<prompt> Pleural effusion with very low glucose isMalignancyTuberculosisSLERheumatoid ahritis  <response>: Rheumatoid ahritis produces an exudative pleural effusion with predominant lymphocytes,positive rheumatoid factor and anti-CCP antibodies,and very low glucose in pleural . Pleural involvement is the most frequent manifestation of rheumatoid ahritis RA in the chest. The effusion is an exudate and is characterized by low pH and glucose level, and high lactic dehydrogenase LDH and cell count low glucose also seen in malignancy,and tubercular effusion. Ref Davidson edition23rd pg 580 