Search PubMed⌕ Search

Biomedical subjects

A N Phillips

Publications and source records attributed to A N Phillips.

At least 91 records · Page 5Linked to original sources
PubMed1998

The incidence of AIDS-defining illnesses in 4883 patients with human immunodeficiency virus infection. Royal Free/Chelsea and Westminster Hospitals Collaborative Group.

BACKGROUND: Acquired immunodeficiency syndrome (AIDS)-defining illnesses are known to occur at different levels of immunosuppression, and the incidence of diagnoses may also vary according to the CD4 lymphocyte count strata. Information about the incidence of disease at different levels of immunosuppression would help clinicians monitoring patients and would allow prophylaxis to be targeted at the most appropriate population. METHODS: Between 1982 and July 1995, 4883 patients testing positive for the human immunodeficiency virus were seen at either the Royal Free or Chelsea and Westminster Hospitals in London, England. The incidence of each diagnosis, both overall and stratified by CD4 lymphocyte count, was calculated using a person-years analysis. Patients who had no CD4 lymphocyte counts measured during follow-up were excluded from the analysis. RESULTS: During a median follow-up period of 27.6 months, 3875 AIDS-defining illnesses were reported in 1713 patients. The incidence of AIDS-defining illnesses ranged from 6.22 per 100 person-years of follow-up for Pneumocystis carinii pneumonia (95% confidence interval, 5.74-6.70) to 0.37 for extrapulmonary tuberculosis (95% confidence interval, 0.26-0.48). The incidence of each AIDS-defining illness increased as the CD4 lymphocyte count declined; diagnoses such as cytomegalovirus and Mycobacterium avium-intracellulare complex infection had a low incidence at CD4 lymphocyte counts above 0.05x10(9)/L (50/mm3), while Kaposi sarcoma, P carinii pneumonia, and esophageal candidiasis had a high incidence throughout all CD4 lymphocyte count strata. CONCLUSIONS: This study provides important information about the risk of AIDS-defining illnesses at lower CD4 lymphocyte counts, enabling disease-specific prophylaxis to be targeted at the most appropriate population. In the future, as more prophylactic therapies are developed, this study will provide historical data of the incidence of diseases before specific prophylaxis was introduced.

AIDS-Related Opportunistic Infections↗
PubMed1998

Survival in 2367 zidovudine-treated patients according to use of other nucleoside analogue drugs. The EuroSIDA Study Group.

To evaluate survival according to use of different nucleoside drugs in a routine clinical setting, we studied a large group of zidovudine-treated patients seen in clinics across Europe. A total of 3128 subjects was recruited to the observational, prospective EuroSIDA study in May 1994. These were consecutive patients (up to a predefined limit) seen at outpatient clinics in 37 centers from 16 European countries and followed at 6-month intervals by use of standardized forms completed by clinicians at the respective centers. This report concerns 2367 subjects who began antiretroviral therapy with a regime that included zidovudine either before study entry or during the course of follow-up. Cox proportional hazards models were fitted, with use of other antiretroviral drugs, CD4 count, and date of development of AIDS fitted as time-dependent covariates. Survival times from start of therapy were left truncated at study entry to avoid survival bias. In addition to zidovudine, antiretroviral drugs used included didanosine (ddI) (n = 1119; median 1.6 years after starting zidovudine), dideoxycytidine (ddC) (n = 592; median 1.9 years after starting zidovudine), stavudine (d4T) (n = 241; median 2.9 years after starting zidovudine) and lamivudine (3TC) (n = 33 ; median 2.7 years after starting zidovudine). Of the 2367 patients, 613 died during follow-up. Overall, risk of death was reduced in those zidovudine-treated patients who began at least one other nucleoside analogue drug with or after taking zidovudine (relative hazard [RH], 0.61; 95% confidence interval [CI], 0.51-0.72, adjusting for CD4 count, development of AIDS, and age). Fitting each drug separately, there was a larger association with reduced mortality for starting 3TC (RH, 0.41; 95% CI, 0.28-0.62) than for starting ddl (RH, 0.79; 95% CI, 0.67-0.93), ddC (RH, 0.74; 95% CI, 0.59-0.92) or d4T (RH, 0.67; 95% CI, 0.49-0.91). These results suggest that the beneficial effect of nucleoside combination therapy identified in controlled trials can be seen in routine clinical practice.

