An African woman with pulmonary cavities: TB or not TB?

Cavitary lung lesions in patients from developing countries are mostly caused by tuberculosis (TB). However, when TB cannot be confirmed, a primary lung abscess caused by anaerobic bacteria from the mouth should be considered, especially in patients with poor dentition. We present a case of a Sudanese woman with a cavitary lung lesion and severe gingivitis. Bulleidia extructa was isolated as a single pathogen from the pulmonary cavity.

Population pharmacokinetics and limited sampling strategy for first-line tuberculosis drugs and moxifloxacin

Therapeutic drug monitoring (TDM) of tuberculosis (TB) drugs currently focuses on peak plasma concentrations, yet total exposure [area under the 24-h concentration-time curve (AUC₀₋₂₄)] is probably most relevant to the efficacy of these drugs. We therefore assessed population AUC₀₋₂₄ data for all four first-line TB drugs (rifampicin, isoniazid, pyrazinamide and ethambutol) as well as moxifloxacin and developed limited sampling strategies to estimate AUC₀₋₂₄ values conveniently. AUC₀₋₂₄ and other pharmacokinetic (PK) parameters were determined following intensive PK sampling in two Dutch TB referral centres. Best subset selection multiple linear regression was performed to derive limited sampling equations. Median percentage prediction error and median absolute percentage prediction error were calculated via jackknife analysis to evaluate bias and imprecision of the predictions. Geometric mean AUC₀₋₂₄ values for rifampicin, isoniazid, pyrazinamide, ethambutol and moxifloxacin were 41.1, 15.2, 380, 25.5 and 33.6 hmg/L, respectively. Limited sampling at various fixed sampling points enabled an accurate and precise prediction of AUC₀₋₂₄ values of all drugs separately and simultaneously. In the absence of clinically validated target values for AUC₀₋₂₄, average AUC₀₋₂₄ values can be used as reference values in TDM. Limited sampling of AUC₀₋₂₄ is feasible in many settings and allows for TDM to be performed at a larger scale.

Risk factors for Mycobacterium tuberculosis infection in Indonesian children living with a sputum smear-positive case

SETTING AND OBJECTIVES

Young children living with infectious tuberculosis (TB) cases are at high risk of infection and disease, and screening is recommended. This is rarely conducted in resource-limited settings. Identifying children most at risk of infection may be useful for setting practical screening policies.

DESIGN

Child contacts of smear-positive adult TB patients were invited for Mycobacterium tuberculosis infection and disease screening by symptoms, tuberculin skin test (TST), QuantiFERON-TB Gold In-Tube assay (QFT-GIT) and chest X-ray. Risk factors for infection were collected using a questionnaire and were calculated separately for TST, for QFT-GIT and for both tests combined.

RESULTS

Of 304 screened children 145/302 (48%) were positive using TST, 152/299 (51%) by QFT-GIT and 180/304 (59%) were positive using either or both tests. Positivity for both tests was associated with index case infectivity (acid-fast bacilli [AFB] 3+ vs. AFB 1+: TST OR 2.93, 95%CI 1.59-5.39; QFT-GIT OR 2.28, 95%CI 1.06-4.90) and exposure (child contact's parent is the index case: TST OR 7.04, 95%CI 2.23-22.28; QFT-GIT OR 4.30, 95%CI 1.48-12.45).

CONCLUSION

M. tuberculosis infection according to either test was high, supporting screening and preventive treatment. Children of smear-positive TB cases who accompany their parents to the clinic should be prioritised for immediate screening.

Heterologous ("nonspecific") and sex-differential effects of vaccines: epidemiology, clinical trials, and emerging immunologic mechanisms

A growing body of evidence from epidemiologic, clinical, and immunologic studies indicates that vaccines can influence morbidity and mortality independent of vaccine-specific B-cell or T-cell immunity. For example, the live attenuated measles vaccine and BCG vaccine may reduce mortality from infections other than measles or tuberculosis, respectively. Immunologists call these heterologous effects and epidemiologists have called them nonspecific effects, indicating that they manifest against a broad range of pathogens/disease. These effects differ by sex, can be beneficial or detrimental, and appear to be mediated by mechanisms including innate immune memory (also known as "trained immunity") and cross-reacting lymphocytes. Herein we review recent studies in this emerging field based on a meeting of experts, the recent Optimmunize meeting, held in Copenhagen, Denmark, in August 2012. Further characterization of these effects is likely to expand the way vaccines are evaluated and alter the manner and sequence in which they are given.

