A controlled trial of nevirapine plus zidovudine versus zidovudine alone in p24 antigenaemic HIV-infected patients. The Dutch-Italian-Australian Nevirapine Study Group.

OBJECTIVES: Nevirapine is a non-nucleoside reverse transcriptase inhibitor of HIV-1 which exhibits synergy in vitro with zidovudine (ZDV) and also is active against ZDV-resistant HIV. We evaluated the activity and safety of nevirapine in combination with ZDV in patients receiving long-term ZDV therapy. METHODS: We conducted a randomized, open-label, controlled 28-week study of nevirapine (200 mg daily for 2 weeks followed by 200 mg twice daily for 26 weeks) and continued ZDV (500-600 mg daily) versus continued ZDV alone in 49 HIV-1 p24 antigenaemic patients with CD4+ lymphocyte counts < 500 x 10(6)/l and who had been treated with ZDV for at least 6 months. RESULTS: Addition of nevirapine to ZDV resulted in a significant and rapid reduction in circulating RNA load (mean, 0.65), a mean CD4+ lymphocyte rise of 34 x 10(6)/l, a reduction in serum beta 2-microglobulin and a median fall in immune complex dissociated p24 antigen levels of 69%. These changes remained statistically significant for 4, 4, 12 and at least 28 weeks, respectively. The principal adverse event due to nevirapine was a hypersensitivity reaction comprising rash with or without fever and mucositis in eight (32%) patients, which was dose-limiting in seven patients. CONCLUSION: Nevirapine exhibits significant although transient anti-HIV activity in ZDV-pretreated patients but its use is frequently associated with a hypersensitivity reaction.

Cerebrospinal fluid antiganglioside antibodies in patients with AIDS.

In this study the presence of brain antiganglioside antibodies in the cerebrospinal fluid (CSF) of patients with HIV infection was analysed. CSF samples were collected from 45 patients with AIDS and from 45 anti-HIV negative subjects, 15 of whom presented aseptic meningitis. Nineteen AIDS patients had clinically well-documented encephalopathy. Thirteen of these patients had white matter lesions shown by magnetic resonance imaging (MRI). Both IgG and IgM antiganglioside antibodies were detected by immunostaining on thin layer chromatography plates in three CSF samples from AIDS patients with progressive encephalopathy with signs of a diffuse demyelination, as revealed by MRI. Two of these CSF samples reacted specifically with GM3, GM1 and GD1a and one with GD1a. In none of the HIV infected patients without demyelinating encephalopathy, but with opportunistic infections or cerebral lymphoma, nor in the anti-HIV negative control subjects were antiganglioside antibodies detected. No association with JCV DNA, CMV DNA, EBV DNA, detected by nested PCR, nor HIV antigen p24 was found. These findings show the presence of brain antiganglioside antibodies in the CSF of AIDS patients for the first time. However, the findings do not suggest relating the presence of these antibodies to HIV encephalopathy or particular viral agents, but indicate that the antibodies are detectable in subjects with progressive encephalopathy with a diffuse demyelination.

High cerebrospinal fluid and serum levels of tumor necrosis factor-alpha in asymptomatic HIV-1 seropositive individuals. Correlation with interleukin-2 and soluble IL-2 receptor.

The relationship between tumour necrosis factor-alpha (TNF-alpha) and the interleukin-2 (ILL-2) system in HIV-1 infection is important in understanding the dynamics of early immune response before the development of acquired immunodeficiency syndrome. Levels of TNF-alpha, IL-2 and soluble IL-2 receptor (sIL-2R) in serum and cerebrospinal fluid (CSF) samples from 31 asymptomatic HIV-1 seropositive individuals were measured. High levels of TNF-alpha were detected in CSF of 17 (55%) and serum of 22 (71%) subjects, 15 (88%) of whom had elevated CSF IL-2 levels and 16 (94%) had high sIL-2R levels. Moreover, CSF levels of TNF-alpha significantly correlated with CSF levels of IL-2 and sIL-2R. TNF-alpha, IL-2 and sIL-2R seem to be released within the intrathecal compartment early in the course of HIV-1 infection. In view of the known cytotoxic effects of TNF-alpha, an early release may contribute to subsequent development of neurological complications.

