Macrophage Activation SyndromeMast CellsArthritis, JuvenileLymphohistiocytosis, HemophagocyticSyndromeCell DegranulationReceptors, IgEFerritinsMacrophage ActivationHistamine ReleaseTryptasesp-Methoxy-N-methylphenethylamineImmunoglobulin ELeukopeniaChymasesMastocytosis, SystemicAnaphylaxisPassive Cutaneous AnaphylaxisAntigens, Differentiation, MyelomonocyticCromolyn Sodiumbeta-N-AcetylhexosaminidasesMastocytosisThioxanthenesThrombocytopeniaInternational CooperationFeverHypersensitivityCells, CulturedMice, Inbred C57BLKetotifenProto-Oncogene Proteins c-kitLymphocyte ActivationPeritoneal CavityStem Cell FactorMice, KnockoutAnti-Allergic AgentsHistamineLeukotriene C4CytokinesLeukotriene E4Receptor AggregationSignal TransductionMacrophagesAntigens, CD98 Light ChainsSerine EndopeptidasesBone Marrow CellsTransition ElementsLeukotrienesAngelicaMice, Inbred BALB CProstaglandin D2