The following is the summary of “Prospective Study on the Efficacy and Impact of Cascade Screening and Evaluation of Hereditary Angioedema (CaSE-HAE)” published in the November 2022 issue of Allergy and Clinical Immunology by Wong, et al.

The recommendations for hereditary angioedema (HAE) family screening continue to vary and are largely based on professional opinion. There needs to be more research examining its use and effectiveness. A novel HAE screening tool was developed to assess the benefits and drawbacks of cascade family screening (CFS) for high-risk relatives. The CFS method was used to identify relatives at risk for HAE. Clinical, psychiatric, and HAE-related outcomes were prospectively recorded at baseline and after a year of treatment. Patients who received a CFS diagnosis were compared to the index patients regarding their long-term prognosis.

Only 153 out of 179 relatives could be reached; of those, 67% agreed to be screened. 29 patients (46%) were newly diagnosed with HAE; of those, half (52%) presented with symptoms at baseline. First-degree relatives had a greater diagnostic yield than second-degree relatives (57.6% vs 33.3%; P=.077), but the difference was not statistically significant. After 1 year, there was a significant decrease in the number of hospitalizations for HAE-related symptoms (1 vs. 0; P=.016) and the length of stay (3 vs. 2 days; P=.001) among symptomatic patients. Anxiety ratings on the Hospital Anxiety and Depression Scale decreased (14.35 ± 6.32 vs. 6.47 ±4.14; P=.001), and Angioedema Quality of Life scores increased (55% vs. 35%; P<.001). 

It has been estimated that the annual cost of treating HAE due to CFS has decreased by at least HK$1,200 ($153). The sensitivity (100%) and specificity (77%) of screening with a C4 threshold greater than the recommended 22.9 mg/dL were significantly higher. Improvements in clinical and psychological outcomes and cost savings due to HAE can be achieved by implementing a cascading family screening strategy.

Source: sciencedirect.com/science/article/abs/pii/S221321982200808X