A rapid calprotectin test for the diagnosis of pleural effusion

Abstract

In previous studies, measuring the levels of calprotectin in patients with pleural effusion (PE) was an exceptionally accurate way to predict malignancy. Here, we evaluated a rapid method for the measurement of calprotectin levels as a useful parameter in the diagnosis of malignant pleural effusion (MPE) in order to minimise invasive diagnostic tests. Calprotectin levels were measured with Quantum Blue® sCAL (QB®sCAL) and compared with the gold standard reference ELISA method. Calprotectin levels in patients with benign pleural effusion (BPE) were significantly higher (p < 0.0001) than for MPE patients. We measured the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive and negative likelihood ratios (LRs) for a cut-off value of ≤ 14,150 ng/mL; the diagnostic accuracy was 64%. The odds ratio for PE calprotectin levels was 10.938 (95% CI [4.133 − 28.947]). The diagnostic performance of calprotectin concentration was better for predicting MPE compared to other individual parameters. Comparison of two assays showed a slope of 1.084, an intercept of 329.7, and a Pearson correlation coefficient of 0.798. The Bland–Altman test showed a positive bias for the QB®sCAL method compared to ELISA fCAL®. Clinical concordance between both these methods was 88.5% with a Cohen kappa index of 0.76 (95% CI [0.68 − 0.84]). We concluded that QB®sCAL is a fast, reliable, and non-invasive diagnostic tool for diagnosing MPE and represents an alternative to ELISA that could be implemented in medical emergencies.

Evaluation of DiaSorin Liaison® calprotectin fecal assay adapted for pleural effusion

“…In addition to its antimicrobial functions, CP is also a molecule with pro- and anti-tumor properties related to cell survival and growth, angiogenesis, DNA damage response, and extracellular matrix remodeling [ 22 ]. Recent evidence reports its usefulness in predicting malignancy [ 6 ], [ 7 ], [ 8 ] and differentiating between parapneumonic and non-parapneumonic pleural effusions [ 22 , 23 ]. Nevertheless, studies examining CP levels in pleural effusions are very scarce and have limitations of the measurement techniques used, since they were based on ELISA procedures, despite that, in recent years, fully automated analyzers have been developed.…”

“…A slightly higher LoQ was observed in pleural fluid than in feces, that should be taken into consideration for future applications where low CP concentrations have clinical interest. Even so, LoQ by this method is lower than that described by ELISA (ELISA fCAL ® ) or lateral flow immunocromatographic method (Quantum Blue ® ) (400 and 5,000 ng/mL respectively) [ 8 ].…”

“…In clinical practice, fecal CP measurement [ 3 ] is widely used for the diagnosis and monitoring of patients suffering from chronic inflammatory gastrointestinal disorders [ 4 ], but CP can be measured in other biological fluids [ 5 ], such as pleural effusions. Recent studies have pointed out its clinical utility to accurately predict malignancy, but all have used ELISA procedures [ 6 ], [ 7 ], [ 8 ] which, among other limitations, are not suitable for tests that require short response times.…”

Adenosine deaminase-based measurement in the differential diagnosis of pleural effusion: a multicenter retrospective study

“… 6 When pleural biopsy is used, cytological examination has a low rate of MPE detection because of the poor preservation of tumor cells and small sample volume. 7 , 8 Thoracoscopic biopsy is an efficient diagnostic method for both TPE and MPE, but its invasiveness limits clinical application. 9 – 11 Furthermore, the performances of tumor biomarkers such as vascular endothelial growth factor, carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 125, CA 15-3, CA 19-9, and CYFRA 21-1 (a fragment of cytokeratin 19) in the diagnosis of MPE are also limited.…”

Evaluación de la prueba fecal Liaison® Calprotectin de DiaSorin adaptada al derrame pleural

“…En la práctica clínica, la determinación de CP fecal [ 3 ] se suele utilizar en el diagnóstico y seguimiento de pacientes con desórdenes gastrointestinales inflamatorios crónicos [ 4 ], aunque también se puede determinar en otros fluidos biológicos [ 5 ], como el derrame pleural. Estudios recientes han señalado su utilidad clínica a la hora de predecir malignidad con precisión, aunque en todos se empleó la técnica ELISA [ 6 ], [ 7 ], [ 8 ] que, entre otras limitaciones, no es adecuada para pruebas que requieren tiempos cortos de respuesta.…”