OUP accepted manuscript

Current methods for tuberculosis treatment monitoring are suboptimal. We evaluated plasma matrix metalloproteinase (MMP) and procollagen III N-terminal propeptide concentrations before and during tuberculosis treatment as biomarkers. Plasma MMP-1, MMP-8, and MMP-10 concentrations significantly decreased during treatment. Plasma MMP-8 was increased in sputum Mycobacterium tuberculosis culture–positive relative to culture-negative participants, before (median, 4993 pg/mL [interquartile range, 2542–9188] vs 698 [218–4060] pg/mL, respectively; P = .004) and after (3650 [1214–3888] vs 720 [551–1321] pg/mL; P = .008) 6 months of tuberculosis treatment. Consequently, plasma MMP-8 is a potential biomarker to enhance tuberculosis treatment monitoring and screen for possible culture positivity.

The effect of a multifaceted postoperative nausea and vomiting reduction strategy on prophylaxis administration amongst higher-risk adult surgical patients

Postoperative nausea and vomiting (PONV) is a common and distressing problem for patients and increases the burden of care in post-anaesthesia care units (PACU). As such it has been a recent focus for quality improvement. Evidence-based guidelines have demonstrated the benefit of PONV risk stratification and prophylaxis, but may be underutilised in clinical practice. This prospective pre-/post-intervention study was conducted at an adult tertiary hospital in non-cardiac adult surgical patients at higher-risk of PONV. The intervention included promotion of an evidence-based PONV guideline, and provision of individualised prescribing and patient outcome data to anaesthetists. Six hundred and twenty-eight patients with ≥2 risk factors for PONV following general anaesthesia for non-cardiac surgery were included (333 pre-intervention and 295 post-intervention). Prior to the intervention, 9.0% (30/333) of moderate- and high-risk patients received antiemetic prophylaxis consistent with our guideline. Post-intervention, the rate of guideline adherence was 19.3% (57/295). In the high-risk PONV group, the time in PACU was significantly reduced post-intervention, 66 minutes versus 83 minutes (<i>P</i>=0.032). This institution-specific PONV reduction strategy had a modest but significant effect on improving prophylaxis administration. However, our findings indicate that further efforts would be required to ensure fuller compliance with the current extensive evidence base for PONV management in higher-risk patients.

The ethics of a clinical trial when the protocol clashes with international guidelines

Due to their nature and complexity, clinical trials often take some time to launch after the protocol has been designed and ethics approval obtained. During this time, there may be changes in international treatment guidelines and recommendations that result in a conflict between study protocol and recommended international best practice. Here, we describe the situation that arose in a pharmacokinetic study on the use of two different doses of rifabutin in patients with human immunodeficiency virus-associated tuberculosis who initiated antiretroviral therapy (ART) with a lopinavir-ritonavir-based regimen in South Africa and Viet Nam. The study protocol specified that ART should be started 10 weeks after the start of anti-tuberculosis treatment. The study in South Africa was approved in June 2008, went ahead as scheduled and was completed in August 2010. The study in Viet Nam was approved in October 2008 and was started in June 2010. A few weeks later, the World Health Organization released their 2010 guidelines for adult ART; one of its strong recommendations (with moderate quality of evidence) was that ART should be started 2-8 weeks after the start of anti-tuberculosis treatment. Emerging scientific evidence also supported this recommendation. The investigators felt that the Viet Nam study protocol was in conflict with recommended international best practice, and the trial was stopped in October 2010. An amended study protocol in which ART was started at 2 weeks was developed and implemented. The ethics issues around this decision and the need to change the study protocol are discussed in this article.

Safety of nevirapine in pregnancy

BACKGROUND

Nevirapine has been widely used in pregnancy for its efficacy, low pill burden, bioavailability and rapid transplacental transfer. Concern about nevirapine toxicity during pregnancy has emerged over recent years.

OBJECTIVES

The aims of the study were to document the frequency of cutaneous and hepatic toxicity secondary to nevirapine use during pregnancy and to compare rates in women starting nevirapine during the current pregnancy with those in women who had commenced nevirapine prior to the current pregnancy.

DESIGN

This was a retrospective, comparative, five-centre study carried out in London, UK, in 1997-2003.

METHODS

All HIV-1-infected women who received nevirapine as part of combination antiretroviral therapy (ART) during pregnancy were included in the study. Data on demographics, HIV infection risk, Centers for Disease Control and Prevention (CDC) status, surrogate markers at initiation of therapy, other medications hepatitis B and C virus coinfection and clinical data relating to potential toxicity were collated and analysed.

