EOSINOPHILIA

Course overview

EOSINOPHILS ARE A KIND OF BLOOD GRANULOCYTES THAT EXPRESS CYTOPLASMIC GRANULES THAT CONTAIN BASIC PROTEINS AND BIND WITH ACIDIC DYES LIKE “EOSIN.” THEY DERIVE FROM BONE MARROW, AND THEIR PRODUCTION IS STIMULATED BY IL-5, IL-3, AND GM-CSF. THEY HAVE A CIRCULATING HALF-LIFE OF 4.5 TO 8 HOURS. THEY CAN RESIDE IN TISSUES, MOSTLY IN THE RESPIRATORY TRACT, GASTROINTESTINAL TRACT, FOR 8 TO 12 DAYS. EOSINOPHILS ARE LESS THAN 5% OF CIRCULATING LEUCOCYTES. EOSINOPHILIA IS DEFINED AS AN INCREASE OF CIRCULATING EOSINOPHILS >500 /MM^3. BASED ON THE COUNTS, EOSINOPHILIA CAN BE DIVIDED INTO DIFFERENT CATEGORIES: MILD (500 TO 1500/MM^3), MODERATE (150 TO 5000/MM^3), AND SEVERE (>5000/MM^3). HYPEREOSINOPHILIC SYNDROME IS DEFINED AS AN ABSOLUTE EOSINOPHIL COUNT GREATER THAN 1500/MM^3 ON TWO OCCASIONS AT LEAST ONE MONTH APART OR MARKED TISSUE EOSINOPHILIA. THIS ACTIVITY REVIEWS EVALUATION AND TREATMENT OF EOSINOPHILIA.