The following is a summary of “Efficacy and Safety of Rituximab-Based Treatments in Angioedema With Acquired C1-Inhibitor Deficiency,” published in the January 2024  issue of Allergy & Immunology by Kalmi, et al.

Angioedema (AE) caused by acquired C1-inhibitor deficiency (AAE–C1-INH) is linked to too much C1-INH or anti–C1–INH antibodies, and it is often connected with lymphoproliferative diseases or monoclonal gammopathies. There isn’t a set standard of care for preventative treatment in this situation. Rituximab might help stop attacks, especially if the lymphoid hemopathy is under control, but there aren’t many studies on this. 

A retrospective multicenter study looked at people with AAE–C1-INH who were given rituximab between April 2005 and July 2019. The study looked at 55 people with AAE–C1-INH, and 23 had an anti–C1–INH antibody. 39 of the patients had lymphoid cancer, and 9 had a monoclonal gammopathy. In 7 cases, there was no other condition that went with it. Thirty patients were given rituximab either by itself or along with chemotherapy (n = 25). About 17 of the 51 patients who could be followed up on had active AE after an average of 3.9 years (interquartile range, 1.7 to 7.7). 

Thirty of them were in clinical remission. Three of the cases died. AE remission was less likely when anti–C1–INH antibodies were present (HR, 0.29 [95% CI, 0.12-0.67]; P =.004). It occurs less often in people with lymphoma (risk ratio, 0.27 [95% CI, 0.09–0.80]; P =.019) and in people who were given rituximab and chemotherapy (risk ratio, 0.31 [95% CI, 0.12-0.79]; P =.014). Rituximab works well and is well accepted as a treatment for AE, especially in cases of lymphoid cancer and when anti–C1–INH antibodies are absent.

Source: sciencedirect.com/science/article/abs/pii/S2213219823011340