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Biomedical subjects

A Lazzarin

Publications and source records attributed to A Lazzarin.

At least 163 records · Page 9Linked to original sources

Transitory expansion of a CD3+TcR gamma/delta+CD16+ lymphocytic population in two patients with advanced human immunodeficiency virus infection and high levels of natural killer activity.

In the present study, we describe an expansion of CD16+ cells with a CD3+ TcR gamma/delta+ phenotype, in the presence of normal numbers of "classic" CD3-CD16+ natural killer (NK) cells, in two patients with human immunodeficiency virus (HIV) infection in late stage. The NK activity of the two subjects was substantially higher then that of HIV+ subjects in the same stage of infection. A second evaluation of one of the patients showed levels of NK activity consistent with the clinical stage of HIV infection, concomitant with a remarkable reduction in the percentage of double-positive CD3/TcR gamma/delta cells. The number of CD16+ cells also reached values comparable to those of the control group. In conclusion, we have identified a population of CD3+TcR gamma/delta+CD16+ cells that have the capability to lyse an NK-sensitive target in two patients with unusually high levels of NK activity.

Acquired Immunodeficiency Syndrome↗

The efficiency of male-to-female and female-to-male sexual transmission of the human immunodeficiency virus: a study of 730 stable couples. Italian Study Group on HIV Heterosexual Transmission.

To compare the efficiency of male-to-female and female-to-male sexual transmission of human immunodeficiency virus (HIV), we studied 524 female partners of HIV-infected men and 206 male partners of HIV-infected women in 16 Italian clinical centers. All of the partners had had a sexual relationship with the index case lasting for at least 6 months and presented no other risk factor than sexual exposure to the HIV-infected partner. Among the 730 couples, 24% of the female partners were HIV positive, in comparison with 10% of the male partners. Using logistic regression analysis, including gender and controlling for condom use, frequency of intercourse, anal sex, partner's CD4+ cell count and clinical stage, sexually transmitted diseases, genital infections, and contraceptive use, we found that the efficiency of male-to-female transmission was 2.3 (95% confidence interval = 1.1-4.8) times greater than that of female-to-male transmission. Between-gender differences in the contact surfaces and the intensity of exposure to HIV during sexual intercourse are possible reasons for the difference in efficiency of transmission.

Acquired Immunodeficiency Syndrome↗

TH1 and TH2 cytokine production by peripheral blood mononuclear cells from HIV-infected patients.

OBJECTIVE: To study the TH1-->TH2 cytokine switch, thought to occur during the progression of HIV infection. DESIGN: We investigated interleukin (IL)-2, interferon (IFN)-gamma, IL-4, IL-6 and IL-10 production by phytohaemagglutinin (PHA)-stimulated and unstimulated peripheral blood mononuclear cell (PBMC) cultures from HIV-negative controls and HIV-positive subjects, stratified according to the Centers for Disease Control and Prevention (CDC) criteria. We correlated the above parameters with markers of disease progression. METHODS: Cytokine production was measured in supernatants using enzyme-linked immunosorbent assay (ELISA) in 40 patients and 17 controls. To evaluate disease progression, we also determined CD4+ cell counts, PHA-induced proliferative response, p24 release and spontaneous immunoglobulin (Ig) G and IgM production. RESULTS: In agreement with the TH1-->TH2 switch hypothesis, we found that in the course of HIV disease mitogen-stimulated IL-2 production decreased, spontaneous and stimulated IL-6 production and spontaneous IL-10 secretion increased; IL-4 showed an increasing trend, although it was reduced in HIV-positive subjects. Finally, immunoglobulin production increased over time. In contrast, mitogen-stimulated IFN-gamma and IL-10 production did not change among the CDC categories, although the former decreased and the latter increased in comparison with HIV-negative controls. CONCLUSIONS: Our data partially agree with the TH1-->TH2 switch hypothesis. Since IL-6 and IL-10 are produced by different cell types, whose proportions and functional features vary in the course of the disease, further experiments with purified lymphocyte subsets and monocytes are required. Nevertheless, as already suggested, we believe that a switch from a type 1 to a type 2 response occurs in HIV infection.

