Treatment of patients with hereditary angioedema with the c.988A>G (p.Lys330Glu) variant in the plasminogen gene

Konrad Bork,Jochen Hardt,Karin Wulff,Thomas Machnig,Guenther Witzke

doi:10.1186/s13023-020-1334-8

Abstract

BackgroundHereditary angioedema (HAE) in patients with normal C1 inhibitor (C1-INH) and the c.988A > G (p.Lys330Glu; p.K330E) variant in the plasminogen gene (HAE-PLG) is associated with skin swellings, abdominal pain attacks, and the risk of asphyxiation due to upper airway obstruction. Aim of this observational, retrospective study is to report about the efficacy of various treatments for acute attacks and long-term prophylaxis.ResultsThe study included 111 patients with HAE-PLG. Thirteen patients were treated with icatibant for 201 acute swelling attacks. The mean duration of the treated attacks (mean 4.3 h; standard deviation [SD] 2.6 h) was significantly shorter than that of the previous 149 untreated attacks (mean 44.7 h; SD 28.6 h, p < 0.0001). Twelve patients were treated with plasma-derived C1-INH for 74 acute swelling attacks. The duration of the treated attacks (mean 31.5 h; SD 18.6 h) was significantly shorter than that of the previous 129 untreated in the same patients (mean 48.2 h; SD 32.5 h, p < 0.0001). Corticosteroids alone showed good response in 61/268 attacks (8 patients), low response in 82/268 attacks (7 patients), and no response in 125/268 attacks (26 patients). Corticosteroids combined with antihistamines showed good response in 13/309 attacks (4 patients), low response in 150/309 attacks (7 patients), and no response in 146/309 attacks (17 patients). Antihistamines alone were ineffective in all 37 attacks of 5 patients. In 2 patients with imminent asphyxiation due to tongue swelling and partial obstruction of the upper airways fresh frozen plasma was used without clinical response. The mean reduction in attack frequency was 46.3% under progestins (6 patients), 93.9% under tranexamic acid (3 patients) and 83.3% under danazol (3 patients).ConclusionsFor patients with HAE-PLG various treatment options are available, which completely or at least partially reduce attack duration or attack frequency.

Highlights

Hereditary angioedema (HAE) in patients with normal C1 inhibitor (C1-INH) and the c.988A > G (p.Lys330Glu; p.K330E) variant in the plasminogen gene (HAE-PLG) is associated with skin swellings, abdominal pain attacks, and the risk of asphyxiation due to upper airway obstruction
All patients had a confirmed diagnosis of HAE-PLG according to the first description of a novel variant of the PLG gene in 2017 [8]
Before 2017, patients were classified as having HAE with normal C1-INH” (HAEnCI) and an unknown genetic background (HAE-unknown) or idiopathic angioedema; after 2017 they were re-diagnosed as HAE-PLG

Summary

Introduction

Hereditary angioedema (HAE) in patients with normal C1 inhibitor (C1-INH) and the c.988A > G (p.Lys330Glu; p.K330E) variant in the plasminogen gene (HAE-PLG) is associated with skin swellings, abdominal pain attacks, and the risk of asphyxiation due to upper airway obstruction. Various variants in different genes including the factor XII (F12), the plasminogen (PLG), angiopoietin-1 (ANGPT1) and kininogen-1 (KNG1) genes were identified in patients of large families with HAEnCI across 3 or more generations and were assumed to be involved in the development of types of HAE [5,6,7,8,9,10] (Table 1) One of these types is “HAE with the c.988A>G (p.Lys330Glu; p.K330E) variant in the PLG gene” or HAEPLG. Additional patients with HAEPLG were identified in Germany and various other European countries, in Japan, and in the US [13,14,15,16]

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