<prompt> Light criteria for pleural effusion are all except -Effusion proteinserum protein ratio greater than 0.5Effusion lactage dehydrogenase LDHserum LDH ratio greater than 0.6Effusion LDH level greater than two-thirds the upper limit of the laboratorys reference range of serum LDHEffusion sugar is less than 23rd of blood sugar  <response>: Ans. is d i.e., Effusion sugar is less than 23rd of blood sugar Lights Criteria of Pleural effusionso Transudative and exudative pleural effusions are distinguished by measuring the lactate dehydrogenase LDH and protein levels in the pleural fluid. Exudative pleural effusions meet at least one of the following criteria, whereas transudative pleural effusions meet none : Pleural fluid proteinSerum protein 0?5 Pleural fluid LDHSerum LDH 0?5 Pleural fluid LDH more than two-thirds normal upper limit for serum. 