Adult↗

Polymerase chain reaction for Toxoplasma gondii DNA in the cerebrospinal fluid of AIDS patients with focal brain lesions.

OBJECTIVE: To study the accuracy of polymerase chain reaction (PCR) for Toxoplasma gondii DNA in the cerebrospinal fluid (CSF) of AIDS patients for the diagnosis of T. gondii encephalitis. PATIENTS: Eighty-two AIDS patients with brain lesions. At autopsy, 19 patients (group A) had toxoplasmic encephalitis and 33 (group B) primary brain lymphoma or other infections. Brain histology was not available for 30 patients; cerebral lesions improved after anti-Toxoplasma therapy in 16 (group C), but there was no improvement in 14 patients (group D). METHODS: T. gondii RH strain was serially diluted in microplate wells. After heat denaturation, nested PCR was performed on diluted tachyzoites and on 10 microliters CSF with primers flanking the B1 repetitive region of T. gondii genome. RESULTS: DNA from one to five tachyzoites was detected in each experiment. PCR was positive in eight (42.1%) out of 19 group A samples, none of the group B samples, 10 (62.5%) out of 16 group C samples and none of the group D samples. Among group A and C patients, PCR was positive in all 11, and in seven out of 24 (29.1%; P < 0.04) patients who had received anti-Toxoplasma therapy for less or more than 1 week at the time of rachicentesis, respectively. CONCLUSIONS: Nested PCR for T. gondii in CSF may improve early differential diagnosis of AIDS-associated focal brain lesions. Higher diagnostic accuracy was achieved when lumbar puncture was performed in the first week of anti-Toxoplasma therapy.

AIDS-Related Opportunistic Infections↗

Fc receptors expression and function in mononuclear phagocytes from AIDS patients: modulation by IFN-gamma.

Fc-receptor (FcR)-mediated phagocytosis and FcR (FcRI, FcRII and FcRIII) membrane expression was studied on freshly separated and cultured monocytes (Mo) from 20 AIDS patients and 20 healthy controls. Both Mo and Mo-derived macrophages from AIDS patients presented a significant defect in their capacity to ingest IgG-coated erythrocytes (EA) compared to control cells. This functional defect did not depend on a decline in the number of FcR+ cells or on a decrease in the expression of FcR on their surface. In fact, the percentages of phagocytes reacting with anti-FcRI MoAb (32.2) or anti-FcRII MoAb (IV.3) were similar for controls and AIDS patients, while the percentage of FcRIII-positive Mo (MoAb 3G8) was higher in the AIDS population than in controls, though this difference was not seen on cultured Mo. The level of FcRI expression, evaluated as mean fluorescence intensity (MFI), was higher on freshly separated Mo from AIDS patients than from controls but this difference disappeared also with differentiation of Mo to Mo-derived macrophages in vitro. Parallel analysis of FcRII and FcRIII on phagocytes revealed no differences in the MFI between the AIDS and control groups. Some observations suggested that this functional defect might be secondary to phagocyte priming by circulating IFN-gamma: (1) in vitro stimulation of Mo with hrIFN-gamma, which increased FcRI expression, actually reduced phagocytosis of IgG-coated particles; and (2) IFN-gamma concentrations were increased in AIDS patients' plasma. In spite of these findings, no significant correlation was found between plasma IFN-gamma concentrations and FcR-mediated ingestion in AIDS patients, making the hypothesis uncertain. Even if the basis for the impaired FcR-mediated phagocytosis in AIDS patients remains unclear, this functional defect may have a role in the immunopathogenesis of AIDS, constituting a component cause of the immunodeficiency.

