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Biomedical subjects

B Gazzard

Publications and source records attributed to B Gazzard.

At least 37 records · Page 2Linked to original sources
PubMed2004

The common heat shock protein receptor CD91 is up-regulated on monocytes of advanced melanoma slow progressors.

Despite advances in our understanding of tumour immunology there is no therapy of proven survival benefit for advanced melanoma. Nevertheless, disease progression is slow in a small proportion of patients with metastatic melanoma, suggesting a contribution to outcome from host factors. Recent data have indicated the importance of the heat shock protein receptor CD91 in immune responses to, and progression of, infectious disease. Here we investigate the relationship between CD91 expression and outcome in malignancy. Rare melanoma patients were recruited with advanced disease that was progressing unusually slowly. CD91 expression on their monocytes was compared with control patients with more typical rapidly advancing metastatic disease. Th1 and Th2 cytokines, as well as innate and adaptive immune subsets, were also measured in the two groups. A significant increase in median CD91 expression levels was observed in slow progressors (P = 0.006). There were no differences in other immune subset markers or inflammatory cytokines. The ability of CD91 to internalize and cross-present tumour antigens through the major histocompatibility complex class I pathway may maintain CD8-positive cytotoxic T cell responses and contribute to slow progression of advanced melanoma.

Adult↗
PubMed2004

Hypokalaemia in ibuprofen and codeine phosphate abuse.

Ibuprofen abuse may be more prevalent than generally considered. Although normally benign, serious complications have been documented. We report an unusual presentation of hypokalaemia and its associated symptoms as a result of Nurofen Plus (200 mg ibuprofen + 12.8 mg codeine phosphate) abuse. Ibuprofen is generally not included in a standard toxicology screen, but should be considered as a rare cause of hypokalaemia.

Analgesics, Non-Narcotic↗
PubMed2004

Evidence of thymic reconstitution after highly active antiretroviral therapy in HIV-1 infection.

OBJECTIVES: We aimed to provide evidence of thymic reconstitution after highly active antiretroviral therapy (HAART) in HIV-1 infected patients and to correlate this with the restoration of peripheral naïve T cells. METHODS: Positron emission tomography (PET) enables definitive evidence of thymic activity, indicating functional potential. In this case study, a single patient who initiated HAART demonstrated reconstitution of the naïve T-cell pool and underwent thymic PET scans at baseline and 2 and 6 months following initiation of therapy. Two patients who failed to demonstrate such reconstitution acted as controls. These patients (mean age 27 years) had chronic HIV infection with low CD4 T-cell counts (mean 82, range 9-160 cells/microL blood). Increased function of the thymus visualized by PET was correlated with phenotypic changes in CD4 and CD8 T cells in the periphery measured by flow cytometry, and with numbers of recent thymic emigrants measured by quantification of the numbers of T-cell receptor excision circles (TRECs) in peripheral cells. RESULTS: In one patient, clear correlations could be drawn between visible activity within the thymus, as measured by increased [F18]fluorodeoxyglucose (FDG) uptake, and regeneration of naïve CD4 (CD45RA/CD62L) T cells, increased numbers of CD4 T cells, controlled viraemia and increased numbers of recent thymic emigrants. A second patient displayed no increase in peripheral CD4 count and no increase in thymic activity. The third patient elected to stop therapy following the 2-month time point. CONCLUSIONS: The use of PET suggests that thymic activity may increase after HAART, indicating that the thymus has the potential to be functional even in HIV-1 infected persons with low CD4 T-cell counts.

Adult↗
PubMed2004

Head and neck cancer in patients with human immunodeficiency virus-1 infection: incidence, outcome and association with Epstein-Barr virus.

Head and neck cancers have been described in patients with human immunodeficiency virus-1 (HIV-1) infection. However the incidence, aetiology and clinical features of the disease remain unclear. Patients with head and neck cancer and HIV were identified from a large HIV centre. The incidence and clinical features were recorded, and the tumours were stained for Epstein-Barr virus (EBV). Head and neck cancer occurred more frequently than in an age-matched control group (1.66 vs 0.55/10,000 patient years respectively p < 0.05). Highly active anti-retroviral therapy has not significantly altered the incidence of the disease. All of the tumours tested were positive for EBV. Patients were moderately immunosuppressed at diagnosis and had aggressive tumours. All but one of the patients died of cancer with a median survival of 28 months. Head and neck cancer occurs more frequently in HIV. It is an aggressive disease and EBV may play a role in its pathogenesis.

