Risk factors for anaphylaxis in patients with mastocytosis

INTRODUCTION Symptoms resulting from the activation and release of mediators from the mast cells are observed in about 30% of the patients with mastocytosis.

OBJECTIVES The aim of the study was to assess the prevalence of anaphylactic reactions and to identify the risk factors for anaphylaxis in patients with mastocytosis depending on the type of the disease. Furthermore, we analyzed a response to treatment of mediator-related symptoms in this patient group.

PATIENTS AND METHODS The study group included 152 adult patients with mastocytosis. The diagnostic workup included a histopathological examination, flow cytometry, KIT mutation analysis, and measurement of tryptase levels. The diagnosis of allergy was confirmed by the skin prick test and serum immunoglobulin E levels.

RESULTS The prevalence of anaphylactic reactions in the study group was 50% and was higher in patients with systemic mastocytosis (P = 0.007), specifically in its indolent variant (P = 0.026), than in patients with cutaneous mastocytosis. The most frequent triggers of anaphylaxis were food (29%), insect stings (22%), and drugs (15%). Tryptase levels were higher in patients with a history of anaphylaxis (P = 0.029) as well as in those with symptoms provoked by physical factors (P = 0.002). Such symptoms were reported in 112 patients (74%) and were more common in patients with systemic mastocytosis compared with those with cutaneous mastocytosis (P = 0.026). The treatment was ineffective in 8 patients (10.5%) and resulted only in partial remission in 14 patients (18.4%).

CONCLUSIONS The study showed a significant incidence of symptoms related to physical factors in patients with mastocytosis and anaphylaxis in history. Risk factors for anaphylaxis included increased serum tryptase levels and indolent variant of systemic mastocytosis. Standard pharmacological treatment was ineffective in 10% of the patients, who may require biological treatment.