Tumour necrosis factor-alpha mediates blood-brain barrier damage in HIV-1 infection of the central nervous system.

The pathogenesis of brain inflammation and damage by human immunodeficiency virus (HIV) infection is unclear. Because blood-brain barrier damage and impaired cerebral perfusion are common features of HIV-1 infection, we evaluated the role of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in mediating disruption of the blood-brain barrier. Levels of TNF-alpha were more elevated in cerebrospinal fluid (CSF) than in serum of HIV-1 infected patients and were mainly detected in those patients who had neurologic involvement. Intrathecal TNF-alpha levels correlated with signs of blood-brain barrier damage, manifested by high CSF to serum albumin quotient, and with the degree of barrier impairment. In contrast, intrathecal IL-1beta levels did not correlate with blood-brain barrier damage in HIV-1 infected patients. TNF-alpha seems to be related to active neural inflammation and to blood-brain barrier damage. The proinflammatory effects of TNF-alpha in the nervous system are dissociated from those of IL-1beta.

Free circulating ICAM-1 in serum and cerebrospinal fluid of HIV-1 infected patients correlate with TNF-alpha and blood-brain barrier damage.

The mechanism for the initiation of blood-brain barrier damage and intrathecal inflammation in patients infected with the human immunodeficiency virus (HIV) is poorly understood. We have recently reported that tumour necrosis factor-alpha (TNF-alpha) mediates active neural inflammation and blood-brain barrier damage in HIV-1 infection. Stimulation of endothelial cells by TNF-alpha induces the expression of intercellular adhesion molecule-1 (ICAM-1), which is an important early marker of immune activation and response. We report herein for the first time the detection of high levels of free circulating ICAM-1 in serum and cerebrospinal fluid of patients with HIV-1 infection. Free circulating ICAM-1 in these patients correlated with TNF-alpha concentrations and with the degree of blood-brain barrier damage and were detected predominantly in patients with neurologic involvement. These findings have important implications for the understanding and investigation of the intrathecal inflammatory response in HIV-1 infection.

HBV and HIV expression in lymph nodes of HIV positive LAS patients: histology and in situ hybridization.

The presence of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) was investigated using hybridization in 15 lymph nodes and one Kaposi's sarcoma skin lesion obtained from HIV-positive patients. Cryostat tissue sections were hybridized with chemically modified DNA probes for HBV and HIV. HIV genome was mainly observed in the cytoplasm of cells present in 7/15 lymph nodes and in the Kaposi's sarcoma skin lesion, thus indicating the expression of HIV replication. Control samples hybridized with an HTLV I probe were negative. HBV genome was found in the cytoplasm of lymphoid mononuclear cells in 2/7 lymph nodes, obtained from HIV+ patients without serum markers of ongoing HBV infection. Lymph node positivity for HBV DNA also confirms that lymphoid cells may be a target for HBV. Since HBV infection seems to precede HIV infection in nearly all patients, it is possible that it may represent a factor facilitating the development of the HIV-related disease.

Influence of methisoprinol (isoprinosine) on HIV-infected human lymphocytes: in vitro immunological, virological, and ultrastructural studies.

Methisoprinol (isoprinosine) is a synthetic compound with reported antiviral and immunomodulating properties. Results of the present study showed that methisoprinol at concentrations greater than or equal to 200 micrograms/ml reduces the p24 and gp120 viral antigen expression on the surface of human immunodeficiency virus (HIV)-infected lymphocytes and the reverse transcriptase levels. In addition, cell viability, the number of the CD4+ cells, and the CD4+/CD8+ cell ratio are higher in methisoprinol-pretreated cell suspensions than in untreated HIV-infected cell cultures. A quantitative freeze-fracture study on the density of the intramembranous particles (IMP) present on both fracture faces of the plasma membrane of lymphocytes has shown that pretreatment with methisoprinol induces a different molecular organization resulting in a nearly three times increase of IMP density.

[Blood antigens and specific anti-core and anti-envelope antibodies as markers of the course of HIV infection]. / Antigenemia ed anticorpi specifici anti-core ed anti-envelope quali markers di evoluzione dell'infezione da HIV.