Acquired Immunodeficiency Syndrome↗

Severe abdominal pain in patients with AIDS: frequency, clinical aspects, causes, and outcome.

BACKGROUND: The exact prevalence of abdominal pain in AIDS patients, as well as the entire spectrum of causative disorders, has not yet been well defined. In addition, the existing data derive almost exclusively from surgical series describing only those patients who have undergone emergency surgical procedures. METHODS: We reviewed our experience with patients presenting with severe abdominal pain from a large series of non-selected consecutive AIDS patients seen at our institution over a period of 4 years. RESULTS: Of 458 patients, 71 (15%) had severe abdominal pain, and its occurrence was associated with a reduced patient survival. Specific diagnoses were made premortem in 42 patients (59%), potential causes of pain were identified at postmortem examination in 23 patients (33%), whereas no specific causes were found in 6 patients (8%). Most of the causative disorders (65%) were AIDS-related, whereas HIV-independent pathologic conditions were found in only 18% of the patients. The predominant site of pain, combined with a few key symptoms, had a high predictive diagnostic value in nearly half of the patients. The indications for emergency laparotomy were limited and substantially similar to those of the non-HIV population. CONCLUSIONS: Severe abdominal pain frequently complicates the course of AIDS, and its occurrence is associated with reduced survival. In most patients it is due to disorders closely associated with the HIV infection. Specific causes of pain may be identified in most of the cases by an appropriate diagnostic evaluation.

AIDS-Related Complex↗

Risk factors for woman-to-man sexual transmission of the human immunodeficiency virus. Italian Study Group on HIV Heterosexual Transmission.

A cross-sectional study of stable monogamous couples, recruited from 16 clinical and surveillance centers in Italy between 1987 and 1992, was carried out to investigate the risk factors of woman-to-man sexual transmission of human immunodeficiency virus (HIV). The male partners of all HIV-infected women attending the centers were invited to participate in the study. Of the 275 male partners who were tested for HIV and interviewed with use of a structured questionnaire, 51 were excluded because they had other possible risk factor for HIV infection, no established risk factor was found in the index case, or they had stopped engaging in sexual intercourse. Fourteen of the 224 men (6.3%) were seropositive for HIV. At logistic regression, the highest risks of transmission were for men practicing peno-anal intercourse [odds ratio (OR), 4.6; 95% confidence interval (CI), 1.0-22.2] and for men whose partner had acquired immune deficiency syndrome (AIDS) or a CD4+ lymphocyte count of < or = 400/mm3. No seropositive men were observed among those who were aware of the woman's HIV seropositivity since the beginning of the relationship or were partners of a zidovudine-treated woman. The results suggest that the risk factors described in man-to-woman and man-to-man HIV sexual transmission also operate in woman-to-man transmission.

Adult↗

Prevention of symptomatic recurrences of esophageal candidiasis in AIDS patients after the first episode: a prospective open study.

OBJECTIVES: To evaluate the efficacy and safety of low-dose antifungals as prophylaxis of recurrent esophageal candidiasis after the first episode in patients with AIDS. METHODS: After the first episode of esophageal candidiasis, 122 consecutive AIDS patients were randomly assigned to two different regimens of continuous long-term antifungal prophylaxis (ketoconazole 200 mg or fluconazole 50 mg/day p.o.) or no antifungal therapy over a period of 2 yr. Patients were followed up by monthly clinical controls and upper GI endoscopy in the case of recurrence of esophageal symptoms. RESULTS: One hundred and six patients were clinically evaluable over a mean observation time of 7.5 months. Prophylaxis with oral antifungals significantly reduced symptomatic relapses of esophageal candidiasis, the cumulative probability of relapse at 12 months being 38% in the prophylaxis group, compared with 84% in the untreated group. Both antifungals were sufficiently safe and well tolerated. The clinical response of a second episode of candidiasis to the reintroduction of standard oral antifungals was markedly worse in patients on prophylaxis (especially with ketoconazole) than in untreated patients, presumably due to the development of resistance to the antifungal. CONCLUSIONS: Continuous prophylaxis with both-fluconazole and ketoconazole is effective in preventing recurrences of Candida esophagitis in AIDS patients; however, the possible emergence of strains resistant to these antifungals, as well as the high cost of the therapy, should raise doubts as to whether or not this type of prophylaxis should be extended to all AIDS patients with Candida esophagitis, rather than to limit its use to specific subgroups of patients, such as those with frequent symptomatic relapses.

