The IDDEA project: a strategy for the detection of alpha-1 antitrypsin deficiency in COPD patients in the primary care setting

Objective: Primary care provides the main route for access to health care for patients with common chronic illnesses such as chronic obstructive pulmonary disease (COPD). Alpha-1 antitrypsin (AAT) deficiency is an underdiagnosed pathology associated with COPD risk which has a very low prevalence. The Information and Detection of the Deficiency of AAT (IDDEA) project was developed to identify AAT-deficient patients at primary care centres by providing adequate diagnostic tools to family doctors.

Methods: Patients with COPD were identified and registered on a specially designed website. Dried blood samples were collected on filter papers and sent to the laboratory for AAT levels and AAT deficiency-related genotype determinations. Results were uploaded to the website and analysed.

Results: Between January 2008 and April 2009, 596 patients were identified by 90 participating physicians. The number of patients who did not have AAT deficiency (serum concentrations ≥60 mg AAT/dl) was 549 (98.9%). Nineteen patients (3.2%) were carriers of the allelic variant Pi*Z among which two were homozygous PiZZ (one of them was an index case) and one was heterozygous PiSZ. These three newly detected cases were registered in the Spanish Registry of Patients with AAT Deficiency. An estimate of the gene frequency of the S allele was 7.65% and the severe deficiency Z allele was 1.76%.

Conclusions: Results confirm that ATT deficiency is still underdiagnosed. The IDDEA system appears to be a useful tool for the detection of AAT deficiency in the primary care setting.