Adult↗
PubMed1998

The rate of CD4 decline as a determinant of progression to AIDS independent of the most recent CD4 count. The Italian Seroconversion Study.

The data of two cohort studies of HIV-infected individuals were used to examine whether the rate of CD4 decline is a determinant of HIV progression, independent of the most recent CD4 count. Time from seroconversion to clinical AIDS was the main outcome measure. Rates of CD4 decline were estimated using the ordinary least squares regression method. AIDS incidences were compared in individuals who had previously experienced either a steeper or a less steep rate of CD4 decline. Cox proportional hazards model including a time-dependent covariate for the rate of CD4 decline was performed. The rate of prior CD4 decline was significantly associated with the risk of developing AIDS independently from the most recent CD4 count, with a 2% increase in hazard of AIDS (P < 0.01) for a difference of 10 cells/mm3 in the estimated yearly drop in CD4 count. This finding gives scientific credit to the belief that individuals with a prior steeper CD4 decline consistently have a higher subsequent risk of developing AIDS than those with a less steep prior decline.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Production of beta-chemokines in human immunodeficiency virus (HIV) infection: evidence that high levels of macrophage inflammatory protein-1beta are associated with a decreased risk of HIV disease progression.

Macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES production were measured by ELISA in whole blood that had been stimulated for 4.5 h with phytohemagglutinin. The blood was from 90 healthy human immunodeficiency virus (HIV)-negative controls and from 245 HIV-infected subjects who were followed for < or = 4.5 years. HIV-infected persons without AIDS had increased levels of MIP-1alpha, MIP-1beta, and RANTES (P < .01) compared with levels in controls. Subjects with AIDS, compared with controls, had decreased production levels of MIP-1beta (P < .0001) and similar levels of MIP-1alpha and RANTES. A high level of MIP-1beta production was associated with a decreased risk of progressing to AIDS or death, as determined by univariate analysis (P < .01) and adjusted for CD4 cell count and age (P = .07, P = .06, respectively). The findings suggest that the production level of beta-chemokine changes during HIV infection and that a high level of beta-chemokine production in peripheral blood lymphocytes may be associated with less rapid disease progression in HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Changes in lymphocyte subsets in human immunodeficiency virus-positive persons with < 5 CD4 T lymphocytes/mm3.

All patients seen at the Royal Free Hospital, London, who had at least one CD4 T lymphocyte count of < 5 cells/mm3 (n = 166) were prospectively followed to assess changes in their total T lymphocyte and CD8 T lymphocyte counts over time. While overall there were no clear trends towards a drop or increase in either count, persons who died during the study experienced a rapid drop in both CD8 T lymphocyte and total T lymphocyte levels in the months preceding death. Multivariate Cox proportional hazards models revealed that both the total T lymphocyte count and CD8 T lymphocyte count provided important prognostic information for survival. Despite almost a complete absence of CD4 T lymphocytes, lymphocyte subset monitoring is useful in identifying decreasing CD8 T lymphocyte levels that predict short-term prognosis.

CD4-Positive T-Lymphocytes↗
PubMed1998

Clinical and immunological features of human immunodeficiency virus infection in patients from Bangkok, Thailand.

