Optimal treatment of Codisease due to HIV and tuberculosis

The Value of 18F-FDG PET/CT in the Diagnosis of Tuberculous Pleurisy and in the Differential Diagnosis between Tuberculous Pleurisy and Pleural Metastasis from Lung Adenocarcinoma

Objectives

This study aims to investigate the diagnostic value of 18F-FDG PET/CT in tuberculous pleurisy (TBP) and the differential diagnostic value of 18F-FDG PET/CT between TBP and pleural metastasis from lung adenocarcinoma (PMLAC).

Materials and Methods

The features of pleura on PET and hybrid CT were retrospectively studied in 20 patients with TBP and 32 patients with PMLAC. The ROC curve was used to evaluate the diagnostic effectiveness of these indices for TBP and PMLAC, and binary logistic regression analysis was conducted to identify independent predictors of TBP and PMLAC.

Results

There were significant differences in pleural 18F-FDG uptake pattern on PET (P=0.001), pleural morphology pattern on CT (P=0.002), the maximum diameter of the pleural nodule (P=0.001), and interlobular fissure nodule (P=0.001) between TBP and PMLAC groups. The diffused pleural FDG uptake type on PET (odds ratio (OR) = 6.0, 95% CI 2.216–16.248, P=0.001) and the lamellar pleural thickening type on CT (OR = 4.4, 95% CI 2.536–7.635, P=0.001) were independent predictors of TBP, with 60% and 55% sensitivity, 96.6% and 90.6% specificity, and 82.7% and 77.0% accuracy. The combined diagnostic sensitivity, specificity, and accuracy for TBP were 70%, 87.5%, and 80.8%. The mixed pleural FDG uptake type on PET (OR = 5.106, 95% CI 2.024–12.879, P=0.001), the mixed pleural thickening type on CT (OR = 2.289, 95% CI 1.442–3.634, P=0.001), and the maximum diameter of the pleural nodule (OR = 1.027, 95% CI 1.012–1.042, P=0.001) were independent predictors of PMLAC, with 78.1%, 71.9%, and 87.5% sensitivity, 85%, 80%, and 85% specificity, and 80.8%, 75%, and 86.5% accuracy. The combined diagnostic sensitivity, specificity, and accuracy for PMLAC were 96.9%, 85%, and 90.4%.

Conclusions

18F-FDG PET/CT is of great clinical value in the diagnosis of TBP and in the differential diagnosis between TBP and PMLAC.

PET/CT imaging of Mycobacterium tuberculosis infection

Tuberculosis has a high morbidity and mortality worldwide. Mycobacterium tuberculosis (Mtb) has a complex pathophysiology; it is an aerobic bacillus capable of surviving in anaerobic conditions in a latent state for a very long time before reactivation to active disease. In the latent tuberculosis infection, the individual has no clinical evidence of active disease, but exhibits a hypersensitive response to proteins of Mtb. Only some 5–10 % of latently infected individuals appear to have reactivation of tuberculosis at any one time point after infection, and neither imaging nor immune tests have been shown to predict tuberculosis reactivation reliably. The complex pathology of the organism provides multiple molecular targets for imaging the infection and targeting therapy. Positron emission tomography (PET) integrated with computer tomography (CT) provides a unique opportunity to noninvasively image the whole body for diagnosing, staging and assessing therapy response in many infectious and inflammatory diseases. PET/CT is a powerful noninvasive tool that can rapidly provide three-dimensional views of disease deep within the body and conduct longitudinal assessment over time in one particular patient. Some PET tracers, such as ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG), have been found to be useful in various infectious diseases for detection, assessing disease activity, staging and monitoring response to therapy. This tracer has also been used for imaging tuberculosis. ¹⁸F-FDG PET relies on the glucose uptake of inflammatory cells as a result of the respiratory burst that occurs with infection. Other PET tracers have also been used to image different aspects of the pathology or microbiology of Mtb. The synthesis of the complex cell membrane of the bacilli for example can be imaged with ¹¹C-choline or ¹⁸F-fluoroethylcholine PET/CT while the uptake of amino acids during cell growth can be imaged by 3′-deoxy-3′-[¹⁸F]fluoro-l-thymidine. PET/CT provides a noninvasive and sensitive method of assessing histopathological information on different aspects of tuberculosis and is already playing a role in the management of tuberculosis. As our understanding of the pathophysiology of tuberculosis increases, the role of PET/CT in the management of this disease would become more important. In this review, we highlight the various tracers that have been used in tuberculosis and explain the underlying mechanisms for their use.