The antigenemia and the patterns of antibodies to core protein (p24) and envelope glycoproteins (gp41, gp120) have been investigated in 81 patients with Human Immunodeficiency Virus (HIV) infection followed prospectively for 24 months. HIV antigen was detectable in 23 (28.4%) patients at entry to the study (13/13 with AIDS and 10/23 with ARC) and in 33 (40.7%) at the end (25/28 with AIDS, 5/12 with ARC e 3/14 with LAS). Anti-p24 were positive in 51 (63.0%) patients at the entry (26/30 symptomless, 13/15 with LAS e 12/23 with ARC) and in 41 (50.6%) at the end of the study (23/27 symptomless, 9/14 with LAS, 7/12 with ARC e 2/28 with AIDS). All patients were positive for anti-gp41 and showed no significant changes in the antibody titers during the two years of follow-up; by contrast, anti-gp120 was undetectable in most patients (26/28) with AIDS. Clinical progression in a high proportion of patients was associated with the appearance of HIV antigen, with the decline of anti-p24 titers and with no antibody reactivity to gp120 glycoprotein.

[Significant bacteriological findings in HIV-positive patients]. / Dati batteriologici significativi in soggetti HIV positivi.

Twenty-four episodes of bacterial infections were identified over a 18 month period in 11 patients (8 with acquired immunodeficiency syndrome and 3 with AIDS related complex). Eight of the 11 infected patients were drug abusers and 3 homosexual people. Nosocomial bacterial infections were common in patients with AIDS and had high fatality rates. Gram-negative bacteria resulted the most common micro-organisms (E.coli, Proteus, Enterobacter, Serratia, Klebsiella). The Aztreonam treatment was very useful in providing bacteria eradication. Gram-positive bacteria as Staphylococcus from a sepsis and Enterococcus from a cystopyelitis were eradicated by B-lactam antibiotics. Common micro-organism are frequent in patients affected by LAS/ARC or AIDS and they negatively interfere with the disease outcome.

Pharmacokinetics of zidovudine and concomitant inosine-pranobex in AIDS patients.

3'-azido-3'-deoxythymidine (AZT) was administered orally to 8 AIDS patients at a dose of 100 mg every 6 hours for 14 days. On days 8 - 14 the patients were also given 1 g inosine-pranobex (INPX) every 6 hours. On day 7, while the subjects were taking AZT alone and on day 14 while they were receiving AZT + INPX, blood samples were obtained over a 6-hour dosing interval for measurement of AZT by a specific AZT radioimmunoassay. AZT levels on day 14 were significantly higher than the corresponding levels on day 7, resulting in a 2-fold increase of the area under the serum concentration-time curve (AUC) and a prolongation of the mean half-life of AZT (44 to 70 min) during the INPX treatment. INPX is an immunomodulatory drug with an inhibitory effect on HIV. The potential advantages of a combined treatment AZT + INPX are: 1) need for lower dose of AZT for maintaining a therapeutic anti-retroviral level; 2) a longer interval period between AZT treatments; 3) a potential to enhance immunological response resulting from INPX treatment; 4) reduced costs of care for patients.

In situ hybridization of human immunodeficiency virus (HTLV-III) in cryostat sections of lymph nodes of lymphadenopathy syndrome patients.

The presence of human immunodeficiency virus (HIV, or HTLV-III) genome sequence was investigated by means of in situ hybridization in cryostat sections of lymph nodes from lymphadenopathy syndrome (LAS) patients. The technique employed involved the modification of the DNA probe by chemical insertion of an antigenic sulfone group in cytosine moieties and the visualization of DNA by a double-antibody immunohistochemical reaction. The hybrid formation was revealed in five out of ten cases: in all positive samples, HIV was mainly observed in the cytoplasm of lymph node cells. The method of in situ hybridization described in the present paper is specific and has some advantages if compared with other techniques based on the use of DNA probes labelled with radioisotopes or biotin by nick translation.

Eosinophil-mediated cellular cytotoxicity induced by zymosan-activated serum.

The aim of the present work was to develop an in vitro model of eosinophil cytotoxicity which mimics numerous in vivo situations characterized by complement activation through the alternative pathway. Our results demonstrate that eosinophilic granulocytes from patients with parasitic diseases and blood eosinophilia were able to damage chicken red blood cells when incubated with zymosan-activated serum (ZAS) as assessed by a 51Cr release assay. The phenomenon was independent of the presence of antibodies directed against the target cells and related to the quantity of ZAS added to the wells. As target cell lysis is totally or partially inhibited by catalase, sodium azide and potassium cyanide, an involvement of toxic oxygen derivatives as cytolytic mediators was suggested.