QuantiFERON®-TB Gold In-Tube assay vs. tuberculin skin test in Indonesian children living with a tuberculosis case

SETTING AND OBJECTIVES

The tuberculin skin test (TST) has limitations in diagnosing latent tuberculosis (TB) infection (LTBI). Interferon-gamma release assays may improve diagnostic accuracy. We compared QuantiFERON®-TB Gold In-Tube (QFT-GIT) and TST in Indonesian children.

DESIGN

Children aged from 6 months to 9 years exposed to a TB case at household and neighbourhood levels were recruited. The children underwent QFT-GIT and TST. Test responsiveness was assessed according to an exposure gradient.

RESULTS

A total of 299 household-exposed and 72 neighbourhood-exposed children were analysed. Overall, respectively 46% and 41% were positive using QFT-GIT and the TST. Test positivity increased with exposure (QFT-GIT P value for trend <0.001, and TST P < 0.001); however, only QFT-GIT responded significantly to a 'within-household' gradient. The TST was less likely to be positive than the QFT-GIT in neighbourhood-exposed children (P = 0.05). BCG-vaccinated children were less likely to be QFT-GIT-positive, while older children were more likely to be QFT-GIT-positive. Both tests had increasing positivity with increasing smear grade.

CONCLUSION

QFT-GIT performed similarly to the TST in Indonesian children living with an infectious TB case. Test accuracy was not compromised by young age or BCG vaccination. Our findings suggest that QFT-GIT offers little advantage over the TST in this population. High rates of LTBI diagnosed in household-exposed children by both tests support preventive therapy.

A step-wise approach to find a valid and feasible method to detect non-adherence to tuberculosis drugs

A step-wise approach to identify valid and feasible methods to detect non-adherence to tuberculosis drugs was evaluated in a prospective study among pulmonary tuberculosis patients in an outpatient clinic in Indonesia. First, adherence was measured by self-reporting with the standardized Morisky questionnaire, physician assessment, pill-count, visit attendance, diary and an electronic medication event monitoring system (MEMS). Next, validity of single methods was assessed against MEMS as gold standard. Feasibility of methods was then judged by physicians in the field. Finally, when valid and feasible methods were combined, it appeared that self-reporting by a questionnaire plus physician assessment could identify all non-adherent patients. It is recommended to use a systematic approach to develop a valid and locally feasible combination of methods to detect non-adherence to TB drugs.

Rifampicin Reduces Plasma Concentrations of Moxifloxacin in Patients with Tuberculosis

BACKGROUND

The long duration of the current tuberculosis (TB) treatment is demanding and warrants the development of new drugs. Moxifloxacin shows promising results and may be combined with rifampicin to shorten the duration of TB treatment. Rifampicin induces the phase II metabolic enzymes that are involved in the biotransformation of moxifloxacin. Therefore, the interaction between rifampicin and moxifloxacin should be investigated.

PATIENTS AND METHODS

Nineteen Indonesian patients with pulmonary TB who were in the last month of their TB treatment completed a 1-arm, 2-period, fixed-order pharmacokinetic study. In phase 1 of the study, they received 400 mg of moxifloxacin every day for 5 days in addition to 450 mg of rifampicin and 600 mg of isoniazid 3 times per week. In phase 2 of the study, after a 1-month washout period, patients received moxifloxacin for another 5 days (without rifampicin and isoniazid). A 24-h pharmacokinetic curve for moxifloxacin was recorded on the last day of both study periods, and its pharmacokinetic parameters were evaluated for an interaction with rifampicin, using a bioequivalence approach.

