ABSTRACT
BACKGROUND: Intestinal and multivisceral transplantation can be complicated by cytomegalovirus (CMV)-related viremia and disease. Intravenous ganciclovir (GCV) and oral valganciclovir remain the treatment of choice in this setting. Limited data are available on GCV-resistant (GCV-R) CMV infection in small intestine and multivisceral transplant recipients. METHOD: A retrospective review was performed on all patients who underwent small intestine or multivisceral transplantation from November 8, 2003 through November 30, 2008. Those with CMV viremia and invasive disease were identified. GCV resistance was suspected in patients who continued to have viremic episodes or invasive disease despite appropriate GCV treatment. Genotypic analyses were performed to detect the presence of GCV resistance genes UL97 and UL54. RESULTS: During the study period, 88 small intestine or multivisceral transplants were performed on 85 patients. Of the 88 transplantations, 16 patients developed CMV viremia with or without end-organ disease (18.2%) and 5.7% developed GCV-R CMV infection. In patients diagnosed with CMV infection, 31.3% (5/16) had GCV-R CMV infection. Of patients with GCV-R CMV infection, 80% (4/5) developed CMV allograft enteritis, resulting in allograft explantation in 3 patients. All patients with GCV-R CMV infection were CMV donor positive/recipient negative. Patients with tissue-invasive CMV disease were 18 times more likely to be infected with GCV-R CMV (95% confidence interval 1.24-260.93; P-value 0.0341). CONCLUSION: Small intestinal and multivisceral transplant recipients have a higher rate of GCV-R CMV infection compared with other solid organ transplant recipients, which is often associated with tissue-invasive disease and allograft loss.
Subject(s)
Antiviral Agents/pharmacology , Cytomegalovirus Infections/virology , Cytomegalovirus/drug effects , Ganciclovir/pharmacology , Intestines/transplantation , Organ Transplantation/adverse effects , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Immunosuppressive Agents , Infant , Male , Middle Aged , Retrospective Studies , Risk Factors , Young AdultABSTRACT
HIV-1 use CD4 receptors to infect their primary targets, CD4+ cells, whereas CD8+ cells have a protective role against HIV-1. We recently isolated HIV-1-producing CD8+ clones from two AIDS patients. Here we show that although HIV-1 produced by CD8+ cells maintained the ability to infect CD4+ cells, these viruses were able to infect CD8+ cells independent of CD4. Evidence indicates that these viruses used CD8 as a receptor to infect CD8+ cells. First, expression of CD8 was downmodulated after infection. Second, anti-CD8 antibodies blocked viral entry and replication in CD8+ cells. Finally, resistant cells became susceptible after expression of CD8. Although these viruses used CXCR4 to enter CD4+ cells, it seems that infection of CD8+ cells was independent of CXCR4 or CCR5 co-receptors. Novel changes were observed in envelope sequences of CD8-tropic viruses. These results provide initial evidence that HIV-1 can mutate to infect CD8+ cells using CD8 as a receptor.
