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Biomedical subjects

F de Wolf

Publications and source records attributed to F de Wolf.

At least 109 records · Page 6Linked to original sources
PubMed1989

Evidence for a role of virulent human immunodeficiency virus (HIV) variants in the pathogenesis of acquired immunodeficiency syndrome: studies on sequential HIV isolates.

Sequential human immunodeficiency virus (HIV) isolates, recovered from a panel of longitudinally collected peripheral blood mononuclear cells obtained from 20 initially asymptomatic HIV-seropositive homosexual men, were studied for differences in replication rate, syncytium-inducing capacity, and host range. Eleven individuals remained asymptomatic; nine progressed to acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) at the time point at which the last HIV isolate was obtained. In 16 individuals, only non-syncytium-inducing (NSI) isolates, with a host range restricted to mononuclear cells, were observed. From four individuals, high-replicating, syncytium-inducing (SI) isolates that could be transmitted to the H9, RC2A, and U937 cell lines were recovered. From two of these four individuals, SI isolates were obtained throughout the observation period. In the two others, a transition from NSI to SI HIV isolates was observed during the period of study. Three of these four individuals developed ARC or AIDS 9 to 15 months after the first isolation of an SI isolate. With the exception of the two individuals in whom a transition from NSI to SI isolates was observed, within a given individual the replication rate of sequential HIV isolates was constant. A significant correlation was found between the mean replication rate of isolates obtained from an individual and the rate of CD4+ cell decrease observed in this individual. In individuals with low-replicating HIV isolates, no significant CD4+ cell loss was observed. In contrast, recovery of high-replicating isolates, in particular when these were SI isolates, was associated with rapid decline of CD4+ cell numbers and development of ARC or AIDS. These findings indicate that variability in the biological properties of HIV isolates is one of the factors influencing the course of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Cellular and humoral immunity in various cohorts of male homosexuals in relation to infection with human immunodeficiency virus.

The relationship between infection with human immunodeficiency virus (HIV) and various immunological parameters was studied in: (a) healthy controls; (b) homosexual individuals from the AIDS risk group without anti-HIV antibodies; (c) idem, but with anti-HIV antibodies; (d) patients with persistent generalized lymphadenopathy (PGL); (e) patients with AIDS-related syndrome; (f) patients with AIDS and opportunistic infections. In each group, consisting of 15-20 individuals, the following parameters were studied: absolute numbers of CD4+ and CD8+ cells; ratio CD4+/CD8+; cellular immune responses as measured in vivo by delayed-type hypersensitivity (DTH) and in vitro; and antibody response in vivo after immunization with a low dose of keyhole limpet haemocyanin. Healthy HIV antibody-positive individuals and patients with persistent generalized lymphadenopathy already showed a decreased CD4+/CD8+ ratio, mainly due to an increase in the number of CD8+ cells. The ratio in the AIDS-related syndrome and AIDS groups was even lower, but this was now due to low numbers of CD4+ cells while the number of CD8+ cells was normal. The lymphocyte proliferative response was low in the HIV antibody-positive group, normal in the group with persistent generalized lymphadenopathy and profoundly decreased in the AIDS-related syndrome and AIDS groups. DTH was enhanced in the PGL group and diminished in both ARC and AIDS. Compared to healthy controls, the antibody response upon immunization with a low dose of keyhole limpet haemocyanin was depressed (although not absent) in all groups studied, even in HIV antibody-negative homosexuals. In the HIV antibody-positive group, the severity of the impairment of the various parameters of immunocompetence was not related to the presence of HIV antigenaemia.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Effect of zidovudine on serum human immunodeficiency virus antigen levels in symptom-free subjects.

18 men with longstanding human immunodeficiency virus (HIV) antigenaemia but no symptoms received zidovudine in low-dose regimens (250 mg 6-hourly, 500 mg 6-hourly, or 500 mg 12-hourly) with or without acyclovir. Serum HIV antigen rose in only 1 patient and declined significantly in 13 (to below cut-off values in 9). In the 1 subject from whom HIV antigen positive cerebrospinal fluid was obtained, the fluid was antigen negative after 12 weeks of treatment. Acyclovir treatment alone or in addition did not seem to influence serum antigen levels. In 7 untreated men serum antigen levels rose or remained stable during follow-up. CD4+ cell counts increased in 14/18 treated subjects and 1/7 untreated subjects. No disease progression was observed in either group. Regression of enlarged lymph nodes was seen in the zidovudine-treated subjects. Adverse reactions to the study drugs were infrequent and mild. Anaemia caused symptoms in 2, but serious leucopenia or neutropenia was not observed.

