Learned cautions regarding antibody testing in mast cell activation syndrome.

Objectives: To describe patterns observed in antibody titer trendlines in patients with mast cell activation syndrome (MCAS, a prevalent but underrecognized chronic multisystem inflammatory disorder of great clinical heterogeneity) and offer clinical lessons learned from such pattern recognition.

Methods: The available records of 104 MCAS patients drawn from the authors' practices were reviewed, including all antibody tests therein.

Results: All patients had positive/elevated antibodies of various sorts at various points, but for most of the antibodies which were found to be positive at least some points, the diseases classically associated with those antibodies were not present, marking such antibodies as clinically insignificant mimickers (likely consequent to inflammatory effects of MCAS on the immune system itself driving spurious/random antibody production) rather than "on-target" and pathogenic antibodies reflecting true disease warranting treatment.

A survey of the currently known mast cell mediators with potential relevance for therapy of mast cell-induced symptoms.

Mast cells (MCs) occupy a central role in immunological as well as non-immunological processes as reflected in the variety of the mediators by which MCs influence other cells. Published lists of MC mediators have all shown only subsets-usually quite small-of the full repertoire. The full repertoire of MC mediators released by exocytosis is comprehensively compiled here for the first time.

Cluster-Analytic Identification of Clinically Meaningful Subtypes in MCAS: The Relevance of Heat and Cold.

Background: Mast cell activation syndrome (MCAS) is a clinically heterogeneous disease with allergy-like symptoms and abdominal complaints. Its etiology is only partially understood and it is often overlooked.

Aims: The aim of this study was to identify subgroups of MCAS patients to facilitate diagnosis and allow a personalized therapy.

Efficacy and toxicity of hydroxyurea in mast cell activation syndrome patients refractory to standard medical therapy: retrospective case series.

Determine efficacy and adverse events (AEs) of hydroxyurea (HU) in mast cell activation syndrome (MCAS) patients who were refractory to standard medical therapy. An electronic chart review was performed to find MCAS patients who received HU in a MCAS medical practice. Diagnosis of MCAS was established on the basis of mast cell (MC) activation symptoms in ≥ 5 systems plus ≥ 1 abnormal MC mediators and/or ≥ 20 MC/high power field on duodenal biopsies.