Biomedical subjects

Roberto Bugarini

Publications and source records attributed to Roberto Bugarini.

17 recordsLinked to original sources

PubMed2006

Immunophenotype of HIV+ patients during CD4 cell-monitored treatment interruption: role of the IL-7/IL-7 receptor system.

OBJECTIVE: To investigate immunological changes during CD4-guided therapy interruption in HIV(+) patients who suspended HAART. PATIENTS: Seventeen patients aged > 18 years, who had received HAART for at least 12 months, and had a pre-interruption CD4+ cell count > 500 cells/microl, interrupted treatment. Median nadir CD4(+) cell count was 288 cells/microl. HIV plasma viral load at discontinuation was < 50 or > 50 copies/ml. Criteria for restarting treatment were: a CD4(+) T-lymphocyte count < 350 cells/microl on two separate occasions, a clinical manifestation of AIDS, and the patient's desire to resume HAART. Eleven patients were still off therapy after 12 months (group A); according to the first criterion, six patients restarted therapy within 12 months (group B). METHODS: Haematological, viro-immunological, cytofluorimetic and molecular assays were performed at baseline and every 2 months following standard methods. Statistical analysis was performed under Stata 7.0. RESULTS: In the first 2 months of treatment interruption, a significant increase in viral load and CD8(+) lymphocyte activation occurred. Then such parameters decreased and remained stable. In all patients, a decrease in CD4(+) lymphocytes took place as well, that affected in a similar manner naive, central memory, effector memory and terminally differentiated cells. Group B always presented lower amounts of CD4(+) effector memory lymphocytes. The expression of CD127 was always higher in group A. CONCLUSIONS: The loss of CD4(+) lymphocytes upon viral rebound is equal among naive and memory subsets. Patients with higher expression of CD127, who are likely to exert a better capacity to utilize endogenous interleukin-7 by T cells, could remain off therapy for longer periods.

Adult↗

PubMed2006

An MF59-adjuvanted inactivated influenza vaccine containing A/Panama/1999 (H3N2) induced broader serological protection against heterovariant influenza virus strain A/Fujian/2002 than a subunit and a split influenza vaccine.

To test whether inactivated influenza vaccines distributed during the 2003-2004 influenza season in the northern hemisphere were able to confer protection against the mismatched variant A/Fujian/411/2002 virus strain, we measured haemagglutination inhibiting (HI) antibodies in elderly subjects vaccinated with three inactivated vaccines against the homologous A/H3N2 vaccine strain (A/Panama) and against the mismatched A/Fujian strain. The results showed that, while 76 to 80% of elder people vaccinated with conventional vaccines had protected levels of antibodies against the A/Fujian heterovariant strain, those vaccinated with the MF59-adjuvanted vaccine have protective levels of antibodies in >98% of the cases. We conclude that MF59-adjuvanted vaccines confer protection also against influenza virus strains which are not fully matched with those included in the vaccine.

Adjuvants, Immunologic↗

PubMed2006

Vaccines with the MF59 adjuvant do not stimulate antibody responses against squalene.

Squalene is a naturally occurring oil which has been used in the development of vaccine adjuvants, such as the oil-in-water emulsion MF59. In past years, by use of noncontrolled and nonvalidated assays, a claim was made that antisqualene antibodies were detectable in the sera of individuals with the so-called Gulf War syndrome. Using a validated enzyme-linked immunosorbent assay for the quantitation of immunoglobulin G (IgG) and IgM antibodies against squalene, we demonstrated that antisqualene antibodies are frequently detectable at very low titers in the sera of subjects who were never immunized with vaccines containing squalene. More importantly, vaccination with a subunit influenza vaccine with the MF59 adjuvant neither induced antisqualene antibodies nor enhanced preexisting antisqualene antibody titers. In conclusion, antisqualene antibodies are not increased by immunization with vaccines with the MF59 adjuvant. These data extend the safety profile of the MF59 emulsion adjuvant.