Use of dot immunobinding assay for the rapid diagnosis of human hydatidosis.

A Dot Immunobinding (DIB) assay has been applied to the serodiagnosis of human hydatidosis and its results have been compared with those obtained with the enzyme-linked immunosorbent assay (ELISA). The two techniques have been shown to be closely related (p greater than 0.001), highly sensitive (92.0% of positive results in 75 sera from patients with hepatic or pulmonary hydatidosis) and specific (93.5% of negative results in 31 sera from patients affected by other parasitic diseases and 100% of negative results in 30 normal controls). DIB however is more economical and takes less time (only 4 hours) than ELISA. DIB could be an useful tool in field epidemiological surveys since it is sensitive, specific, simple to perform and it does not require any expensive apparatus.

[Radial counter-immunoelectrophoresis in the determination of specific anti-hydatidosis antibodies. Preliminary observations]. / La counter-immunoelettroforesi radiale nella determinazione degli anticorpi specifici anti-idatidei. Osservazioni preliminari.

Radial counter-immunoelectrophoresis was evaluated with sera from surgically-confirmed hydatidosis cases, patients with other parasitic diseases and healthy controls. Radial counter-immunoelectrophoresis was a sensitive as classic counter-immunoelectrophoresis based on the same positivity criterion and was equally specific for the immunodiagnosis of human hydatidosis. The procedure appears to be simple and rapid (the immunoprecipitation step requires just 5 minutes) and merits consideration.

Anti-Ia reactivity in sera from subjects with Entamoeba histolytica infection.

Sera from 15 patients with Entamoeba histolytica infection were tested for anti T-cell antibodies by assessing cross-reacting specificities with the antigens defined by an anti-Ia hybridoma antibody. T cells prepared by sheep erythrocyte rosetting were preincubated with the test sera and then with the anti-Ia antibody. Binding of the specific monoclonal antibody was assessed by rosetting with ox erythrocytes conjugated with goat anti-mouse IgG. Eight sera from amoebic patients were found to block the binding of monoclonal mouse hybridoma anti Ia-antibody to T cells. Blocking of anti-Ia binding was not due to Fc IgG receptor binding by immune complexes nor was it HLA-DR restricted. T cells pre-treatment with the amoebic sera positive for anti-Ia activity showed reduced activity when tested in the autologous mixed lymphocyte reaction (AMLR). The results of our study seem to suggest the existence of specific anomalies of immunoregulation during E. histolytica infection which may play a role in inducing immune disregulation in vivo.

Fractionation and characterization of hydatid fluid antigens with identification of an antigen similar to human serum albumin.

Human and sheep hydatid fluids were separated by ultrafiltration, gel chromatography and immunoabsorption into several immunogenic fractions in which both parasite antigens and host substances were present. The immunological characterization of proteic antigens was carried out by immunodiffusion and immunoelectrophoresis with rabbit and ram antisera. A line of identity was observed between a human fraction (labelled as III) and a sheep fraction (labelled as 2B). Further evidence of the presence of a parasitic antigen in fraction III was given by its reaction against an antiserum from ram directed against sheep fraction 2B. The immunological characterization of fraction III indicated a close similarity between human serum albumin and parasitic antigens.

Detection and partial characterization of circulating immune complexes in hydatid disease.

Thirty sera from eight patients with disseminated or localized hydatid disease have been examined for the presence of circulating immune complexes (CICs) by the conglutinin-binding assay and for immunoglobulin levels. The highest levels of CICs were of the immunoglobulin A (IgA) class, with lower values of IgG-CIC and IgM-CIC; these results did not correlate, except for IgG, with the free immunoglobulin levels. Efforts to identify parasitic antigen(s) involved in the CIC formation with different methods have been unsuccessful. In the follow-up of each patient, CIC appeared to be better correlated to clinical conditions than to hemagglutination titers. We have concluded that the presence of CIC in hydatid disease is probably an expression of B-cell polyclonal activation and that these complexes are valuable in the clinical monitoring of the disease.