Diagnostic Value of Lactate Dehydrogenase Isoenzyme Pattern in Pleural Effusions

Abstract

Summary: Lactate dehydrogenase isoenzymes have been used to classify the nature of pleural effusion. Nevertheless, studies have reported conflicting results. The objective of this study was to evaluate the diagnostic value of lactate dehydrogenase isoenzymes in the analysis of pleural effusions.Pleural fluid samples obtained from three respective diagnostic groups: group I transudate (n = 23), group II parapneumonic effusion (n = 29) and group III malignant effusion or pleuritis carcinomatosa (n = 41) were evaluated.Total lactate dehydrogenase activity and lactate dehydrogenase (LDH) isoenzyme pattern were significantly different between transudative (group I) and exudative (group II and III) effusions. Group II and III showed a low percentage of LDH 1 (p < 0.001), whereas the percentages of LDH4 (p < 0.001) and LDH5 (p < 0.001) were higher compared to group I. Moreover, in exudative effusions the percentage of LDH1 (p < 0.005), LDH4 (p < 0.005), as well as LDH5 (p < 0.005) were significantly different between parapneumonic and malignant effusions. In contrast to relative lactate dehydrogenase isoenzyme values, the absolute values of lactate dehydrogenase isoenzymes did not differ between group II and group III. Logistic regression analysis yielded a strong discrimination between group I and 11+III, simultaneously using lactate dehydrogenase, glucose and protein as explanatory variables. Logistic regression analysis yielded only a weak discrimination between group II and III, simultaneously using lactate dehydrogenase, glucose and the absolute values of LDH2 and LDH4 as explanatory variables.In conclusion, the lactate dehydrogenase isoenzyme pattern differed between pleural effusions of transudative and exudative origin. However, including lactate dehydrogenase isoenzyme activities in the biochemical work-up of pleural effusions did not reveal an additional discriminatory value in the assessment of the classification of these effusions.

Diagnostic utility of measuring lactate dehydrogenase levels and its isoenzyme activities for the evaluation of malignancy in feline pleural effusion and ascitic fluid

“…Hypoxic areas in malignancy have been shown to increase (Fantin et al 2006). Human LDH-4 activity in PE and AF were found to be signi cantly higher in malignancy than in nonmalignancy (Cobben et al 1997;Sevinc et al 2005). These studies included patients with non-blood cancers.…”

“…This study demonstrated that LDH-1 activity in PE or AF increased in cats with CHF and liver disease. In humans, CHF increases the percentile of LDH-1 activity in PE and AF due to aerobic conditions in heart tissue (Firth et al 1995;Cobben et al 1997;Sevinc et al 2005). Increasing in LDH-1 activity in AF was also observed in patients with chronic liver disease (Sevinc et al 2005).…”

“…However, the diagnostic values of serum LDH level and LDH isoenzyme patterns are still controversial (Dawson et al 1964;Wroblewski and Gregory 1961). In contrast, LDH isoenzyme activities in PE and AF are useful biomarkers for distinguishing neoplastic and non-neoplastic diseases (Cobben et al 1997;Lossos et al 1999;Paavonen et al 1991;Sevinc et al 2005). Interestingly, LDH-1 activity, which works e ciently under aerobic conditions, is signi cantly lower in neoplastic diseases than in non-neoplastic diseases, whereas LDH-4 level, which works e ciently under anaerobic conditions, is signi cantly higher in neoplastic diseases than in non-neoplastic diseases (Paavonen et al 1991;Sevinc et al 2005).…”