title: Reticulocytes and their immature fraction do not detect acute rejection after kidney transplantation.
abstract: BACKGROUND
  Early detection of an acute rejection episode is an important problem in monitoring transplant patients. Erythropoietin (EPO) production is diminished in patients suffering from chronic renal insufficiency or acute rejection. Therefore, a decrease of reticulocyte counts and of young reticulocytes might indicate the emergence of an acute rejection episode. This pilot study examined the value of reticulocyte parameters as indicators of acute rejection episodes.
  
  
  METHODS
  Reticulocyte parameters were examined in 25 renal transplant patients. Initial immunosuppressants therapy was based on a combination of methylprednisolone, mycophenolatmofetil, cyclosporine and antithymocyte globulin or basiliximab, CellCept, cyclosporine, and ATG or Simulect. During the first 3 weeks after the procedure, blood samples were collected three times per week. Complete blood counts were performed on XE-2100 analyzers (Sysmex). Acute rejection was biopsy-proven.
  
  
  RESULTS
  Acute rejection episodes were not accompanied by significantly altered reticulocyte parameters. During the first weeks, the reticulocyte count or the immature fraction, respectively, did not differ between patients with delayed versus immediate onset of renal function: reticulocyte count 1.70 +/- 1.06% vs 1.58 +/- 1.10% and ratio of immature (high fluorescent) reticulocytes 22.8 +/- 7.9% vs 17.6 +/- 9.4%).
  
  
  CONCLUSIONS
  Reticulocyte counts and determination of the immature reticulocyte fraction were not significantly altered by an acute rejection episode. Various influences modulate the release of EPO and reaction of erythropoiesis upon an EPO stimulus.
authors.affiliation: Central Institute of Laboratory Medicine and Pathobiochemistry, Charité Hospital, Campus Virchow Clinic, Berlin, Germany. andreas.weimann@charite.de
authors.forename: A
authors.initials: A
authors.lastname: Weimann
authors.forename: S
authors.initials: S
authors.lastname: Lun
authors.forename: C
authors.initials: C
authors.lastname: Müller
authors.forename: J
authors.initials: J
authors.lastname: Pratschke
authors.forename: P
authors.initials: P
authors.lastname: Reinke
authors.forename: A
authors.initials: A
authors.lastname: Lun
mesh_terms: D000328:Adult; D000368:Aged; D003404:Creatinine / Q000097:blood; D004921:Erythropoietin / Q000097:blood; D005260:Female; D006084:Graft Rejection / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D017701:Reticulocyte Count; D014508:Urea / Q000097:blood
chemical_list: D004921:Erythropoietin; D014508:Urea; D003404:Creatinine