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Q1: What are the clinical and pathological diagnoses?
Chronic obstructive pulmonary disease and pulmonary emphysema.
Q2: What aetiologies should be considered?
The α1-antitrypsin levels should be checked, as deficiency is associated with pulmonary emphysema.1This was normal. In addition, α1-antitrypsin dysfunction and α1-antichymotrypsin deficiency2 should be considered. Inorganic dust exposure3 and cadmium exposure4 have been associated with pulmonary emphysema and it has been described in intravenous drug abusers, particularly of heroin, methadone,5 and injected dissolved methylphenidate (Ritalin) tablets.6 Hereditary bullous emphysema can develop precociously in rare syndromes such as Salla's disease, cutis laxa, and idiopathic non-arteriosclerotic cerebral calcification syndrome.4 None of these unusual aetiologies were identified in our patient.
Q3: What treatment options are available?
Inhaled bronchodilator therapy is the mainstay of treatment, with β2-agonists and anticholinergic agents. A trial of oral corticosteroids should be performed and if significant improvements in symptoms and lung function documented, this may justify inhaled corticosteroids. There is however no evidence that steroids halt the progression of smoking induced emphysema. In this case, there was no response to oral steroids. In advanced pulmonary emphysema, surgical options include lung volume reduction surgery and bullectomy, to improve lung mechanics and thereby reduce dyspnoea and increase exercise capacity. In younger subjects, significant ventilatory impairment progressing to respiratory failure may be treated with lung transplantation. In this case, reduction surgery was not performed but the patient did progress to single lung transplantation 30 months after presentation. However, even with transplantation, outcome is poor, with a five year actuarial survival of only 42.6%.7
Emphysema (abnormal enlargement of airspace beyond the terminal bronchioles, with destruction of their walls without fibrosis), in the majority of cases, is related to cigarette smoking, though in rare cases other factors may be involved as outlined above. Other possible factors considered in this case were exposures to fibreglass and inhalational anaesthetic gases. Exposure to fibreglass does not cause airway obstruction3 and there have been no reports of associations between emphysema and anaesthetic gases. We did not perform a functional assessment of α1-antitrypsin or measure α1-antichymotrypsin levels, but even if abnormal, the speed of progression in a non-smoker would be remarkable, making this an unlikely causative factor. We have identified only one previous similar report,8 with idiopathic emphysema and rapid deterioration in ventilatory function, progressing to respiratory failure in a young non-smoker.
Recent research suggests that protease-antiprotease,9 and oxidant-antioxidant imbalance,4 9 may be involved in the pathogenesis of emphysema. We suggest that a single exposure to a toxic or infectious agent may have caused inflammatory cell sequestration, protease and reactive oxidant species release, and progressive lung destruction in our patient.
It has been suggested that emphysema may progress, even after removal of the stimulus.10 This case demonstrates deteriorating lung function, with no obvious ongoing inflammatory stimulus and illustrates that chronic inflammation and lung destruction over many years is not always required to produce emphysema and end stage respiratory failure.
Idiopathic pulmonary emphysema.
Pulmonary emphysema does not always occur in tobacco smokers.
Emphysema progresses at variable rates and can be rapidly progressive.
The inflammatory mechanisms causing pulmonary emphysema are incompletely understood.
In young patients with symptoms suggestive of asthma, an alternative diagnosis should be considered when poorly responsive to conventional treatment.