Background/Purpose: Vasculitis has been reported in patients with various forms of primary immunodeficiency (PID) in case reports in the literature. The goal of this study is to evaluate the frequency of vasculitis in a large national database of patients with primary immunodeficiency.

Methods: The United States Immunodeficiency Network (USIDNET) is a large national consortium organized to collect registry data on patients with primary immune deficiencies. The USIDNET database was queried for patient records with a documented history of vasculitis. Data regarding demographics, type of vasculitis diagnosis, specific PID diagnosis, immunologic laboratory results and immunomodulatory treatment was abstracted from the records and descriptive statistics are presented. Focused analyses were also performed for patients with common variable immune deficiency (CVID) and Wiskott-Aldrich syndrome (WAS).

Results: As of March 12, 2018 data were available on 4,888 patients and 76 patients (1.6%) with vasculitis were identified. CVID (n=29, [38%]) and WAS (n=20, [26%]) were the most common PID associated with vasculitis (Table 1). Table 2 describes the results for the total PID cohort, as well as CVID and WAS sub-populations. Overall, 76% of patients were Caucasian, and 46% of patients were female. Central nervous system (CNS) vasculitis was the most common specific vasculitis syndrome identified among patients with PID in the USIDNet Registry (n=11, [14 %]). Glucocorticoids were the most frequent immunomodulatory therapy reported in all populations studied and occurred in more than half of cases (59-69%). In the CVID cohort, 29 cases of vasculitis were identified, with CNS vasculitis being the most common (n=5, [17%]). About half of cases of vasculitis were reported to be present before or at the diagnosis of the PID (n=37, [49%]) and CVID (n=14, [48%]). Henoch-Schonlein Pupura was the most common vasculitis (n=6, [30]) associated with WAS, with most cases (75%) being present before or at diagnosis of WAS.

Conclusion:    Vasculitis is an uncommon complication of PID but can be encountered in a variety of syndromes, and was most frequently associated with CVID and WAS in the USIDNet Registry. Vasculitis complicating PID can represent a challenging confounder and mimic of serious infections.  Clinicians caring for patients with PID need to be aware that vasculitis may be a rare autoimmune manifestation associated with PID especially those with CNS involvement.