HIV-infected liver and kidney transplant recipients: 1- and 3-year outcomes.

Improvements in human immunodeficiency virus (HIV)-associated mortality make it difficult to deny transplantation based upon futility. Outcomes in the current management era are unknown. This is a prospective series of liver or kidney transplant recipients with stable HIV disease. Eleven liver and 18 kidney transplant recipients were followed for a median of 3.4 years (IQR [interquartile range] 2.9-4.9). One- and 3-year liver recipients' survival was 91% and 64%, respectively; kidney recipients' survival was 94%. One- and 3-year liver graft survival was 82% and 64%, respectively; kidney graft survival was 83%. Kidney patient and graft survival were similar to the general transplant population, while liver survival was similar to the older population, based on 1999-2004 transplants in the national database. CD4+ T-cell counts and HIV RNA levels were stable; and there were two opportunistic infections (OI). The 1- and 3-year cumulative incidence (95% confidence intervals [CI]) of rejection episodes for kidney recipients was 52% (28-75%) and 70% (48-92%), respectively. Two-thirds of hepatitis C virus (HCV)-infected patients, but no patient with hepatitis B virus (HBV) infection, recurred. Good transplant and HIV-related outcomes among kidney transplant recipients, and reasonable outcomes among liver recipients suggest that transplantation is an option for selected HIV-infected patients cared for at centers with adequate expertise.

Use of overlapping peptide mixtures as antigens for cytokine flow cytometry.

Intracellular cytokine staining and flow cytometry can be used to measure T-cell responses to defined antigens. Although CD8+ T-cell responses to soluble proteins are inefficiently detected by this approach, peptides can be used as antigens. Using overlapping peptides spanning an entire protein sequence, CD8+ T-cell responses can be detected to multiple epitopes, regardless of HLA type. In this study, overlapping peptide mixes of various lengths were compared and 15 amino acid peptides with 11 amino acid overlaps were found to stimulate both CD4+ and CD8+ T-cell responses. Such peptide mixes stimulated CD4+ T-cell responses equivalent to those observed with whole recombinant protein, while simultaneously stimulating CD8+ T-cell responses much higher than those observed with whole protein. Although 8-12 amino acid peptides produced the highest level of CD8+ T-cell responses, 15 amino acid peptides were still very effective. Peptides that were 20 amino acids in length, however, did not stimulate strong CD8+ T-cell responses at the same peptide dose. The cytokine responses to individual epitopes added up approximately to the response to the entire mix, demonstrating that large mixes can detect responses in a quantitative fashion. Unlike whole protein antigens, peptide mixes were effective at stimulating responses in both cryopreserved PBMC and blood stored for 24 h at room temperature. Thus, overlapping 15 amino acid peptide mixes may facilitate the analysis of antigen-specific CD4+ and CD8+ T-cell responses by cytokine flow cytometry, using clinical specimens that include shipped blood or cryopreserved PBMC.

Cytomegalovirus (CMV)-specific CD4+ T lymphocyte immune function in long-term survivors of AIDS-related CMV end-organ disease who are receiving potent antiretroviral therapy.

To better understand the relation of cytomegalovirus (CMV)-specific CD4+ T lymphocyte immunity and clinical outcome in AIDS-related CMV end-organ disease, 2 patient groups were prospectively studied: patients recently diagnosed with active CMV end-organ disease and survivors of CMV retinitis who had responded to highly active antiretroviral therapy and had quiescent retinitis when anti-CMV therapy was discontinued. Most patients with active CMV disease had negative CMV-specific CD4+ T lymphocyte responses at diagnosis, as measured by lymphoproliferation (7/7) or cytokine flow cytometry (3/5) assays. In contrast, all 10 subjects with quiescent retinitis and >150 absolute CD4+ T lymphocytes/microL whose anti-CMV therapy was discontinued during 6 months of follow-up had positive CMV-specific immune responses at least once by each assay. However, 6 of these 10 subjects also had negative CMV-specific immune responses > or =1 time. Such patients may be at risk for future CMV disease progression and should be closely monitored.

Restoration of cytomegalovirus-specific CD4+ T-lymphocyte responses after ganciclovir and highly active antiretroviral therapy in individuals infected with HIV-1.

Recent studies of subjects infected with human immunodeficiency virus (HIV-1) have produced conflicting results about the extent of reconstitution possible in the CD4+ lymphocyte repertoire after highly active antiretroviral therapy (HAART). The effect of HAART on the incidence of opportunistic infections will probably depend on reconstitution of antigen-specific CD4+ lymphocyte responses to important pathogens, including cytomegalovirus (CMV), the leading cause of blindness in AIDS. Several studies have demonstrated an important role for CD4+ lymphocytes in controlling CMV replication in vitro and in clinical studies. It is now possible to quantitate antigen-specific CD4+ lymphocyte responses by flow cytometry. Using this method, we studied CMV-specific CD4+ lymphocyte responses in individuals infected with HIV-1 with and without a history of active CMV-associated end organ disease (EOD), and in those with quiescent CMV EOD after ganciclovir therapy and HAART. The presence of active CMV-associated EOD strongly correlated with loss of CMV-specific lymphocyte responses (P = 0.0004). In contrast, patients with no history of CMV-associated EOD and most patients with quiescent EOD after HAART demonstrated strong CMV-specific CD4+ lymphocyte responses. These data indicate that the loss of CMV-specific CD4+ lymphocyte responses in individuals infected with HIV-1 who have active CMV EOD may be restored after ganciclovir therapy and HAART, which provides evidence for functional immune reconstitution to an important pathogen.