[Detection of hereditary angioedema: first approach to laboratory diagnosis and patient characterization in Paraguay]

To establish, at the first time in Paraguay, for the first time in Paraguay, the laboratory diagnosis of HAE and to characterize affected patients.

An observational, descriptive, and cross-sectional study was conducted from 2023 to 2024 in patients older than one year with clinical symptoms of hereditary angioedema and asymptomatic relatives registered with the AEH-Paraguay Association, and 20 healthy donors. Quantitative C1-INH was determined by radial immunodiffusion and functional C1-INH by ELISA. Clinical and sociodemographic characteristics were evaluated.

Forty patients were included: 26 with clinical symptoms of hereditary angioedema and 14 asymptomatic relatives. Fifty-three percent (21/40) were female, and 15/40 were minors (1-16 years). Decreased quantitative and functional C1-INH levels (HAE-1) were observed in 21/40 patients, and decreased functional C1-INH levels (HAE-2) were observed in 4/40. In this group (n = 25), 20 had edema and 5 were asymptomatic relatives; in addition, 6 patients in this group had a previous laboratory diagnosis, and 19 were newly detected cases. The most frequent edemas appeared in the extremities, face, abdomen, and larynx (n = 9). Fifty-six percent (14/25) reported having a deceased relative with a history of edema. Stress and puberty were the main triggering factors, and the median age of onset was 13 years. Six patients reported prophylactic treatment; the median duration of edema-related crises at one year was 6, with a median of 14 days of disability.

We studied C1-INH in patients with recurrent edema and asymptomatic relatives, detecting 19 new cases and characterizing 25 patients with hereditary angioedema. This is the first diagnostic approach in Paraguay, and we report these initial data, which may be useful for the public health system in developing policies that address the diagnosis and treatment of patients with hereditary angioedema.