RESULTS

Fifteen of 235 eligible women (6.4%) developed rash and eight (3.4%) developed hepatotoxicity, including four with coexistent rash, giving a combined incidence of 19 potential cases of nevirapine toxicity during pregnancy (8.1%). Alternative causes of rash/hepatotoxicity were suspected in seven cases and only 10 mothers (5.8%) discontinued nevirapine. Of the 170 women who commenced nevirapine during this pregnancy, 13 (7.6%) developed rash and eight (4.7%) hepatotoxicity, a combined incidence of 10%. Only two of 65 women with nevirapine exposure prior to this pregnancy developed rash (3.1%).

CONCLUSIONS

Nevirapine-containing ART was well tolerated in this cohort of pregnant women. Although pregnancy did not appear to increase the risk of nevirapine-associated toxicity compared to published adult data, CD(4) count may be less predictive of toxicity in pregnancy.

Comparative genomics of the mycobacteria

The genus mycobacteria includes two important human pathogens Mycobacterium tuberculosis and Mycobacterium lepra. The former is reputed to have the highest annual global mortality of all pathogens. Their slow growth, virulence for humans and particular physiology makes these organisms extremely difficult to work with. However the rapid development of mycobacterial genomics following the completion of the Mycobacterium tuberculosis genome sequence provides the basis for a powerful new approach for the understanding of these organisms. Five further genome sequencing projects of closely related mycobacterial species with differing host range, virulence for humans and physiology are underway. A comparative genomic analysis of these species has the potential to define the genetic basis of these phenotypes which will be invaluable for the development of urgently needed new vaccines and drugs. This minireview summarises the different techniques that have been employed to compare these genomes and gives an overview of the wealth of data that has already been generated by mycobacterial comparative genomics.

Risk factors for tuberculosis in patients with AIDS in London: a case-control study

OBJECTIVE

To identify risk factors for the acquired immune-deficiency syndrome (AIDS) associated with tuberculosis, in patients with AIDS attending 11 of the largest human immunodeficiency virus (HIV)/AIDS Units in London.

DESIGN

Case-control study nested in a retrospective cohort of 2048 HIV-1 positive patients. Cases were defined as patients with a definitive diagnosis of tuberculosis, and controls as patients with AIDS and without tuberculosis during follow-up.

RESULTS

Of 627 patients diagnosed with AIDS, 121 had a definitive diagnosis of tuberculosis. Significant risk factors for tuberculosis in the univariate analysis were sex, ethnicity, age, HIV exposure category and hospital attended, and in the multiple regression analysis ethnicity, age and hospital attended. African ethnicity was the strongest risk factor for tuberculosis (adjusted odds ratio [AOR] 5.9, 95% confidence interval 3.4-10.2). The risk of tuberculosis was higher in the younger age groups (test for trend P < 0.001). The hospital-associated risk of tuberculosis was more heterogeneous in the non-African group, and non-Africans attending Hospital 1 had an increased risk of tuberculosis which was statistically significant.

CONCLUSIONS

The risk factors for AIDS-associated tuberculosis in London are sub-Saharan African origin, younger age group, and, among the non-Africans only, attending one hospital in east London. Different transmission patterns and mechanisms for the development of tuberculosis may operate in different settings depending on the background risk of tuberculous infection. Screening for tuberculosis infection and disease among HIV-positive individuals in London is important for the provision of preventive or curative therapy, and prophylaxis policies need to be designed in accordance with the transmission patterns and mechanisms of disease.

Disease progression and survival in HIV-1-infected Africans in London

OBJECTIVE

To examine differences in progression to AIDS and death between HIV-1-positive Africans (most infected in sub-Saharan Africa and therefore with non-B subtypes) and HIV-1-positive non-Africans in London.

DESIGN

Retrospective cohort study of 2048 HIV-1-positive individuals.

SETTING

HIV-1-infected individuals attending 11 of the largest HIV/AIDS units in London.

PATIENTS

Subjects were 1056 Africans and 992 non-Africans seen between 1982-1995.

RESULTS

There were no differences in crude survival from presentation to death between Africans and non-Africans (median 82 and 78 months, respectively; P = 0.22). Africans progressed more rapidly to AIDS [hazard ratio (HR), 1.21; 95% confidence interval (CI), 1.02-1.45] but after adjustment for age, sex, Centers for Disease Control and Prevention category B symptoms and CD4+ lymphocyte count at presentation, year of HIV diagnosis and hospital attended, this difference was no longer significant (adjusted HR, 1.15; 95% CI, 0.93-1.43). Africans with AIDS had a reduced risk of death compared with non-Africans (HR, 0.78; 95% CI, 0.63-0.96) but not after adjustment for age, CD4+ lymphocyte count at AIDS, initial AIDS-defining conditions (ADC) and hospital attended (HR, 0.98; 95% CI, 0.76-1.27). Tuberculosis as the first ADC was associated with a 64% reduction in the risk of death. CD4+ lymphocyte decline was not significantly different between Africans and non-Africans (P = 0.18).

