The diagnostic utility of pleural fluid adenosine deaminase for tuberculosis in a low prevalence area

TY - JOUR

T1 - The diagnostic utility of pleural fluid adenosine deaminase for tuberculosis in a low prevalence area

AU - Sivakumar, P.

AU - Marples, L.

AU - Breen, R.

AU - Ahmed, L.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - Background: Pleural fluid adenosine deaminase (pfADA) is not routinely measured in patients with undiagnosed pleural effusion due to limited evidence of its diagnostic utility in areas of low tuberculosis (TB) prevalence. M E T H O D S : We conducted a retrospective consecutive case series analysis of all patients who underwent pfADA testing from 2009 to 2015 at a tertiary service pleural centre in south London. Using receiver operating characteristic (ROC) curve analysis, we identified the optimal threshold at which maximal sensitivity and specificity were achieved. Results: Of the 132 patients tested for pfADA, 27 had confirmed pleural TB and 105 did not, with median pfADA levels of respectively 63 IU/l (interquartile range [IQR] 47-88) and 12 IU/l (IQR 7.5-22.5). ROC curve analysis determined the optimal pfADA cut-off to be 30 IU/l, which had positive and negative predictive values of respectively 60.5% and 98.9%, 96.3% sensitivity (95%CI 0.892-1.000) and 83.8% specificity (95%CI 0.768- 0.909). The calculated area under the ROC curve was 0.934 (95%CI 0.893-0.975). Conclusion: A pfADA level ,30 IU/l makes a diagnosis of TB highly unlikely in the South London population. Its high sensitivity and negative predictive values make pfADA a valuable screening test for excluding suspected pleural TB.

AB - Background: Pleural fluid adenosine deaminase (pfADA) is not routinely measured in patients with undiagnosed pleural effusion due to limited evidence of its diagnostic utility in areas of low tuberculosis (TB) prevalence. M E T H O D S : We conducted a retrospective consecutive case series analysis of all patients who underwent pfADA testing from 2009 to 2015 at a tertiary service pleural centre in south London. Using receiver operating characteristic (ROC) curve analysis, we identified the optimal threshold at which maximal sensitivity and specificity were achieved. Results: Of the 132 patients tested for pfADA, 27 had confirmed pleural TB and 105 did not, with median pfADA levels of respectively 63 IU/l (interquartile range [IQR] 47-88) and 12 IU/l (IQR 7.5-22.5). ROC curve analysis determined the optimal pfADA cut-off to be 30 IU/l, which had positive and negative predictive values of respectively 60.5% and 98.9%, 96.3% sensitivity (95%CI 0.892-1.000) and 83.8% specificity (95%CI 0.768- 0.909). The calculated area under the ROC curve was 0.934 (95%CI 0.893-0.975). Conclusion: A pfADA level ,30 IU/l makes a diagnosis of TB highly unlikely in the South London population. Its high sensitivity and negative predictive values make pfADA a valuable screening test for excluding suspected pleural TB.

KW - London

KW - Lymphocytic effusion

KW - Pleural effusion

UR - http://www.scopus.com/inward/record.url?scp=85018935702&partnerID=8YFLogxK

U2 - 10.5588/ijtld.16.0803

DO - 10.5588/ijtld.16.0803

M3 - Article

C2 - 28482965

AN - SCOPUS:85018935702

SN - 1027-3719

VL - 21

SP - 697

EP - 701

JO - International Journal of Tuberculosis and Lung Disease

JF - International Journal of Tuberculosis and Lung Disease

IS - 6

ER -