RESULTS

Coadministration of moxifloxacin with rifampicin and isoniazid resulted in an almost uniform decrease in moxifloxacin exposure (in 18 of 19 patients). The geometric means for the ratio of phase 1 area under the curve to phase 2 area under the curve and for the ratio of phase 1 peak plasma concentration to phase 2 peak plasma concentration were 0.69 (90% confidence interval, 0.65-0.74) and 0.68 (90% confidence interval, 0.64-0.73), respectively. The median time to reach peak plasma concentration for moxifloxacin was prolonged from 1 h to 2.5 h when combined with rifampicin and isoniazid (P=.003).

CONCLUSIONS

Coadministration of moxifloxacin with intermittently administered rifampicin and isoniazid results in reduced moxifloxacin plasma concentrations, which is most likely the result of induced glucuronidation or sulphation by rifampicin. Further studies are warranted to evaluate the impact of the interaction on the outcome of TB treatment.

Plasma granulysin levels and cellular interferon-gamma production correlate with curative host responses in tuberculosis, while plasma interferon-gamma levels correlate with tuberculosis disease activity in adults

Granulysin is a recently identified cytolytic protein which is expressed by human cytotoxic T-lymphocytes and natural killer (NK)-cells, and has broad antimicrobial and tumoricidal activity. Circulating granulysin levels are associated with T- and NK-cell activity, and may thus reflect protection-associated cellular immune responses. In a case-control study in Indonesia, a highly tuberculosis (TB)-endemic country, we therefore determined plasma granulysin levels in adults with active pulmonary TB before, during, and after TB treatment, both in mild/moderate-TB and advanced-TB patients, and compared these to healthy neighbourhood controls. Adults with active pulmonary TB had significantly lower plasma granulysin levels compared to controls. After 2 months of anti-TB therapy, levels in TB patients had significantly increased, reaching values similar to those in controls. Plasma granulysin levels further increased after completion of TB therapy, being significantly higher than those in controls. Plasma granulysin levels correlated inversely with TB disease activity but not with TB disease severity. In contrast, plasma interferon-gamma (IFN-gamma) levels were significantly higher in active TB cases than in controls, normalised during treatment and correlated with both TB disease activity and TB disease severity. At the cellular level, granulysin and IFN-gamma expression both correlated inversely with disease activity. Interestingly, granulysin was predominantly expressed by IFN-gamma negative T-cells, suggesting that the cellular sources of IFN-gamma and granulysin in TB are partly non-overlapping. The observation that plasma granulysin levels and cellular IFN-gamma production correlate with curative host responses in pulmonary tuberculosis points to a potentially important role of granulysin, next to IFN-gamma, in host defence against M. tuberculosis.

Diabetes mellitus is strongly associated with tuberculosis in Indonesia

SETTING

Diabetes mellitus is a known risk factor for tuberculosis (TB), but no studies have been reported from South-East Asia, which has a high burden of TB and a rapidly growing prevalence of diabetes.

OBJECTIVE

To examine if and to what extent diabetes is associated with an increased risk of TB in an urban setting in Indonesia.

DESIGN

Case-control study comparing the prevalence of diabetes mellitus (fasting blood glucose level >126 mg/dl) among newly diagnosed pulmonary TB patients and matched neighbourhood controls.

RESULTS

Patients and control subjects had a similar age (median 30 years) and sex distribution (52% male), but malnutrition was more common among TB patients (median body mass index 17.7 vs. 21.5 kg/m2). HIV infection was uncommon (1.5% of patients). Diabetes mellitus was present in 60 of 454 TB patients (13.2%) and 18 of 556 (3.2%) control subjects (OR 4.7; 95%CI 2.7-8.1). Adjustment for possible confounding factors did not reduce the risk estimates. Following anti-tuberculosis treatment, hyperglycaemia reverted in a minority (3.7%) of TB patients.

CONCLUSION

Diabetes mellitus is strongly associated with TB in young and non-obese subjects in an urban setting in Indonesia. This may have implications for TB control and patient care in this region.

