Reticulated platelet counts correlate with treatment response in patients with idiopathic thrombocytopenic purpura and help identify the complex causes of thrombocytopenia in patients after allogeneic hematopoietic stem cell transplantation.
BACKGROUND
In thrombocytopenic conditions of unknown origin, quantification of reticulated platelets (RP) in the peripheral blood by flow cytometry has been shown to differentiate increased platelet (Plt) turnover from insufficient Plt production.


METHODS
We used a whole blood flow cytometry method combining thiazole orange and anti-CD41a-staining to assess RP in 71 healthy subjects, six with thrombocytopenic myelodysplastic syndrome (MDS), nine with liver cirrhosis, 14 patients with idiopathic thrombocytopenic purpura (ITP), and 12 patients who had undergone hematopoietic stem cell transplantation (HSCT).


RESULTS
Patients with MDS had normal, patients with liver cirrhosis had slightly elevated RP counts compared to healthy subjects. ITP patients had elevated RP counts, and RP >15% were associated with treatment response (P = 0.015). In 7/10 patients after HSCT, an increase of RP preceded Plt recovery, whereas in patients with secondary thrombocytopenia after normal regeneration, the assessment of RP allowed the differentiation between conditions with high Plt turnover, such as GvHD and microangiopathy, indicated by high RP counts, and graft failure, indicated by low RP counts.


CONCLUSIONS
Our data provide the rationale for prospective studies on the diagnostic and prognostic value of RP counts in larger patient populations with ITP and after HSCT.
Thomas-Kaskel
Anna-Katharina
AK
Department of Hematology/Oncology, Freiburg University Medical Center, D-79106 Freiburg, Germany. kaskel@mm11.ukl.uni-freiburg.de
Mattern
Dominik
D
Köhler
Gabriele
G
Finke
Jürgen
J
Behringer
Dirk
D
D000328:Adult; D000368:Aged; D052160:Benzothiazoles; D001792:Blood Platelets / Q000166:cytology* / Q000473:pathology; D002452:Cell Count / Q000379:methods / Q000639:trends; D005260:Female; D005434:Flow Cytometry / Q000379:methods* / Q000639:trends; D006084:Graft Rejection / Q000175:diagnosis / Q000503:physiopathology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000175:diagnosis / Q000503:physiopathology; D040201:Platelet Membrane Glycoprotein IIb / Q000276:immunology; D011237:Predictive Value of Tests; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000175:diagnosis* / Q000628:therapy; D011804:Quinolines; D020127:Recovery of Function / Q000502:physiology; D012038:Regeneration / Q000502:physiology; D013921:Thrombocytopenia / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy; D014184:Transplantation, Homologous / Q000009:adverse effects
D052160:Benzothiazoles; D040201:Platelet Membrane Glycoprotein IIb; D011804:Quinolines; C051000:thiazole orange