An overview of novel therapies for acute hereditary angioedema

A pilot study for triple combination therapy with a low-fluence 1064 nm Q-switched Nd:YAG laser, hydroquinone cream and oral tranexamic acid for recalcitrant Riehl's Melanosis

BACKGROUND

Riehl's melanosis presents as a diffuse gray-brown to black hyperpigmentation around face. The treatment of this disease is challenging and quite limited despite patients' excessive psychological stresses.

OBJECTIVE

In this prospective pilot study, we evaluated the efficacy and safety for a novel combination therapy based on low-fluence Q-switched 1064 nm Nd:YAG laser, hydroquinone cream and oral tranexamic acid for recalcitrant Riehl's melanosis.

METHODS

Totally eight patients with Riehl's melanosis who had failed improvements previously received multiple sessions (10-18 times) of combination treatment regimen. The primary endpoint was clinical score by the physician and the secondary endpoints were clinical score by the patients, instrumental analysis using melanin and erythema values, and histopathological score.

RESULTS

Among eight patients, three received "Almost clear" grade, the other five patients received "Marked improvement" grade at final visits. No serious adverse events and post-treatment downtime was observed. Mean Melanin and Erythema Indexes also showed significant decreases compared with baseline. Histopathologic examination confirmed a significantly greater reduction of melanin content in melanophages.

CONCLUSION

This combination method can be a viable option for Asian patients having Riehl's melanosis with high risk of post-inflammatory hyperpigmentation, maintaining low-dose laser irradiation.

Perioperative management for patients with hereditary angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant disease that results from mutations in the C1-esterase inhibitor (C1-INH) gene. HAE is characterized by recurrent episodes of angioedema of the skin (face, extremities, genitalia, trunk), the gastrointestinal tract, and respiratory tract. Symptoms experienced can be debilitating, may impact quality of life, and can be life threatening. Preventing attacks particularly for patients undergoing procedures is critical. Patients with HAE may now treat acute attacks or prevent attacks with medications that have recently become available in the United States; however, these same medications can be used for perioperative management for patients undergoing medical, surgical, and dental procedures. Periprocedural planning is important for patients to reduce the incidence of acute attacks. Education is critical and increasing awareness of short-term prophylaxis options will allow providers to develop an appropriate action plan for their patients. The goal of this review is to increase awareness for HAE treating physicians, surgeons, anesthesia, and emergency room physicians by examining the available treatment options, researching the literature, and summarizing available data for periprocedural management. The availability of treatment options has increased over the past few years, expanding options for physicians and patients living with HAE and improve safety during the perioperative period and at the time of other procedures.

Icatibant for the Treatment of Hereditary Angioedema

OBJECTIVE

To review the pharmacology, pharmacokinetics, clinical trials, and safety of icatibant, a recently approved bradykinin B2 receptor antagonist for treatment of acute attacks of hereditary angioedema (HAE).

DATA SOURCES

Articles indexed in MEDLINE (1948-June 2012), International Pharmaceutical Abstracts(1970-May 2012), and Cumulative Index to Nursing and Allied Health Literature (1981-June 2012) were identified using the search terms icatibant, bradykinin B2 receptor antagonist, and hereditary angioedema. Additional references were identified from the reference lists of the articles identified.

STUDY SELECTION AND DATA EXTRACTION

English-language articles were reviewed.

DATA SYNTHESIS

Icatibant was evaluated in 3 Phase 3 clinical trials and found to be a safe and effective option for treatment of acute HAE. Icatibant was compared to placebo in 2 clinical trials (FAST-1 and FAST-3) and to tranexamic acid in the FAST-2 trial. Patients receiving icatibant in FAST-1 did not experience a significant improvement in median time to clinically significant relief of the index symptom (p = 0.14), whereas patients receiving icatibant in FAST-3 experienced a significant improvement in median time to at least 50% reduction in symptom severity (p < 0.001). When icatibant was compared to tranexamic acid in FAST-2, the median time to clinically significant relief of the index symptom was shorter for patients receiving icatibant (p < 0.001). The most common adverse events associated with the administration of icatibant were injection-site reactions, which were mild to moderate and transient. These data suggest that icatibant is a safe and effective treatment for acute attacks of HAE. Although direct comparisons of recently approved alternatives for treatment of acute attacks are lacking, there are administration advantages of icatibant over other agents. Additionally, the cost of icatibant is comparable to that of the C1 esterase inhibitor Berinert and less expensive than ecallantide.

CONCLUSIONS

Available efficacy data support that icatibant should be considered a safe and effective treatment for acute attacks of HAE. Additionally, limited treatment options for this rare condition, ease of administration, and comparable cost profile support its consideration for formulary inclusion.

[Successful use of C1 esterase inhibitor in capillary leak syndrome]

This article reports the successful use of C1 esterase inhibitor in the treatment of capillary leak syndrome. The coincidence of exposure to latex during surgery and medication with ramipril led to prolonged shock complicated by secondary hyperfibrinolysis, capillary leak syndrome and multiple organ failure. Initial treatment according to relevant guidelines failed to stabilize the condition. Treatment was only successful after administration of 1,500 IU of human C1 esterase inhibitor.

Disease-causing mutations in genes of the complement system

Recent studies have revealed profound developmental consequences of mutations in genes encoding proteins of the lectin pathway of complement activation, a central component of the innate immune system. Apart from impairment of immunity against microorganisms, it is known that hereditary deficiencies of this system predispose one to autoimmune conditions. Polymorphisms in complement genes are linked to, for example, atypical hemolytic uremia and age-dependent macular degeneration. The complement system comprises three convergent pathways of activation: the classical, the alternative, and the lectin pathway. The recently discovered lectin pathway is less studied, but polymorphisms in the plasma pattern-recognition molecule mannan-binding lectin (MBL) are known to impact its level, and polymorphisms in the MBL-associated serine protease-2 (MASP-2) result in defects of complement activation. Recent studies have described roles outside complement and immunity of another MBL-associated serine protease, MASP-3, in the etiology of 3MC syndrome, an autosomal-recessive disorder involving a spectrum of developmental features, including characteristic facial dysmorphism. Syndrome-causing mutations were identified in MASP1, encoding MASP-3 and two additional proteins, MASP-1 and MAp44. Furthermore, an association was discovered between 3MC syndrome and mutations in COLEC11, encoding CL-K1, another molecule of the lectin pathway. The findings were confirmed in zebrafish, indicating that MASP-3 and CL-K1 underlie an evolutionarily conserved pathway of embryonic development. Along with the discovery of a role of C1q in pruning synapses in mice, these recent advances point toward a broader role of complement in development. Here, we compare the functional immunologic consequences of "conventional" complement deficiencies with these newly described developmental roles.