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Biomedical subjects

S Madge

Publications and source records attributed to S Madge.

At least 19 recordsLinked to original sources

Airway function in infants newly diagnosed with cystic fibrosis.

The lung function of infants with cystic fibrosis is often reduced shortly after diagnosis. We measured the airway function of newly diagnosed infants to test whether this reduction is independent of clinically recognised lower respiratory illness. We compared the airway function of 33 infants with cystic fibrosis and 87 healthy controls after adjustment for sex, age, bodyweight and length, and exposure to maternal smoking. Airway function was significantly reduced in children with cystic fibrosis, even in those without clinically recognised previous lower respiratory illness. Our findings raise important questions about the onset and natural history of impaired airway function in infants with cystic fibrosis.

Case-Control Studies↗

Reduced bone mineral density in HIV-positive individuals.

A total of 105 HIV-positive patients underwent dual-energy X-ray absorbtiometry (DEXA) scan to assess bone mineral density (BMD). The prevalence of reduced BMD was found to be 71% and was higher in patients who had ever been treated with protease inhibitors (PI). Our results suggest a possible association between PI and reduced BMD, and further complicate the debate regarding when to commence treatment of HIV and with what agents to start.

Absorptiometry, Photon↗

Gender differences in virologic response to treatment in an HIV-positive population: a cohort study.

OBJECTIVE: To establish whether a gender difference in virologic response to highly active antiretroviral treatment (HAART) exists. METHODS: A cohort of HIV-positive individuals was examined. OUTCOMES: Achievement of viral load <500 copies/ml and "failure" (failure to suppress viral load <500 copies/ml after 24 weeks or two consecutive measurements above this level after having suppressed below it). Hazard ratios (HRs) comparing the rate in women to that in men were derived using the Cox model. RESULTS: Of 366 male subjects, 79% were white and 82% were homosexual. Sixty-three percent of the 91 female subjects were African and 87% were heterosexual. The median follow-up after HAART was 94 weeks. The baseline CD4 count was higher in men (228 x 106 per liter) than in women (171 x 106 per liter) (p =.01), but the viral load was similar (p =.88). The median time to <500 copies/ml was 16 weeks. Women achieved a viral load of <500 copies/ml at a faster rate than men, with an adjusted HR of 1.46 (95% confidence interval [CI]: 0.99-2.16; p =.06). Some 261 patients failed treatment (58% of men and 53% of women) with an HR of 0.78 (95% CI: 0.51-1.21; p =.27). CONCLUSIONS: Women may achieve virologic suppression at a faster rate than men and have a more durable response. Further research should examine these responses in conjunction with clinical outcomes, because gender differences in virologic response may ultimately be of little relevance if clinical outcomes are similar.

Adult↗

Reasons for modification and discontinuation of antiretrovirals: results from a single treatment centre.

OBJECTIVE: To describe the reasons for, and factors associated with, modification and discontinuation of highly active antiretroviral therapy (HAART) regimens at a single clinic. SUBJECTS: A total of 556 patients who started HAART at the Royal Free Hospital were included in analyses. Modification was defined as stopping or switching any antiretrovirals in the regimen, whereas discontinuation was defined as the simultaneous stopping of all antiretrovirals included in the initial regimen. Reasons were classified as immunological/virological failure (IVF) and toxicities and patient choice/poor compliance (TPC). RESULTS: The median CD4 count at starting HAART was 171 x 10(6) cells/l and viral load 5.07 log copies/ml. During a median follow-up of 14.2 months, 247 patients (44.4%) modified their HAART regimen, 72 due to IVF (29.1%) and 159 due to TPC (64.4%) and a total of 148 patients (26.6%) discontinued HAART. Older patients were less likely to modify HAART [relative hazard (RH), 0.73 per 10 years; P = 0.0008], as were previously treatment-naive patients (RH, 0.65; P = 0.0050), those in a clinical trial (RH, 0.64; P = 0.027) and those who started nelfinavir (RH, 0.57; P = 0.035). Patients who started with four or more drugs (RH, 2.21, P < 0.0001), who included ritonavir in the initial regimen (RH, 1.41; P = 0.035) or who had higher viral loads during follow-up (RH per log increase, 1.51; P < 0.0001) were more likely to modify HAART. CONCLUSIONS: There was a high rate of modification and discontinuation of HAART regimens in the first 12 months, particularly due to toxicities, patient choice or poor compliance.