Diagnosis and treatment of tuberculosis among children at an HIV care program in Dar es Salaam, Tanzania

Diagnosis and treatment of tuberculosis is challenging in children with human immunodeficiency virus (HIV) infection. We describe the clinical features, diagnostic testing results, tuberculosis and HIV treatment and clinical outcomes of 57 HIV-infected children diagnosed with tuberculosis at the DarDar Pediatric Program in Dar es Salaam, Tanzania. In this cohort, tuberculosis was common, microbiologic studies were frequently negative and mortality was high.

Nutritional status of HIV-infected women with tuberculosis in Dar es Salaam, Tanzania

SETTING

Tuberculosis (TB) treatment clinics in Dar es Salaam, Tanzania.

OBJECTIVE

To quantify anthropometrics and intake of en-ergy and protein among human immunodeficiency virus (HIV) positive women with TB.

DESIGN

HIV-positive women with newly diagnosed TB were assessed on their anthropometric characteristics and dietary intake. Energy and protein intake were determined using Tanzania food composition tables and compared with standard recommendations. Patients were re-evaluated after 4-6 months of anti-tuberculosis treatment.

RESULTS

Among 43 women, the baseline median CD4 count was 209 cells/µl (range 8-721); 19 (44%) had a CD4 count of <200; 20 (47%) were on antiretroviral therapy. Body mass index was <18.5 kg/m(2) in 25 (58%); the median food insecurity score was 6. The median level of kcal/day was 1693 (range 1290-2633) compared to an estimated need of 2658; the median deficit was 875 kcal (range -65-1278). The median level of protein/day was 42 g (range 27-67) compared to 77 g estimated need; the median protein deficit was 35 g (range 10-50). The median weight gain among 29 patients after 4-6 months was 6 kg.

CONCLUSION

HIV-positive women with TB have substantial 24-h deficits in energy and protein intake, report significant food insecurity and gain minimal weight on anti-tuberculosis treatment. Enhanced dietary education together with daily supplementation of 1000 kcal with 40 g protein may be required.

Test characteristics of urinary lipoarabinomannan and predictors of mortality among hospitalized HIV-infected tuberculosis suspects in Tanzania

Background

Tuberculosis is the most common cause of death among patients with HIV infection living in tuberculosis endemic countries, but many cases are not diagnosed pre-mortem. We assessed the test characteristics of urinary lipoarabinomannan (LAM) and predictors of mortality among HIV-associated tuberculosis suspects in Tanzania.

Methods

We prospectively enrolled hospitalized HIV-infected patients in Dar es Salaam, with ≥2 weeks of cough or fever, or weight loss. Subjects gave 2 mLs of urine to test for LAM using a commercially available ELISA, ≥2 sputum specimens for concentrated AFB smear and solid media culture, and 40 mLs of blood for culture.

Results

Among 212 evaluable subjects, 143 (68%) were female; mean age was 36 years; and the median CD4 count 86 cells/mm³. 69 subjects (33%) had culture confirmation of tuberculosis and 65 (31%) were LAM positive. For 69 cases of sputum or blood culture-confirmed tuberculosis, LAM sensitivity was 65% and specificity 86% compared to 36% and 98% for sputum smear. LAM test characteristics were not different in patients with bacteremia but showed higher sensitivity and lower specificity with decreasing CD4 cell count. Two month mortality was 64 (53%) of 121 with outcomes available. In multivariate analysis there was significant association of mortality with absence of anti-retroviral therapy (p = 0.004) and a trend toward association with a positive urine LAM (p = 0.16). Among culture-negative patients mortality was 9 (75%) of 12 in LAM positive patients and 27 (38%) of 71 in LAM negative patients (p = 0.02).

Conclusions

Urine LAM is more sensitive than sputum smear and has utility for the rapid diagnosis of culture-confirmed tuberculosis in this high-risk population. Mortality data raise the possibility that urine LAM may also be a marker for culture-negative tuberculosis.