A practical approach to the diagnosis and management of malignant pleural effusions in resource-constrained settings.

No pleural intervention in a patient with confirmed malignant pleural effusion (MPE) prolongs life, but even the recommended interventions for diagnosis and palliation can be costly and therefore unavailable in large parts of the world. However, there is good evidence to guide clinicians working in low- and middle-income countries on the most cost-effective and clinically effective strategies for the diagnosis and management of MPE. Transthoracic ultrasound-guided closed pleural biopsy is a safe method of pleural biopsy with a diagnostic yield approaching that of thoracoscopy. With the use of pleural fluid cytology and ultrasound-guided biopsy, ≥90% of cases can be diagnosed. Cases with an associated mass lesion are best suited to an ultrasound-guided fine needle aspiration with/without core needle biopsy. Those with diffuse pleural thickening and/or nodularity should have an Abrams needle (<1 cm thickening) or core needle (≥1 cm thickening) biopsy of the area of interest. Those with insignificant pleural thickening should have an ultrasound-guided Abrams needle biopsy close to the diaphragm. The goals of management are to alleviate dyspnoea, prevent re-accumulation of the pleural effusion and minimise re-admissions to hospital. As the most cost-effective strategy, we suggest early use of indwelling pleural catheters with daily drainage for 14 days, followed by talc pleurodesis if the lung expands. The insertion of an intercostal drain with talc slurry is an alternative strategy which is noninferior to thoracoscopy with talc poudrage. Educational aims: To provide clinicians practising in resource-constrained settings with a practical evidence-based approach to the diagnosis and management of malignant pleural effusions.To explain how to perform an ultrasound-guided closed pleural biopsy.To explain the cost-effective use of indwelling pleural catheters.

Diagnostic Accuracy of the Cepheid 3-gene Host Response Fingerstick Blood Test in a Prospective, Multi-site Study: Interim Results.

BACKGROUND: The development of a fast and accurate, non-sputum-based point-of-care triage test for tuberculosis (TB) would have a major impact on combating the TB burden worldwide. A new fingerstick blood test has been developed by Cepheid (the Xpert MTB Host Response [MTB-HR] prototype), which generates a "TB score" based on messenger RNA (mRNA) expression of 3 genes. Here we describe the first prospective findings of the MTB-HR prototype. METHODS: Fingerstick blood from adults presenting with symptoms compatible with TB in South Africa, The Gambia, Uganda, and Vietnam was analyzed using the Cepheid GeneXpert MTB-HR prototype. Accuracy of the Xpert MTB-HR cartridge was determined in relation to GeneXpert Ultra results and a composite microbiological score (GeneXpert Ultra and liquid culture) with patients classified as having TB or other respiratory diseases (ORD). RESULTS: When data from all sites (n = 75 TB, 120 ORD) were analyzed, the TB score discriminated between TB and ORD with an area under the curve (AUC) of 0.94 (95% confidence interval [CI], .91-.97), sensitivity of 87% (95% CI, 77-93%) and specificity of 94% (88-97%). When sensitivity was set at 90% for a triage test, specificity was 86% (95% CI, 75-97%). These results were not influenced by human immunodeficiency virus (HIV) status or geographical location. When evaluated against a composite microbiological score (n = 80 TB, 111 ORD), the TB score was able to discriminate between TB and ORD with an AUC of 0.88 (95% CI, .83-.94), 80% sensitivity (95% CI, 76-85%) and 94% specificity (95% CI, 91-96%). CONCLUSIONS: Our interim data indicate the Cepheid MTB-HR cartridge reaches the minimal target product profile for a point of care triage test for TB using fingerstick blood, regardless of geographic area or HIV infection status.

Autologous Blood Patch Pleurodesis for the Management of a Persistent Air Leak after Secondary Spontaneous Pneumothorax.

Patients with secondary spontaneous pneumothorax (SSP) complicated by persistent air leak (PAL) and who are poor surgical candidates have limited treatment options. This case series explored autologous blood patch pleurodesis as a possible cost-effective management option. A total of 46 episodes of SSP with PAL were included. The procedure was successful in 33 (71.7%). Of these, 17 (51.5%) resolved within 1 day. The mean duration of intercostal drainage prior to the blood patch was 22 days in the successful group. Pneumothoraces with incomplete lung re-expansion at the time of procedure were successful in 20 of 30 (66.7%). Only human immunodeficiency virus infection was associated with failure (p = 0.03). Adverse events included transient fever (n = 3) that resolved spontaneously, and empyema (n = 3) which were successfully managed with antibiotics and pigtail drainage. We conclude that a large proportion of patients with SSP complicated by PAL who are unfit for surgery may be liberated from intercostal drainage by an autologous blood patch pleurodesis, with minimal adverse effects.

