RT Journal Article
SR Electronic
T1 Change in LDH assay can affect classification of pleural effusions using Light's criteria
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P3085
VO 42
IS Suppl 57
A1 Matthew Evison
A1 Mohamed Al-Aloul
A1 Andrew Bentley
A1 Nazia Chaudhuri
A1 Ed Hinchliffe
A1 Anne-Marie Kelly
A1 Jayne Holme
YR 2013
UL http://erj.ersjournals.com/content/42/Suppl_57/P3085.abstract
AB INTRO:Following a change in assay & ref range for LDH in pleural fluid (from Roche to Abbott), we noted a greater proportion of exudates using Light's criteria, necessitating invasive investigation.METHOD:Pleural fluid from Nov’10 to Sep’11 (Roche cohort [RC]) and Sep’11 to Jul’12 (Abbott cohort [AC]) were identified. Only samples with full Lights criteria and an established diagnosis were included. The proportion of exudates using Lights criteria (full set and components) were determined and related to the final diagnosis to examine any differences between cohorts.RESULTS:498 samples were identified. 141 (75 RC, 66 AC) were included.Using full Light’s criteria, 56/75 (75%) RC and 53/66 (80%) AC were exudates.Using LDH criteria alone, a greater proportion [52/75 (69%)] RC were classed as exudates compared with AC [51/66 (77%)], mainly because the proportion with fluid LDH>2/3 ULN was greater in AC(49/66=74%) than RC(42/75=56%).Using protein criteria alone, only 49% RC and 44% AC were exudates.There was disagreement between protein and LDH criteria in 23/75 (31%) of the RC, and 26/66 (39%) of the AC. In the RC, 19/75 (25%) effusions were classed as a transudate by protein criteria but as an exudate by LDH criteria, compared with 24/66 (36%) of the AC.Using final diagnosis as gold standard for cause of effusion, 57/75 (76%) of the RC and 48/66 (73%) of the AC were expected to result in an exudate, and the sensitivity (91%) and accuracy (80%) of the AC method were greater than the RC method (84% and 77% respectively), but specificity was less (50% v. 56%).CONCLUSION:Different LDH assays can result in changes in the classification of pleural effusions which could affect further management.