Aortitis Diagnosed by F–18–Fluorodeoxyglucose Positron Emission Tomography in a Patient with Syphilis and HIV Coinfection

The most common manifestation of cardiovascular syphilis, a rare diagnosis since the introduction of penicillin, is aortitis of the ascending aorta. Since the majority of patients with uncomplicated aortitis are asymptomatic, early diagnosis is difficult. We report the case of an HIV-positive patient with asymptomatic syphilitic aortitis that was incidentally diagnosed with F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET). We conclude that FDG-PET could become a promising new imaging technique for both diagnosis and follow-up of patients with syphilitic aortitis.

Toxoplasmosis after renal transplantation: implications of a missed diagnosis

We describe a renal transplant patient with a primary Toxoplasma gondii infection presenting as pneumonitis, with subsequent chorioretinitis and encephalitis. The diagnostic challenges of T. gondii infection in immunocompromised patients are discussed.

Better patient instruction for sputum sampling can improve microscopic tuberculosis diagnosis

To examine the effect of patient instruction for provision of sputum samples, we performed a randomised controlled trial involving 174 patients with suspected tuberculosis (TB) in an urban TB clinic in Indonesia. TB was diagnosed in 50.6% of patients who received additional counselling by paramedics compared with 35.5% of patients in the control group following routine diagnostic procedure, corresponding to a 15.1% higher detection rate (95%CI 2.9-27.4). Significant differences were also found for sputum volume, consistency, positivity rate and density of acid-fast bacilli. Simple interventions such as these may increase TB case detection in Indonesia and elsewhere.

[A Dutchman from Mali with a perianal ulcer caused by cutaneous amoebiasis]

A 66-year-old Dutchman, living in Mali, presented with an extensive progressive perianal ulcer despite local and antibiotic treatment. Microscopic examination of the stool revealed Entamoeba histolytica/dispar cysts and phagocytosing trophozoites were seen in fresh scrapings of the ulcer, a diagnostic feature of infection with E. histolytica. The diagnosis was cutaneous amoebiasis and the patient was effectively treated with metronidazole and local debridements. Primary cutaneous amoebiasis is a rare disease. Diagnosis and treatment are relatively simple but lack of familiarity with the disease may lead to misdiagnosis or diagnosis at a late stage ofthe infection.

Ocular syphilis acquired through oral sex in two HIV-infected patients

Two cases of ocular syphilis are described in HIV-infected individuals after unprotected oral sex. The primary syphilitic lesion remained unnoticed and lues was therefore only diagnosed after visual symptoms developed.

Bioavailability of rifampicin in Indonesian subjects: a comparison of different local drug manufacturers

To examine the bioavailability of rifampicin formulations produced in Indonesia, we conducted a single-dose, double-blind, cross-over bioavailability study. Antituberculosis drugs from three Indonesian manufacturers and one international manufacturer were compared in 12 healthy Indonesian subjects. Out of three local manufacturers, two showed equal bioavailability compared to the reference standard, and one showed slightly lower bioavailability (ratio 0.86; 90% confidence interval 0.80-0.91) and substandard rifampicin content of drug preparations. Plasma rifampicin concentrations in this study were more than three-fold higher than concentrations recently found in tuberculosis patients in Indonesia, which suggests that unknown (disease-related) determinants may reduce the bioavailability of rifampicin formulations.

[Tuberculosis among Trio-Indians in Surinam]

OBJECTIVE

Evaluation of the extent and possible causes of the increased incidence of tuberculosis among Amazonian Indians in Surinam.

DESIGN

Descriptive.

METHOD

In two cross-sectional surveys in 1998 and 2000, the inhabitants of Kwamalasamutu, a village of Trio-Indians in Surinam, were examined for the presence of active and latent tuberculosis. Previous cases from the period 1995-2000 were evaluated retrospectively by consulting individual physicians and the archives of the 'Medische Zending' (Medical Mission), the 'Diakonessenhuis' hospital, the clinic for pulmonary diseases, and the Central Laboratory. Family ties and other factors that might be associated with tuberculosis were examined. Spoligotyping was done on all patient isolates.

