Table 4.

Signs suggestive of venous and capillary (pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis) involvement

Pulmonary function tests	Decreased DLCO (<50%).
	Severe hypoxemia.
High-resolution chest CT	Septal lines, centrilobular ground glass opacities, and mediastinal lymphadenopathy.
Response to PAH therapy	Possible pulmonary edema.
Genetic background	Biallelic EIF2AK4 mutations.
Occupational exposure	Organic solvent (trichloroethylene).

DLCO, diffusing capacity of the lungs for carbon monoxide; PAH, pulmonary arterial hypertension.