The usefulness of serum adenosine deaminase 2 (ADA2) activity in adults for the diagnosis of pulmonary tuberculosis

Rapid diagnosis of Mycobacterium tuberculosis remains an obstacle for therapy of tuberculosis (TB). Adenosine deaminase isoform 2 (ADA2) is produced by activated macrophages and has been used for diagnosis of TB from extra-pulmonary sites. However, few studies adequately address whether serum ADA2 activity is useful for diagnosis of active pulmonary tuberculosis (PTB). We prospectively measured serum ADA2 activity in 110 patients with pulmonary disease (65 cases with active PTB and 45 cases with other respiratory diseases) and 78 healthy volunteers (eight with tuberculin skin test positive). The serum ADA2 for the diagnosis of PTB had the sensitivity of 36.9%, the specificity of 84.5%, the positive predictive value of 10.9% and the negative predictive value of 96.2%. We concluded that serum ADA2 activity is neither useful to diagnosis of active PTB nor to differentiate from other respiratory diseases.     

Preferential recruitment of phagocytes into the lung of patients with advanced acquired immunodeficiency syndrome and tuberculosis

Limited data are available on the cellular and immunocytological characteristics of bronchoalveolar lavage (BAL) fluid in individuals infected with the human immunodeficiency virus (HIV) and pulmonary tuberculosis (TB). The immune host response against tuberculosis in early HIV-infection may differ from that in later stages of HIV disease, as is strongly suggested by different clinical and radiographic patterns. We studied the cellular elements in the lungs of 15 HIV-infected patients with advanced immunosuppression and pulmonary tuberculosis (TB/AIDS). The findings were compared with data from four other groups: 1) 15 HIV-seronegative patients with pulmonary TB; 2) 12 HIV-seropositive TB patients without previous AIDS-defining illnesses and with CD4+ >200 cells mm(-3); 3) five AIDS patients without pulmonary lesions; and 4) five healthy controls. BAL fluid and differential cell counts, as well as lymphocyte subsets, were determined. Despite a low CD4/CD8 ratio, the TB/AIDS group had a higher absolute number of CD8+ lymphocytes in the BAL fluid than the other groups. Alveolar macrophages and neutrophils were significantly increased in TB/AIDS patients compared to control groups. The number of eosinophils was increased in TB/HIV--patients but not in TB/AIDS patients. We conclude that tuberculosis in late stage HIV-infected patients has a distinct inflammatory cell profile, suggesting an enhanced compensatory mechanism that amplifies the unspecific inflammatory reaction.     

Drug-resistant tuberculosis in subjects included in the Second National Survey on Antituberculosis Drug Resistance in Porto Alegre, Brazil,

OBJECTIVE:

To describe the prevalence of multidrug-resistant tuberculosis (MDR-TB) among tuberculosis patients in a major Brazilian city, evaluated via the Second National Survey on Antituberculosis Drug Resistance, as well as the social, demographic, and clinical characteristics of those patients.

METHODS:

Clinical samples were collected from tuberculosis patients seen between 2006 to 2007 at three hospitals and five primary health care clinics participating in the survey in the city of Porto Alegre, Brazil. The samples were subjected to drug susceptibility testing. The species of mycobacteria was confirmed using biochemical methods.

RESULTS:

Of the 299 patients included, 221 (73.9%) were men and 77 (27.3%) had a history of tuberculosis. The mean age was 36 years. Of the 252 patients who underwent HIV testing, 66 (26.2%) tested positive. The prevalence of MDR-TB in the sample as a whole was 4.7% (95% CI: 2.3-7.1), whereas it was 2.2% (95% CI: 0.3-4.2) among the new cases of tuberculosis and 12.0% (95% CI: 4.5-19.5) among the patients with a history of tuberculosis treatment. The multivariate analysis showed that a history of tuberculosis and a longer time to diagnosis were both associated with MDR-TB.

CONCLUSIONS:

If our results are corroborated by other studies conducted in Brazil, a history of tuberculosis treatment and a longer time to diagnosis could be used as predictors of MDR-TB.     