BACKGROUND: To assess the association between the CD4 count and clinical diseases in a cohort of Thai patients. METHODS: In all, 1902 patients who presented with human immunodeficiency virus (HIV) infection at the Chulalongkorn University Hospital in Bangkok were investigated. RESULTS: At the time of presentation 295 (15.5%) patients had acquired immunodeficiency syndrome (AIDS) and there was a highly significant tendency for lower CD4 counts in this group (median 67/mm3) than in patients free of AIDS (median 369/mm3). A total of 757 patients had data available on follow-up and were free of AIDS at the first visit. During a median follow-up of 0.9 years, 110 developed AIDS or AIDS-related death (12.2/100 person years). Subjects with CD4 count < 200/mm3 at initial visit showed over a ninefold increase in risk of developing AIDS compared to subjects with levels > or = 500/mm3 (relative risk [RR] = 9.1; 95% CI: 5.4-16.0). The rate/100 person years was 47.1 compared with 6.0 in subjects with levels > or = 500/mm3. After adjusting for initial CD4 count, homosexual men showed over a twofold increase in risk of developing AIDS compared to heterosexuals (RR = 2.4; 95% CI: 1.6-4.4) and intravenous drug users (IVDU) showed nearly a twofold increase (RR = 1.8; 95% CI: 0.9-3.9). The increased risk in homosexual men persisted even after further adjustment for clinical stage (RR = 2.2; 95% CI: 1.3-3.7) but the increased risk in IVDU was attenuated (RR = 1.5; 95% CI: 0.7-3.2) although it remained increased albeit non-significantly. Men tended to progress faster to AIDS than women but the difference was not significant. However, the faster progression in homosexual men was seen even when compared to heterosexual men only. CONCLUSION: The rate of progression of AIDS according to CD4 count group at baseline in this Thai cohort is broadly comparable with Western cohorts. It appears that heterosexuals in Thailand show slower progression to AIDS than homosexual men.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Demographic, clinical and social factors associated with human immunodeficiency virus infection and other sexually transmitted diseases in a cohort of women from the United Kingdom and Ireland. MRC Collaborative Study of women with HIV.

BACKGROUND: Clinical experience suggests many women with HIV infection have experienced no other sexually transmitted diseases (STD). Our objective was to test the hypothesis that a substantial proportion of women with HIV infection in the United Kingdom and Ireland have experienced no other diagnosed STD and to describe the demographic, clinical and social factors associated with the occurrence of other STD in a cohort of HIV infected women. METHOD: Analysis of cross-sectional baseline data from a prospective study of 505 women with diagnosed HIV infection. The setting was 15 HIV treatment centres in the United Kingdom and Ireland. The main outcome measures were occurrence of other STD diagnosed for the first time before and after HIV diagnosis. Data were obtained from interview with women and clinic notes. We particularly focused on occurrence of gonorrhoea, chlamydia and trichomoniasis after HIV diagnosis, as these are the STD most likely to reflect recent unprotected sexual intercourse. RESULTS: The women were mainly infected via heterosexual sex (n = 304), and injection drug use (n = 174). 151 were black Africans. A total of 250 (49.5%) women reported never having been diagnosed with an STD apart from HIV, 255 (50.5%) women had ever experienced an STD besides HIV, including 109 (21.6%) who had their first other STD diagnosed after HIV. Twenty-five (5%) women reported having had chlamydia, gonorrhoea or trichomoniasis diagnosed for the first time after HIV diagnosis, possibly reflecting unprotected sexual intercourse since HIV diagnosis. In all 301 (60%) women reported having had sex with a man in the 6 months prior to entry to the study. Of these, 168 (58%) reported using condoms 'always', 66(23%) 'sometimes' and 56 (19%) 'never'. CONCLUSIONS: Half the women in this study reported having never experienced any other diagnosed STD besides HIV. However, after HIV diagnosis most women remain sexually active and at least 5% had an STD diagnosed which reflect unprotected sexual intercourse.

Adolescent↗
PubMed1997

Relation between soluble CD30 levels measured soon after HIV seroconversion and disease progression in men with hemophilia.

Soluble CD30 (sCD30) levels within 3 years of HIV seroconversion were studied in 85 hemophilic men infected with HIV. All men were coinfected with hepatitis C virus (HCV). Levels of sCD30 were elevated in these men when compared with controls. These elevated levels did not appear to be a result of treatment with intermediate-purity clotting factor concentrates and were unlikely to be due to HCV coinfection inasmuch as hemophilic patients infected with HCV alone showed only mildly elevated sCD30 levels when compared with those of hemophilic controls uninfected with HCV. Initial sCD30 levels were not significantly associated with progression to any endpoint, although a tendency was present for those with the highest initial levels to progress less rapidly than those with lower values. Despite elevated sCD30 levels in these men, we have not been able to confirm that high sCD30 levels are associated with more rapid HIV progression.

