A randomized clinical trial assessing immunogenicity and safety of a double dose of virosomal-adjuvanted influenza vaccine administered to unprimed children aged 6-35 months.

This study evaluated the immunogenicity of a double dose of the seasonal virosomal-adjuvanted influenza vaccine (Inflexal V, Crucell, The Netherlands) in 65 previously unvaccinated children aged less than 3 years: 43 received double doses (two doses of 0.50 mL 4 weeks apart) and 22 standard doses (two doses of 0.25 mL 4 weeks apart). Both treatments evoked a response that satisfied the EMEA criteria for adequate immunogenicity for all three vaccine strains, but the double dose had a significantly greater effect on all of the studied parameters of humoral and cell-mediated immune response (p<0.05). This result was achieved without any increase in the incidence of local and systemic adverse events. This means that doubling the dose of the virosomal-adjuvanted influenza vaccine (i.e. administering the same dose as that usually given to older children) effectively and safely increases the immune response to inactivated influenza vaccine in unprimed children aged less than 3 years.

Costimulatory pathways in multiple sclerosis: distinctive expression of PD-1 and PD-L1 in patients with different patterns of disease.

T lymphocytes costimulatory molecules, including CD80, CD86, CD28, CTLA4, PD-1, PD-L1, and B7-H3, are associated with the preferential production of pro- or anti-inflammatory cytokines. We analyzed the expression of these molecules and myelin basic protein (MBP)-specific IL-10 and IFN-gamma production in patients with multiple sclerosis (MS) with relapsing-remitting acute (AMS, n = 40) or stable (SMS, n = 38). Twenty-two patients successfully undergoing therapy with glatimer acetate (n = 12) or IFNbeta (n = 10) were also analyzed. MBP-specific and PD-1-expressing T lymphocytes, PD-L1-expressing CD19(+) cells, and PD-L1(+)/IL-10(+)/CD14(+) and CD19(+) cells were significantly augmented in SMS patients. Additionally, MBP-specific and annexin V-expressing CD4(+) and CD8(+) (apoptotic) T lymphocytes were augmented and pAkt-positive (proliferating) cells were decreased in SMS compared with AMS patients. PD-1 ligation resulted in the increase of pAkt(+) lymphocytes in AMS patients alone. B7-H3 expression and IFN-gamma production were comparable in all individuals but the PD-L1(+)/IL-10(+) over B7-H3(+)/IFN-gamma(+) ratio was significantly lower in AMS compared with SMS patients. Finally, PD-L1 expression on immune cells was reduced in treated patients, suggesting that therapy-induced disease remission is not associated with the modulation of the expression of this molecule. The PD-1/PD-L1 pathway plays an important role in modulating immune functions in MS patients; monitoring and targeting these proteins could offer diagnostic and therapeutic advantages.

T lymphocyte maturation is impaired in healthy young individuals carrying trisomy 21 (Down syndrome).

Cytokine production, immune activation, T lymphocytes maturation, and serum IL-7 concentration were examined in 24 youngsters with Down syndrome and no acquired diseases (healthy Down syndrome [12 prepubertal, 13 pubertal]) and 42 age- and gender-matched controls (20 prepubertal, 22 pubertal). Results showed that a complex immune and impairment is present in healthy individuals with Down syndrome in whom interferon gamma, interleukin (IL) IL-10 production, as well as serum IL-7 concentrations and activation markers-bearing T lymphocytes were significantly augmented. Additionally, a complex skewing of post-thymic lymphocyte maturation pathways was observed in patients: significant reduction of CD4+ and CD8+ naive (RA+CCR7+) lymphocytes, significant increase of CD4+ and CD8+ central memory (RA-CCR7+), and terminally differentiated (TD) (RA+CCR7-) lymphocytes.

FDG-PET imaging in HIV-infected subjects: relation with therapy and immunovirological variables.