Antiretroviral Therapy, Highly Active↗

Changes in CD4 lymphocyte counts after interruption of therapy in patients with viral failure on protease inhibitor-containing regimens. Royal Free Centre for HIV Medicine.

OBJECTIVE: To describe the short-term changes in CD4 lymphocyte counts after the interruption of antiretroviral HIV therapy in order to increase the understanding of CD4 lymphocyte dynamics, and so that appropriate monitoring strategies can be designed. METHODS: We studied 35 HIV-infected patients with late-stage disease who had therapy interruptions leading to high viral load levels, median greater than 750 000 RNA log10 copies/ml, and in whom two CD4 cell counts (median 28 days apart) were available before beginning a salvage regimen. RESULTS: Overall, there was a substantial decline in CD4 cell counts from a median of 125 to 83 cells/mm3 in the average 28 day period, with median proportionate and absolute losses of 26% and 24 cells/mm3 per month, respectively (P < 0.008). This tended to be greater in individuals studied sooner after interrupting therapy (P = 0.03) and in those with CD4 cell counts above the pre-therapy baseline (P = 0.06). There was a strong negative correlation between the proportionate increase in viral load and the absolute change in CD4 cell count (-0.66, P = 0.0002). CONCLUSION: Patients with relatively advanced HIV infection interrupting antiretroviral therapy after failing a protease inhibitor-containing regimen require frequent monitoring because CD4 cell counts appear to fall quite rapidly, at least in the first few weeks after interruption.

Adult↗

Immunological, virological and clinical response to highly active antiretroviral therapy treatment regimens in a complete clinic population. Royal Free Centre for HIV Medicine.

BACKGROUND: Highly active antiretroviral therapy (HAART) is now widely used in clinical practice and gives rise to a range of immunological, virological and clinical responses. OBJECTIVES: To describe the immunological, virological and clinical response to HAART and to examine the frequency of modification of the HAART regimen among patients from a single treatment centre. METHODS: Kaplan-Meier estimation and incidence rates were used to describe responses to HAART (a protease inhibitor or non-nucleoside drug in addition to at least two nucleoside analogues) among 421 patients from the Royal Free Hospital in London. RESULTS: The median CD4 cell count at starting HAART was 186 x 10(6) cells/l [interquartile range (IQR) 76-310] and viral load was 5.13 log10 copies/ml (IQR 4.66-5.56). At 6 months after starting HAART, 51.1% of patients were estimated to have experienced a 100 x 10(6) cells/l increase in CD4 cell count; the median time for viral load to fall below 400 copies/ml was 3.7 months (95% confidence interval 3.2-4.4). At 6 months after the first viral load was < 400 copies/ml, 16.4% of patients were estimated to have failed on the basis of a single viral load > 400 copies/ml and 12.4% were estimated to have failed if the more stringent definition of two viral loads above the limit of detection was used. Compared with the pre-HAART era, the incidence of death among patients on HAART was one sixth of that level; new AIDS-defining illnesses was one seventh; and hospital admissions was one fifth. In total, 141 patients (33.5%) stopped at least one of the antiretroviral agents included as part of their HAART regimen; the occurrence of side effects was the most common reason (n = 63; 44.7%). CONCLUSION: A good response occurred to an initial HAART regimen. There was a high rate of virological relapse, which varied considerably according to the definition of failure used. Even so, the rates of clinical progression and hospital admissions observed to date were low. Further follow-up of these patients is required to determine their long-term immunological, virological and clinical outcome.

Anti-HIV Agents↗

Participation in clinical studies among patients infected with HIV-1 in a single treatment centre over 12 years.

OBJECTIVE: To examine a complete population of clinic attenders in order to compare the demographics of patients who participated in a clinical study with those who had not. These were subdivided into trials of antivirals, trials for drugs used in opportunistic infections or symptomatic HIV and epidemiological studies. The setting was an established London teaching hospital. All patients diagnosed HIV-positive and attending between July 1983 and 1 January 1999 with one measured CD4 count and at least one follow-up visit were included. METHODS: The demographics of those participating in a clinical study were compared to those not enrolling using chi2 tests and Wilcoxon tests. Cox models were used to determine factors related to participation in clinical studies. RESULTS: Data from 2703 patients representing 5342.7 person-years' follow-up were assessed. Median time of follow-up was 23.6 months. Six hundred and eighty-seven (33%) patients had ever participated in a clinical study. After adjustment for demographic factors in multivariate analysis using Cox models, homosexuals were more likely to participate compared with heterosexuals or injecting drug users (IDU) (P = 0.0035 and P = 0.0001, respectively). Women were more likely to enter a study (P = 0.02) and there was no difference between Caucasians and black Africans (P = 0.35). Between the three types of studies few differences were seen. CONCLUSION: High rates of participation in clinical trials and epidemiological studies were seen in this cohort. In keeping with other studies, homosexual men were well represented but IDU were under-represented. However, women and black African patients showed good uptake of all clinical studies. Hence in this population there is some success in targeting representative groups to participate in clinical studies, but more effort needs to be made with IDU.

