Prophylactic treatment with plasma-derived C1 inhibitor in idiopathic non-histaminergic angioedema

Omalizumab for Idiopathic Nonhistaminergic Angioedema: Evidence for Efficacy in 2 Patients

Presently, there is inconclusive evidence regarding the most effective treatment for idiopathic nonhistaminergic acquired angioedema (InH-AAE). Omalizumab may, however, prove to be a promising option. This case report describes two patients who presented with recurrent angioedema attacks, which was refractory to antihistamine therapy. Hence, they were treated with 300 mg omalizumab, every 4 weeks, for a period of 6 months. Both patients had shown a rapid response to the treatment and achieved complete resolution of symptoms without further AE attacks throughout the entire duration of the treatment period. After omalizumab's suspension, one patient remained symptom free for the following 6 months and the other patient had recurrence of symptoms after 2 months for which he was retreated with omalizumab and once again became symptom free. Although omalizumab seems to be effective as a prophylactic treatment for InH-AAE, the determining factors leading to the differences in time-to-relapse between patients after its suspension remain unclear. Further studies are needed in order to better determine the potential therapeutic application of omalizumab and its role in maintenance therapy.

Idiopathic non-histaminergic acquired angioedema: a case series and discussion of published clinical trials

Background

Idiopathic non-histaminergic acquired angioedema (InH-AAE) is a rare disease for which there are no available laboratory parameters to clearly define the disorder. Therapy is often difficult and various treatment options have been proposed. In this paper, we have evaluated the most effective therapies for InH-AAE on the basis of current literature and report the therapeutic effect of omalizumab in three patients with InH-AAE.

Methods

Literature was searched with a combination of MeSH/EMTREE terms and freetext search for angioedema and therapy/omalizumab in the databases Medline (Ovid), PubMed/Premedline, Embase, Cochrane library and Scopus with no time or language restrictions. In three patients affected by InH-AAE the therapeutic effect of omalizumab was demonstrated by clinical outcome. In one patient the FcεRI receptor density on basophils was monitored under therapy with omalizumab.

Results

From the review of the current literature, 25 out of 286 publications dealing with relevant therapeutic recommendations for InH-AAE were analyzed. Six publications with 98 patients referred to tranexamic acid, of which 27 had a complete, 70 a partial and 1 no response. In three case reports ecallantide showed 2 patients with a complete and 1 a partial response. In four case reports for Icatibant 2 had a complete and 3 a partial response. When evaluated in three reports, C1-INH found complete and partial responses in 2 patients each. One patient had a complete response to progestin. Omalizumab was described in 6 reports with 20 patients, all of whom showed a complete response. All three patients described in our study responded to omalizumab with a complete remission. Density of FcεRI receptors on basophils, monitored in patient 1 on a long-term course of 31 months, decreased from 74,051.61 to a minimal level of 1907 receptors per cell.

Conclusions

Omalizumab seems to be the most effective therapy in InH-AAE. The continuous decrease of FcεRI-receptor density on basophils under therapy with omalizumab along with clinical improvement observed in one patient, could serve as a new approach for further studies to evaluate FcεRI-receptor density as a surrogate marker for therapeutic efficacy and for dosing and determining injection intervals of omalizumab.

Trial registration BASEC-Nr. Req-2016-00692. Retrospectively registered 24.11.2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-017-0164-9) contains supplementary material, which is available to authorized users.

Angioedema suppressed by a combination of anti-histamine and leukotriene modifier

Rationale

Angioedema without co-existent urticaria is due to a limited number of causes, including hereditary and acquired C1 esterase inhibitor deficiency, drug-induced angioedema or idiopathic histaminergic or non-histaminergic angioedema. We describe a cohort of patients with recurrent angioedema whose clinical features and response to medications are distinct from the causes above.

Methods

Patients were accrued retrospectively from an academic allergy practice between 2007 and 2014. After institutional research ethics board approval, patients’ charts were reviewed and demographic, clinical and laboratory data were extracted.

Results

A total of 11 patients were recruited. The mean age at presentation was 54.9 years (range 19–70 years) and 6 of 11 were male. The mean number of episodes per year was 18.7 (range 2–60) and mean duration of episodes was 22.4 h (range 4–96). About half of episodes (52%) began overnight. Areas of involvement were lips (73%), tongue (64%), eyelids (18%), feet (36%) and hands (27%). None of the patients had low C3, C4, or CH50; none had significantly positive ANA; C1 esterase inhibitor level and function and C1q were normal in all patients tested. In these 11 patients, complete suppression of recurrences by the combination of cetirizine 20 mg daily and montelukast 10 mg daily was reported by 9 (82%) of patients; whereas 2 (18%) of patients had a partial response to this combination of medications.

Conclusions

Herein, we report a form of angioedema without urticaria, mediated by a combination of histamine and leukotrienes. Clinical, demographic and therapeutic characteristics differentiate this from other recognized causes of angioedema.