Optimizing hereditary angioedema management through tailored treatment approaches.

Hereditary angioedema (HAE) is a rare but serious and potentially life threatening autosomal dominant condition caused by low or dysfunctional C1 esterase inhibitor (C1-INH) or uncontrolled contact pathway activation. Symptoms are characterized by spontaneous, recurrent attacks of subcutaneous or submucosal swellings typically involving the face, tongue, larynx, extremities, genitalia or bowel. The prevalence of HAE is estimated to be 1:50,000 without known racial differences. It causes psychological stress as well as significant socioeconomic burden. Early treatment and prevention of attacks are associated with better patient outcome and lower socioeconomic burden. New treatments and a better evidence base for management are emerging which, together with a move from hospital-centered to patient-centered care, will enable individualized, tailored treatment approaches.

Use of recombinant C1 inhibitor in patients with resistant or frequent attacks of hereditary or acquired angioedema.

BACKGROUND: Conestat alfa (Ruconest, rhC1INH) is the first recombinant human C1 inhibitor protein (C1INH) for the treatment of acute attacks of hereditary angioedema (HAE). OBJECTIVE: To assess clinical experience of the first 11 adult patients who received rhC1INH in clinical practice in the UK. METHODS: Eleven patients (nine HAE type 1, one HAE type 2 and one acquired angioedema with C1 inhibitor deficiency) received between one and six, mostly self-administered, doses of rhC1INH for acute HAE attacks. They were asked to record their time to first response and complete resolution following the treatment. This cohort included our most severely affected and difficult to treat patients. RESULTS: In most cases, time to first improvement following rhC1INH and complete resolution was recorded as comparable to their typical response to pdC1INH, although 4/11 patients reported that the time to first improvement was much quicker than their average pdC1INH response. Five of the 11 patients continued with rhC1INH as their preferred rescue treatment. Of those who chose not to continue the treatment, four reported a recurrence or early return of symptoms with rhC1INH. CONCLUSION: In our experience, rhC1INH is a beneficial treatment for patients with preference for a C1INH that is not plasma derived and it is suitable for home treatment. In some cases it demonstrates cost saving, especially for heavier patients who require higher doses. In some patients rhC1INH may result in faster resolution of symptoms. It may be associated with an early return of symptoms in patients with exceptionally frequent attacks.

Anaphylaxis to Patent Blue V: a case series.

Blue dyes such as Patent Blue V (PBV) have been used in medical procedures for decades, and in the United Kingdom they are routinely utilised in sentinel lymph node biopsy (SLNB) for staging the axilla in early breast cancer. However, it has long been recognised that such dyes are associated with anaphylaxis. It has recently been estimated in a prospective study that allergy to PBV occurs with a frequency of 0.9%. Since repeated SLNB (and therefore further exposure to PBV) is increasingly being advocated for the small proportion of patients who develop a local (in-breast) recurrence, and because anaphylaxis can be life-threatening, it is important that those individuals that are allergic to PBV are recognised on their first medical exposure. The measurement of serum mast-cell tryptase (MCT) and skin prick test (SPT) are used in the investigation of suspected anaphylaxis because positive results are supportive of type-1 mediated hypersensitivity. Here we report the clinical features, MCT results and SPT results that pertain to a series of four patients referred to our drug allergy clinic with suspected anaphylaxis following SLNB. We recommend that all patients that show clinical evidence of allergy following exposure to PBV are referred to a specialist drug allergy service for further evaluation to investigate the cause.