title: Transfusion-transmitted anaplasmosis from a leukoreduced platelet pool.
abstract: BACKGROUND
  Human granulocytic anaplasmosis is an emerging tick-borne illness. Anaplasma phagocytophilum resides intracellularly, can cause asymptomatic infection, and can survive blood component refrigeration conditions for at least 18 days. To date, eight cases of transfusion-transmitted anaplasmosis (TTA) have been reported: seven attributed to red blood cell (RBC) units, five of which were prestorage leukoreduced using RBC leukoreduction filters, and one involving a process leukoreduced apheresis platelet (PLT) unit. Here, we report a case of TTA from a whole blood-derived PLT pool.
  
  
  METHODS
  Donation segments from the 7 units of RBCs and two PLT pools transfused were examined. Fast protocol multiplex real-time A. phagocytophilum polymerase chain reaction (PCR) and serologic testing for immunoglobulin (Ig)M and IgG antibodies to A. phagocytophilum by enzyme immunoassay were performed.
  
  
  RESULTS
  Transmission was confirmed by positive A. phagocytophilum PCR and serology in one of 16 donors and by positive PCR and seroconversion in the recipient.
  
  
  CONCLUSIONS
  This is the first confirmed case of TTA from a whole blood-derived PLT pool prepared from PLT concentrates leukoreduced by in-line filtration of PLT-rich plasma.
authors.affiliation: Infectious Diseases Division, Warren Alpert Medical School of Brown University, Providence, Rhode Island.
authors.forename: Antonella B
authors.initials: AB
authors.lastname: Fine
authors.affiliation: Transfusion Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Sweeney
authors.affiliation: Transfusion Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Nixon
authors.affiliation: Infectious Diseases Division, Warren Alpert Medical School of Brown University, Providence, Rhode Island.
authors.forename: Bettina M
authors.initials: BM
authors.lastname: Knoll
mesh_terms: D000368:Aged; D041081:Anaplasma phagocytophilum / Q000235:genetics / Q000502:physiology; D016873:Ehrlichiosis / Q000635:transmission*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000032:analysis; D053657:Platelet-Rich Plasma; D010983:Plateletpheresis / Q000009:adverse effects*; D016133:Polymerase Chain Reaction
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M