Surface changes in the dental enamel resulting from acid etching and the bonding and removal of orthodontic fixation devices (based on data from scanning electron microscopy)

The effect of acid etching of the enamel, its adhesion with Concise compound, and the state of enamel after removal of orthodontic fixing rods attached right to the dental enamel, were studied on 32 teeth extracted for orthodontic reasons. Best conditions for retention were achieved with 2-min etching with 40% phosphoric acid. This ensured the concise penetration into the enamel to 60 microns depth. The fixing rods removal did not lead to irreversible enamel damage.     

Health sector reform in Brazil: impact on tuberculosis control.

This paper comments on the reform process of the health sector policies that took place after 1986 in Brazil, and its negative impact on the National Tuberculosis Control Programme (NTP). Decentralisation was followed by a slow transition from a vertical programme to an integrated programme. In 1990, the NTP was dismantled due to fiscal constraints, and in 1992, the NTP component was reorganised, with national and regional coordinators and subsequent increased support to state programmes. In 1996, the health sector reform continued its process, but this consisted mainly of cuts in health budgets and rapid decentralisation from federal level to unprepared states and municipalities, leading to the weakening of local tuberculosis control programmes. Only recently has government commitment been secured, with a new National Plan on Tuberculosis Control which includes the World Health Organization strategy for TB control--the implementation of the DOTS strategy (directly-observed treatment, short-course)--and efforts are being concentrated in 5500 municipalities. The programme has a centralised administration which supports decentralised implementation through out-patient clinics, and resources will be focused on local service delivery.     

Pulmonary function changes in the acute stage of histoplasmosis, with follow-up. An analysis of eight cases

We have studied eight patients, six children and two adults, during a microepidemic of soil- and patient-proven histoplasmosis. Pulmonary function tests were performed between the 15th and 23rd days after the onset of symptoms, and repeated between the fifth and sixth, the ninth and tenth and the 15th and 22nd months afterward. Initial abnormalities were mild in seven cases and severe in one. There was a restrictive pattern in three cases and an obstructive pattern in two. The fraction of CO extraction was reduced in five cases and the diffusing capacity for CO was reduced in five of six cases so tested. Hypoxemia was present in three cases. On follow-up, the obstructive defect had disappeared by the sixth month, the restrictive pattern by the tenth month, and the diffusing defect still remained in three cases by the end of follow-up. Hypoxemia remained only in the severe case.     

Cost effectiveness of antituberculosis interventions

The treatment of tuberculosis (TB) is ranked as the most cost effective of all therapeutic programmes in terms of cost per year of life saved. Nevertheless, TB kills or debilitates more adults aged between 15 and 59 years than any other disease in the world; furthermore, about 2 to 4% of the burden of disease, 7% of all deaths and 26% of all preventable deaths are directly attributable to TB. About one-third of the world's population is infected with the TB bacillus. In the developing world, more women of childbearing age die from TB than from causes directly associated with pregnancy and childbirth. The death of adults in their prime, who are parents, community leaders and producers in most societies, causes a particularly onerous burden besides being a serious public health problem. In the poorest countries, where the magnitude of the TB problem is greatest, those TB control strategies that are economically feasible tend to be less effective. Therefore, in low and middle income countries, cost-effectiveness considerations aimed at prioritising resource allocation in the health sector in general, and in TB control programmes in particular, are of paramount importance. Operationally, the main components of a TB control programme are: (i) detection and treatment of TB; and (ii) prevention of TB through BCG vaccination and chemoprophylaxis. Priority should be given to ensuring that TB patients complete their prescribed course of chemotherapy. Adequate treatment is the most effective way of preventing the spread of TB and the emergence of drug resistance. This article reviews evidence of the effectiveness and cost effectiveness of different approaches to TB care, particularly those that are applicable to low income countries, in both HIV-infected and noninfected patients. Financial implications and ways to implement directly observed therapy for TB in large urban areas are discussed, and the need to address some relevant operational issues is highlighted. The current role of chemoprophylaxis and BCG vaccination is also reviewed.