Acquired Immunodeficiency Syndrome↗
PubMed1988

No predictive value of GC phenotypes for HIV infection and progression to AIDS.

The genetic polymorphism of group-specific component (GC) was investigated with isoelectric focusing in 351 homosexual men at risk for HIV infection, 96 male patients with AIDS, and 86 heterosexual controls. No significant differences in GC phenotype distribution were seen between controls and any of the at risk groups or patients, neither between HIV-Ab-positive/Ag-negative and HIV-Ab-positive/Ag-positive homosexual men nor between HIV-Ab-positive/Ag-positive homosexual men and AIDS patients, suggesting that the GC system is not involved in the infective susceptibility or progression of HIV infection to AIDS-related complex and AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Numbers of CD4+ cells and the levels of core antigens of and antibodies to the human immunodeficiency virus as predictors of AIDS among seropositive homosexual men.

The relation between serological and immunologic profiles and the risk of developing AIDS was assessed in 306 initially asymptomatic, human immunodeficiency virus-infected homosexual men studied for 30 mo. Twenty-nine men developed AIDS (attack rate, 16.8%). The attack rate in core antibody-negative men was 35.7%; this rate was 43.9% in antigen-positive men, 51.9% in men with low (less than 0.5 x 10(9)/L) CD4+ cell counts, 6.8% in core antibody-positive men, 6.9% in antigen-negative men, and 6.1% in men with normal CD4+ cell counts. The disappearance of core antibody, the expression of antigen, and the occurrence of low CD4+ cell counts preceded AIDS by a median of 624, 544, and 466 d, respectively. Seronegativity for core antibody preceded AIDS in 21 of 26 patients, 20 of whom were also antigen positive. Four more cases of AIDS developed among the antigen-negative, core antibody-positive men with low CD4+ cell counts. Only one patient with AIDS escaped detection by using these three markers.

AIDS-Related Complex↗
PubMed1988

Diagnostic value of specific IgM antibodies in primary HIV infection.

Sequential serum samples from 55 homosexual men with primary HIV infection were tested for IgM anti-HIV. An early IgM response was found in 27 out of 55 (49%). In five cases IgM anti-HIV was detected 1-3 1/4 months prior to IgG anti-HIV seroconversion, as detected by a commercially available ELISA, but in no case was IgM detected prior to IgG anti-HIV seroconversion, as detected by the more sensitive GACRIA (IgG antibody captive radio-immunoassay, see Subjects and methods) and immunoblot assays. In 22 out of 23 men (96%) the primary IgM response did not persist beyond 3 months. HIV antigenaemia was found before HIV antibody seroconversion in 6 out of 55 (11%) and concomitant with HIV antibody seroconversion in 8 out of 55 (15%) subjects. A 'flu-like' illness that might be ascribed to primary HIV infection was found in 37 out of 50 men (74%). A blood sample was taken from 11 men during or within 2 weeks of the illness: no serological markers of HIV infection were detected in four subjects, HIV antigen, IgM and IgG anti-HIV were detected in another four, HIV antigen was the only marker of HIV infection in two subjects, and in one subject, IgM and IgG anti-HIV were detected but not HIV antigen. These results indicate that no conclusive value can be attached to a negative IgM test in suspected primary HIV infection, and that any role for IgM anti-HIV testing in blood donor screening is highly questionable.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Decline of HIV antigen levels in cerebrospinal fluid during treatment with low-dose zidovudine.