Adjuvants, Immunologic↗

PubMed2006

Phase I evaluation of intranasal trivalent inactivated influenza vaccine with nontoxigenic Escherichia coli enterotoxin and novel biovector as mucosal adjuvants, using adult volunteers.

Trivalent influenza virus A/Duck/Singapore (H5N3), A/Panama (H3N2), and B/Guandong vaccine preparations were used in a randomized, controlled, dose-ranging phase I study. The vaccines were prepared from highly purified hemagglutinin and neuraminidase from influenza viruses propagated in embryonated chicken eggs and inactivated with formaldehyde. We assigned 100 participants to six vaccine groups, as follows. Three intranasally vaccinated groups received 7.5-microg doses of hemagglutinin from each virus strain with either 3, 10, or 30 microg of heat-labile Escherichia coli enterotoxin (LTK63) and 990 microg of a supramolecular biovector; one intranasally vaccinated group was given 7.5-microg doses of hemagglutinin with 30 microg of LTK63 without the biovector; and another intranasally vaccinated group received saline solution as a placebo. The final group received an intramuscular vaccine containing 15 microg hemagglutinin from each strain with MF59 adjuvant. The immunogenicity of two intranasal doses, delivered by syringe as drops into both nostrils with an interval of 1 week between, was compared with that of two inoculations by intramuscular delivery 3 weeks apart. The intramuscular and intranasal vaccine formulations were both immunogenic but stimulated different limbs of the immune system. The largest increase in circulating antibodies occurred in response to intramuscular vaccination; the largest mucosal immunoglobulin A (IgA) response occurred in response to mucosal vaccination. Current licensing criteria for influenza vaccines in the European Union were satisfied by serum hemagglutination inhibition responses to A/Panama and B/Guandong hemagglutinins given with MF59 adjuvant by injection and to B/Guandong hemagglutinin given intranasally with the highest dose of LTK63 and the biovector. Geometric mean serum antibody titers by hemagglutination inhibition and microneutralization were significantly higher for each virus strain at 3 and 6 weeks in recipients of the intramuscular vaccine than in recipients of the intranasal vaccine. The immunogenicity of the intranasally delivered experimental vaccine varied by influenza virus strain. Mucosal IgA responses to A/Duck/Singapore (H5N3), A/Panama (H3N2), and B/Guandong were highest in participants given 30 microg LTK63 with the biovector, occurring in 7/15 (47%; P=0.0103), 8/15 (53%; P=0.0362), and 14/15 (93%; P=0.0033) participants, respectively, compared to the placebo group. The addition of the biovector to the vaccine given with 30 microg LTK63 enhanced mucosal IgA responses to A/Duck/Singapore (H5N3) (P=0.0491) and B/Guandong (P=0.0028) but not to A/Panama (H3N2). All vaccines were well tolerated.

Adjuvants, Immunologic↗

PubMed2005

Genetic polymorphisms of Fas (CD95) and Fas ligand (CD178) influence the rise in CD4+ T cell count after antiretroviral therapy in drug-naïve HIV-positive patients.

Fas and Fas ligand (FasL) are the main genes that control cell death in the immune system. Indeed, they are crucial for the regulation of T lymphocyte homeostasis because they can influence cell proliferation. A strong debate exists on the importance of Fas/FasL system during HIV infection, which is characterized by the loss of CD4+ T cells directly, or indirectly, caused by the virus. To investigate whether the genetic background of the host plays a role in the immunoreconstitution, we studied the influence of different Fas and FasL polymorphisms on CD4+ T lymphocyte count and plasma viral load following initiation of highly active antiretroviral therapy (HAART) in drug-naïve HIV+ patients. We studied 131 individuals, who were compared to 136 healthy donors. Statistical analysis was performed by using Chi2 test, Fischer's Exact Test, and analysis for repeated measurements. The group of HIV+ patients had an unexpected lower frequency of FasLnt169 polymorphism (delT allele) than healthy controls (p = 0.039). We then observed no significant differences in the immune reconstitution, in terms of CD4+ T cell increase, when the influence of single alleles of the gene Fas or FasL was considered. However, the combination of some polymorphisms of Fas or FasL significantly influenced CD4+ T cell production and viral load decrease, showing that these genes can play a role in the immunoreconstitution triggered by antiretroviral therapy.