Disease Progression↗
PubMed1997

Regional differences in use of antiretroviral agents and primary prophylaxis in 3122 European HIV-infected patients. EuroSIDA Study Group.

Little is known about how widely HIV-related drugs are used outside controlled clinical trials. We therefore assessed factors associated with use of antiretroviral (ARV) therapy and primary prophylactic regimens to prevent HIV-associated opportunistic infections. Baseline data from a prospective study from May to August 1994, on 3122 consecutive HIV infected patients with a CD4 count <500 cells/microl, followed in 37 centers from 16 European countries, were analyzed. Two thousand and twenty patients (65%) were receiving at least 1 ARV drug at the time of the study. ARV therapy was more frequently used among patients from southern and central Europe as compared with patients from northern Europe, especially among patients with CD4 counts >200 cells/microl (73%, 57%, and 42%, respectively, p < 0.0001). Of patients on ARV therapy, 34% received open-label combination therapy. This proportion was higher in central Europe compared with other regions (27%, 50%, and 31% for southern, central, and northern Europe, respectively, p < 0.0001). Primary prophylaxis against Pneumocystis carinii pneumonia (PCP) was used by 85% of patients with a CD4 count <200 cells/microl, without marked regional differences. In patients without esophageal candidiasis or other invasive fungal infections, antifungal drugs were far less frequently used in patients from southern and central Europe compared with patients from northern Europe (10%, 10%, and 25%, respectively, p < 0.0001). Only 5% of patients with a CD4 count <100 cells/microl received rifabutine as primary prophylaxis against nontuberculous mycobacterioses. ARV and antifungal therapies are used differently in different parts of Europe, whereas primary PCP prophylaxis is uniformly administered to most at-risk patients. U.S. recommendations on the use of antimycobacterial prophylaxis have not been implemented in Europe.

AIDS-Related Opportunistic Infections↗
PubMed1997

Long-term perspective on the prevalent-cohort biases in studies of human immunodeficiency virus progression.

Because considerable information about progression of human immunodeficiency virus (HIV) infection has been provided by studies of cohorts of individuals with prevalent HIV infection, this study was designed to investigate bias due to onset confounding (differential time-since-infection distributions) and differential length-biased sampling in epidemiologic analyses of data from such cohorts. Subjects were participants in the Italian Seroconverters Study, a seroincident cohort of more than 1,200 adults seen at ambulatory care clinics in Italy, with observed HIV seroconversion in 1980-1988. Acquired immunodeficiency syndrome (AIDS) diagnoses, based on the 1987 Centers for Disease Control case definition, and mortality were ascertained through Italian national registries through 1994. To estimate bias in prevalent cohorts, a series of pseudoseroprevalent (PSP) cohorts were drawn by sampling, from among the total seroincident cohort, prevalent AIDS-free subjects in each calendar year. The relative AIDS risk associated with a given covariate was calculated in each PSP cohort and compared with the relative AIDS risk for that covariate in the seroincident cohort. Relative risks were estimated by both the ratio of AIDS incidence densities and the relative AIDS hazards from proportional hazards regression. Differential length bias was not evident, as assessed in the following way: Among 338 individuals with seroconversion dates in 1983-1986, the relative risk of AIDS for subjects born before 1951 compared with those born more recently was 1.67 (95% confidence interval (CI) 1.30-2.14). Although differential length-biased sampling was expected to bias this relative risk toward 1.0, the observed relative risk for earlier birth ranged from 1.79 to 2.86 in 1987-1992 PSP cohorts. Onset bias was observed: Among 644 subjects with seroconversion in 1980-1988, the AIDS relative risk for 1980-1985 seroconverters compared with 1986-1988 seroconverters was 1.09 (95% CI 0.76-1.55). Onset bias was seen in 1988-1990 PSP cohorts (relative risks for early seroconversion = 1.47, 1.46, and 1.34, respectively); in 1991-1992, relative risks were close to the expected value of 1.09, and CIs on relative risks from all PSP cohorts after 1989 included 1.0. Confounding attributable to differential length-biased sampling in prevalent cohorts does not necessarily bias estimates of the impact of covariates on rate of progression to AIDS. Bias can arise when a covariate suspected of affecting AIDS risk is closely linked to date of acquisition of HIV infection. However, onset bias appears to wane as subjects' dates of infection become more remote.

