Serum Baseline Tryptase Level as a Marker for the Severity of Anaphylaxis

BACKGROUND

Anaphylaxis is a severe and potentially fatal allergic disease or hypersensitivity reaction with variable clinical presentation. Biomarkers in anaphylaxis could be useful to improve diagnosis, to allow endotyping of patients, and to predict risk.

OBJECTIVE

To investigate the role of serum basal tryptase (sBT) levels in the management of patients with anaphylaxis.

METHODS

Patients with at least 1 episode of anaphylaxis were selected among those who attended the Allergy Clinics of the Clinical Hospital of the Ribeirão Preto Medical School, University of São Paulo, Brazil, upon evaluation by allergy/immunology specialists of our medical staff. Demographic and clinical data were obtained using a structured questionnaire. sBT levels were determined using the ImmunoCAP Tryptase immunoassay.

RESULTS

57 patients (56.1% female) with a median age of 35 years (range 7-87 years) participated in the study. sBT levels ranged from 2.57 to 21.19 ng/mL (mean 5.17 ng/mL), with no significant differences in patients with anaphylaxis due to different triggers. Mean levels were 4.93; 5.2; 5.41, and 5.24 ng/mL for patients who had anaphylaxis due to Hymenoptera venom (n = 17), foods (n = 13), drugs (n = 13), and idiopathic disease (n = 14), respectively. Significantly higher sBT levels were observed in patients with severe anaphylaxis (grade IV) than in patients with mild-moderate disease (grades II/III) (mean levels 6.61 vs. 4.71 ng/mL, respectively).

CONCLUSION

High sBT levels may help to identify patients at increased risk of more severe anaphylaxis, prompting physicians to initiate immediate therapy to avoid further acute episodes.

Acquired Angioedema due to C1 Inhibitor Deficiency Preceding Splenic Marginal Zone Lymphoma: Further Insights from Clinical Practice

BACKGROUND

Acquired angioedema due to C1 inhibitor deficiency (AAE-C1-INH) is a very rare disease. In clinical practice, it may be difficult to differentiate AAE-C1-INH from hereditary angioedema due to C1-INH deficiency (HAE-C1-INH). In both conditions, patients are at an increased risk of death from asphyxiation due to upper airway obstruction. The association of AAE-C1-INH with lymphoproliferative and autoimmune diseases, and with presence of anti-C1-INH antibodies has been well documented, and treatment of the underlying condition may result in complete remission of angioedema.

OBJECTIVES

To discuss the clinical evaluation, diagnosis, and treatment outcomes of AAE-C1-INH in the context of the care of 2 patients with recurrent isolated angioedema.

METHODS

Two patients were followed up prospectively at our clinic. Measurements of C3, C4, C1-INH, and C1q levels were carried out by nephelometry, and the functional activity of C1-INH was determined by a chromogenic assay. Hematological investigation included morphological and immunophenotyping analysis of peripheral blood, bone marrow, and spleen histopathology. Sequencing of the 8 exons and adjacent intronic regions of the SERPING1 gene was performed using the Sanger method.

RESULTS

Two patients were diagnosed with AAE-C1-INH associated with splenic marginal zone lymphoma during follow-up.

CONCLUSIONS

Close follow-up, including detailed clinical history, physical examination, and laboratory tests, of our patients with AAE-C1-INH was essential for the early diagnosis and successful treatment of the lymphoproliferative disease, leading to the resolution of the angioedema attacks.