Incidence and Temporal Trends of Primary Immunodeficiency: A Population-Based Cohort Study

摘要

OBJECTIVE: To determine the incidence and temporal trends of primary immunodeficiency diseases (PIDs) and examine whether an association exists between delayed diagnosis and increased morbidity.PATIENTS AND METHODS: We performed a historical cohort study to describe the epidemiology of PIDs in Olmsted County, Minnesota, during a 31-year period from January 1, 1976, through December 31, 2006, using the Rochester Epidemiology Project. Incidence and trends over time, presence of comorbid conditions, and trends in management were determined.RESULTS: During the 31-year study period, 158 new cases of PIDs were diagnosed, with an overall incidence rate of 4.6 per 100,000 person-years. The rate of PIDs from 2001 through 2006 (10.3 per 100,000 person-years) was nearly 5 times higher than that from 1976 through 1980 (2.4 per 100,000 person-years). The associations between continuous variable(s) and categorical outcome(s) were assessed by using the Wilcoxon rank sum test. Longer delay in diagnosis was significantly associated with recurrent sinusitis (P<.001), recurrent pneumonia (P=.03), and subsequent treatment with immunoglobulins (P<.001). On the basis of Kaplan-Meier survival estimates, the proportion of patients surviving at 10 years after diagnosis was 93.5% (95% confidence interval, 85.9%-97.1%). However, older age at diagnosis was significantly associated with mortality (P=.01).CONCLUSION: This is one of the first population-based studies to examine the temporal trends of PIDs. The incidence of PIDs increased markedly between 1976 and 2006. In this cohort, a delay in diagnosis was common and was associated with increased morbidity. Despite substantial morbidity, most patients with PIDs can expect a normal life span.