Acquired Immunodeficiency Syndrome↗
PubMed1997

The molecular epidemiology of human immunodeficiency virus type 1 in six cities in Britain and Ireland.

We have sequenced the p17 coding regions of the gag gene from 211 patients infected either through injecting drug use (IDU) or by sexual intercourse between men from six cities in Scotland, N. England, N. Ireland, and the Republic of Ireland. All sequences were of subtype B. Phylogenetic analysis revealed substantial heterogeneity in the sequences from homosexual men. In contrast, sequence from over 80% of IDUs formed a relatively tight cluster, distinct both from those of published isolates and of the gay men. There was no large-scale clustering of sequences by city in either risk group, although a number of close associations between pairs of individuals were observed. From the known date of the HIV-1 epidemic among IDUs in Edinburgh, the rate of sequence divergence at synonymous sites is estimated to be about 0.8%. On this basis we estimate the date of divergence of the sequences among homosexual men to be about 1975, which may correspond to the origin of the B subtype epidemic.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Low production of interferon gamma is related to disease progression in HIV infection: evidence from a cohort of 347 HIV-infected individuals.

A total of 347 HIV-seropositive individuals attending the Department of Infectious Diseases at Rigshospitalet in Copenhagen and 110 age- and sex-matched healthy controls not at risk for HIV infection were included in this study. Interferon gamma (IFN-gamma) production was measured in whole blood of 223 HIV-seropositive individuals (68 had developed AIDS at enrollment) and 99 healthy sex- and age-matched controls 4.5 hr after challenge with phytohemagglutinin. HIV-infected individuals for whom IFN-gamma production was measured were followed with a median follow-up time of 2.89 years (range, 0.02-4.54 years) from the date of enrollment. Survival analysis was performed considering three different end points: (1) a CD4 count below 100 cells/mm3, (2) an AIDS diagnosis defined according to the 1993 Centers for Disease Control definition, and (3) death. The production of IFN-gamma was highly increased in the blood of HIV-infected individuals without AIDS, but decreased in the blood of AIDS patients (both compared to controls). In the HIV-infected individuals, the total production of IFN-gamma was positively correlated with the number of CD8+ T lymphocytes and with the number of CD16+/CD56+ natural killer cells and negatively correlated with serum levels of beta2-microglobulin. Low levels of IFN-gamma production were associated with an increased risk of experiencing a CD4 count below 100 cells/m3 and death, analyzed in both univariate analysis and in multivariate analysis adjusting for CD4 counts and age. Thus, changes in production of IFN-gamma seem to be truly related to the risk for disease progression in HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Survival after a very low (< 5 x 10(6)/l) CD4+ T-cell count in individuals infected with HIV.

OBJECTIVE: To describe survival after a CD4+ T-cell count of less than 5 x 10(6)/l and to identify possible baseline factors associated with outcome. DESIGN: A prospective cohort study. SETTING: A large teaching hospital in North London. PATIENTS AND PARTICIPANTS: Patients treated at the Royal Free Hospital, London, who had at least one reported CD4+ T-cell count of less than 5 x 10(6)/l and were being followed up for clinical care prior to the date of this cell count. MAIN OUTCOME MEASURE: Death. METHODS: Proportional hazards models, Kaplan-Meier analysis. RESULTS: One-hundred and sixty-nine patients were included in the study. The median survival after a very low CD4+ T-cell count was 0.95 years (95% confidence interval, 0.78-1.19), although 20% survived for over 2 years. Older age and a previous AIDS diagnosis were related to poorer outcome. A higher CD8+ T-cell count at baseline was also associated with a better prognosis. CONCLUSIONS: A CD4+ T-cell count of less than 5 x 10(6)/l did not necessarily mean imminent death, with a median survival after this count of just under 1 year. These results will enable clinicians to provide appropriate counselling for patients at this late stage and to plan terminal care.

Adolescent↗