Adult↗
PubMed2003

Comparison of metabolic abnormalities 48 weeks after switching from highly active antiretroviral therapy containing a non-nucleoside reverse transcriptase inhibitor to Trizivir versus continued highly active antiretroviral therapy.

Forty patients participating in the TRIZAL study were treated with a non-nucleoside reverse transcriptase inhibitor (NNRTI)-containing regimen before being randomly assigned either to continue their baseline therapy or to switch to a triple nucleoside regimen. No difference was observed in treatment efficacy between the two groups, and total cholesterol was observed to improve significantly in the switch group. Switch maintenance may be an appropriate strategy in patients treated with an NNRTI.

Antiretroviral Therapy, Highly Active↗
PubMed2003

Does HIV adversely influence the outcome in advanced non-small-cell lung cancer in the era of HAART?

The objectives of the study are to assess the impact of HIV status on the outcome of patients with non-small-cell lung cancer (NSCLC) in the era of highly active antiretroviral therapy (HAART). Patients diagnosed with HIV-related NSCLC in the HAART era (since January 1996) were identified from a prospective single-centre lung cancer database. The clinicopathological characteristics and outcome of each HIV-positive patient were compared to three age- and stage-matched HIV-negative controls with NSCLC who were diagnosed over the same time period and treated in an identical manner. The results showed that the two groups had similar disease characteristics and received a similar amount of chemotherapy. The median overall survival of the two groups was the same (4 months, log rank P=0.55). None of the HIV-positive patients developed an AIDS defining illness or died of HIV during treatment or follow-up. In conclusion, in this cohort, HIV status does not influence the prognosis of advanced NSCLC. This suggests that the survival of patients with HIV-related NSCLC may have improved since the introduction of HAART, and this may be due to a decrease in HIV-related deaths.

Adult↗
PubMed2003

Multicenter study of human immunodeficiency virus-related germ cell tumors.

PURPOSE: Testicular germ cell tumors (GCT) occur at increased frequency in men with human immunodeficiency virus (HIV). This multicenter study addresses the characteristics of these tumors. PATIENTS AND METHODS: Patients with HIV-related GCT were identified from six HIV treatment centers. The incidence was calculated from the center with the most complete linked oncology and HIV databases. RESULTS: Thirty-five patients with HIV-related GCT were identified. The median age at GCT diagnosis was 34 years (range, 27 to 64 years). The median CD4 cell count was 315/mm3 (range, 90 to 960/mm3) at this time. The histologic classification was seminoma in 26 patients (74%) and nonseminomatous GCT in nine patients (26%). Twenty-one patients (60%) had stage I disease and 14 patients had metastatic disease. Overall six patients relapsed, three died from GCT, and seven died from HIV disease, resulting in a 2-year overall survival rate of 81%. HIV-related seminoma occurred more frequently than in the age- and sex-matched HIV-negative population, with a relative risk of 5.4 (95% confidence interval, 3.35 to 8.10); however, nonseminomatous GCT did not occur more frequently, and there was no change in the incidence of GCT since the introduction of highly active antiretroviral therapy. CONCLUSION: Testicular seminoma occurs significantly more frequently in HIV-positive men than in the matched control population. Patients with HIV-related GCTs present and should be treated in a similar manner to those in the HIV-negative population. After a median follow-up of 4.6 years, 9% of the patients died from GCT. Most of the mortality relates to HIV infection.

Adolescent↗
PubMed2003

An open-label study of tenofovir in HIV-1 and Hepatitis B virus co-infected individuals.