AIDS-Related Opportunistic Infections↗

Understanding the dynamics of the HIV epidemic among Italian intravenous drug users: a cross-sectional versus a longitudinal approach.

We studied annual human immunodeficiency virus (HIV) seroprevalence and incidence in a large number of intravenous drug users attending drug treatment centers in three Italian urban areas. We also evaluated risk factors for HIV seropositivity and for HIV seroconversion. The results showed that HIV prevalence and incidence are declining. HIV prevalence declined dramatically in study participants that were < 25 years old. Prevalent HIV cases were associated with older age and longer duration of intravenous drug use; however, short duration of drug use increased the risk of seroconversion. The findings of our study suggest that comparing cross-sectional and longitudinal data contributes to a better understanding of the dynamics of the HIV epidemic among intravenous drug users.

Adult↗

Epstein-Barr virus DNA in cerebrospinal fluid from patients with AIDS-related primary lymphoma of the central nervous system.

Epstein-Barr virus (EBV) is constantly associated with AIDS-related primary lymphomas of the central nervous system (CNS). To assess whether EBV DNA in cerebrospinal fluid (CSF) could be used as a tumour marker, CSF samples that had been taken within 180 days before death from 85 patients with HIV infection and neurological disorders at necropsy were examined retrospectively by nested polymerase chain reaction (PCR) for EBV. Histologically evident primary CNS lymphomas were found in 17 patients, and EBV was shown in tissue by in-situ hybridisation in 16 of the 16 cases examined. All 17 patients with primary CNS lymphoma had EBV DNA in CSF. EBV DNA was found in CSF from 1 of 68 HIV-infected patients without histologically detectable lymphoma at necropsy. PCR for EBV DNA in CSF was 100% sensitive and 98.5% specific for AIDS-associated primary CNS lymphoma, and may be useful as a diagnostic tumour marker.

Base Sequence↗

Discrete regions of HIV-1 gp41 defined by syncytia-inhibiting affinity-purified human antibodies.

OBJECTIVE: Fine mapping of HIV-1 gp41 fusion-critical sites. DESIGN AND METHODS: Antibodies from human HIV-1-positive sera were affinity-purified on a panel of synthetic overlapping peptides spanning residues 526-682 of the extracellular portion of HIV-1 gp41. The syncytium-inhibiting capacity of the immunopurified antibodies and their differential reactivity on the synthetic peptides were tested. RESULTS: This approach enabled the identification of residues 583-591 (ARILAVERY), 595-599 (QQLLG), 603-609 (CSGKLIC) and 664-673 (ELLELDKWAS) as possibly involved in the fusion process. Reduction in the anti-ARILAVERY, anti-CSGKLIC and anti-ELLELDKWAS antibody titres and frequencies correlates with disease progression. Syncytia-inhibition capacity of sera did not correlate with the presence of high-titre antibodies reacting with any of the peptides tested, suggesting that most fusion-affecting antibodies are not directed towards gp41. CONCLUSIONS: This strategy may be relevant for understanding the contribution of anti-gp41 antibodies in protecting against the pathogenic effects of the virus and in the design of an effective env vaccine.

Amino Acid Sequence↗

Comparison of two dose regimens of zidovudine in an open, randomized, multicentre study for severe HIV-related thrombocytopenia.