Six HIV-antigenaemic patients with AIDS or AIDS-related complex were studied to assess the effect of treatment with low-dose zidovudine (250 mg) in 6-hourly doses on HIV antigen (HIV-Ag) levels in cerebrospinal fluid (CSF). HIV-Ag was detected in CSF of three patients before treatment. These patients became CSF HIV-Ag-negative within 8 weeks of treatment. One initially CSF HIV-Ag-negative patient became strongly CSF HIV-Ag-positive during interruption of zidovudine treatment; CSF HIV-Ag disappeared again after treatment was restarted. None of our patients showed a significant neurological improvement during the study. These results show that low-dose zidovudine can suppress viral expression in CSF. Whether suppression of viral replication can prevent future HIV-related neurological disease remains to be investigated.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Immunological abnormalities in human immunodeficiency virus (HIV)-infected asymptomatic homosexual men. HIV affects the immune system before CD4+ T helper cell depletion occurs.

To investigate the effect of persistent HIV infection on the immune system, we studied leukocyte functions in 14 asymptomatic homosexual men (CDC group II/III) who were at least two years seropositive, but who still had normal numbers of circulating CD4+ T cells. Compared with age-matched heterosexual men and HIV-negative homosexual men, the CD4+ and CD8+ T cells from seropositive men showed decreased proliferation to anti-CD3 monoclonal antibody and decreased CD4+ T-helper activity on PWM-driven differentiation of normal donor B cells. Monocytes of HIV-infected homosexual men showed decreased accessory function on normal T cell proliferation induced by CD3 monoclonal antibody. The most striking defect in leukocyte functional activities was observed in the B cells of HIV-infected men. B cells of 13 out of 14 seropositive men failed to produce Ig in response to PWM in the presence of adequate allogeneic T-helper activity. These findings suggest that HIV induces severe immunological abnormalities in T cells, B cells, and antigen-presenting cells early in infection before CD4+ T cell numbers start to decline. Impaired immunological function in subclinically HIV-infected patients may have clinical implications for vaccination strategies, in particular the use of live vaccines in groups with a high prevalence of HIV seropositivity.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Impact of HIV antibody testing on changes in sexual behavior among homosexual men in The Netherlands.

Between October 1984 and May 1986, 746 homosexual men, living in and around Amsterdam, The Netherlands, were surveyed at three consecutive six months periods regarding their sexual behavior. At the start of the study all subjects, of whom 234 (31 per cent) were HIV-Ab seropositive, were informed about their HIV antibody status. Seropositives initially reported more sexual partners than seronegatives; they also showed a greater reduction in the number of sexual partners and the number of partners with whom all forms of sexual practices were performed than did seronegatives. In both groups subjects were more likely to terminate orogenital intercourse than anogenital intercourse and masturbation.

AIDS Serodiagnosis↗
PubMed1988

Influenza-like syndrome in homosexual men: a prospective diagnostic study.

In the course of a prospective study of the prevalence and incidence of infection with the human immunodeficiency virus (HIV) and risk factors for the acquired immune deficiency syndrome among 961 homosexual men, 97 initially HIV antibody seronegative men reported a febrile period lasting at least three days. In 60 of these men serological evidence for an infection was found: influenza A or B virus (17 men), HIV (14), Epstein-Barr virus (seven), parainfluenza virus type I, 11 or Ill (five), hepatitis A virus (three), cytomegalovirus (three), adenovirus (two), respiratory syncytial virus (two), hepatitis B virus (one) and Toxoplasma gondii (one). Combined infections were found in five men. A total of 17 men seroconverted for HIV antibody. The clinical symptoms of acute HIV infection closely resembled those of influenza A or B infection. Skin rashes also occurred frequently in men with HIV infection. HIV antibody seroconversion gives rise to a number of different symptoms and primary HIV infection should be included in the differential diagnosis of prolonged febrile illness in those at risk of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Risk of AIDS related complex and AIDS in homosexual men with persistent HIV antigenaemia.

One hundred and ninety eight men seropositive for human immunodeficiency virus (HIV) antibody and 58 HIV antibody seroconverters were studied for an average of 19.3 (SEM 0.5) months to assess the relation between HIV antigenaemia and the risk of developing the acquired immune deficiency syndrome (AIDS) and AIDS related complex. Forty (20.2%) of the 198 HIV antibody seropositive men were antigen positive at entry and remained so during follow up. Eight (13.8%) of the 58 HIV antibody seroconverters and 20 (12.7%) of the remaining 158 HIV antibody seropositive men became antigen positive during follow up, resulting in an end point attack rate for HIV antigenaemia of 14.3%. AIDS related complex was diagnosed in 25 (15.8%) of the HIV antigen negative men and in 14 (20.7%) of the HIV antigen positive men. AIDS was diagnosed in 15 men, resulting in an end point attack rate for AIDS of 23.9% in the HIV antigen positive group and 1.3% in the antigen negative group. HIV antibody seropositive men without symptoms but with persistent HIV antigenaemia are at increased risk of developing AIDS and AIDS related complex.