Adult↗

PubMed2005

Effect of treatment interruption monitored by CD4 cell count on mitochondrial DNA content in HIV-infected patients: a prospective study.

BACKGROUND: HIV infection per se and HAART can alter mitochondrial functionality, leading to a decrease in mitochondrial DNA content. OBJECTIVE: To evaluate whether treatment interruption monitored by CD4 cell count can restore mitochondrial DNA content in peripheral blood lymphocytes. METHODS: Mitochondrial DNA content was measured in platelet-free CD4 and CD8 T cells by real-time polymerase chain reaction; flow cytometry was used to identify and quantify activated CD4 and CD8 T lymphocytes. RESULTS: The 30 patients had been treated for a mean of 107 months (range, 27-197). Median CD4 cell count at discontinuation was 702 cells/microl (range, 547-798). Median observational time from HAART discontinuation was 11.3 months (range, 4-26). Discontinuation of treatment provoked significant increases in mitochondrial DNA in CD8 T cells, which started only 6 months after therapy discontinuation [5.12 copies/cell per month from 0 to 6 months (P = 0.37) and 26.96 copies/cell per month from 6 to 12 months (P < 0.0001)]. CONCLUSIONS: This study is the first showing that mitochondrial DNA content can increase in peripheral blood lymphocytes during treatment interruption, but only after at least 6 months of interruption. Consequently, interruptions of shorter periods, whether by clinician or patient decision, are unlikely to allow restoration of mitochondrial DNA and so decrease HAART-related toxicity.

Adult↗

PubMed2005

Cross-reactivity to highly pathogenic avian influenza H5N1 viruses after vaccination with nonadjuvanted and MF59-adjuvanted influenza A/Duck/Singapore/97 (H5N3) vaccine: a potential priming strategy.

Antigenically well-matched vaccines against highly pathogenic avian influenza H5N1 viruses are urgently required. Human serum samples after immunization with MF59 or nonadjuvanted A/duck/Singapore/97 (H5N3) vaccine were tested for antibody to 1997-2004 human H5N1 viruses. Antibody responses to 3 doses of nonadjuvanted vaccine were poor and were higher after MF59-adjuvanted vaccine, with seroconversion rates to A/HongKong/156/97, A/HongKong/213/03, A/Thailand/16/04, and A/Vietnam/1203/04 of 100% (P < .0001), 100% (P < .0001), 71% (P = .0004), and 43% (P = .0128) in 14 subjects, respectively, compared with 27%, 27%, 0%, and 0% in 11 who received nonadjuvanted vaccine. These findings have implications for the rational design of pandemic vaccines against influenza H5.

Adjuvants, Immunologic↗

PubMed2004

Highly active antiretroviral therapy restores CD4+ Vbeta T-cell repertoire in patients with primary acute HIV infection but not in treatment-naive HIV+ patients with severe chronic infection.

In drug-naive HIV+ patients, we analyzed the effects of highly active antiretroviral therapy (HAART) on the reconstitution of the T-cell receptor (TCR) repertoire. We followed 2 groups of patients for 1 year: 18 individuals who experienced acute HIV infection and 24 patients who had HIV infection for many years but never took HAART. They were compared with 10 healthy controls who were longitudinally analyzed for the same period. We performed cytofluorometric analysis of the Vbeta TCR repertoire and detected the clonality of different Vbeta families by the spectratyping method. A new statistical approach based on the use of mixed models was then employed to analyze the data. Before the beginning of therapy, the repertoire of patients with acute or chronic infection was significantly different from that of healthy controls. After therapy, patients with acute HIV infection showed an improvement of the repertoire among either CD4+ or CD8+ T lymphocytes. Conversely, patients with chronic infection were capable of changing their repertoire among CD8+ but not CD4+ T lymphocytes. Our results indicate that HAART can restore the T-cell repertoire in individuals whose immune system is not severely compromised by the infection.

