SERPING1 and monoclonal gammopathy: A distinction between 2 subtypes has been suggested: one is characterized by C1INH consumption and is frequently associated with lymphoproliferative diseases, whereas the other is characterized by anti-C1INH antibodies and is thought to have an autoimmune mechanism.[10] However, the relevance of this distinction is questioned, as AAE with anti-C1INH antibodies is also associated with monoclonal gammopathy and lymphoma.[7,8]