HEREDITARY ANGIOEDEMA C1-INH REPLACEMENT THERAPY AND COEXISTING AUTOIMMUNE DISORDERS: FINDINGS FROM A CLAIMS DATABASE

Abstract

Introduction Hereditary angioedema (HAE) has been linked with an increase in autoimmune diseases. Plasma-derived C1 esterase inhibitor (C1-INH) is safe and effective for treatment and prevention of HAE attacks. It is plausible that C1-INH replacement decreases autoimmunity by normalizing complement. Methods HAE patients were identified in the IMS Health PharMetrics Plus claims database between Jan 2012 and Dec 2015 by diagnosis code, and classified by their HAE treatment into “Plasma-derived C1-INH FDA-approved treatments”, or “Other (non-C1-INH) treatments” groups. Continuous enrollment in the health plan with at least 12 months of follow-up was required. The frequency of visit claims for autoimmune conditions during follow-up was identified by primary or secondary diagnosis codes, including lupus, rheumatoid arthritis (RA), alopecia, sicca, connective tissue disorders and immuno-deficiency disorders. Mean visits per patient per year (PPPY) by treatment group, gender and age ( Results 589 HAE patients were identified: 69% female and 27% age ≥50 years. 276 (729) patients (patient years) received C1-INH and 313 (860) other treatments. The mean (95% CI) number of visits for autoimmune diagnoses PPPY were 1.75 (0.82, 2.67) vs 3.67 (1.56, 5.78) respectively for C1-INH vs other treatments. Fewer visits with C1-INH treatment were predominantly observed in females Conclusions This exploratory analysis suggested a possible benefit of HAE treatment with plasma-derived C1-INH, particularly in younger women with coexisting autoimmune disorders. Confirmation with larger independent samples and further research are needed/warranted.