Complement Component C1q as an Emerging Biomarker for the Diagnosis of Tuberculous Pleural Effusion

Background and Objective: The accurate differential diagnosis of tuberculous pleural effusion (TPE) from other exudative pleural effusions is often challenging. We aimed to validate the accuracy of complement component C1q in pleural fluid (PF) in diagnosing TPE.Methods: The level of C1q protein in the PF from 49 patients with TPE and 61 patients with non-tuberculous pleural effusion (non-TPE) was quantified by enzyme-linked immunosorbent assay, and the diagnostic performance was assessed by receiver operating characteristic (ROC) curves based on the age and gender of the patients.Results: The statistics showed that C1q could accurately diagnose TPE. Regardless of age and gender, with a cutoff of 6,883.9 ng/mL, the area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of C1q for discriminating TPE were 0.898 (95% confidence interval: 0.825–0.947), 91.8 (80.4–97.7), 80.3 (68.2–89.4), 78.9 (69.2–86.2), and 92.5 (82.6–96.9), respectively. In subgroup analysis, the greatest diagnostic accuracy was achieved in the younger group (≤ 50 years of age) with an AUC of 0.981 (95% confidence interval: 0.899–0.999) at the cutoff of 6,098.0 ng/mL. The sensitivity, specificity, PLR, NLR, PPV, and NPV of C1q were 95.0 (83.1–99.4), 92.3 (64.0–99.8), 97.4 (85.2–99.6), and 85.7 (60.6–95.9), respectively.Conclusion: Complement component C1q protein was validated by this study to be a promising biomarker for diagnosing TPE with high diagnostic accuracy, especially among younger patients.

Tuberculous pleural effusion in a patient with sympathetic ophthalmia on immunosuppression: a case report

Background Tuberculous pleural effusion (TPE) is paucibacillary, making its diagnosis difficult based on laboratory investigations alone. We present a case of a patient with a TPE who was initially misdiagnosed to have azathioprine-induced lung injury. The diagnosis of TPE was arrived at with the help of clinical assessment, laboratory and radiological investigations. Case presentation A 25-year-old chronic smoker with sympathetic ophthalmia on long-term immunosuppression, latent tuberculosis infection and a significant family history of tuberculosis presented with a three-week history of productive cough, low-grade fever, night sweats and weight loss. Examination of the lungs showed reduced breath sounds at the right lower zone. Chest x-ray showed minimal right pleural effusion with a small area of right upper lobe consolidation. The pleural fluid was exudative with predominant mononuclear leukocytes. Direct smears of sputum and pleural fluid; polymerase chain reaction of pleural fluid; and sputum, pleural fluid and blood cultures were negative for M. tuberculosis (MTB) and other organisms. As he did not respond to a course of broad-spectrum antibiotics, he was then treated as a case of azathioprine-induced lung injury. However, his condition did not improve despite the cessation of azathioprine. A contrast-enhanced computed tomography of the thorax showed right upper lobe consolidation with tree-in-bud changes, bilateral lung atelectasis, subpleural nodule, mild right pleural effusion and mediastinal lymphadenopathy. Bronchoalveolar lavage was negative for malignant cells and microorganisms including, MTB. However, no pleural biopsy was done. He was empirically treated with anti-tubercular therapy for 9 months duration and showed complete recovery. Conclusion A high index of suspicion for TPE is required in individuals with immunosuppression living in regions endemic to tuberculosis. Targeted investigations and sound clinical judgement allow early diagnosis and prompt treatment initiation to prevent morbidity and mortality.

An efficient scoring model for diagnosis of tuberculous pleural effusion

Background: Due to the low efficiency of single clinical feature or laboratory variable in the diagnosis of tuberculous pleural effusion (TBPE), The diagnosis of TBPE is still challenging. This study aimed to build an efficient scoring diagnostic model based on laboratory variables and clinical features to differentiate TBPE from non-tuberculous pleural effusion(non-TBPE). Methods: A retrospective study of 125 patients (63 with TBPE; 62 with non-TBPE) were undertaken. Univariate analysis was used to select the laboratory and clinical variables relevant to the model composition. The statistically different variables were selected to undergo binary logistic regression. Variables B coefficients were used to define a numerical score to calculate a scoring model. A receiver operating characteristic (ROC) curve was used to calculate the best cut-off value and evaluate the performance of the model. Results: Six variables were selected in the scoring model: Age ≤ 46 years old (4.96 point), Male (2.44 point), No cancer (3.19 point), Positive T-cell Spot (T-SPOT) results (4.69 point), Adenosine Deaminase (ADA) ≥ 24.5U/L (2.48 point), C-reactive Protein (CRP) ≥ 52.8mg/L (1.84 point). With a cut-off value of total score was 11.038 points, the sensitivity, specificity and accuracy of the scoring model was 93.7%, 96.8% and 99.2% respectively. Conclusion: The scoring model was efficient to differentiate TBPE from non-TBPE.

Clinical and Epidemiological Features of Tuberculous Pleural Effusion in Alicante, Spain

We aimed to (1) evaluate the incidence of tuberculous pleural effusion (TPE) over 25 years in our centre; (2) measure the yield of different diagnostic techniques; (3) compare TPE features between immigrant and native patients. Retrospective study of patients who underwent diagnostic thoracentesis and pleural biopsy in our hospital between 1995 and 2020. TPE was diagnosed in 71 patients (65% natives, 35% immigrants). Onset was acute in 35%, subacute in 26% and prolonged in 39%. Radiological features were atypical in 42%. Thoracentesis specimens were lymphocyte-predominant in 84.5% of patients, with elevated adenosine deaminase in 75% of patients. Diagnostic yield of pleural biopsy was 78%. Compared with native patients, more immigrants had previous contact with TB (54% vs. 17%, p = 0.001), prior TB (21% vs. 4%, p < 0.02) and atypical radiological features (58% vs. 34%, p < 0.03). TPE incidence was six times higher in the immigrant population (6.7 vs. 1.1 per 100,000 person-years, p < 0.001). TPE has an acute onset and sometimes atypical radiological features. Pleural biopsy has the highest diagnostic yield. Reactivation, prior contact with TB, atypical radiological features, complications, and positive microbiology results are more common in immigrant patients.