BACKGROUND: Tenofovir is a novel nucleotide analogue recommended for use in HIV-1 infected treatment-experienced patients. Recent data suggest an effect on Hepatitis B virus (HBV) replication. We therefore investigated the use of tenofovir in HIV-1 and HBV co-infected individuals. METHODS: Twenty HIV-1/HBV co-infected patients with a median of 108 weeks lamivudine experience (range, 0-270 weeks) received tenofovir 245 mg daily in addition to or as part of their combination antiretroviral therapy. Their immunologic parameters and HIV-1 RNA and HBV DNA viral loads were followed over a period of 52 weeks. In addition, their HBV DNA polymerase was sequenced at baseline to measure the frequency of YMDD mutations that are associated with lamivudine resistance. FINDINGS: A significant decrease in HBV DNA viral load (4 x log ) and alanine aminotransferase levels was observed. There were no significant overall differences between the lamivudine-experienced (n = 15) and -naive (n = 5) individuals and tenofovir was well tolerated. Five patients (25%) underwent HBe antigen seroconversion during the study period. Out of the 15 lamivudine-experienced individuals, 10 had YMDD mutations and one had YIDD mutations in HBV DNA. INTERPRETATION: These results indicate that 52 weeks of tenofovir in addition to antiretroviral therapy is active against HBV, and it appears to overcome lamivudine resistance.

Adenine↗
PubMed2003

TRIZAL study: switching from successful HAART to Trizivir (abacavir-lamivudine-zidovudine combination tablet): 48 weeks efficacy, safety and adherence results.

OBJECTIVE: To assess the antiviral efficacy, safety, and adherence in subjects who switched to Trizivir following long-term HIV-1 RNA suppression. STUDY DESIGN: A randomized, open-label, multicentre, 48-week comparative study in subjects who have received two nucleoside reverse transcriptase inhibitors plus a protease inhibitor or an nonnucleoside reverse transcriptase inhibitor or three nucleoside reverse transcriptase inhibitors for at least 6 months, with a history of undetectable plasma HIV-1 RNA since initiation of therapy and plasma viral load of < 50 HIV-1 RNA copies/mL at screening. METHODS: Subjects were randomized 1:1 to continue their current treatment or to switch to a simplified treatment with Trizivir administered twice daily. Assessments included plasma HIV-1 RNA, lymphocyte counts, clinical laboratory evaluations, adverse events, and adherence to treatment (obtained via subject self-report). Treatment failure was defined as a plasma viral load of >/= 400 HIV-1 RNA copies/mL on two consecutive occasions or premature discontinuation of randomized treatment. RESULTS: At week 48, the proportion of treatment failures in Trizivir arm (23/106, 22%) was noninferior to that observed in continued arm (23/103, 22%) with a treatment difference stratified by prior ART of 1.2%[-10.1; 12.5]. Incidence of adverse events was similar in both treatment groups. The incidence of possible hypersensitivity reaction in the Trizivir trade mark arm was 10%. Significant reductions in cholesterol and triglyceride plasma levels were observed in the Trizivir arm (P < 0.001 and P = 0.006, respectively). CONCLUSION: Switching to Trizivir offers a potent and simplified regimen with equivalent efficacy and significant improvement in lipid abnormalities compared to continued triple therapy.

Adult↗
PubMed2003

Matched case-control study to evaluate risk factors for hyperlactataemia in HIV patients on antiretroviral therapy.

BACKGROUND: Lactic acidosis is a life-threatening event during antiretroviral therapy (ART). Hyperlactataemia may be a prelude to acidosis. Our database study suggested that female gender, intercurrent illness and didanosine (ddI)-based regimens may increase risk of lactic acidosis. The aim of this matched case-control study was to identify risk factors for hyperlactataemia requiring screening. METHODS: Cases were defined as patients with two consecutive lactate samples > or =3.5 mmol/L taken more than 1 week apart. Cases were matched to two controls on gender, use of ddI and total duration of therapy using a 6-month window on either side. Controls never had raised lactate >2.5 mmol/L. A conditional logistic regression analysis using the PHREG procedure in SAS (SAS Institute Inc, Cary, NC) was performed with a discreet logistic model stratified by matching variables. RESULTS: Twenty-one cases were matched to 42 controls. In the univariate model, current use of stavudine (d4T), total cholesterol >5.3 mmol/L and glucose levels > or =5.2 mmol/L gave increased likelihood of persistent hyperlactataemia. The multivariate model showed current use of d4T to be a significant independent predictor of persistent hyperlactataemia. CONCLUSIONS: The results of this case-control study indicate that, when controlling for ddI use, d4T use is an additional risk factor for hyperlactataemia.

Acidosis, Lactic↗
PubMed2003

Loss of the CD56hiCD16- NK cell subset and NK cell interferon-gamma production during antiretroviral therapy for HIV-1: partial recovery by human growth hormone.

