Diagnostic accuracy of pleural fluid lactate dehydrogenase to adenosine deaminase ratio for tuberculous pleural effusion: an analysis of two cohorts

Diagnostic accuracy of pleural fluid complement C1q for tuberculous pleural effusion in elderly patients

BACKGROUND

Previous studies indicated that pleural fluid complement C1q was helpful for diagnosing tuberculous pleural effusion (TPE), but the participants in these studies were young. The diagnostic accuracy of C1q for TPE in elderly patients remains unknown. This study aimed to investigate the diagnostic accuracy of C1q for TPE in elderly patients.

METHODS

We prospectively recruited patients with undiagnosed pleural effusion who visited the Affiliated Hospital of Inner Mongolia Medical University between September 2018 and July 2021. Their C1q in pleural fluid was detected, and the diagnostic accuracy of C1q was assessed by the receiver operating characteristic (ROC) curve analysis.

RESULTS

The median ages of patients with TPE and non-TPE were 75 and 71 years, respectively. TPE patients had significantly higher C1q than non-TPE. The area under the ROC curve (AUC) of C1q was 0.67 (95 %CI: 0.51-0.82). At the threshold of 100 mg/L, C1q had a sensitivity of 0.44 (95 %CI: 0.19-0.69) and specificity of 0.79 (95 %CI: 0.71-0.86).

CONCLUSION

C1q in pleural fluid has low diagnostic accuracy for TPE in elderly patients.

Apolipoprotein E in patients with undiagnosed pleural effusion: a prospective diagnostic test accuracy study

INTRODUCTION

Pleural effusion is common in clinical practice, and its differential diagnosis remains challenging for clinicians. This study investigates the diagnostic value of apolipoprotein E (apoE) in patients with undetermined pleural effusion.

METHODS

This prospective, double-blind study enrolled 152 patients with undiagnosed pleural effusion. Their pleural fluid apoE levels were measured, and a receiver operating characteristics (ROC) curve was used to evaluate the diagnostic accuracy of apoE. Decision curve analysis (DCA) was used to assess apoE's net benefit. Subgroup analyses were performed to investigate the effect of age on the diagnostic accuracy of apoE.

RESULTS

Among the included participants, 23 had heart failure (HF). HF patients had the lowest apoE level among pleural effusion patients. The area under the curve (AUC) of apoE for HF was 0.79 (95% CI: 0.69-0.89). At the threshold of 40 mg/L, the sensitivity and specificity of apoE were 0.96 (95% CI: 0.87-1.00) and 0.33 (95% CI: 0.25-0.42), respectively. The decision curve for apoE was above reference lines. The AUC of apoE decreased in older patients.

CONCLUSION

Pleural fluid apoE has moderate diagnostic value for HF and has net benefits in patients with undiagnosed pleural effusion. The diagnostic accuracy of apoE decreases with age.

Diagnostic accuracy and cellular origin of pleural fluid CXCR3 ligands for tuberculous pleural effusion

BACKGROUND

Pleural biomarkers represent potential diagnostic tools for tuberculous pleural effusion (TPE) due to their advantages of low cost, short turnaround time, and less invasiveness. This study evaluated the diagnostic accuracy of two CXCR3 ligands, C-X-C motif chemokine ligand 9 (CXCL9) and CXCL11, for TPE. In addition, we investigated the cellular origins and biological roles of CXCL9 and CXCL11 in the development of TPE.

METHODS

This double-blind study prospectively enrolled patients with undiagnosed pleural effusion from two centers (Hohhot and Changshu) in China. Pleural fluid on admission was obtained and levels of CXCL9 and CXCL11 were measured by an enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristic (ROC) curve and the decision curve analysis (DCA) were used to evaluate their diagnostic accuracy and net benefit, respectively. THP-1 cell-derived macrophages were treated with Bacillus Calmette-Guérin (BCG), and quantitative real-time PCR (qRT-PCR) and ELISA were used to determine the mRNA and protein levels of CXCL9 and CXCL11. The chemoattractant activities of CXCL9 and CXCL11 for T helper (Th) cells were analyzed by a transwell assay.

