Doxycycline for epistaxis in hereditary hemorrhagic telangiectasia: genotype-stratified outcomes.

Patients with hereditary hemorrhagic telangiectasia (HHT) experience recurrent epistaxis. Doxycycline has been proposed as a possible treatment, although its efficacy remains controversial. Whether the most common genotypes (activin receptor-like kinase 1, endoglin, and SMAD4) contribute to a differential response has not been investigated. In this study, we evaluate the effectiveness of doxycycline among the different HHT genotypes. A retrospective cohort study was conducted at the University of Florida's Hereditary Hemorrhagic Telangiectasia Center. Forty-one adult patients (aged ≥18 years) with HHT, diagnosed by Curacao criteria and genetic testing, were classified as responders and nonresponders based on the minimal clinically important change between pre- and posttreatment epistaxis severity scores (ESS). Hemoglobin and hematocrit values were also collected to assess treatment response. Overall, the cohort was 61% female and 90.2% White, with a mean age of 58.1 years; 26 responders had a decrease (P < .0001) in ESS from a baseline median of 4.6 (interquartile range [IQR], 3.3) to posttreatment ESS of 2.4 (IQR, 1.9). The median baseline ESS for the total cohort was 4.4 (IQR, 3.3), and after a mean follow-up of 4.1 months, it significantly (P < .0001) decreased to an ESS of 3.3 (IQR, 3.2). The mean hemoglobin and hematocrit values did not exhibit significant changes. The relationship between genotype and doxycycline response was not statistically significant. Patients with HHT treated with doxycycline showed an overall reduction in epistaxis severity, which did not appear to be associated with genotype. Doxycycline may be a safe, effective, and accessible treatment option for epistaxis in HHT.