RESULTS

Between 1995 and 2000, active tuberculosis was diagnosed in 25 Indians from Kwamalasamutu, equal to 4.2 cases/1000 person-years (95% CI: 2.7-6.1). Tuberculin skin tests were positive in 105/733 Indians (14.3%). Cases of tuberculosis were found predominantly within certain families, who were genetically related. Spoligotyping of 5 Mycobacterium tuberculosis isolates from Trio-Indians showed unique patterns, which were also found in 34 isolates from elsewhere in Surinam.

CONCLUSION

Tuberculosis was relatively common among Trio-Indians, clustering in certain families. This isolated tribe may have a genetic predisposition for tuberculosis, but their lifestyle and limited access to health care certainly play a role as well.

[Tuberculosis and HIV coinfection in three patients: the possibilities for simultaneous treatment]

Three patients received simultaneous treatment for tuberculosis and HIV: a 23-year-old woman and a 33-year-old man who were asylum seekers from Africa and a 45-year-old woman who was an intravenous drug addict. During the treatment with antiretroviral and anti-tuberculous drugs, several problems arose: drug interactions (between rifampicine and protease inhibitors/non-nucleoside reverse transcriptase inhibitors), side effects, non-compliance and immune reconstitution reactions. These problems were solved either by temporary withdrawal of the medication or by substituting other drugs. There are a number of possible treatment strategies that minimise the risks. Despite the potential problems, in patients with advanced HIV infection, antiretroviral treatment should not be delayed until after the end of the tuberculosis treatment.

Low plasma concentrations of rifampicin in tuberculosis patients in Indonesia

SETTING

Although rifampicin is a key drug in tuberculosis treatment, little is known about its quality and bioavailability in countries endemic for tuberculosis. High drug levels may lead to increased toxicity, while low drug levels may predispose to treatment failure and relapse.

OBJECTIVE

To investigate possible variations in the bioavailability of plasma rifampicin in tuberculosis patients in Indonesia.

DESIGN

Plasma concentrations of rifampicin and the rifampicin content of drug formulations in use were measured among 62 non-selected tuberculosis patients in Jakarta, Indonesia.

RESULTS

Plasma concentrations of rifampin were generally low: 70% of patients had 2-hour plasma concentrations (Cmax) below 4 mg/L. No toxic plasma concentrations of rifampicin (>20 mg/L) were found. The strongest predictive factor for the magnitude of rifampicin concentrations was the drug manufacturer. The rifampicin content of the different drug preparations used was normal (90.5-103.6% of the reference standard). No association was found between low plasma rifampicin concentrations and delayed sputum conversion or treatment failure.

CONCLUSION

The unexpectedly low plasma concentrations of rifampicin in this setting are most likely due to reduced bioavailability of local drug preparations, as the rifampicin content of the drug preparations was found to be normal. The clinical significance of these findings remains to be determined.

The impact of nontuberculous mycobacteria on management of presumed pulmonary tuberculosis

BACKGROUND

The presence of nontuberculous mycobacteria (NTM) in sputum or bronchial washings may cause diagnostic problems which affect clinical management.

PATIENTS AND METHODS

In a retrospective analysis of 135 patients in a Dutch tuberculosis center, patients with NTM isolates were thoroughly investigated. Colonization or contamination by NTM was differentiated from true lung disease.

RESULTS

25 HIV-seronegative and two HIV-seropositive patients with NTM were identified. NTM were a likely cause of disease in only 14 (52%) patients. In 15 (55%), their presence led to preliminary diagnosis and treatment of tuberculosis. Unnecessary or inappropriate treatment was instituted in 17 (63%) patients with NTM. In two patients, detection of NTM in sputum also led to delay in diagnosing malignant disease.

CONCLUSION

In this series, NTM in sputum or bronchial washings poorly reflected disease and often led to diagnostic and therapeutic errors. Although it is common knowledge that the presence of NTM should be considered in smear-positive patients, this apparently is a diagnostic pitfall in clinical practice. Reliable DNA-based techniques and better communication between physicians and microbiologists may improve management of suspected mycobacterial infections.