AIDS-Related Complex↗
PubMed1987

Spread of human T-cell leukemia virus (HTLV-I) in the Dutch homosexual community.

Sequential sera of 697 homosexual men, participating in a prospective study (1984-1986) of the risk to acquire human immunodeficiency virus (HIV) or AIDS, were tested for antibodies to human T-cell leukaemia virus (HTLV-I) by particle agglutination and immunoblotting. No intravenous drug users were included in this trial. Three men (0.4%) were HTLV-I antibody positive at intake and an additional 2 at the end of the observation period, resulting in an attack rate of approximately 0.3%. One of the 3 men with HTLV-I antibodies at intake was a Brazilian. One man had an acute HTLV-I infection after sexual intercourse with a Brazilian during holiday in Brazil. No serological cross-reactivity with HIV was observed nor a relationship with other sexually transmissible viral or bacterial infections. In contrast to HIV no relationship with anogenital intercourse was noted; both primary HTLV-I infected men practiced only orogenital intercourse. This suggests that HTLV-I was imported in the Dutch homosexual community after HIV was introduced in the Netherlands. HTLV-I appears to spread slower within the homosexual community than HIV and possibly by other routes.

Adult↗
PubMed1987

Risk factors and prevalence of HIV antibodies in homosexual men in the Netherlands.

As part of the prospective AIDS study in Amsterdam, blood samples were collected from 741 healthy homosexual men with multiple sexual partners, between October 1984 and May 1985. Samples were analyzed for the presence of antibodies to the human immunodeficiency virus (anti-HIV). Anti-HIV was demonstrated in 233 (31%) of the respondents. Seropositive respondents engaged in anal receptive sexual techniques with more sexual partners than did seronegative respondents, whereas seronegatives engaged in manual sexual techniques with more sexual partners than did seropositives. As far as it was possible to control for the interrelations between the measured variables, a direct relation with anti-HIV was established. This leads to the conclusion that when the number of sexual partners is considered a risk factor for HIV, a clear distinction should be made between the sexual techniques practiced with these partners. Two other risk factors for the presence of anti-HIV were the use of cannabis and of nitrite.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Viral gene expression, antibody production and immune complex formation in human immunodeficiency virus infection.

Human immunodeficiency virus (HIV) antigen (HIV-Ag) in polyethylene glycol (PEG) precipitates and supernatants and HIV antibodies (HIV-Ab) to core and envelope antigens were studied in serial serum samples of three HIV-Ab seroconverters and 11 HIV-Ab seropositive men with a mean follow-up time of 16.1 months. In five men not progressing beyond persistent generalized lymphadenopathy (PGL) and two progressing to AIDS, HIV-Ag was detected once in 'free' configuration before HIV-Ab seroconversion and persistently or intermittently 'complexed' thereafter; in six of these men HIV core antibodies were continuously present with a declining level in one. In two men not progressing beyond PGL and five progressing to AIDS HIV-Ag was detected 'complexed' before HIV-Ab seroconversion once and persisted predominantly in 'free' configuration thereafter, while no HIV core antibody was detected in six of these men and a declining level in one. HIV-Ag was detected in 37% (14 out of 38) of HIV core antibody seropositive samples, mostly in 'complexed' form, while HIV-Ag was detected in 86% (43 out of 50) of HIV core antibody seronegative samples, mostly in both 'complexed' and 'free' configuration. Antibodies to HIV envelope antigen were detected in all HIV-Ab seropositive samples. These results indicate that the level of HIV-Ag expression is the primary determinant of detectability of HIV core antigens as well as antibodies. Enhancement of HIV-Ag expression, in a significant number of cases associated with clinical deterioration, appears to lead to clearance of HIV core antibodies in immune complexes, while HIV envelope antibody levels remain relatively unaffected.

Acquired Immunodeficiency Syndrome↗