PURPOSE: To characterise tissue sites of immune activation and HIV replication we performed FDG-PET in ART-treated and ART-naive HIV-infected individuals. Specific aims were to establish whether HIV-infected patients can be differentiated on the basis of the detection of specific locations of viral replication, even in the presence of an apparently optimal immunovirological response to ART, and whether these FDG-PET findings can be related to immunovirological variables and AIDS history status. PATIENTS AND METHODS: Patients were divided into five groups as follows: subgroup A1 (full responders, n = 8): current ART treatment, CD4+ T lymphocytes >500/mL, viral load <50 copies/mL; subgroup A2 (full responders, n = 5): same criteria as A-1, but with a previous history of AIDS; subgroup A3 (immunological non responders, n = 5): current ART treatment, viral load <50 copies/mL, low CD4+ T lymphocytes (<200/mL); group B (virological non responders, n = 2): current ART treatment, CD4+ T lymphocytes around 500/mL, viral load >50,000 copies/mL; group C (ART-naïve, n = 5): no current or previous ART treatment, increased viral load. RESULTS: PET images revealed different patterns of FDG uptake. All ART-treated patients with either suppressed (<50 copies/mL; Group A) or high viremia (group B) showed a normal pattern of FDG uptake. On the contrary, the ART-naïve subjects with high viraemia (group C) displayed multiple foci of increased glucose metabolism in the lymph nodes. In the ART-naïve subjects, FDG uptake, apparently related to viraemia level, was observed in the upper torso mainly in the axillary nodes bilaterally in patients with viraemia below 100,000 copies/mL; in those with viraemia higher than 100,000 copies/mL, FDG uptake was also observed in the inguinal lymph nodes. CONCLUSIONS: The emergence, in our study, of a correlation between the percentage of CD8+/CD38+/RO+ T cells (well established markers of progression to AIDS independently of CD4+ T lymphocytes) and positive FDG-PET in ART-naive patients is a novel finding that seems to confer prognostic value on FDG uptake. FDG uptake is strongly associated with response to ART independently of a previous AIDS diagnosis. Notably, no differences were observed between ART-treated subjects classed as immunological responders and those classed as non responders. Data herewith indicate that FDG uptake and immunological variables are unrelated when ART is being administered. This is evidence of the complementarity of immunological and FDG measures. FDG uptake is a sensitive marker of disease state and its relation with CD8+/CD38+/CD45RO+ T cells indicates that it can be considered a marker of disease status. The lack of a correlation between FDG uptake and immunological variables in patients under ART warrants further investigation.

Treatment of periodontal disease results in improvements in endothelial dysfunction and reduction of the carotid intima-media thickness.

Several cohort studies reported a relation of cardiovascular events and periodontal disease. In particular, Porphyromonas gingivalis is associated with the development of atherosclerotic plaques. We verified in a longitudinal study whether inflammation biomarkers, endothelial adhesion molecules, leukocyte activation markers, and intima-media thickness could be beneficially modified by periodontal treatment alone. Thirty-five otherwise healthy individuals affected by mild to moderate parodontopathy were enrolled in the study. Echo-Doppler cardiography of the carotid artery, fluorescence-activated cell sorting analyses on lymphocytes and monocytes, and plasma inflammatory indices were evaluated at baseline and at multiple time points after the periodontal treatment. Results showed that inflammation biomarkers were abnormally increased at baseline. Periodontal treatment resulted in a significant reduction of the total oral bacterial load that was associated with a significant amelioration of inflammation biomarkers and of adhesion and activation proteins. Notably, intima-media thickness was significantly diminished after treatment. Inflammatory alterations associated with the genesis of atherosclerotic plaques are detected in otherwise healthy individuals affected by parodontopathy and are positively influenced by periodontal treatment. Reduction of oral bacterial load results in a modification of an anatomical parameter directly responsible for atherosclerosis. These results shed light on the pathogenesis of atherosclerosis and could have practical implications for public health.

Fully immunocompetent CD8+ T lymphocytes are present in autologous haematopoietic stem cell transplantation recipients despite an ineffectual T-helper response.

BACKGROUND: Reduced CD4 T lymphocytes counts can be observed in HIV infection and in patients undergoing autologous haematopoietic stem cell transplantation (ASCT). Nevertheless, whereas opportunistic infections (OI) are frequent in HIV-infected individuals with low cell counts, OI are uncommon in ASCT patients. METHODOLOGY/PRINCIPAL FINDINGS: To verify whether this observation could be secondary to intrinsic HIV-correlated T cell defects, we performed in-depth immunologic analyses in 10 patients with comparable CD4 counts in whom lymphopenia was secondary either to HIV-infection or ASCT-associated immunosuppressive therapy and compared them to age-matched healthy subjects. Results showed the presence of profound alterations in CD4+ T lymphocytes in both groups of patients with respect to healthy controls. Thus, a low percentage of CCR7+ CD4+ T cells and a compensative expansion of CD45RA-CCR7- CD4+ T cells, a reduced IL-2/IFN-gamma cytokine production and impaired recall antigens-specific proliferative responses were detected both in ASCT and HIV patients. In stark contrast, profound differences were detected in CD8+ T-cells between the two groups of patients. Thus, mature CD8+ T cell prevailed in ASCT patients in whom significantly lower CD45RA-CCR7- cells, higher CD45RA+CCR7- CD8+ cells, and an expansion of CCR7+CD8+ cells was detected; this resulted in higher IFN-gamma +/TNFalpha production and granzyme CD8+ expression. The presence of strong CD8 T cells mediated immune responses justifies the more favorable clinical outcome of ASCT compared to HIV patients. CONCLUSION/SIGNIFICANCE: These results indicate that CD8 T cells maturation and functions can be observed even in the face of a profound impairment of CD4+ T lymphocytes in ASCT but not in HIV patients. Primary HIV-associated CD8 defects or an imprinting by an intact CD4 T cell system in ASCT could justify these results.

Humoral and cellular response to influenza vaccine in HIV-infected children with full viroimmunologic response to antiretroviral therapy.

