Acquired angioedema with C1-inhibitor deficiency (AAE-C1-INH) is a rare medical condition that shares similarities with hereditary angioedema (HAE), but it presents later in life. Unlike HAE, AAE-C1-INH is characterized by a deficiency in the C1-inhibitor (C1-INH) protein due to its consumption, often linked to autoimmune diseases and, notably, lymphatic malignancies. Being significantly rarer than HAE, approximately ten times less frequent, knowledge about AAE-C1-INH and established treatments are limited. Accurate Aae Diagnosis is therefore crucial for effective patient management.
A recent study conducted in Germany aimed to enhance our understanding of AAE-C1-INH. Researchers analyzed data from 20 patients diagnosed with AAE-C1-INH across two angioedema centers in southern Germany. This retrospective analysis focused on several key aspects, including the time taken for diagnosis, the ratio of AAE-C1-INH cases compared to HAE, associated underlying health conditions, and the therapeutic strategies employed.
The study revealed that the average age when symptoms first appeared was 64 years, with a higher prevalence in females (60%). A predominant symptom was swelling of the face, observed in 85% of patients. Consistently, almost all patients exhibited low levels of C1-INH. The study also confirmed the rarity of AAE-C1-INH, with a ratio of AAE-C1-INH to HAE of 1:9.7. Concerning diagnostic timelines, the median delay from the onset of symptoms to receiving an aae diagnosis was 7.5 months. For those patients who also had an underlying hematological condition (9 individuals), the diagnosis of this condition followed the onset of AAE-C1-INH symptoms by a median of 4 months. Furthermore, four patients had a history of solid tumors, and in one case, papillary thyroid carcinoma was identified as the likely cause of AAE-C1-INH. Remarkably, treating this malignancy led to the resolution of AAE-C1-INH symptoms in this patient.
In terms of treatment, all patients experiencing symptoms were treated with medications used off-label. These included subcutaneous icatibant or intravenous C1-INH concentrate for on-demand treatment of acute swelling episodes. For six patients with severe and frequent attacks, off-label long-term prophylaxis was necessary and proved effective in controlling symptoms.
In conclusion, AAE-C1-INH is distinguished by swellings that predominantly affect the face and are accompanied by low C1-INH levels, typically appearing later in life. Encouragingly, the time taken to achieve an aae diagnosis is decreasing, despite its rarity compared to HAE. The study highlights that patients severely affected by AAE-C1-INH, especially those without identifiable underlying conditions or for whom treatment of the underlying condition is not indicated, may find significant benefit from off-label therapeutic interventions to manage their symptoms effectively.
