Boyle JM, Buckley RH. J Clin Immunol. 2007;27(5):497–502
PURPOSE OF THE STUDY. To measure the prevalence of primary immunodeficiency diseases (PIDs) in the United States.
STUDY POPULATION. A random sample of 10 005 American households (26 657 people) was included in the study.
METHODS. Households were selected by random-digit dialing stratified according to time zone. Calls were placed by trained interviewers with computer assistance. Eighty percent of the households contacted completed the interview. Respondents were asked, “Has anyone in your household ever been diagnosed with a primary immunodeficiency disease such as common variable immunodeficiency, IgA [immunoglobulin A] deficiency, IgG subclass deficiency, or any other immunodeficiency? (This is not acquired immunodeficiency—AIDS).” If they replied “yes,” they were further questioned with details of the diagnosis and limited demographic information about the affected individual(s).
RESULTS. Twenty-three individuals in 18 households were identified as having a specific PID (including common variable immunodeficiency, IgA deficiency, IgG subclass deficiency, X-linked agammaglobulinemia, severe combined immunodeficiency, and chronic granulomatous disease). The calculated prevalence of diagnosed immunodeficiency was 1 in 2000 children, 1 in 1200 people of all ages, and 1 in 600 households. The 95% confidence limits for the estimate for all individuals were between 1 in 824 and 1 in 1956. Several of the identified individuals with primary immunodeficiency were not receiving therapy that is standard of care for their diagnoses (γ-globulin replacement).
CONCLUSIONS. Quoting the authors, “The current study suggests that these conditions are sufficiently common that primary care physicians are likely to see patients with underlying primary immunodeficiency disorders in their practice and should test for these disorders in patients with recurring, unusual or serious infections. In the absence of routine screening, physician awareness of the relative frequency of these disorders is critical to early diagnosis and treatment.”
REVIEWER COMMENTS. This is an extremely important message for all primary care physicians. These patients are in your practices now. The authors also pointed out that several studies have shown that many cases of PID are diagnosed late or are “mild” enough that they are never diagnosed and that patients suffer excess morbidity and mortality as a result. Some severe cases may be missed because children die before they are diagnosed. Thus, the true prevalence of PID is likely to be higher than what was found in this study. I found it discouraging that two thirds of the people who should have been receiving γ globulin were not.
- Copyright © 2008 by the American Academy of Pediatrics