Quasispecies tropism and compartmentalization in gut and peripheral blood during early and chronic phases of HIV-1 infection: possible correlation with immune activation markers.

HIV quasispecies was analysed in plasma and proviral genomes hosted by duodenal mucosa and peripheral blood cells (PBMC) from patients with early or chronic infection, with respect to viral heterogeneity, tropism compartmentalization and extent of immune activation. Seventeen HIV-1-infected combined antiretroviral therapy naive patients were enrolled (11 early infection and six chronic infection). V3 and nef genomic regions were analysed by ultra-deep pyrosequencing. Sequences were used to infer co-receptor usage and to construct phylogenetic trees. As markers of immune activation, plasma sCD14 and soluble tumour necrosis factor receptor II (sTNFRII) levels were measured. Median diversity of HIV RNA was lower in patients with early infection versus chronic infection patients. Overall, direct correlation was observed between V3 diversity and X4 frequency; V3 diversity of HIV RNA was inversely correlated with CD4 T-cell count; median sCD14 and sTNFRII values were similar in early and chronic patients, but X4 frequency of HIV RNA was directly correlated with plasma sCD14. The proportion of patients harbouring X4 variants and median intra-patient X4 frequency of proviral genomes tended to be higher in chronic infection than early infection patients. More pronounced compartmentalization of proviral quasispecies in gut compared with PBMC samples was observed in patients with early infection compared with chronic patients. The loss of gut/PBMC compartmentalization in more advanced stages of HIV infection was confirmed by longitudinal observation. More studies are needed to understand the pathogenetic significance of early HIV quasispecies compartmentalization and progressive intermixing of viral variants in subsequent phases of the infection, as well as the role of immune activation in tropism switch.

Ability of peripheral blood mononuclear cells to activate interferon response in vitro is predictive of virological response in HCV patients.

The most reliable predictor of treatment efficacy in hepatitis C is HCV viremia decay at week 12 [early virological response (EVR)]. We investigated whether the ability of peripheral blood mononuclear cells (PBMC) to mount an interferon (IFN) response in vitro could be predictive of EVR. Fifteen patients treated with PEG IFNalpha + RBV, with pre-therapy frozen PBMC, were retrospectively selected. After a 3 hr PBMC exposure to IFNalpha in vitro, up-regulation of mRNA for IFN-stimulated genes (ISG) was measured by membrane super-array. ISG mRNA levels in unstimulated PBMC were low, but beta2M and CASP1 were significantly higher in EVR vs non-EVR. ISG mRNA up-regulation by IFN was more pronounced in EVR vs non-EVR. For 7 genes (IP-10, IFIT1, IFIT2, IFIT3, TRAIL, KIAA1628 and OAS2) cut-off levels were established, by ROC analysis, able to correctly classify all EVR and non-EVR. Early virological response to PEG IFNalpha +RBV is correlated with the pre-therapy ability of PBMC to activate an IFN response in vitro. If validated in a wider cohort of patients, the ability of this set of ISG to discriminate between EVR and non-EVR may be useful for pre-therapy evaluation, particularly in patients with unfavourable combinations of conventional response predictors.

Virological characterization of patients treated early is able to control HIV-1 replication after multiple cycles of structured therapy interruption.

This study aimed to define clinical and virological parameters associated with spontaneous control of HIV replication in patients having initiated HAART during primary HIV infection, who underwent structured therapy interruption by two protocols with either fixed or HIV viremia-guided scheme. At the end of the protocol all patients were changed to viremia-guided scheme and observed for 12 months (follow-up). Patients maintaining HIV viremia below the indications for resumption of HAART during the follow-up, were defined controllers, those who had to resume HAART were defined non-controllers. The following parameters were examined: pre-interruption therapy duration, CD4(+), HIV RNA, proviral DNA, evolution of viral quasispecies. No specific advantage was conferred by either interruption of structured therapy in the proportion of controllers and non-controllers. Pre-HAART and zenith CD4(+), pre-therapy interruption, HAART duration, but not pre-HAART HIV RNA, were significantly higher in controllers as compared to non-controllers. HIV RNA levels after the first interruption cycle of therapy were significantly lower in controllers than in non-controllers. Proviral DNA levels were also lower in controllers at this time point. HIV RNA and proviral DNA levels associated with the last interruption of therapy cycle were not different from those associated with the first cycle, and, in spite of multiple waves of virus rebound, very few gag quasispecies variants emerged in each patient. The data suggest that pre-treatment clinical parameters and virological events associated with the first viral rebound are crucial factors in determining the ability to control viral replication after multiple cycles of interruption of treatment.

Imported malaria at Italy's National Institute for Infectious Diseases Lazzaro Spallanzani, 1984-2003.

Imported malaria is the most common cause of fatal infections in returning travellers. The increased amount of both tourist movement and migration has resulted in a growing number of people at risk of infection. In the present study, 507 malaria patients admitted to Italy's National Institute for Infectious Diseases in Rome between January 1984 and December 2003 were studied. Overall, 445 cases, or 87.7%, were acquired in Africa, of which 55% were acquired in five sub-Saharan countries. Plasmodium falciparum accounted for 393 (77.5%) of the imported cases. Patients consisted of short-term travellers (n = 213, 42%), long-term visitors (n = 134, 26.4%), and immigrants from endemic areas (n = 137, 27%). Malaria chemoprophylaxis was completed in less than one-quarter of all patients, with immigrants having the lowest rate of completion: only 3.6% of immigrants fully completed chemoprophylaxis compared to 31% of short-term travellers and 29.1% of long-term visitors (p < 0.001). Upon multivariate analysis, the lack of chemoprophylaxis was independently associated with the occurrence of severe malaria (p = 0.009). Severe malaria was reported in 59 (11.6%) individuals: all 11 deaths due to severe P. falciparum infection occurred in patients from sub-Saharan countries, two of whom were immigrants from countries where malaria is endemic. Malaria poses a serious health threat to individuals visiting endemic areas. Ensuring the correct chemoprophylaxis for all travellers, including immigrants from endemic areas, and providing prompt access to healthcare providers for unhealthy returning travellers are major points still to be addressed in Italy.