Pleural Tuberculosis.

Pleural tuberculosis (TB) is common and often follows a benign course but may result in serious long-term morbidity. Diagnosis is challenging because of the paucibacillary nature of the condition. Advances in Mycobacterium culture media and PCR-based techniques have increased the yield from mycobacteriologic tests. Surrogate biomarkers perform well in diagnostic accuracy studies but must be interpreted in the context of the pretest probability in the individual patient. Confirming the diagnosis often requires biopsy, which may be acquired through thoracoscopy or image-guided closed pleural biopsy. Treatment is standard anti-TB therapy, with optional drainage and intrapleural fibrinolytics or surgery in complicated cases.

Inhaled particulate matter affects immune responsiveness of human lung phagocytes to mycobacteria.

The influence of smoke-derived or air pollution-derived cytoplasmic particulate matter (PM) can be detrimental and can lead to failed lung immunity. We investigated mycobacterial uptake, intracellular replication, and soluble immune-mediator responses of human bronchoalveolar lavage cells (BALCs) loaded with/without PM, to infection with mycobacterial strains. We observed that only BALCs containing PM display an ex vivo phenotypic profile dominated by spontaneous interleukin (IL)-10 production. PM-loaded BALCs retained the ability to phagocytose both Mycobacterium bovis Bacille Calmette Guérin (BCG) and Mycobacterium tuberculosis (M.tb) ΔleuDΔpanCD at equal efficacy as clear non-PM-loaded BALCs. However, immune responsiveness, such as the production of IL-6 (P = 0.015) and tumor necrosis factor-α (TNF)-α (P = 0.0172) immediately post M. bovis BCG infection, were dramatically lower in black BALCs loaded with PM versus clear non-PM-loaded BALCs. By 24 h post infection, differential immune responses to M. bovis BCG between black versus clear BALC waned, and instead, production of IL-6 (P = 0.03) and IL-1α (P = 0.04) by black BALCs was lower versus clear BALCs following M.tb ΔleuDΔpanCD infection. Considering that TNF-α and IL-6 are characterized as critical to host protection against mycobacteria, our findings suggest that BALCs loaded with inhaled PM, display lower levels of antimycobacterial mediators and that the response magnitude differs according to infective mycobacterial strain. Even though this did not translate into altered mycobacterial killing at early time points post infection, the long-term impact of such changes remains to be established.

Tuberculous pleural effusion.

Tuberculous effusion is a common disease entity with a spectrum of presentations from a largely benign effusion, which resolves completely, to a complicated effusion with loculations, pleural thickening and even frank empyema, all of which may have a lasting effect on lung function. The pathogenesis is a combination of true pleural infection and an effusive hypersensitivity reaction, compartmentalized within the pleural space. Diagnostic thoracentesis with thorough pleural fluid analysis including biomarkers such as adenosine deaminase and gamma interferon achieves high accuracy in the correct clinical context. Definitive diagnosis may require invasive procedures to demonstrate histological evidence of caseating granulomas or microbiological evidence of the organism on smear or culture. Drug resistance is an emerging problem that requires vigilance and extra effort to acquire a complete drug sensitivity profile for each tuberculous effusion treated. Nucleic acid amplification tests such as Xpert MTB/RIF can be invaluable in this instance; however, the yield is low in pleural fluid. Treatment consists of standard anti-tuberculous therapy or a guideline-based individualized regimen in the case of drug resistance. There is low-quality evidence that suggests possible benefit from corticosteroids; however, they are not currently recommended due to concomitant increased risk of adverse effects. Small studies report some short- and long-term benefit from interventions such as therapeutic thoracentesis, intrapleural fibrinolytics and surgery but many questions remain to be answered.

Contemporary best practice in the management of malignant pleural effusion.

Malignant pleural effusion (MPE) affects more than 1 million people globally. There is a dearth of evidence on the therapeutic approach to MPE, and not surprisingly a high degree of variability in the management thereof. We aimed to provide practicing clinicians with an overview of the current evidence on the management of MPE, preferentially focusing on studies that report patient-related outcomes rather than pleurodesis alone, and to provide guidance on how to approach individual cases. A pleural intervention for MPE will perforce be palliative in nature. A therapeutic thoracentesis provides immediate relief for most. It can be repeated, especially in patients with a slow rate of recurrence and a short anticipated survival. Definitive interventions, individualized according the patient's wishes, performance status, prognosis and other considerations (including the ability of the lung to expand) should be offered to the remainder of patients. Chemical pleurodesis (achieved via intercostal drain or pleuroscopy) and indwelling pleural catheter (IPC) have equal impact on patient-based outcomes, although patients treated with IPC spend less time in hospital and have less need for repeat pleural drainage interventions. Talc slurry via IPC is an attractive recently validated option for patients who do not have a nonexpandable lung.

