Usefulness of serum lactate dehydrogenase/pleural fluid adenosine deaminase ratio for differentiating Mycoplasma pneumoniae parapneumonic effusion and tuberculous pleural effusion

- Mycoplasma pneumoniae pneumonia-related pleural effusion is sometimes encountered.
- It usually presents as a lymphocytic exudate with elevated adenosine deaminase.
- The differential diagnosis includes tuberculous pleural effusion.
- Serum lactate dehydrogenase/pleural fluid adenosine deaminase ratio may be useful.