Macrophage Activation SyndromeMast CellsArthritis, JuvenileSyndromeLymphohistiocytosis, HemophagocyticCell 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 C4CytokinesSignal TransductionLeukotriene E4Receptor AggregationMacrophagesAntigens, CD98 Light ChainsSerine EndopeptidasesBone Marrow CellsBipolar DisorderTransition ElementsLeukotrienesAngelicaMice, Inbred BALB CProstaglandin D2