Some asthmatics admitted to hospital due to serious attack, are found to have very low levels of GSNO (s-nitrosoglutathione) in their lungs. Low s-nitrosoglutathione can be discovered when, for example, hospital admittance (or asthma clinic attendance) results in a patient agreeing to a consultant's proposal for bronchoscopy examination. Bronchoscopy may reveal low GSNO to be an issue 'providing' the Examining Consultant has included a 'check' of a patient's GSNO levels among his various reasons for conducting bronchoscopy. (Bronchoscopy, as you may know, is a somewhat invasive examination, not routinely carried out on patients unless circumstances truly warrant it).
GSNO helps protect airways, and is the body's natural bronchodilator. As indicated by its name, it involves nitric oxide and glutathione (glutathione being the body's primary 'naturally produced' anti-oxidant).
The efficient production of GSNO can be disrupted by the enzyme GSNOR (s-nitrosoglutathione reductase). This may occur where, for example, a genetic mutation exists (NOS3 ?) - though 'other' factors might also cause, or contribute to, low GSNO.
A clinical trial is underway that may result in the development of a test that doctors can eventually carry out in their Practice, to determine low GSNO, without recourse to requesting hospital bronchoscopy procedure.
While not intended as a suggestion or recommendation, I came across some info indicating that a diet which strongly emphasises vegetables - in combination with maintaining adequate zinc and arginine blood plasma levels 'might' - together - help 'some' with a deficiency of GSNO. However, please don't change your diet or rush out and 'supplement' without first checking with a medical professional, as dietary changes and supplements may effect / interact with your medication, exacerbate an existing medical condition or cause a new one to occur. (Also, if someone's underlying reason for low GSNO proves to be 'genetic', then diet changes and supplements alone are unlikely to resolve the issue - though they 'might' help if a genetic mutation is 'not' the cause - or, at least, 'not' the 'only' cause).
Its likely that only a sub-set of asthmatics are effected by this issue - though not necessarily a 'small' sub-set. Even if someone has a genetic mutation that 'can' cause low GSNO, the mutation 'might' not - in every instance - result in deficiency.
Still, it's worth being aware that this is an issue for a number of asthmatics, particularly if you turn out to be one of them. If you've been encouraged to have a bronchoscopy for other reasons (and have decided to go ahead) it may be worth asking if your GSNO level can / will be investigated at the same time. Otherwise, maybe just keep an eye out for future news on availability of any 'less invasive' GP Administered GSNO Test.