Maurizio Carlesimo

Long-term evaluation of T-cell subsets and T-cell function after HAART in advanced stage HIV-1 disease.

OBJECTIVES Evaluation of immunological reconstitution after 2 years of highly active antiretroviral therapy (HAART) in AIDS patients. DESIGN Previous data showed the effectiveness of HAART but conflicting evidence of immune reconstitution has been found in severely immunocompromised patients. Therefore, T-cell subsets and functions were analysed during 24 months of HAART in 21 AIDS patients (mean baseline CD4 cell count, 20 x 10(6)/l). METHODS Subjects were tested at baseline and after 4, 12 and 24 months of therapy for clinical symptoms and the following investigations were carried out: plasma HIV RNA, T-cell subsets and lymphoproliferative responses to mitogens (phytohaemagglutinin, anti-CD3), and recall antigens (Candida mannoprotein, tetanus toxoid and recombinant glycoprotein 160). RESULTS Increase in body weight, improvement of Karnofskys score and reduction of opportunistic infections were observed. All patients showed an initial increase in the CD4 memory subset, whereas naive CD4 cells consistently increased only after 1 year. The magnitude of immune recovery was stronger in patients showing a significant reduction in viral load. However seven out of 21 patients who did not reach a sustained suppression of viral load showed also an increase in T-cell subsets. The majority of patients recovered lymphoproliferative responses to mitogens, whereas only four subjects showed a functional response to Candida mannoprotein. No patients showed a response to HIV recombinant glycoprotein 160 or tetanus toxoid. CONCLUSIONS The immune recovery observed is slower and not complete in severely immunocompromised patients. Our data suggest that HAART may be continued also in the absence of a significant HIV RNA decrease if alternative drugs are not available.

Clinical and Immunologic Response without Decrease in Virus Load in Patients with AIDS after 24 Months of Highly Active Antiretroviral Therapy

This study reports an analysis of clinical, virological, and immunologic outcomes in a cohort of 77 multidrug-experienced AIDS patients during 24 months of highly active antiretroviral therapy (HAART). Our results have shown a reduced risk of AIDS complications, prolonged survival, and immunologic benefit even in the absence of sustained virus suppression. The degree of immunodepression, the risk factors for HIV-1 infection, the use of 2 drugs instead of 3, and a change in protease inhibitor were independently correlated with virological failure. In the majority of studied patients, an increase in CD4+ T cells was observed after HAART. However, the increase was more pronounced in patients who showed a decrease in virus load than in those who did not. Moreover, we observed an absence of relapses among patients who permanently discontinued prophylaxis for Cytomegalovirus retinitis and atypical mycobacterial infections. Peripheral lipodystrophy developed in the majority of patients, regardless of treatment used and virological outcome.

Phase II controlled trial of post-exposure immunization with recombinant gp160 versus antiretroviral therapy in asymptomatic HIV-1-infected adults

Objective:To alter the natural course of HIV-1 infection by inducing or potentiating immune responses to HIV-1 envelope glycoprotein. Design:Multicentre, double-blind, three-arm, placebo-controlled study. Setting:Outpatients attending clinics in two University Hospitals. Patients:Ninety-nine asymptomatic HIV-1-infected adults with CD4+ T-cell counts > 400 and < 600 × 106/l and no previous antiretroviral therapy were included. Interventions:Patients were randomly assigned to three groups treated with: (i) gp160 in alum over a 2-year period in combination with placebo for the full study duration (n = 32); (ii) gp160 in alum over a 2-year period in combination with zidovudine for the full study duration (n = 34); and (iii) alum over a 2-year period in combination with zidovudine for the full study duration (n = 33). Results:Immunotherapy was well tolerated and no significant differences in disease progression were seen in the treatment groups. The majority of patients (85%) receiving gp160 showed persistent lymphoproliferative responses to the immunogen and to a different Env antigen preparation. CD4+ cell count changes in patients receiving zidovudine alone were significantly higher than those seen in patients receiving immunotherapy alone after 1 year of treatment. Zidovudine administration was associated with initial transient reduction of plasma viraemia. Conclusions:Prolonged immunization with a soluble HIV-1 subunit provided no benefit to asymptomatic HIV-1-infected patients and was inferior to zidovudine monotherapy. Furthermore, immunization with gp160 shortened the duration of the transient viral load reduction induced by zidovudine.

HIV-specific lymphoproliferative responses in asymptomatic HIV-infected individuals

In vitro lymphoproliferative responses to HIV‐1 recombinant antigens (gp160, p24, and Rev protein) were studied in 83 patients with asymptomatic HIV‐1 infection (CDC groups 11 and III) and circulating CD4 lymphocyte numbers > 400/mm3. Significant response to at least one of the three antigens was detected in 52.4% of the subjects, but the responses were weak, and concordance of the response to the three antigens was rare, the frequency of individuals responding to each antigen not exceeding 22.4%. Increasing frequencies of response were observed when recall antigens (tetanus toxoid and Candida albicans glycomannoprotein) (65.5%) and anti‐CD3 MoAb (76.6%) were used as stimuli. Although a significant association between lymphocyte response to p24, but not gp160, and steadiness of CD4 lymphocyte numbers before the assay was observed, no predictive value for lack of CD4 cell decrease was confirmed for either antigen, and fluctuation of the responses to HIV antigens was seen during subsequent follow up. The panel of T cell assays used could be regarded as appropriate for monitoring both HIV‐specific responses and T lymphocyte function during immunotherapy with soluble HIV antigens.

