The autoreactivity of B cells in hereditary angioedema due to C1 inhibitor deficiency

A. Kessel, R. Peri, R. Perricone, M. D. Guarino, Z. Vadasz, R. Novak, T. Haj, S. Kivity, E. Toubi

Research output: Contribution to journalArticlepeer-review


Patients with hereditary angioedema (HAE) tend to produce autoantibodies and have a propensity to develop immunoregulatory disorders. We characterize the profile of autoantibodies in a group of HAE patients and investigate their memory B cells' phenotype and activation status. We studied the activity status phenotype, Toll-like receptor (TLR)-9 expression and total phosphotyrosine in B cells isolated from HAE patients. Additionally, the following autoantibodies were assessed in the serum of 61 HAE patients: anti-nuclear, rheumatoid factor, anti-cardiolipin, anti-tissue transglutaminase, anti-endomysial, anti-Saccharomyces cerevisiae, anti-thyroid and anti-neutrophil cytoplasmic antibodies. In 47·5% of HAE patients we detected at least one of the tested autoantibodies. Expression of CD69, CD5 and CD21 was found to be significantly higher on memory B cells from HAE patients compared to healthy controls (4·59±4·41 versus 2·06±1·81, P=0·04, 8·22±7·17 versus 3·65±3·78, P=0·05, 2·43±0·54 versus 1·92±0·41, P=0·01, respectively). Total phosphotyrosine in B cells from HAE patients was significantly higher compared to healthy controls (4·8±1·1 versus 2·7±1·3, P=0·0003). Memory B cells isolated from the HAE group contained higher amounts of TLR-9 compared to healthy controls (8·17±4·1 versus 4·56±1·6, P=0·0027). Furthermore, the expression of TLR-9 in memory B cells from HAE patients with autoantibodies was significantly higher than the control group (10±4·7 versus 4·56±1·6, P=0·0002) and from that in HAE patients without autoantibodies (10±4·7 versus 5·8±0·9, P=0·036). HAE patients have enhanced production of autoantibodies due most probably to the increased activation of B cells, which was found to be in association with a high expression of TLR-9.

Original languageEnglish
Pages (from-to)422-428
Number of pages7
JournalClinical and Experimental Immunology
Issue number3
StatePublished - Mar 2012


  • Autoantibodies
  • B cells
  • Hereditary angioedema
  • TLR-9
  • Total phosphotyrosine


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