AIDS-Related Opportunistic Infections↗

Multidisciplinary teams in the United Kingdom: problems and solutions.

Creating a team requires a clear strategy with objectives and boundaries. Teams succeed or fail depending on the enthusiasm and dedication of the members. Important points to consider in maintaining effectiveness include team philosophy, leadership, dynamics, communication, and workload. Members provide a unique contribution that must be valued and respected. Maintaining a productive and friendly team can become difficult. Issues such as uncertainty of the team's position in the overall service, caseload, poor coordination between team members, and uneven work distribution may cause disruption. To ensure a functioning and useful team, members must be constantly aware of their working relationships with each other and the impact they have on patients, families, and colleagues.

Child↗

A comparison of exposure groups in the EuroSIDA study: starting highly active antiretroviral therapy (HAART), response to HAART, and survival.

BACKGROUND: Concerns have been raised that intravenous drug users may be less likely to start highly active antiretroviral therapy (HAART) and that adherence to therapy may be poor among this group of patients. Given the decreased mortality and incidence of AIDS-defining illnesses among patients with HIV who start HAART, this may lead to a poorer prognosis among intravenous drug users. PURPOSE: To compare homosexual men, intravenous drug users, and heterosexuals in EuroSIDA, a prospective European cohort of 7331 patients with HIV in terms of starting a HAART treatment regimen, immunologic and virologic response to therapy, and survival. METHODS: 6645 patients were included in this analysis. Logistic regression and Cox proportional hazards models were used to investigate the factors associated with use of HAART regimens and survival following recruitment to the EuroSIDA study. RESULTS: In a multivariate logistic regression model, intravenous drug users were significantly less likely to be receiving HAART at recruitment to EuroSIDA (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.37-0.62; p<.0001) when compared with homosexual men. Similarly, during follow-up, intravenous drug users were at a 27% reduced risk of starting HAART, after adjustment for other factors related to starting HAART (relative hazard [RH], 0.73; 95% CI, 0.64-0.82; p<.0001). There were no differences between heterosexual and homosexual patients, and similar results were found within regions of Europe (South, Central and Northern). Among those patients who started HAART, there were no significant differences between exposure groups in CD4 lymphocyte count response to HAART or virologic response to HAART. After adjustment for factors related to survival, intravenous drug users were at a small, but nonsignificant increased risk of death compared with homosexuals (RH 1.16; 95% CI, 0.99-1.38; p = .074). CONCLUSIONS: Intravenous drug users were significantly less likely to start HAART, but among those who did, response to therapy was similar to that of other exposure groups. There were no differences in risk of death. If intravenous drug users continue to use HAART less commonly than other exposure groups, it may result in a poorer prognosis, a different spectrum of AIDS-defining illnesses, and differential long-term clinical needs.

Adult↗

Changes in AIDS-defining illnesses in a London Clinic, 1987-1998.

