Table 1.

Proposed severity classification of PTLD^*

Category	Description	Prognosis*
Not detected	Does not meet the definition of PTLD	Effects on future lung health, symptoms and survival not well defined
	No detectable abnormality on lung function testing or chest imaging	Normal future lung health and survival can be expected
Mild	No or minimal symptoms	Possibility of accelerated decline in lung function and increased risk of future lung pathology and exacerbations
	Normal lung function
	Normal or minimal structural lung disease detected on chest imaging
Moderate	Variable symptoms	Increased risk of accelerated decline in lung function, future lung pathology, exacerbations
	Abnormal lung function (obstructive, mixed, restrictive, reduced DLCO)
	Detectable abnormalities on chest imaging such as bronchiectasis, fibronodular scarring
Severe	Significant and debilitating symptoms that reduce a person’s quality of life and may also affect ability to carry out daily tasks	High risk of future complications such as recurrent chest infections, chronic fungal infection (including aspergillosis) and haemoptysis
	Lung function testing typically shows abnormalities	Increased mortality risk
	Chest imaging typically demonstrates significant structural lung disease such as parenchymal lung destruction, bronchial wall thickening, bronchiectasis and cavitation

^* Based on limited and/or low-quality evidence.

PTLD = post-TB lung disease; DL_CO = diffusion capacity of lungs for carbon monoxide.