Increased malignancy incidence in IgE deficient patients not due to concomitant Common Variable Immunodeficiency

Background Immunoglobulin E (IgE) deficiency (<2.5 kU/L) has unclear clinical significance. Very little is known about the clinical characteristics of IgE deficiency in patients with Common Variable Immunodeficiency (CVID). Objective To evaluate the clinical and laboratory differences between patients with IgE deficiency and those with non-IgE deficiency with and without CVID diagnosis. Methods This is a retrospective study of adult patients who had total serum IgE levels measured at our facility from 2010 through 2015. Patients with IgE levels lower than 2.5 kU/L composed the IgE deficiency group. We used Clinical Looking Glass software to identify laboratory results and comorbid conditions including CVID and malignancy. Results The IgE levels were measured in 2,339 patients and 63 (2.7%) had IgE deficiency. Of those with IgE deficiency, 14 of 63 (22%) had CVID diagnosis compared with only 62 of 2,276 patients (2.7%) with non-IgE deficiency and CVID. A significantly higher rate of prior malignancy was found in patients with IgE deficiency (21 of 63, 33%) compared with those with non-IgE deficiency (197 of 2,276, 8.7%; P =.001; odds ratio 5.51, 95% confidence interval 3.07–9.88). Six of 14 patients with CVID and IgE deficiency (43%) had a prior malignancy diagnosis compared with 8 of 62 patients (13%) with CVID and non-IgE deficiency (P =.009; odds ratio 10.65, 95% confidence interval 1.79–63.19). In addition to the higher rate of malignancy, patients with CVID and IgE deficiency did not have more severe disease than those with CVID and non-IgE deficiency. Conclusion The rate of prior malignancy is significantly higher in patients with IgE deficiency than in those without IgE deficiency. Similarly, patients with CVID and IgE deficiency have a higher frequency of prior malignancy than those with CVID and non-IgE deficiency. However, patients with IgE deficiency have higher frequency of malignancy than patients with normal IgE levels even in the absence of CVID.