Previous studies have shown that human natural killer (NK) cells are lost from the periphery and are functionally suppressed during HIV-1 infection, and that the administration of highly active antiretroviral therapy (HAART) results in a recovery of NK cell numbers in HIV-1-infected individuals. However, despite this recovery, interleukin (IL)-2 + IL-12-driven interferon (IFN)-gamma production by NK cells has been shown to remain suppressed after HAART. Here we show that the innate immune factor IL-15 in combination with IL-12 is also unable to recover NK cell IFN-gamma production in HAART-treated individuals. Furthermore, we also demonstrate an imbalance in the distribution of CD56loCD16hi and CD56hiCD16- NK subsets after successful HAART, CD56hiCD16- cells being reduced substantially in HIV-1 patients on HAART. Treatment of patients with combined human growth hormone and antiretroviral therapy resulted in further enhancement in the absolute numbers and the proportion of NK cells in some individuals in the absence of parallel effects on CD4+ T cells. Furthermore, in these individuals HAART with growth hormone resulted in an enhancement of cytokine-driven NK cell activation and IFN-gamma production compared to the HAART-only baseline.

Anti-HIV Agents↗
PubMed2003

Prospective cohort study showing changes in the monthly incidence of Pneumocystis carinii pneumonia.

Pneumocystis carinii pneumonia (PCP) remains a serious opportunistic infection in HIV infected individuals. Seasonal changes in climate are associated with changes within individual susceptibility to infection. The possibility of monthly variability in the incidence of PCP was therefore examined by means of a cohort study of a database of 8640 HIV infected individuals attending the Chelsea and Westminster Hospital. There were 792 cases of PCP diagnosed since 1985. A marked decline was observed in the incidence of PCP in mid-1992 coincident with the introduction of PCP prophylaxis. There was a further decline in 1996 after the introduction of highly active antiretroviral therapy. Despite no significant monthly variation in the mean attendance to clinic and CD4 count, both new and all cases of PCP were higher in January than in other months (15.9% and 14.5% of all cases, respectively). A correlation with low rainfall in January and new cases of PCP was observed. These data are consistent with an influence of climatic conditions on the presentation of PCP. The diagnosis of PCP is more common in winter months suggesting that this is a transmissible infection.

AIDS-Related Opportunistic Infections↗
PubMed2003

Pneumonia due to antibiotic resistant Streptococcus pneumoniae and Pseudomonas aeruginosa in the HAART era.

Antibiotic resistance profiles are useful in directing therapeutic strategies during bacterial infections. Patterns of antimicrobial resistance in Streptococcus pneumoniae and Pseudomonas aeruginosa associated pneumonia were investigated in an HIV-1 infected cohort during the era of highly active antiretroviral therapy. The median CD4 count at presentation was significantly lower for cases of P aeruginosa than for S pneumoniae. However, the number of antibiotic resistant cases of P aeruginosa decreased throughout the study period, while the incidence of S pneumoniae remained unchanged. In contrast to pneumococcal pneumonia, we show that antiretrovirals have protected from pneumonia due to antibiotic resistant P aeruginosa. These findings have implications for the treatment of individuals presenting with serious infections in which antibiotic therapy needs to be instituted before identification and sensitivities are known.

AIDS-Related Opportunistic Infections↗
PubMed2002

Impact of NNRTI compared to PI-based highly active antiretroviral therapy on CCR5 receptor expression, beta-chemokines and IL-16 secretion in HIV-1 infection.