Adolescent↗

PubMed2003

Correlates of HIV-1 shedding in cervicovaginal secretions and effects of antiretroviral therapies.

OBJECTIVES: To evaluate the determinants of HIV-1 RNA shedding in cervicovaginal secretions and the effects of antiretroviral therapy in a group of infected women. METHODS: A total of 122 women from whom paired peripheral blood and cervicovaginal lavage samples were available were enrolled in the study. HIV-1 RNA was quantified in the plasma and cell-free fraction of cervicovaginal lavages by the nucleic acid sequence-based amplification assay (lower limit of detection 80 copies/ml). RESULTS: Seventy-one per cent of the women had detectable viral load in the cervicovaginal lavage and this appeared to be correlated to plasma viral load and to the degree of immunodeficiency as expressed by the absolute number of CD4 cells. Antiretroviral-treated patients had a lower risk of shedding the virus in the genital tract, but this association was limited to patients treated with highly active antiretroviral therapy (HAART). However, in 25% of women with undetectable plasma viral load, a genital shedding of the virus was demonstrated. CONCLUSION: Plasma viral load may fail as a marker of infectivity of genital secretions. HAART treatment seems to be more efficacious in suppressing viral shedding at the genital level. The female genital tract represents a distinct compartment for HIV-1 replication/evolution.

Adult↗

PubMed2003

Persistently biased T-cell receptor repertoires in HIV-1-infected combination antiretroviral therapy-treated patients despite sustained suppression of viral replication.

In most HIV-1-infected patients, highly active antiretroviral therapy (HAART) reduces plasma viral load to <50 copies/mL and increases CD4+ T-cell number and function. However, it is still unclear whether alterations of T-cell receptor (TCR) beta-chain variable region (BV) repertoire, tightly related to disease progression, can be fully recovered by long-term treatment with HAART. This study analyzed the evolution of both T-cell subset composition and TCRBV perturbations in chronically HIV-1-infected patients with moderate immunodeficiency during 36 months of HAART. Despite persistently suppressed HIV replication, the rate of CD4+ T-cell repopulation, after an initial burst, progressively declined throughout the study period, resulting in a mean CD4+ T-cell count at the end of follow-up that was still significantly lower in HIV patients than in HIV-seronegative controls. This was seen in association with an incomplete restitution of both CD4 and CD8 TCRBV repertoire disruptions and was also demonstrated by the appearance of new TCRBV oligoclonal expansions occurring during HAART. In conclusion, these data indicate that 3 years of fully suppressive HAART may be not adequate to normalize CD4 counts and TCRBV repertoires in patients starting HAART with moderately advanced disease.

Acquired Immunodeficiency Syndrome↗

PubMed2003

Antibody responses and HIV-1 viral load in HIV-1-seropositive subjects immunised with either the MF59-adjuvanted influenza vaccine or a conventional non-adjuvanted subunit vaccine during highly active antiretroviral therapy.

OBJECTIVE: To study immunological and virological parameters in HIV-1-seropositive adults treated with highly active antiretroviral therapy (HAART) for at least 7 months after immunisation with MF59-adjuvanted (FLUAD, Chiron, Siena, Italy) or with non-adjuvanted (AGRIPPAL, Chiron) trivalent influenza vaccine. DESIGN: Blood samples, collected before and after vaccination, were analysed for the presence of antibodies against the vaccine antigens, for number of CD4+ T lymphocytes and HIV-1 RNA levels. RESULTS: Forty-four volunteers received FLUAD and 40 AGRIPPAL influenza vaccine. Thirty days after vaccination both adjuvanted and non-adjuvanted vaccines induced significant increases of anti-influenza virus antibodies. However, antibody titres found in volunteers receiving adjuvanted vaccine were in general significantly higher when compared with those found in the non-adjuvanted vaccine group. The requirements of the European Commission of influenza vaccine for a non-elderly adult population were always met by recipients of the adjuvanted vaccine, even in those with the lowest CD4+ cell counts (<200 cells/mmc). The subjects receiving the non-adjuvanted vaccine failed to met these requirements. The CD4+ T lymphocytes and plasma HIV-1 RNA levels remained stable in the long term, both in people receiving adjuvanted or non-adjuvanted vaccine. CONCLUSION: MF59-adjuvanted influenza induced a significant higher immune responses as compared with conventional vaccine in HIV-seropositive HAART-treated patients. Both vaccines were safe regarding HIV RNA viral replication and loss of CD4+ T lymphocytes.