RESULTS

One hundred and fifty-three (20 TPEs and 133 non-TPEs) patients were enrolled in the Hohhot Center, and 58 (13 TPEs and 45 non-TPEs) were enrolled in the Changshu Center. In both centers, we observed increased CXCL9 and CXCL11 in TPE patients. The areas under the ROC curves (AUCs) of pleural CXCL9 and CXCL11 in the Hohhot Center were 0.70 (95 % CI: 0.55-0.85) and 0.68 (95 % CI: 0.52-0.84), respectively. In the Changshu Center, the AUCs of CXCL9 and CXCL11 were 0.96 (95 % CI: 0.92-1.00) and 0.97 (95 % CI: 0.94-1.00), respectively. The AUCs of CXCL9 and CXCL11 decreased with the advancement of age. The decision curves of CXCL9 and CXCL11 showed net benefits in both centers. CXCL9 and CXCL11 were upregulated in BCG-treated macrophages. Pleural fluid from TPE and conditioned medium from BCG-treated macrophages were chemotactic for Th cells. Anti-CXCL9 or CXCL11 neutralizing antibodies could partly block the chemotactic activity.

CONCLUSIONS

Pleural CXCL9 and CXCL11 are potential diagnostic markers for TPE, but their diagnostic accuracy is compromised in elderly patients. CXCL9 and CXCL11 can promote the migration of peripheral Th cells, thus representing a therapeutic target for the treatment of TPE.

Infective Pleural Effusions-A Comprehensive Narrative Review Article

Infective pleural effusions are mainly represented by parapneumonic effusions and empyema. These conditions are a spectrum of pleural diseases that are commonly encountered and carry significant mortality and morbidity rates reaching upwards of 50%. The causative etiology is usually an underlying bacterial pneumonia with the subsequent seeding of the infectious culprit and inflammatory agents to the pleural space leading to an inflammatory response and fibrin deposition. Radiographical evaluation through a CT scan or ultrasound yields high specificity and sensitivity, with features such as septations or pleural thickening indicating worse outcomes. Although microbiological yields from pleural studies are around 56% only, fluid analysis assists in both diagnosis and prognosis by evaluating pH, glucose, and other biomarkers such as lactate dehydrogenase. Management centers around antibiotic therapy for 2-6 weeks and the drainage of the infected pleural space when the effusion is complicated through tube thoracostomies or surgical intervention. Intrapleural enzymatic therapy, used to increase drainage, significantly decreases treatment failure rates, length of hospital stay, and surgical referrals but carries a risk of pleural hemorrhage. This comprehensive review article aims to define and delineate the progression of parapneumonic effusions and empyema as well as discuss pathophysiology, diagnostic, and treatment modalities with aims of broadening the generalist's understanding of such complex disease by reviewing the most recent and relevant high-quality evidence.

Pleural tuberculosis and endocarditis as complications of multifactorial origin in granulomatosis with polyangiitis: Clinical case report

We present the case of a 36-year-old woman with a history of granulomatosis with polyangiitis; chronic kidney disease; systemic arterial hypertension. Debut with dyspnea, weakness, and hemoptysis, she was suspected in atypical pneumonia, discarded, persisting with tachypnea, tachycardia, chest pain. The protocol for pulmonary tuberculosis was started with negative sputum samples, positive blood culture for S. haemolyticus, chest tomography with left pneumothorax and ipsilateral pleural effusion, exudate-type pleural fluid was obtained, acid-fast staining, negative PCR for M. tuberculosis; A follow-up echocardiogram was performed due to a new murmur, reporting valvular vegetation, concluding a diagnosis of pleural tuberculosis and endocarditis as complications of multifactorial origin associated with immunosuppression in granulomatosis with polyangiitis.

Diagnostic flowchart for tuberculous pleurisy, pleural infection, and malignant pleural effusion

BACKGROUND

Several markers for the diagnosis of pleural effusion have been reported; however, a comprehensive evaluation using those markers has not been performed. Therefore, this study aimed to develop a diagnostic flowchart for tuberculous pleurisy, pleural infection, malignant pleural effusion, and other diseases by using these markers.

METHODS

We retrospectively collected data from 174 patients with tuberculous pleurisy, 215 patients with pleural infection other than tuberculous pleurisy, 360 patients with malignant pleural effusion, and 209 patients with other diseases at Fukujuji Hospital from January 2012 to October 2022. The diagnostic flowchart for four diseases was developed by using several previously reported markers.