Pleural tuberculosis: A concise clinical review.

Tuberculosis (TB) is the leading infectious cause of death worldwide, and the commonest cause of death in people living with HIV. Globally, pleural TB remains one of the most frequent causes of pleural exudates, particularly in TB-endemic areas and in the HIV positive population. Most TB pleural effusions are exudates with high adenosine deaminase (ADA), lymphocyte-rich, straw-coloured and free flowing, with a low yield on mycobacterial culture. TB pleurisy can also present as loculated neutrophil-predominant effusions which mimic parapneumonic effusions. Rarely, they can present as frank TB empyema, containing an abundance of mycobacteria. Up to 80% of patients have parenchymal involvement on chest imaging. The diagnosis is simple if M. tuberculosis is detected in sputum, pleural fluid or biopsy specimens, and the recent advent of liquid medium culture techniques has increased the microbiological yield dramatically. Where the prevalence of TB is high the presence of a lymphocyte-predominant exudate with a high ADA has a positive predictive value of 98%. In low prevalence areas, the absence of an elevated ADA and lymphocyte predominance makes TB very unlikely, and pleural biopsy should be performed to confirm the diagnosis. Pleural biopsy for liquid culture and susceptibility testing must also be considered where the prevalence of drug resistant TB is high. Treatment regimens are identical to those administered for pulmonary TB. Initial pleural drainage may have a role in symptom relief and in hastening the resolution of the effusion. Surgical intervention may be required in loculated effusions and empyemas.

Integrated positron emission tomography/computed tomography for evaluation of mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic area: A 5-year prospective observational study.

BACKGROUND: Integrated positron emission tomography/computed tomography (PET-CT) is a well-validated modality for assessing mediastinal lymph node metastasis in non-small-cell lung cancer (NSCLC), which determines management and predicts survival. Tuberculosis (TB) is known to lead to false-positive PET-CT findings. OBJECTIVES: To assess the diagnostic accuracy of PET-CT in identifying mediastinal lymph node involvement of NSCLC in a high TB-endemic area. METHODS: Patients who underwent both PET-CT and lymph node tissue sampling for the investigation of suspected NSCLC were prospectively included in this observational study. Results were analysed per patient and per lymph node stage. A post-hoc analysis was performed to test the validity of a maximum standardised uptake value (SUV-max) cut-off for lymph node positivity. RESULTS: PET-CT had a sensitivity of 92.6%, specificity of 48.6%, positive predictive value of 56.8% and negative predictive value (NPV) of 90.0% in the per-patient analysis. Diagnostic accuracy was 67.2%. Similar values were obtained in the per-lymph node stage analysis. TB was responsible for 21.1% of false-positive results. A SUVmax cut-off of 4.5 yielded an improvement in diagnostic accuracy from 64.0% to 84.7% compared with a cut-off of 2.5, but at the cost of decreasing the NPV from 90.6% to 83.5%. CONCLUSION: In a high TB-endemic area, PET-CT remains a valuable method for excluding mediastinal lymph node involvement in NSCLC. Patients with a negative PET-CT may proceed to definitive management without further invasive procedures. However, PET-CT-positive lymph nodes require pathological confirmation, and the possibility of TB must be considered.

Ectopic 5' splice sites inhibit gene expression by engaging RNA surveillance and silencing pathways in plants.

The quality control of mRNA maturation is a highly regulated process that surveys pre-mRNA integrity and eliminates improperly matured pre-mRNAs. In nature, certain viruses regulate the expression of their genes by hijacking the endogenous RNA quality control machinery. We demonstrate that the inclusion of 5' splice sites within the 3'-untranslated region of a reporter gene in plants alters the pre-mRNA cleavage and polyadenylation process, resulting in pre-mRNA degradation, exemplifying a regulatory mechanism conserved between kingdoms. Altered pre-mRNA processing was associated with an inhibition of homologous gene expression in trans and the preferential accumulation of 24-nucleotide (nt) short-interfering RNAs (siRNAs) as opposed to 21-nt siRNA subspecies, suggesting that degradation of the aberrant pre-mRNA involves the silencing machinery. However, gene expression was not restored by coexpression of a silencing suppressor or in an RNA-dependent RNA polymerase (RDR6)-deficient background despite reduced 24-nt siRNA accumulation. Our data highlight a complex cross talk between the quality control RNA machinery, 3'-end pre-mRNA maturation, and RNA-silencing pathways capable of discriminating among different types of aberrant RNAs.