Common non-cardiogenic causes include inflammation in the lungs or system-wide inflammation which causes the pulmonary capillaries to be more permeable.
It seems that receptors without GluA2 are much more permeable to calcium flow, and that makes them vulnerable to the harmful chemical effects of loud noises.
All of these can cause direct injury to the alveoli, and when this happens there is usually an inflammatory process that makes nearby capillaries more permeable.
This doesn't necessarily mean gluten itself was causing illness but the researchers propose that some part of wheat prompts the intestinal lining to become more permeable.