RESULTS

The flowchart was developed by including seven markers: pleural ADA ≥40 IU/L, pleural fluid LDH <825 IU/L, pleural fluid ADA/TP < 14, neutrophil predominance or cell degeneration, peripheral blood WBC ≥9200/μL or serum CRP ≥12 mg/dL, pleural amylase ≥75 U/L, and the presence of pneumothorax according to the algorithm of a decision tree. The accuracy ratio of the flowchart was 71.7 % for the diagnosis of the four diseases, with 79.3 % sensitivity and 75.4 % positive predictive value (PPV) for tuberculosis pleurisy, 75.8 % sensitivity and 83.2 % PPV for pleural infection, 88.6 % sensitivity and 68.8 % PPV for malignant pleural effusion, and 33.0 % sensitivity and 60.0 % PPV for other diseases in the flowchart. The misdiagnosis ratios were 4.6 % for tuberculosis pleurisy, 6.8 % for pleural infection, and 8.3 % for malignant pleural effusion.

CONCLUSION

This study developed a useful diagnostic flowchart for tuberculous pleurisy, pleural infection, malignant pleural effusion, and other diseases.

Pleural fluid soluble Fas ligand and tuberculous pleural effusion: a prospective diagnostic test accuracy study

Background

The diagnosis of tuberculous pleural effusion (TPE) is challenging for pulmonologists. Adenosine deaminase (ADA), interferon-gamma (IFN-γ), and interleukin-27 (IL-27) have some limitations for diagnosing TPE. Soluble Fas ligand (sFasL) had a high diagnostic value for TPE. However, it remains unknown: (I) whether sFasL has an additional diagnostic value to the traditional markers (e.g., ADA); (II) whether sFasL provides a net benefit in patients with undiagnosed pleural effusion; (III) factors affecting the diagnostic accuracy of sFasL for TPE. This study aimed to evaluate the additional diagnostic value and benefit of pleural fluid sFasL for TPE.

Methods

We prospectively enrolled 211 patients with undiagnosed pleural effusion. The concentration of sFasL in pleural fluid was measured by an enzyme-linked immunosorbent assay (ELISA). The diagnostic accuracy and net benefit of sFasL and ADA for TPE were analyzed by a receiver operating characteristic (ROC) curve, decision curve analysis (DCA), net reclassification improvement (NRI), and integrated discriminant improvement (IDI).

Results

The area under the ROC curves (AUCs) of sFasL and ADA were 0.74 (95% CI: 0.65-0.83) and 0.80 (95% CI: 0.71-0.90), respectively. The decision curve of sFasL revealed net benefit. The continuous NRI and IDI of sFasL were 0.36 (0.00-0.72, P=0.05) and 0.02 (-0.01-0.06, P=0.18), respectively.

Conclusions

Pleural fluid sFasL has moderate diagnostic accuracy for TPE.

Age affects the diagnostic accuracy of the cancer ratio for malignant pleural effusion

BACKGROUND AND OBJECTIVE

Cancer ratio (CR), which is defined as serum lactate dehydrogenase (LDH) to pleural fluid adenosine deaminase (ADA) ratio, has been reported to be a useful diagnostic marker for malignant pleural effusion (MPE). Whether its diagnostic accuracy is affected by age remains unknown. This study aimed to investigate the effects of age on the diagnostic accuracy of CR.

METHODS

The participants in this study were from a prospective cohort (SIMPLE cohort, n = 199) and a retrospective cohort (BUFF cohort, n = 158). All participants were patients with undiagnosed pleural effusion (PE). We used receiver operating characteristic (ROC) curves to evaluate the diagnostic accuracy of CR. The effect of age on the diagnostic accuracy of CR was investigated by adjusting the upper limit of age for participant enrolment.

RESULTS

Eighty-eight MPE patients were verified in the SIMPLE cohort, and thirty-five MPE patients were verified in the BUFF cohort. The AUCs of CR in the SIMPLE and BUFF cohorts were 0.60 (95% CI: 0.52-0.68) and 0.63 (95% CI: 0.54-0.71), respectively. In both cohorts, the AUCs of CR decreased with the advancement of age.

CONCLUSION

Age can affect the diagnostic accuracy of CR for MPE. CR has limited diagnostic value in older patients.

KEY MESSAGE

Cancer ratio is a promising diagnostic marker for malignant pleural effusion. This study revealed that its diagnostic accuracy decreased in older patients. Its diagnostic accuracy is overestimated by previous studies using tuberculosis and pneumonia patients as controls.