Prevalence and Correlates of Immunoglobulin IgG deficiency in Adult Outpatient Population
IgG subclasses are low in 2.5 percent of the general population. Few studies have explored the prevalence and risk factors for IgG deficiency in adult patient population.
Methods: Four hundred patients examined at Ayass Lung Clinic & Sleep Center in 2013 were included in the study to analyzed IgG levels and their association with other diseases and immunoglobulin deficiencies. Demographic, clinical; and laboratory information were obtained from medical records. Logistic regression models were employed to determine association between risk factors and the presence of IgG deficiency.
Results: Seventy three patients (18%) were IgG deficient (< 750mg/dl). Among those who were IgG deficient were 18% deficient in IgM and 22% in IgA. Three quarter were aged (>65 years), 62% females and 92% were white. Analysis showed that being White, being in age groups >65, suffering from OSA and other immunoglobulin deficiencies were associated with the IgG deficiency.
White adult patients compared to non-White patients were eight times more likely to develop IgG deficiency (CI, 02.30-30.0) after controlling for the demographics. Similarly patients with IgA deficiency and IgM deficiency, were 18 times (CI, 6.40-55.4) and 3.4 times (CI, 1.40-8.40) more likely to develop IgG deficiency, respectively. Patients with obstructive sleep apnea were 63% (CI, 0.17-0.78) and older patients were 73% less likely to develop IgG deficiency (CI, 0.14-0.53), respectively.
The prevalence of IgG deficiency in adult outpatient population is Texas was 18%. IgG subclass deficiency is the major phenotype of primary Immunodeficiency and being White, and suffering from OSA were associated with IgG deficiency.