Circulating megakaryocytic progenitor cells in patients with primary thrombocythaemia and reactive thrombocytosis: results using a serum‐deprived culture assay and a positive detection technique

摘要

Abstract:A serum‐free culture method was used to study the growth of megakaryocytic progenitor cells (CFU‐Meg) from patients with elevated platelet counts. The culture technique was combined with immunocytochemistry (APAAP, CD61) for the identification of CFU‐Meg derived cells in cytopreparations of cells eluted from the culture dishes. Twenty‐six patients with primary thrombocythaemia (14 untreated patients, UPT, 12 treated patients, TPT), 14 patients with reactive thrombocytosis (RT) and 9 normal individuals were studied. Unstimulated growth of CD61‐positive cells was detected in 8/14 UPT, 8/12 TPT, 12/14 RT and 5/9 normal subjects (with mean CD61‐positive cell counts of 75, 579, 236 and 7 per cytopreparation respectively). Cultures supplemented with interleukin 3 contained CD61‐positive cells in 11/14 UPT, 7/12 TPT, 14/14 RT and 5/9 normal subjects (with mean CD61‐positive cell counts of 157, 589, 250 and 7 per cytopreparation respectively). Thus, this serum‐free culture technique combined with sensitive positive identification of CFU‐Meg derived cells failed to discriminate between PT and RT. These results cast doubt on the usefulness of serum‐free culture assays for the detection of unstimulated CFU‐Meg growth in the differential diagnosis of patients with e