OBJECTIVE: To compare the effect of two dose regimens of zidovudine in the treatment of severe HIV-related thrombocytopenia (TP). DESIGN: Eighty-four patients with severe HIV-related TP and platelet counts < 50 x 10(9)/l were enrolled in an open study at six centres. Patients were randomized into two groups to receive zidovudine (group A, 500 mg per day; group B, 1000 mg per day) for 6 months. METHODS: Platelet counts were determined monthly and patients categorized as complete responders (CR; platelets > 100 x 10(9)/l), partial responders (PR; platelets > 50 to < 100 x 10(9)/l), or failures (F; platelets to < 50 x 10(9)/l). CD4+ and CD8+ lymphocytes, HIV antigenaemia, beta 2-microglobulin, white blood cells, mean cell volume and haemoglobin were also determined. RESULTS: Seventy-one patients (35 and 36 in groups A and B, respectively) completed the study; 11.4% of group A patients were CR and 45.7% PR; 38.9% of group B were CR and 33.3% PR. Increase in mean platelet counts was dose-related, more rapid in the higher dose group and remained significantly higher after 6 months of treatment (56.4 x 10(9)/l in group A versus 98.2 x 10(9)/l in group B; P < 0.01). CONCLUSIONS: The results confirm the efficacy of zidovudine in the treatment of severe HIV-related TP. The average for CR and PR in the two groups was 64.8%; the higher dose of zidovudine was more effective at increasing platelet counts.

Adult↗

Long-term treatment with zidovudine in patients with human immunodeficiency virus (HIV)-associated thrombocytopenia: modes of response and correlation with markers of HIV replication.

The effects of zidovudine on the platelet count were studied in 152 patients with HIV-related thrombocytopenia of severe grade (platelet count < 50 x 10(9)/l) and moderate grade (platelet count < 100 and > 50 x 10(9)/l). In both groups of patients there was a significant increase in the mean platelet count from the baseline value, after 2 weeks (from 21 x 10(9)/l to 48 x 10(9)/l and from 75 x 10(9)/l to 97 x 10(9)/l) and 3 months of therapy (to 59 x 10(9)/l and to 144 x 10(9)/l). Sixty-five and 39 patients were followed up for 12 and 18 months, respectively, and the mean platelet values after 12 and 18 months of therapy were still significantly increased, compared to the respective mean baseline values, in both groups of patients. Clinical progression of the disease was observed in 23 treated patients, none of them showing concomitant reductions of the platelet number. An increase in the mean CD4+ cell count after 3 months of therapy was followed by a progressive decline in the 65 patients with a 12-month follow-up, while no significant changes of the p24 antigenemia rates were observed after 1 year of therapy in 53 patients evaluated. The long-term effects of zidovudine on the platelet count, but not on other parameters of clinical outcome, might be explained by the involvement of specific mechanisms in the pathogenesis of this kind of thrombocytopenia and of its response to zidovudine.

Acquired Immunodeficiency Syndrome↗

Autoantibodies against beta 2-microglobulin-free HLA antigens in AIDS patients.

Serum samples from 88 human immunodeficiency virus (HIV)-positive drug addicts have been investigated for the presence of antibodies to both beta 2-microglobulin (beta 2m)-free and beta 2m-associated HLA class I molecules. Using HIV-negative drug addicts as background control, we found that none of the Centers for Disease Control (CDC) stage II, 9.1% of CDC III, 36.4% of CDC IV A, and 45.5% of CDC IV C1 patients had significant levels of autoantibodies competing with the binding of the monoclonal antibody specific for beta 2m-free HLA I (L31 mAb). Using the mAb 01.65, recognizing the beta 2m-associated form of HLA class I molecules, a similar percentage of positive samples was found in the CDC II, CDC III, and CDC IV A patient groups; conversely, the percentage of positive serum samples was lower in the CDC IV C1 group. A lower number of systemic lupus erythematosus serum samples and none of the specimens from healthy adult subjects or patients suffering from recurrent Epstein-Barr virus infections were positive in both assays. Our data demonstrate the existence of an ongoing HLA class I-specific autoimmune response during AIDS disease development, which probably reflects a molecular mimicry between autologous histocompatibility antigens and HIV components. The relationship between the prevalence of autoantibodies against beta 2m-free HLA class I and disease progression suggests a possible pathogenetic role of these antibodies in the induction of the HIV-associated immune deficiency.