Adjuvants, Immunologic↗

PubMed2003

Infection with human herpesvirus-8 and its correlation with hepatitis B virus and hepatitis C virus markers among rural populations in Cambodia.

Among 164 individuals in a rural population of Cambodia, antibodies to human herpesvirus-8 (HHV-8) were found among 56.6% of the women and 50.6% of the men. Seropositivity for HHV-8 tended to decrease with age (P < 0.001) and was not associated with exposure to hepatitis B virus (HBV) or HCV. Human herpesvirus-8, which shows a high rate of infection during childhood, does not seem to have the same pattern of transmission as HBV. This suggests very early acquisition of infection with HHV-8 in Cambodia.

Adolescent↗

PubMed2002

Coinfection with hepatitis viruses and outcome of initial antiretroviral regimens in previously naive HIV-infected subjects.

BACKGROUND: The effect of chronic coinfection with hepatitis viruses on the response to therapy against human immunodeficiency virus 1 (HIV-1) remains debated. METHODS: In a prospective cohort study, the effect of hepatitis B virus (HBV) and hepatitis C virus (HCV) serostatus on the outcome of potent HIV-1 therapy was analyzed in HIV-1-infected patients previously naive to antiretroviral therapy. Changes from baseline CD4+ cell counts and HIV RNA levels over time were analyzed by linear regression models. Time to clinical progression and time to reach virologic and immunologic response were analyzed by multivariate Cox proportional hazards regression models. RESULTS: We studied 1320 patients, among whom 600 were HCV antibody-positive and 90 were HBV surface antigen-positive. During a median follow-up of 37 months (range, 1-48 months), clinical progression was observed in 99 patients (56 new acquired immunodeficiency syndrome-defining events and 43 deaths). In multivariate models, HCV-positive HBV-negative patients showed a shorter time to clinical progression (hazard ratio, 1.55; 95% confidence interval, 1.00-2.41). Patients who were HCV-positive also showed mean CD4+ recoveries over time that were at least 30 cells/ micro L fewer than those of seronegative patients. Hepatitis virus serostatus did not affect the virologic response to HIV-1 therapy. CONCLUSIONS: Clinical progression of HIV-1 disease after starting potent antiretroviral therapy is accelerated by concomitant infection with HCV. Compared with patients without coinfection, coinfected patients showed impaired CD4+ cell recovery, despite similar virologic response to HIV-1 therapy. These findings may have important implications for the treatment of HCV and for the timing of initiation of HIV-1 therapy in coinfected individuals.

AIDS-Related Opportunistic Infections↗

PubMed2002

Kinetics of CD4 cells after discontinuation of antiretroviral therapy in patients with virological failure and a CD4 cell count greater than 500 cells/microl.

After a median of 37 months on antiretroviral therapy, 16 patients were asked to discontinue treatment instead of changing it. After a median observation time of 10.5 months, most patients experienced a rapid and progressive decrease in their CD4 cell count, even without a high viral load rebound. This decline was unrelated to the CD4 cell count and HIV-RNA values at interruption, but was more profound in patients in whom the M184V mutation had disappeared after lamivudine discontinuation.

Adult↗

PubMed2002

Primary human herpesvirus 8 infection in immunocompetent children.

