Elevated plasma levels of 90K (Mac-2 BP) immunostimulatory glycoprotein in HIV-1-infected children.

90K is a secreted serum glycoprotein with immune stimulatory activity. In this study, 90K plasma levels were determined by an enzyme-linked immunosorbent assay in 18 HIV-1-infected children and 10 uninfected control children. 90K levels in HIV-1-infected children (median, 12.5 microg/ml) were higher than in HIV-1 uninfected control group (6.3 microg/ml; P < 0.05). 90K levels of HIV-1-infected children classified as stage B and C (median, 15.0 microg/ml and 22.7 microg/ml, respectively) were higher compared to children with stage A disease (median, 7.0 microg/ml; P < 0.05). A positive correlation (r = 0.5; P < 0.05) was found between 90K levels and HIV-1 RNA levels in 137 plasma samples of 18 HIV-1-infected children collected during a period of 1 year. No correlation was found between 90K levels and CD4 cell counts. These results suggest that 90K plasma levels may represent a novel marker of disease progression in HIV-1-infected children.

In vitro production of type 1 and type 2 cytokines by peripheral blood mononuclear cells from subjects coinfected with human immunodeficiency virus and Leishmania infantum.

To explore the type 1 and type 2 cytokine profile in cases coinfected with human immunodeficiency virus (HIV) and Leishmania infantum, production of interleukin-4 (IL-4), interleukin-10 (IL-10), interferon-gamma (IFN-gamma), and interleukin-2 receptor (IL-2R) was investigated in mitogen-stimulated and unstimulated peripheral blood mononuclear cell cultures from eight HIV/Leishmania coinfected subjects matched with eight anti-HIV-positive subjects with no evidence of Leishmania coinfection. Levels of IL-4 and IL-2R increased significantly from the baseline levels in the peripheral blood mononuclear cell supernatants of HIV/Leishmania coinfected subjects following stimulation with phytohemoagglutin, whereas the postchallenge concentration of IFN-gamma was significantly increased in the HIV-infected group. The levels of IL-4 and IL-10 were significantly higher in the HIV/Leishmania group throughout evaluation. Post-stimulation IFN-gamma production was significantly higher in the HIV-positive group in comparison with that of the HIV-Leishmania coinfected subjects. These observations support the notion that a Th2 cytokine response is present during a Leishmania infection, even among HIV-coinfected individuals.

Quantification of viral load: clinical relevance for human immunodeficiency virus, hepatitis B virus and hepatitis C virus infection.

Quantitative determination of viral load using nucleic acid amplification techniques represents the most accurate prognostic marker for human immunodeficiency virus type 1 (HIV-1) infection, independently of CD4+ cell count. Overall, the different methods for HIV-1 RNA determination (RT-PCR, nucleic acid sequence-based amplification, branched DNA) show a good reproducibility (0.5 log), however for low copy numbers and in HIV-1-infected children the variability may exceed 0.7 log. In non-HIV-1 subtype B infections the copy number is underestimated. While serology permits an accurate follow-up of hepatitis B virus (HBV) infection, HBV DNA quantification is used for monitoring of antiviral therapy, determination of infectiosity and in combination with serological markers for the resolution of unusual profiles, i.e. isolated anti-HBc reactivity. The prognostic relevance of hepatitis C virus (HCV) RNA determination is of limited value for the long-term prognosis of chronic hepatitis C, however the viral load may predict the outcome of antiviral therapy. Genetic diversity represents a challenge for HCV RNA quantification.

Increased serum and mRNA levels of RANTES associated with elevated levels of activated CD8+CD38+ T cells in HIV-1 infected individuals.

The serum levels of the beta-chemokine RANTES and, albeit less, MIP-1 beta were found to be increased in 37 HIV-1 infected compared to seronegative individuals. In contrast the serum levels of IL-16 were only sporadically elevated in seropositives as well as in seronegatives. Concomitantly, the RANTES gene expression increased about tenfold in seropositives, whereas the MIP-1 beta and IL-16 mRNA levels were not elevated. No correlation between the increase of the MIP-1 beta and RANTES serum concentrations and the plasma virus load, the number of the peripheral CD4+ T cells or the therapy status of the patients was found. However, the increased proportion of activated CD8+CD38+ T cells in the peripheral blood of all seropositives paralleled the increased RANTES serum levels detected indicating that immune activation in HIV-1-infected individuals may contribute to increased RANTES serum levels.

Quantitative detection of human immunodeficiency virus (HIV) antigen by the Enzymun-Test: comparison with alternative assays and nucleic acid sequence-based amplification of HIV type 1 RNA.

