The European internet-based patient and research database for primary immunodeficiencies: update 2011.

In order to build a common data pool and estimate the disease burden of primary immunodeficiencies (PID) in Europe, the European Society for Immunodeficiencies (ESID) has developed an internet-based database for clinical and research data on patients with PID. This database is a platform for epidemiological analyses as well as the development of new diagnostic and therapeutic strategies and the identification of novel disease-associated genes. Since its start in 2004, 13,708 patients from 41 countries have been documented in the ESID database. Common variable immunodeficiency (CVID) represents the most common entity with 2880 patients or 21% of all entries, followed by selective immunoglobulin A (sIgA) deficiency (1424 patients, 10·4%). The total documented prevalence of PID is highest in France, with five patients per 100,000 inhabitants. The highest documented prevalence for a single disease is 1·3 per 100,000 inhabitants for sIgA deficiency in Hungary. The highest reported incidence of PID per 100,000 live births was 16·2 for the period 1999-2002 in France. The highest reported incidence rate for a single disease was 6·7 for sIgA deficiency in Spain for the period 1999-2002. The genetic cause was known in 36·2% of all registered patients. Consanguinity was reported in 8·8%, and 18·5% of patients were reported to be familial cases; 27·9% of patients were diagnosed after the age of 16. We did not observe a significant decrease in the diagnostic delay for most diseases between 1987 and 2010. The most frequently reported long-term medication is immunoglobulin replacement