Hereditary angioedema

Hereditary angioedema (C1 inhibitor deficiency, OMIM: 106100 ) is a genetically determined disease of the immune system with autosomal dominant inheritance. This is not a classic immunodeficiency, where the affected individual would be exposed to a higher risk of infectious disease, but it is a hereditary disease of the immune system, where a mutation in the gene for one of the components of the immune system damages its carrier.

Pathogenesis
The mutation affects the gene for the C1 inhibitor of the complement component (C1-INH, localization 11q11-q13.1). The product of the mutated gene is either not formed at all or is non-functional. This fact means that any (even if minimal and harmless, such as a minor injury) stimulus leads to the activation of the entire complement cascade, the increased production of bradykinin is responsible for the clinical manifestations , which is normally regulated by inhibiting the conversion of prekallikrein to kallikrein thanks to C1-INH.

Clinical picture
Externally, the disease is manifested by swelling of the subcutaneous tissue and mucous membranes, which are pale, non-itchy, without a local increase in temperature. Swelling of the mucous membranes of the respiratory tract can be dangerous , damage to the mucous membranes of the digestive tract can manifest itself in digestive difficulties, in a more severe form, pain and partial intestinal obstruction and mimic a sudden abdominal attack, in the case of damage to the mucous membranes of the urinary tract, there is a risk of urine retention .

The disease has a later onset, sometimes in adulthood.

Diagnosis
The diagnosis is based on the evidence of a low level of the C4 component of the complement (due to consumption) and a very low (in the case of a non-functional form of C1-INH and normal or high) levels of C1-INH.

Differential diagnosis
In terms of differential diagnosis, it is necessary to distinguish the acquired forms - paraneoplastic (consumption of C1-INH in the tumor tissue), parainfectious (rarely in Hellicobacter pylori infection ) and drug-induced (in ACEI therapy in up to 0.3-1%  ).

Treatment
In acute treatment, B2R receptor antagonist for bradykinin − icatibant sc and iv substitution of C1-INH are used. Antifibrinolytics (tranexamic acid) and danazol (ethinyltestosterone derivative) are given as long-term prophylaxis

Related Articles [ edit | edit source ]

 * Primary immunodeficiency
 * Complement
 * Deficiency of complement components

Source [ edit | edit source ]

 * ŠIPEK, Antonín. Genetically determined disorders of the immune system  [online]. Last revision 9/6/2006, [cit. 4/1/2010]. < http://www.genetika-biologie.cz/primarni-immunodeficiency >.

References [ edit | edit source ]

 * 1) ↑ HAKL, Roman and Pavel KUKLÍNEK. Hereditary angioedema in theory and practice. Practicus [online] . 2015, year 14, vol. 5, pp. 9-10, also available from < http://www.practicus.eu >. ISSN 1213-8711.

References [ edit | edit source ]

 * BARTŮŇKOVÁ, Jiřina. Immunodeficiency. 1st edition. Prague: Grada, 2002. 228 pp.  ISBN 80-247-0244-4.


 * GUTOVA, Václava. Current treatment options for hereditary angioedema. Remedia [online] . 2012, year 2012, vol. 6, pp. 393-397, also available from < http://www.remedia.cz/Clanky/Farmakoterapie/Soucasne-moznosti-lecby-projevu-hereditarniho-angioedemu/6-L-1oM.magarticle . aspx >. ISSN 2336-3541.