Interleukin-16 (IL-16) and the beta-chemokines (RANTES, monocyte chemotactic protein-1 (MCP-1), macrophage inhibitory protein (MIP)-1alpha and (MIP)-1beta) are soluble in vitro suppressors of macrophage tropic HIV-1 strains. The reduction of HIV-1 RNA plasma levels in late-stage patients receiving protease inhibitors has been associated with increased concentrations of MIP-1alpha, MIP-1beta, RANTES and IL-16 and a decrease in levels of MCP-1. We determined plasma levels of MCP-1, MIP-1alpha, MIP-1beta, RANTES and IL-16 during the first 16 weeks of highly active antiretroviral therapy (HAART) in chronic HIV-1-infected patients. Patients were administered one of two therapeutic regimens based on either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI). No differences were seen in the levels of RANTES and IL-16 over the first 16 weeks of HAART in either treatment group. MCP-1 decreased significantly in the PI-treated group over the first 16 weeks of HAART (P = 0.0003). A significant increase was observed in the levels of MIP-1alpha and MIP-1beta in the NNRTI cohort (P = 0.0010 and P = 0.0012, respectively). A significant decrease in levels of MIP-1alpha and MIP-1beta (P = 0.0015 and P = 0.0299, respectively) was observed over the 16 weeks in the PI cohort. A significant difference was seen when the levels of MIP-1alpha and MIP-1beta were compared between the NNRTI and the PI cohorts at week 16 (P = 0.04 and P = 0.05, respectively). Evaluation of CCR5 expression ex vivo revealed no difference between the two treatment groups. Patients were genotyped for CCR5 Delta32 and the incidence of heterozygosity was lower than in the HIV-1 seronegative controls (3% compared to 19%).

Adult↗
PubMed2002

Thymic activity in late-stage HIV-1 infected individuals receiving highly active antiretroviral therapy: potential effect of steroid therapy.

OBJECTIVE: Our objective was to monitor the effect of steroid therapy on the thymic output and function of late-stage HIV-1-infected patients undergoing highly active antiretroviral therapy (HAART). DESIGN: The indirect measurement of T cells that have recently emigrated from the thymus as a means of quantifying thymic output, and therefore thymic function, was achieved through use of the polymerase chain reaction-based signal joint T cell receptor rearrangement excision circles (sjTREC) assay. Proliferative capacity and interleukin (IL)-2 and IL-4 production by T cells after antigenic, mitogenic and IL-2 stimulation were also analysed. METHOD: Measurements were made of sjTREC levels in peripheral blood mononuclear cell DNA samples from five HIV-1 infected patients (one on steroid therapy prior to and at the time of sample extraction) receiving HAART. IL-2 and IL-4 production and proliferative capacity were also measured in three patients, including the patient receiving steroids. RESULT: The sjTREC assay gave an extremely weak result for the patient on steroids but, under the same assay conditions, provided clear, positive readings for the four patients not on steroids. Comparison of the patients' cytokine profiles revealed that IL-2 production was generally low or absent in all three patients tested but that IL-4 production was significantly higher in the patient given steroids. Functional potential as revealed by proliferation assays showed very low or absent cellular proliferation. CONCLUSION: The thymic contribution to the restoration of T lymphocyte numbers, particularly during the treatment of HIV-1 infection, may become compromised if thymic inhibitory factors such as steroids are used. Furthermore, the use of steroids may also favour the development of a T helper 2 response, which could prove particularly undesirable during HIV-1 infection.

Adult↗
PubMed2002

Naively changing HAART.

BACKGROUND: Few UK studies have systematically investigated which antiretroviral therapy (ART) combinations HIV-infected people are commenced on, when they start and reasons for stopping or changing their regimens. OBJECTIVE: To describe when HIV-infected ART-naive patients started first-, second- or third-line triple ART, classes of drugs prescribed and whether stopping ART was associated with virological, immunological or clinical indicators of treatment failure. DESIGN: A multicentre prospective open cohort study, employing the National Prospective Monitoring System on the use, cost and outcome of HIV service provision in UK hospitals-HIV Health-economics Collaboration (NPMS-HHC). SETTING: Five hundred and eighty-five ART-naive patients seen in one London and two non-London HIV clinics between 1 January 1998 and 31 December 1999. RESULTS: Of 4,044 HIV-infected individuals seen, 585 (15%) were ART naive. Median time interval (interquartile range, IQR) between HIV diagnosis and starting triple ART was 800 (63-2,094) days. Median CD4 count when first diagnosed with HIV infection was 278 (IQR 127-481) cells/ micro L which dropped to 190 (IQR 86-297) cells/ micro L when starting triple ART. Of these 585 patients, 162 started second-line and 46 third-line ART during the study period. Of those patients who stopped ART, 51% did not have evidence of virological, immunological or clinical indicators of therapy failure. CONCLUSIONS: Reasons for the delay between diagnosis of HIV infection and starting ART are varied. The large proportion of individuals who stopped ART for reasons other than virological, immunological or clinical indicators of therapy failure, are most likely due to drug-associated toxicity. Both of these findings need to be elucidated in greater detail through prospective studies.

Adult↗