In the annual EAACI meeting in Copenhagen, June 2014, the EAACI Executive Committee approved the establishment of an Interest Group (IG) in the field of primary immunodeficiency (PID) syndromes.
Why another IG and what will be the role of this group within the framework of our EAACI? In the last few years, novel developments in gene discovery and increased knowledge in the mechanisms that govern immune functions have resulted in the identification of several novel PID syndromes. The new IG is expected to contribute to establish a solid platform for our members that will cover all aspects of PID, including clinical and translational medicine, clinical research and basic research. PID with associated eczema, increased serum IgE levels and recurrent infections include hyper IgE, Omenn, Wiskott-Aldrich, IPEX and Comèl-Netherton syndromes. Being monogenic, these diseases might be considered to be clue conditions in revealing mechanisms involved in the pathogenesis of atopy. However, understanding the effect of disruptions of these pathways could provide useful insights for several allergic diseases.
The new IG will promote the development of diagnostic protocols for allergists. Two examples are provided here. PID as hyper IgE syndromes should be considered in the differential diagnosis of allergy and asthma, in particular when a subject with hypergammaglobulinemia E is susceptible to recurrent infections. In turn, infectious events in a patient with severe atopic dermatitis and increased serum IgE levels may be observed with a frequency that often resembles that observed in patients with hypogammaglobulinemia. In fact, because of impaired innate immunity and decreased barrier function of the skin, atopic patients may be at risk of disseminated viral infections and bacterial colonization. Thus, emphasis should always be posed on evaluating atopy and PID as possible (con)causes of an increased infectious susceptibility with obvious therapeutic implications. This consideration is particularly important if we consider that serum IgE levels may be elevated in a broad array of clinical settings, including IgA deficiency, the most frequent antibody defect associated with atopy.
Another aspect that will be covered by members of this IG is the relationship between hypogammaglobulinemia and chronic lung diseases. Common variable immunodeficiency (CVID) is the most clinically important PID in adults. Although therapy with intravenous or subcutaneous immunoglobulin reduces the incidence of acute infections, replacement therapy does not allow the management of a series of respiratory complications whose importance is emerging for prognosis and quality of life, including asthma, COPD, interstitial lung diseases and lung granulomatosis. How to cure these chronic respiratory complications (unfortunately associated with a poor prognosis) is still being debated.
Allergists should be aware that PID are more common than had been previously estimated. Timely identification of PID is mandatory for leading to an appropriate therapy, and is the only way to limit structural organ and tissue damage in most patients. Specialists in allergology and clinical immunology have a crucial role in recognising patients with immune deficiency and directing appropriate investigation and management. In this context, it is hoped that promoting education on PID will reinforce primary care practice on this field among members of our beloved Academy.
Carlo Agostini, MD, Prof.
Chair of the Primary Immunodeficiency Diseases IG
Last updated 01 July 2015