of circulating virus-specific T cells from patients who recover spontaneously from acute hepatitis is Th1-like. Longitudinal analysis of the T cell response to HCV antigens from the early stages of HCV infection in patients who recover from hepatitis and those who do not indicates that weaker responses and a prevalent Th2 pattern of cytokine production is associated with viral persistence and chronic evolution of disease. Although similar sequential studies are missing in hepatitis B, the observation that HBV-specific T cell responses are very weak or totally undetectable in the peripheral blood of patients with long-lasting chronic hepatitis B suggests that strength and quality of virus-specific T cell responses at the early stages of infection may influence the final outcome of both hepatitis B and C. While T cell hyporesponsiveness seems to be an important determinant for HBV persistence once chronic hepatitis has developed, this mechanism appears to be less critical in chronic HCV infection, because the vigor and quality of HCV-specific T cell responses seem to improve as a function of the duration of infection. This is shown by the finding that HCV-specific CD4- and CD8-mediated responses are easily detectable in the peripheral blood of patients with long-lasting chronic hepatitis C and that production of Th1 cytokines predominates within their livers. HCV therefore seems to be able to persist even in the face of an active T cell response and to acquire the capacity to survive within a host environment apparently unfavorable to its persistence. The high variability of HCV may explain its efficiency in escaping immune surveillance.

Effects of interferon treatment on the antiviral T-cell response in hepatitis C virus genotype 1b- and genotype 2c-infected patients

The viral genotype may influence the response to interferon (IFN) treatment in chronic hepatitis C virus (HCV) infection. To characterize potential mechanisms responsible for this effect, we assessed whether IFN modulation of HCV-specific T-cell responses differs in patients infected by different genotypes. The T-cell response to HCV core protein was sequentially analyzed before and during IFN treatment in two groups of patients chronically infected with HCV genotype 1b (eight patients) or 2c (eight patients). Overlapping 20 mer peptides corresponding to the amino acid sequence of the prevalent viral population identified in the serum of each patient were used for the analysis of the T-cell proliferative response to avoid possible problems caused by amino acid differences between infecting virus and HCV proteins used in vitro. Recombinant HCV core antigen was used in parallel. The level of viremia was monitored by competitive polymerase chain reaction (PCR). The T-cell response to HCV peptides and recombinant core protein detected throughout the follow-up was significantly more vigorous in genotype 2c- than in genotype 1b-infected patients. This difference was the result of a greater enhancement of the T-cell response caused by IFN treatment in genotype 2c- compared with genotype 1b-infected patients. The different IFN modulatory effect on T cells from genotype 1b- and genotype 2c-infected patients illustrates an aspect of the virus-host interaction, which may contribute toward the explanation of why different genotypes differ in responsiveness to IFN treatment.

Different clinical behaviors of acute hepatitis C virus infection are associated with different vigor of the anti-viral cell-mediated immune response

The anti-viral T cell response is believed to play a central role in the pathogenesis of hepatitis C virus infection. Since chronic evolution occurs in > 50% of HCV infections, the sequential analysis of the T cell response from the early clinical stages of disease may contribute to define the features of the T cell response associated with recovery or chronic viral persistence. For this purpose, 21 subjects with acute hepatitis C virus infection were sequentially followed for an average time of 44 wk. Twelve patients normalized transaminase values that remained normal throughout the follow-up period; all but two cleared hepatitis C virus-RNA from serum. The remaining nine patients showed persistent viremia and elevated transaminases. Analysis of the peripheral blood T cell proliferative response to core, E1, E2, NS3, NS4, and NS5 recombinant antigens and synthetic peptides showed that responses to all hepatitis C virus antigens, except E1, were significantly more vigorous and more frequently detectable in patients who normalized transaminase levels than in those who did not. By sequential evaluation of the T cell response, a difference between the two groups of patients was already detectable at the very early stages of acute infection and then maintained throughout the follow-up period. The results suggest that the vigor of the T cell response during the early stages of infection may be a critical determinant of disease resolution and control of infection.