CONTEXT: Human herpesvirus 8 (HHV-8) infection causes Kaposi sarcoma and lymphoproliferative disorders in immunosuppressed adults. Its manifestations in immunocompetent hosts are unknown. OBJECTIVES: To determine whether HHV-8 primary infection is symptomatic in immunocompetent children and to identify the epidemiological and virological correlates of HHV-8 infection. DESIGN AND SETTING: Prospective cohort study conducted in the pediatric emergency department of a hospital in Alexandria, Egypt, between December 1, 1999, and April 30, 2000. PATIENTS: Eighty-six children aged 1 to 4 years who were evaluated for a febrile syndrome of undetermined origin. MAIN OUTCOME MEASURES: Serological assay and polymerase chain reaction of blood and saliva samples for HHV-8. Information on potential risk factors for HHV-8 infection was also collected. RESULTS: Thirty-six children (41.9%) were seropositive; HHV-8 DNA sequences were detected in 14 (38.9%) of these 36 children (detected in saliva in 11 of 14). Significant associations were found between HHV-8 infection and close contact with at least 2 other children in the community (36 of 63 vs 6 of 23 for <2 children; adjusted odds ratio [OR], 3.50; 95% confidence interval [CI], 1.11-12.22) and admission to the emergency department in December or January (28 of 47 vs 14 of 39 for February-April; adjusted OR, 3.15; 95% CI, 1.23-8.58). Six children had suspected primary HHV-8 infection; all but 1 had a febrile cutaneous craniocaudal maculopapular rash, which was more common among these children (5 of 6 vs 10 of 75; P<.001). For 3 of these 6 children, a second blood sample was obtained after the convalescence phase, and all 3 seroconverted for HHV-8. CONCLUSIONS: Primary infection with HHV-8 may be associated with a febrile maculopapular skin rash among immunocompetent children. The finding of HHV-8 DNA sequences in saliva supports the hypothesis that transmission through saliva is the main mode of transmission in the pediatric age group.

Antibodies, Viral↗

PubMed2002

Age-related disability in multiple sclerosis.

There is evidence that the clinical course of multiple sclerosis is age related. The present study evaluated the relationship between age and rate of disability progression in a large hospital-based cohort of definite cases of multiple sclerosis (n= 1,463). Patients were followed every 6 to 12 months for a total period of observation of 11,387.8 person-years. Expanded Disability Status Scale scores increased significantly with increasing current age and longer duration of disease (p=0.007). Median times to reach Expanded Disability Status Scale scores of 4.0 and 6.0, assessed using an extended Kaplan-Meier method with age as a categorical time-varying covariate, were significantly longer among patients aged 20 to 35 years compared with patients aged 36 to 50 and 51 to 65 years (p < 0.0001). Significant associations were observed between mean Expanded Disability Status Scale scores and age at disease onset, current age, and the interaction of age at disease onset and current age (p < 0.001). Current age had a greater effect (59% of variability in the model) on disease severity than did age at disease onset. Furthermore, a multiplicative effect on Expanded Disability Status Scale score was observed for age at disease onset and current age combined, indicating a faster rate of disease progression in older patients. In conclusion, the results of the current study demonstrate the impact of age on rate of disability progression in multiple sclerosis and suggest that an age-adjusted progression index may be a more relevant criterion for defining differences between multiple sclerosis groups.

Adult↗

PubMed2002

HIV protease inhibitors are potent anti-angiogenic molecules and promote regression of Kaposi sarcoma.

Treatment with HIV-1 protease inhibitors (PI) is associated with a reduced incidence or regression of Kaposi sarcoma (KS). Here we show that systemic administration of the PIs indinavir or saquinavir to nude mice blocks the development and induces regression of angioproliferative KS-like lesions promoted by primary human KS cells, basic fibroblast growth factor (bFGF), or bFGF and vascular endothelial growth factor (VEGF) combined. These PIs also block bFGF or VEGF-induced angiogenesis in the chorioallantoic membrane assay with a potency similar to paclitaxel (Taxol). These effects are mediated by the inhibition of endothelial- and KS-cell invasion and of matrix metalloproteinase-2 proteolytic activation by PIs at concentrations present in plasma of treated individuals. As PIs also inhibit the in vivo growth and invasion of an angiogenic tumor-cell line, these data indicate that PIs are potent anti-angiogenic and anti-tumor molecules that might be used in treating non-HIV KS and in other HIV-associated tumors.

Angiogenesis Inhibitors↗