Acquired Immunodeficiency Syndrome↗

Reduced frequency of HIV-induced brain lesions in AIDS patients treated with zidovudine.

We evaluated the effect of zidovudine on HIV-induced lesions of the brain by comparing the neuropathological findings in 82 treated and 120 untreated patients who died from AIDS. We observed a statistically significant reduction of the number of cases with multinucleated giant cells (MGCs) in the brain and MGC-associated neuropathological damage in patients treated with zidovudine. The effects of zidovudine were time and dose related in the first 12 months of treatment, while longer periods of therapy produced no further results. The antiretroviral treatment particularly affected the frequency of diffuse demyelinating lesions of the cerebral white matter. In the patients who died with HIV-induced brain lesions but no other opportunistic brain diseases, the percentage of cases with clinical history of severe dementia was significantly lower in the group treated with zidovudine.

AIDS Dementia Complex↗

[Solid tumors associated with HIV infection].

Between December 1986 and December 1991, the Italian Cooperative Group on AIDS-related tumours documented 94 HIV related solid tumours. Of 21 germinal testicular tumours collected, ten were seminomas. Cervical carcinoma was observed observed in 28 IVDAs (intraepithelial in 8 and advanced, with rapid progression, in one). Lung cancer associated with HIV infection was reported in 14 patients. Also reported were two cases of colorectal carcinoma, one anorectal carcinoma, one pancreatic carcinoma, one carcinoid, one oral carcinoma. Of the central nervous system tumours, were diagnosed 3 cases of glioblastomas, one medulloblastoma and one meningioma. This retrospective study shows that while oral and anorectal tumours were very rarely observed, a wide spectrum of other HIV-related solid tumours were found in this series. The required therapeutic approaches may not necessarily be influenced by the HIV infection, in contrast with the observed pattern for treatment of EKS and lymphomas in HIV infected subjects.

Adult↗

Parenteral and sexual transmission of human immunodeficiency virus in intravenous drug users: a study of seroconversion. The Northern Italian Seronegative Drug Addicts (NISDA) Study.

To evaluate the role of parenteral and sexual transmission of human immunodeficiency virus, we studied seronegative intravenous drug users recruited from 25 drug dependence treatment centers in northern Italy. All attending intravenous drug users were asked for their consent and screened for antibodies to human immunodeficiency virus; those who were seronegative were enrolled, interviewed about their habits, and invited to follow-up visits. Between 1987 and 1989, 1,195 seronegative intravenous drug users were enrolled, 635 were followed up (mean duration, 11.9 months), and 35 seroconversions were observed. The incidence rate ratios were 3.3 (95% confidence interval (CI) 1.4-7.5) for subjects aged less than 20 years, 2.4 (95% CI 1.2-4.7) for less than 2 years of intravenous drug use, 2.2 (95% CI 0.9-5.5) for syringe sharing, and 1.0 for subjects with a sexual partner who had tested positive for human immunodeficiency virus. A case-control approach, using logistic regression and adjusting for sex, age, area, and prevalence, showed odds ratios of 13.2 (95% CI 3.1-56.8) for frequent syringe sharing and 4.0 (95% CI 1.5-10.4) for sexual contacts with seropositive partners; frequent use of condoms was associated with a reduction in risk that did not reach statistical significance. Parenteral transmission is the most important route of infection with the human immunodeficiency virus among intravenous drug users, and sexual transmission plays a relevant, additive role.

Adult↗