OBJECTIVE: It is unclear whether the ability to respond to vaccines is restored by antiretroviral therapy. We evaluated the influenza-specific immune responses elicited by a virosomal vaccine in HIV-infected children on long-term successful highly active antiretroviral therapy (HAART). METHODS: This was an observational, prospective, open-label study enrolling 24 HIV-infected, HAART-treated (85 months' mean exposure), vaccine-naive children (median age=11.9 years) and 14 age- and gender-matched healthy controls. Mean CD4 T-cell counts (>900 cells/microL) and percentages (>37%) were comparable. The HIV RNA level was <50 copies/mL in all patients. Children received a single dose of trivalent virosome-adjuvanted influenza vaccine. A/H3N2-, A/H1N1-, and B-antigen-specific antibody (Ab) titers and subclasses and vaccine-specific interferon-gamma (IFNgamma)- and interleukin (IL)-2-producing T lymphocytes were analyzed at baseline and 1 and 6 months after immunization. RESULTS: Seroconversion (>or=4-fold Ab titer raise in >40% of patients) and seroprotection (Ab titer>or=1:40 in >70% of patients) was achieved at 1 month in both groups; however, fewer HIV-infected children fulfilled these criteria. The A/H3N2- and A/H1N1-specific Ab geometric mean titers were lower in HIV-infected children compared with healthy controls at 1 and 6 months; interestingly, a boost in vaccine-specific IgG3 T helper 1 type Ab was seen in healthy controls alone. Finally, vaccine specific-IFNgamma- and IL-2-producing T lymphocytes were reduced at both time points in HIV-infected children compared with healthy controls. CONCLUSIONS: One injection of virosomal-adjuvanted influenza vaccine stimulates good immune responses, although the humoral and cellular immune responses are reduced in HIV-infected children compared to healthy children. This indicates that immunologic function impairments may persist upon HIV infection even if HIV-positive viremia is suppressed and immune recovery seems to be achieved.

An immunological comparison of third companion in advanced drug-naive HIV-infected patients.

An immunological comparison of three different third companions (abacavir [ABC], efavirenz [EFV], ritonavir-boosted indinavir [IDVr]) on a backbone of either zidovudine plus didanosine (AZT/ddI) or zidovudine plus lamivudine (AZT/3TC) was performed in 76 HIV-infected, advanced-naive patients. Baseline median CD4 count and viremia were 217/microL and 238,301 copies/mL, respectively. Immunologic parameters were measured at baseline and after months of therapy. By the end of the study, 36 patients (mostly in the protease inhibitor [PI]-containing arms) had dropped out of the study; 22/36 cases of drop out were due to tolerability issues. All regimens resulted in increases in CD4 counts, with the most solid changes seen in patients using ABC as a third companion. Median HIV plasma viremia at month 12 was <50 copies/mL, and viremia was undetectable in 26/38 patients (68%). At the end of the study period, HIV antigen- and mitogen-stimulated proliferation overall was better in patients using either of the PI-boosted third companions. In these patients, the strongest down-modulation of activation marker-bearing cells was also observed. Finally, CD8+/28-/CD45RA+ lymphocytes (effector cells) were increased in all groups of patients with the exception of individuals receiving PI-boosted therapies. Results of this pilot study, although very preliminary, suggest that different combinations of antivirals result in a range of effects on immune cell functions. The clinical implications of these results need to be further analyzed in follow-up studies and in larger cohorts of patients.

Low interleukin-10 production is associated with diabetes in HIV-infected patients undergoing antiviral therapy.

Reduced interleukin-10 (IL-10) production is associated with type 2 diabetes in elderly individuals. Antiviral therapy (ARV)-induced immune modulation results in diminished IL-10 production, and diabetes can be observed in ARV-treated human immunodeficiency virus (HIV)-infected individuals. We analyzed, in a cross-sectional pilot study, HIV-antigen-stimulated IL-10 and tumor necrosis factor alpha (TNFalpha) production, and intracellular concentration (ICC), as well as B7-H1 expression, a marker preferentially presented by IL-10-producing cells, in 20 ARV-treated individuals in whom diabetes did (n=10; diabetes mellitus, DM) or did not (n=10; controls) develop. Pre-ARV glucose, cholesterol, and triglycerides levels, duration of HIV infection and of therapy, exposure to protease inhibitors (PI), HIV plasma viremia, CD4 counts, and nadir were similar in DM and control patients. Results showed that: (1) IL-10 production was lower; (2) IL-10 ICC was reduced; (3) B7-H1-expressing CD19(+) cells were diminished; and (4) TNFalpha production and ICC by CD4(+) T cells was augmented in DM patients. Development of diabetes in HIV infected, ARV-treated individuals could be a response to therapy. Similar to what is observed in elderly individuals, low IL-10 production is associated with diabetes in antiviral-treated HIV infection. Further studies will be necessary to clarify whether low IL-10 is a risk factor for, or a consequence of, diabetes.