Glossary of mast cell related terms: P-Z
Parasympathetic nervous system: Part of the autonomic nervous system. Regulates digestion and other functions.
Prostaglandin D2 (PGD2): The dominant prostaglandin produced by mast cells.
9a,11b-PGF2: a breakdown product of prostaglandin D2; can be measured to assess level of mast cell activation
Platelet activating factor (PAF): a mast cell mediator that correlates with severity of anaphylaxis; induces degranulation and release of leukotrienes and prostaglandins
Postural orthostatic tachycardia (POTS): increase of 30 bpm or more when standing in the absence of orthostatic hypotension.
Premedication: taking medication in advance of an event in order to suppress an undesirable reaction during the event, such as premedicating before surgery
Pre-stored: as relates to mast cell biology, mediators that are made inside the cell and stored in granules to be released at a later time
Progenitor cell: a cell that develops into another type of cell
Proliferation: growth and expansion of a cell population
Prostaglandin: a type of eicosanoid with wide ranging biological effects; PGD2 is the prostaglandin most abundantly produced by mast cells
Protracted anaphylaxis: a long episode of anaphylaxis symptoms despite treatment
Rare disease: a disease that affects only a small amount of people in a population; in the US, defined as affecting 200,000 people or less in the US
Rebound: a resurgence of symptoms after quelling symptoms earlier
Receptor: a protein on the outside of cells that bind specific molecules, causing a specific action to occur
Secretion: the release of molecules from inside the cell to the outside environment without degranulation
Sensitization: production of IgE specific to an allergen without obvious allergic reaction to the allergen
Serotonin: a neurotransmitter released by a number of cell types, including mast cells
Smouldering systemic mastocytosis (SSM): a form of SM in which organ damage and failure could eventually occur; diagnosed when someone with SM has two or more B findings
Splenomegaly: swelling of the spleen
Stem cell factor (SCF): a mast cell growth factor; SCF binds to CKIT and tells mast cells to stay alive and make more mast cells
Sympathetic nervous system: Part of the autonomic nervous system. Controls the fight or flight response
Systemic mastocytosis (SM): a proliferative mast cell disease in which too many mast cells are produced
Systemic mastocytosis with associated clonal hematologic non-mast cell lineage disease (SM-AHNMD): co-occurrence of SM with another proliferative blood cell disorder, such as essential thrombocythemia or chronic myelogenous leukemia
Tachycardia: rapid heartbeat
Third spacing: when fluid is forced out of a place the body can use it and becomes trapped, such as ascites or angioedema
TLR: toll like receptor; receptors on the outside of many cells (including mast cells) that activate immune response to infections
Telangiectasia macularis eruptive perstans (TMEP): a less common form of cutaneous mastocytosis. Found almost exclusively in adults.
Tryptase: a mast cell mediator; when tested outside of a symptomatic episode, it is used to measure the baseline amount of mast cells present ; when tested during a symptomatic episode, it can be used to identify mast cell activation
Urticaria pigmentosa (UP): also called maculopapular cutaneous mastocytosis (MPCM). The most common form of cutaneous mastocytosis.
Wheal and flare response: a reaction marked by redness and raised, taut skin due to histamine release