A new modular automated enzyme immunoassay (EIA) (Enzymun-Test HIV Ag: Boehringer Mannheim) for quantitative human immunodeficiency virus (HIV) antigen detection was evaluated by testing a panel of 1,506 serum samples, including seroconversions, dilution series, follow-up samples from patients under antiretroviral therapy, single serum specimens from HIV-seropositive individuals in different stages of infection, potentially cross-reactive samples, and sera from HIV-negative hospitalized patients. The Abbott HIV type 1 (HIV-1) antigen monoclonal antibody assay served as the reference assay, and nucleic acid sequence-based amplification (Organon Teknika) for quantitative amplification of HIV-1 RNA was used for follow-up of patients under antiretroviral chemotherapy. The Boehringer Mannheim and Abbott EIAs showed concordant results for the early detection of HIV antigen in all the seroconversion panels. The follow-up samples from 29 HIV-infected individuals under antiretroviral therapy gave divergent results between both antigen tests. For the detection of HIV antigen in single serum samples from HIV-infected patients in different stages of HIV infection, a higher number of positive samples was detected with the Abbott HIV-1 antigen monoclonal antibody assay in samples from patients in stages II and III of HIV infection. The Enzymun-Test detected three or more positive samples than did the Abbott assay among the samples of patients with AIDS. The concordance on a sample-to-sample basis between the Boehringer Mannheim and Abbott EIAs was 98.6%. The sensitivity of the Enzymun-Test in comparison to the reference assay was 97.2%; the specificity was 98.8%. Although no close correlation could be found between the amount of viral RNA in serum detected by nucleic acid sequence-based amplification and the concentration of HIV antigen, a high HIV-1 RNA copy number was mostly associated with high levels of HIV antigen. In conclusion, the Enzymun-Test permits accurate HIV antigen detection and offers, in contrast to previous assays, the possibility of completely automated detection.

Immunological findings in HIV-Leishmania coinfection.

It is supposed that Leishmania infection increases human immunodeficiency virus (HIV) replication in seropositive individuals. Two groups of 9 HIV-infected intravenous drug users each, one group with HIV-Leishmania coinfection (as determined by bone marrow microscopy, culture and an immunofluorescent assay, the other with HIV infection alone, but no evidence of Leishmania coinfection were matched for sex, age, time since first diagnosis of HIV infection, number of AIDS-defining diseases, proportion of patients treated with AZT and months of treatment, CD4/CD8 ratio, beta 2-microglobulin level and HIV p24 antigen positivity rate. IL-4, -6, -10 and -12 and IFN-gamma levels were determined by commercial enzyme immunoassays. The HIV-1 RNA copy number was quantified with the nucleic-acid-sequence-based amplification method (NASBA). The differences between the two groups were highly significant for all markers determined except for IL-12 and IFN-gamma. We found a higher viral load in the patients with HIV-Leishmania coinfection compared to the patients with HIV infection alone (p < 0.009). In 6 HIV-positive individuals without Leishmania coinfection, the HIV-1 RNA copy number was below the detection limit of NASBA (i. e. < 400 copies/100 microliters). Plasma levels of IL-4, -6, and -10 were significantly elevated in the coinfected group (p < 0.0001; p < 0.02, and p < 0.005). The results of our study show that the viral load is increased in patients with HIV-Leishmania coinfection in comparison to the controls. This might be partly due to Th2 immune activation, as demonstrated by higher plasma levels of IL-4, -6 and -10 in HIV-Leishmania-coinfected patients than in HIV-infected individuals.

Low correlation of human cytomegalovirus DNA amplification by polymerase chain reaction with cytomegalovirus disease in organ transplant recipients.

Seventy-five organ transplant recipients underwent prolonged virological and serological follow-up for early detection of human cytomegalovirus (HCMV) infection after transplantation. HCMV DNA detection by nested polymerase chain reaction (PCR) and HCMV early structural antigen (pp65) detection were carried out in 576 peripheral blood leucocyte (PBL) samples. Furthermore, 563 blood specimens were investigated by a commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of specific immunoglobulins G, M, and A against HCMV structural antigens. In eight of nine symptomatic organ transplant recipients, HCMV DNA was detected in one or more consecutive blood samples. HCMV DNA PCR was also positive in one or more samples from eight patients who never developed HCMV-related symptoms. HCMV pp65 antigen was detected almost exclusively in PBL samples from organ transplant recipients suffering from HCMV disease. However, antigenaemia was not detected in four PCR positive patients presenting clinical signs attributable to HCMV infection. Two of the initially HCMV DNA positive samples were not confirmed by retesting and hybridisation. The results of the present study demonstrate that despite the high specificity of nested PCR, HCMV DNA may be detected in the absence of clinical symptoms attributable to HCMV infection. In asymptomatic reactivation, limited replication of viral DNA may be responsible for positive results of PCR without any clinical relevance. In this context, pp65-antigen detection from PBL seems to have a better prognostic value, but is not always detected when clinical symptoms are present.