Mapping IPF helps identify geographic regions at higher risk for disease development and potential triggers.

BACKGROUND AND OBJECTIVE: The relationship between IPF development and environmental factors has not been completely elucidated. Analysing geographic regions of idiopathic pulmonary fibrosis (IPF) cases could help identify those areas with higher aggregation and investigate potential triggers. We hypothesize that cross-analysing location of IPF cases and areas of consistently high air pollution concentration could lead to recognition of environmental risk factors for IPF development. METHODS: This retrospective study analysed epidemiological and clinical data from 503 patients registered in the Observatory IPF.cat from January 2017 to June 2019. Incident and prevalent IPF cases from the Catalan region of Spain were graphed based on their postal address. We generated maps of the most relevant air pollutant PM2.5 from the last 10 years using data from the CALIOPE air quality forecast system and observational data. RESULTS: In 2018, the prevalence of IPF differed across provinces; from 8.1 cases per 100 000 habitants in Barcelona to 2.0 cases per 100 000 in Girona. The ratio of IPF was higher in some areas. Mapping PM2.5 levels illustrated that certain areas with more industry, traffic and shipping maintained markedly higher PM2.5 concentrations. Most of these locations correlated with higher aggregation of IPF cases. Compared with other risk factors, PM2.5 exposure was the most frequent. CONCLUSION: In this retrospective study, prevalence of IPF is higher in areas of elevated PM2.5 concentration. Prospective studies with targeted pollution mapping need to be done in specific geographies to compile a broader profile of environmental factors involved in the development of pulmonary fibrosis.

Diagnostic Accuracy of CYFRA21-1 in the Differential Diagnosis of Pleural Effusions.

BACKGROUND/AIM: Approximately 20% of pleural effusions are associated with cancer; about 50% require invasive procedures to perform diagnosis. Determination of the concentration of soluble cytokeratin 19-fragments (CYFRA21-1) may help identify patients with malignant effusions. However, pathologies other than cancer can increase its concentration. The identification of these possible false positives with routine tests CRP, ADA, % polymorphonuclear cells (PN) may improve diagnostic accuracy. This study aimed to determine the diagnostic accuracy of CYFRA21-1 in the detection of malignant pleural effusions and the possible false positives. MATERIALS AND METHODS: Analysis of CYFRA21-1, adenosine deaminase (ADA), C-reactive protein (CRP), and the percentage of polymorphonuclear leukocytes (PN%) in the fluid from 643 consecutive undiagnosed pleural effusions was performed. RESULTS: CYFRA21-1 showed 38.7% sensitivity and 97.3% specificity at 175 ng/ml cut-off. Effusions not suspicious of a false-positive showed 39.0% sensitivity and 98.2% specificity, while effusions suspicious of false positive showed lower sensitivity (36.4%) and specificity (95.0%). CONCLUSION: The diagnostic accuracy of CYFRA21-1 in pleural effusions can be improved by classification according to the possibility of false positives.

Evaluation of two strategies for the interpretation of tumour markers in pleural effusions.

BACKGROUND: Pleural effusions present a diagnostic challenge. Approximately 20% are associated with cancer and some 50% require invasive procedures to perform diagnosis. Determination of tumour markers may help to identify patients with malignant effusions. Two strategies are used to obtain high specificity in the differential diagnosis of malignant pleural effusions: a) high cut-off, and b) fluid/serum (F/S) ratio and low cut-off. The aim of this study is to compare these two strategies and to establish whether the identification of possible false positives using benign biomarkers - ADA, CRP and % of polymorphonuclear cells - improves diagnostic accuracy. METHODS: We studied 402 pleural effusions, 122 of them malignant. Benign biomarkers were determined in pleural fluid, and CEA, CA72-4, CA19-9 and CA15-3 in pleural fluid and serum. RESULTS: Establishing a cut-off value for each TM for a specificity of 100%, a joint sensitivity of 66.5% was obtained. With the F/S strategy and low cut-off points, sensitivity was 77% and specificity 98.2%, Subclassifying cases with negative benign biomarkers, both strategies achieved a specificity of 100%; sensitivity was 69.9% for single determination and 80.6% for F/S ratio. CONCLUSIONS: The best interpretation of TM in the differential diagnosis of malignant pleural effusions is obtained using the F/S ratio in the group with negative benign biomarkers.

Diagnostic accuracy of tumour markers in serous effusions: a validation study.

The utility of tumour markers (TM) in the differential diagnosis of cancer in serous effusion (fluid effusion (FE)) has been the subject of controversy. The aim of this study was to prospectively validate our previous study and to assess whether the addition of adenosine deaminase (ADA), C-reactive protein (CRP) or percentage of polymorphonuclear cells (%PN) allows the identification of false positives. In this study, carcinoembryonic antigen, cancer antigen 15-3, cancer antigen 19-9, ADA, CRP and %PN in FE were determined in 347 patients with 391 effusions. Effusions were considered as malignant effusion when at least one TM in serum exceeded the cutoff and the ratio FE/S was higher than 1.2. Also, cases with values of ADA, CRP and %PN above the established cutoffs in serous effusion were considered as potential false positives. The combined sensitivity and specificity of the three TM was 76.2 % (95 % confidence intervals (CI) 67.8-83.3 %) and 97.0 % (95 % CI 94.1-98.7), respectively. Subanalysis of the 318 cases with previous criteria and negative ADA, CRP and %PN obtained sensitivities of 78.4 % (95 % CI 69.4-85.6) and a specificity of 100 % (95 % CI 98.2-100). The results obtained validate our previous study and are improved with the addition of ADA, CRP and %PN. TM in serous effusions and serum could be useful for the diagnostic assessment of patients with serous effusions.