Expression of biomarkers of interferon type I in patients suffering from chronic diseases

Interferons (IFNs) are used widely in the treatment of viral infections, tumours and neurological disorders. The aim of this study was to evaluate the endogenous expressions of various IFN‐induced compounds [specifically: neopterin (NPT), beta2microglobulin (β2mg) and 2–5 oligoadenylate synthetase (2–5 OAS)] in patients with various chronic diseases requiring treatment with IFN type I. The results showed that patients with such chronic diseases as hepatitis C virus‐associated type II mixed cryoglobulinaemia (MC), chronic hepatitis C (CHC) and relapsing–remitting multiple sclerosis (RRMS) are characterized by different activations of the IFN system. Furthermore, the interindividual variability in baseline levels of IFN‐induced biomarkers was higher in patients with chronic diseases than in healthy individuals. When levels of the above biomarkers were measured 24 h after the first injection of IFN in patients with CHC or RRMS, significant increases in expression levels of IFN‐induced compounds were recorded but, again, there is a broad range of variability in the degree of increase. Further, a significant inverse correlation between baseline levels of NPT, β2mg and 2–5 OAS activity and their relative increases after IFN administration was found in patients with CHC or RRMS. Together, the results are consistent with the observation that there is considerable interindividual heterogeneity in the clinical response to IFNs, which suggests that host factors other than disease markers must be taken into account in order to manage and optimize the IFN therapy.

CD28 costimulation and T lymphocyte proliferative responses in HIV-1 infection

To investigate whether defective costimulatory signals could be involved in the loss of T lymphocyte functions during HIV‐1 infection, we tested the effect of CD28 costimulation on both T cell receptor/CD3 and HIV‐1 antigen‐induced proliferative responses. Although CD3‐mediated responses significantly decreased with more advanced stages of HIV‐1 infection, the ability of potentiating the responses through CD28 costimulation was maintained at all stages and did not differ from that of HIV‐1− subjects. When CD28 costimulation was studied in lymphocyte cultures stimulated with HIV‐1 gp160 or p24, potentiation was seen only when a significant response was present without additional CD28 triggering, namely in subjects receiving active immunization with recombinant gp160. These results confirm the integrity of the CD28 pathway of costimulation during HIV‐1 infection, and suggest that lymphocytes responding to soluble HIV‐1 antigen are not deleted in HIV‐1‐infected patients, but do not receive significant priming during the natural course of the infection.

Long-Term Evaluation of Cellular Immunity during Antiretroviral Therapy and Immunization with Human Immunodeficiency Virus Type 1 (HIV-1) Env Glycoprotein in HIV-1-Infected Persons

Cellular immune responses to human immunodeficiency virus type 1 (HIV-1) antigens, microbial recall antigens, and CD3 monoclonal antibody were studied in HIV-1-infected asymptomatic patients in a phase II, double-blind trial of immunization with recombinant HIV-1 gp160 in or not in association with zidovudine. A vigorous and persistent lymphoproliferative response (LPR) to HIV-1 Env antigens was observed in vaccinated patients. Neither Env-specific lymphocyte cytotoxicity nor LPR to recall antigens was significantly influenced by gp160 administration. The induction of LPRs to HIV-1 envelope proteins did not show positive effects on the course of HIV-1 infection. Patients treated with zidovudine alone or in combination with the immunogen showed improvement of T lymphocyte responses and transient reduction of viremia. These results suggest that antiretroviral therapy is more beneficial than immunization with gp160 and should always be considered in association with future vaccination and immunotherapeutic interventions in HIV-1-infected subjects.

Influence of inherited and acquired thrombophilic defects on the clinical manifestations of mixed cryoglobulinaemia

OBJECTIVE To investigate the contribution of inherited and acquired thrombophilic defects to the clinical manifestations of mixed cryoglobulinaemia vasculitis. METHODS The following thrombophilic defects were investigated in 64 consecutive patients with HCV-associated mixed cryoglobulinaemia: aPLs, lupus anti-coagulant, homocysteinaemia, protein C and protein S concentrations, activated protein C resistance, plasminogen activator inhibitor-1 4G4G and 5G5G genotypes, and the presence of mutations of factor V (Leiden and H1299R), of prothrombin (G20210A) and of methyl tetrahydrofolate reductase (C677T and A1298C). Additional variables were demographic data, duration of the disease, cryocrit level and vascular risk factors (diabetes, hypertension, hypercholesterolaemia and smoking habit). The following clinical manifestations of mixed cryoglobulinaemia were analysed as dependent covariates: severity of purpura, presence of necrotic skin ulcers, presence of peripheral neuropathy and presence of kidney disease. RESULTS Logistic regression analysis identified hyperhomocysteinaemia as a risk factor for severe purpura (P < 0.0001) and for the presence of skin ulcers (P < 0.0001), whereas none of the other thrombophilic defects influenced the clinical presentation of mixed cryoglobulinaemia. Purpura improved in two patients after lowering homocysteine with vitamin supplementation. CONCLUSIONS Hyperhomocysteinaemia may be a risk factor for severe cutaneous manifestations in mixed cryoglobulinaemia.