Mycobacterium tuberculosis Beijing genotype strains associated with febrile response to treatment

DNA fingerprinting has demonstrated predominance of the Beijing genotype among Mycobacterium tuberculosis strains isolated in Southeast Asia. We prospectively examined the occurrence of Beijing genotype strains in tuberculosis patients in Indonesia. Early in treatment, patients infected with Beijing genotype strains more often had fever unrelated to disease severity, toxicity, or drug resistance, indicating that Beijing genotype strains may have specific pathogenic properties.

Modulation of LPS-, PHA- and M. tuberculosis-mediated cytokine production by pentoxifylline and thalidomide

Pentoxifylline and thalidomide have been used to downregulate the production of TNF-alpha in several disease entities including mycobacterial infections and autoimmune disorders. These drugs inhibit the production of TNF-alpha by different mechanisms, but little is known about possible synergism and modulation of other cytokines. Pentoxifylline and thalidomide inhibited the in vitro stimulated production of TNF-alpha, IL-1 beta and IFN-gamma in blood mononuclear cells. No significant modulation of antiinflammatory cytokines was found. When used together, these agents demonstrated additive inhibition, but no synergism. Modulation of cytokine response was similar when different stimuli were used, including M. tuberculosis in tuberculin-positive individuals. Therefore, the balance between efficacy and toxicity may be more favourable when pentoxifylline and thalidomide are used together instead of either drug alone. Clinical studies are needed to establish this advantage when anti-cytokine strategies are considered.

Increased production of interleukin 4 by CD4+ and CD8+ T cells from patients with tuberculosis is related to the presence of pulmonary cavities

In tuberculosis, cellular immunity is considered to be responsible for the eradication of infection but also for damage of host tissues. In animal models, the balance between Th1-type cytokines, especially interferon (IFN)-gamma, and Th2-type cytokines, primarily interleukin (IL)-4, seems crucial for these effects. Reports on Th1-type and Th2-type cytokines in human tuberculosis are conflicting, and little is known about their role in tissue damage. Flow-cytometric assessment of cytokine responses was performed in human immunodeficiency virus (HIV)-seronegative patients with active tuberculosis and in healthy controls. Patients and controls showed no significant difference in expression of IFN-gamma. However, patients showed a striking increase in production of IL-4 in CD4+ as well as CD8+ T cells. Most remarkably, the expression of IL-4 was especially elevated in patients with cavitary tuberculosis. The Th2-type response with increased production of IL-4 in patients with tuberculosis may antagonize host defense and lead to tissue necrosis.

Disease-specific ex vivo stimulation of whole blood for cytokine production: applications in the study of tuberculosis

As a simple method for field studies to assess the cytokine-status of patients with tuberculosis (TB), the use of whole blood instead of isolated cells has advantages, especially since the risk of contamination is minimal. Therefore, cytokine production in whole blood cultures was determined using non-specific and disease-specific stimuli. Heparinized blood from healthy volunteers was either incubated in closed vacutainer tubes or in tissue culture wells after dilution in culture medium. Dose-response and kinetics were investigated for the production of TNFalpha, IL-1beta, IL-1ra, IL-10 and IFNgamma. Patients with TB and healthy individuals were examined for IFN-gamma production in whole blood. In the absence of a stimulus, the production of cytokines is negligible in whole blood cultures. LPS induces the production of TNFalpha, IL-1beta, IL-1ra and IL-10; PHA induces the production of IFNgamma and IL-10. Live BCG induces the production of proinflammatory cytokines, irrespective of tuberculin skin status. In contrast, PPD and MTB-culture filtrate induce production of IFNgamma in skin-test positive and not in skin-test negative healthy subjects. Five out of 13 patients with TB had a low antigen-specific IFNgamma production, suggestive of a minimal or absent specific T-cell response. For most purposes, cultures in closed vacutainer tubes are optimal. If one wishes to focus on T-cell cytokines or if only small volumes of blood are available, dilution of whole blood in culture medium before incubation in tissue culture wells may be preferable.