OBJECTIVES: To describe the incidence of AIDS-defining illnesses within a single large clinic setting, to describe temporal changes over a 10-year period in the overall incidence and of individual AIDS-defining illnesses and to investigate the impact of HIV treatment regimen on the incidence of AIDS-defining illnesses. SUBJECTS AND METHODS: A person-years analysis was used to determine the incidence of AIDS-defining illnesses according to calendar year and stratification by CD4 lymphocyte count and treatment regimen in 1806 patients from the Royal Free Centre for HIV Medicine with at least one CD4 lymphocyte count and follow-up visit. RESULTS: Prior to 1992, the incidence of all AIDS-defining illnesses was 27.4/100 person-years of follow-up (PYFU; 95% confidence interval [CI], 22.8-32.0) and during 1997 this incidence had dropped to 6.9/100 PYFU (95% CI, 4.7-9.1; p < .0001, test for trend). The decline in incidence over time occurred in esophageal candidiasis, cytomegalovirus disease (including retinitis), Kaposi's sarcoma, lymphoma, wasting syndrome, and Pneumocystis carinii pneumonia (p < .05, test for trend), but there was no evidence of a decline in AIDS dementia or in Mycobacterium avium complex. In 1997, among patients with CD4 lymphocyte counts of < or =200 cells/mm3, the incidence rates for any AIDS-defining illness was 51.1/100 PYFU for patients taking no therapy (95% CI, 27.9-85.7), 34.5 among patients on monotherapy (95% CI, 4.2-124.6), 13.2 among patients taking dual combination therapy (95% CI, 3.6-33.8) and 6.1 among patients taking triple therapy or more complex regimens (95% CI, 0.7-22.0; p < .0001, test for trend). CONCLUSIONS: There was a considerable decline in AIDS-defining illnesses during 1996 and 1997, coinciding with the rapid development of new antiretroviral treatments and combinations of treatment. Further follow-up of large observational cohorts is essential to monitor the incidence of diagnoses less common than we were able to consider, such as tuberculosis, cryptosporidiosis, and cryptococcosis, and also to investigate whether the incidence of disease continues to fall, or whether it starts to rise again, as toxicities, compliance, drug resistance, and long-term side effects begin to appear.

AIDS Dementia Complex↗

In vivo HIV-1 replicative capacity in early and advanced infection.

OBJECTIVE: Previous studies on patients treated with potent antiretroviral therapy have shown that viral clearance rates do not tend to change between early and advanced HIV-1 infection. Our objective was to investigate whether the other major aspect of virus dynamics, viral replicative capacity, does change. In vitro work has indicated that the viral replicative, capacity increases but in vivo evidence has been lacking. METHODS: As an in vivo measure of the viral replicative capacity, we studied the rate of rebound of plasma HIV RNA level during a 1-week therapy interruption in previously untreated patients who had received 2 weeks of antiretroviral therapy. RESULTS: Such therapy in five previously drug-naive patients with high CD4 lymphocyte counts (mean, 611 x 10(6)/l) and five patients with low counts (mean, 49 x 10(6)/l) led to a mean 2.2 log10 copies/ml decrease in plasma HIV-1 levels (from 5-6 log10 copies/ml) in 2 weeks. This was similar in the two groups. Interruption of therapy for the ensuing week resulted in a stable HIV-1 level for approximately 2 days followed by a rebound towards pretherapy level, which was much more marked in the patients with low CD4 cell counts (estimated mean rise 2.22 log10 versus 1.06 log10 copies/ml; P < 0.02). After restarting therapy, HIV RNA levels returned to pre-interruption levels. CONCLUSIONS: These findings need confirmation, but the ability of HIV-1 to replicate in vivo appears to increase during HIV-1 infection. This increased replicative capacity, for which there are several potential explanations, may be the cause of gradual CD4 lymphocyte depletion.

HIV Infections↗

Changing treatment patterns among patients with HIV: Royal Free Hospital 1987-97.

OBJECTIVE: Following the publication of results of large-scale clinical trials, antiretroviral treatment for HIV has changed dramatically. The aim of this study was to describe changes in antiretroviral treatment and the way treatments were combined among 1806 patients with HIV seen at a single centre at the Royal Free Hospital, London, UK. DESIGN AND METHOD: Each calendar year was divided into quarters, and the number of patients receiving treatment and participating in clinical trials was determined. RESULTS: The proportion of patients on no therapy decreased from over 90% at the beginning of 1988 to under 15% at the end of 1997. Monotherapy was the only form of treatment available before 1992 but its use dropped to 2% by the end of 1997. The standard of care at the end of 1997 was triple combination therapy, used in over 40% of patients. There were dramatic changes in the use of individual agents; use of zidovudine decreased from 50% during 1989 to 25% during 1997, while use of lamivudine and stavudine saw an exponential rise in 1997. The protease inhibitors were used in equal proportions in this clinic population; the use of dual protease therapy began in 1997 and was rising rapidly by the end of the year. CONCLUSIONS: There have been major changes in the use of antiretroviral therapy at this centre, particularly during 1996 and 1997. The long-term cost implications and side-effects of intensive treatment regimens remain to be addressed.

Adult↗