CONCLUSIONS

Differences in progression to AIDS and death and CD4+ lymphocyte decline between HIV-1-infected Africans and non-Africans in London could not be attributed to ethnicity or different viral subtypes. Age and the clinical and immunological stage at presentation, or AIDS, were the major determinants of outcome. Compared with other diagnoses, tuberculosis as the initial ADC was associated with increased survival. Lack of access to health care and exposure to environmental pathogens are the most likely causes of reduced survival with AIDS in Africa, rather than inherently different rates of progression of immune deficiency due to racial differences or viral subtypes.

Disease progression and survival following specific AIDS-defining conditions: a retrospective cohort study of 2048 HIV-infected persons in London

OBJECTIVE

To assess the impact of specific AIDS-defining conditions on survival in HIV-infected persons, with emphasis on the effect of tuberculosis.

METHODS

A retrospective cohort analysis of HIV-infected Africans and non-Africans attending 11 specialist HIV/AIDS units in London enrolled for a comparison of the natural history of HIV/AIDS in different ethnic groups.

RESULTS

A total of 2048 patients were studied of whom 627 (31%) developed 1306 different AIDS indicator diseases. Pneumocystis carinii pneumonia accounted for 159 (25%) of initial AIDS episodes and tuberculosis for 103 (16%). In patients with HIV disease, tuberculosis had the lowest risk [relative risk (RR), 1.11; 95% confidence interval (CI), 0.75-1.63], and high-grade lymphoma had the highest risk (RR, 20.56; 95% CI, 2.70-156.54) for death. For patients with a prior AIDS-defining illness, the development of subsequent AIDS indicator diseases such as Pneumocystis carinii pneumonia (RR, 1.18; 95% CI, 0.77-1.83) and tuberculosis (RR, 1.36; 95% CI, 0.76-2.47) had the best survival, and non-Hodgkin's lymphoma had the worst survival (RR, 9.67; 95% CI, 1.26-74.33). Patients with tuberculosis had a lower incidence of subsequent AIDS-defining conditions than persons with other initial AIDS diagnoses (rate ratio, 0.47; 95% CI, 0.37-0.59).

CONCLUSIONS

Considerable variation exists in the relative risk of death following different AIDS-defining conditions. The development of any subsequent AIDS-defining condition is associated with an increased risk of death that differs between diseases, and this risk should be considered when evaluating the impact of specific conditions. Like other AIDS-defining conditions, incident tuberculosis was associated with adverse outcome compared with the absence of an AIDS-defining event, but we found no evidence of major acceleration of HIV disease attributable to tuberculosis.

Spectrum of disease in Africans with AIDS in London

OBJECTIVE

To compare the spectrum of disease, severity of immune deficiency and chemoprophylaxis prescribed in HIV-infected African and non-African patients in London.

DESIGN

Retrospective review of case notes of all HIV-infected Africans and a comparison group of non-Africans attending 11 specialist HIV/AIDS Units in London.

MAIN OUTCOME MEASURES

Comparison of demographic information, first and subsequent AIDS-defining conditions, levels of immune deficiency, and chemoprophylactic practices between the African and non-African groups.

RESULTS

A total of 1056 Africans (313 developing AIDS) and 992 non-Africans (314 developing AIDS) were studied. Africans presented later than non-Africans (median CD4+ lymphocyte counts at diagnosis 238 and 371 x 10(6)/l, respectively). Tuberculosis accounted for 27% of initial episodes of AIDS in Africans and 5% in non-Africans; Pneumocystis carinii pneumonia (PCP) was the initial AIDS-defining condition in 34% of non-Africans and 17% of Africans. The incidence of tuberculosis in Africans with another AIDS-indicator disease was 16 per 100 person-years. PCP prophylaxis was prescribed for 40% Africans and 32% non-Africans; only 8% of Africans received tuberculosis preventive therapy.

CONCLUSIONS

HIV-infected African patients presented at lower levels of CD4+ lymphocyte count, at a more advanced clinical stage, and with different AIDS-indicator diseases as compared with non-Africans. Prophylaxis against tuberculosis should be considered for all HIV-infected African patients in industrialized countries. The high incidence of diseases that are indicative of advanced immunodeficiency (e.g., cytomegalovirus disease) in African patients contrasts with data from Africa, suggesting better survival chances in the UK.