Objective: To explore prospective diagnostic criteria for preleukemia.
Methods: A case control study of the discrepancies of clinical and laboratory features between patients with preleukemia and those with chronic aplastic anemia (CAA) or atypical paroxysmal nocturnal hemoglubinuria (a-PNH).
Results: There were eight variables of significance: (1) lymphocytoid micromegakaryocytes in marrow; (2) immature granulocytes in peripheral blood; (3) >or= 2% myeloblasts in marrow; (4) positive periodic acid schiff (PAS) staining of nucleated erythrocytes; (5) myeloid differentiation index >or= 1.8; (6) clonal karyotypic abnormalities; (7) negative sister chromatid differentiation; (8) > 4.0 cluster/colony ratio of granulocyte-macrophage colony-forming units (CFU-GM). The following criteria was assigned: A: To meet (1) and at least two of the other seven variables; B: To meet at least four of the eight variables. All of the patients with preleukemia met A or B and none of the patients with CAA or a-PNH did.
Conclusion: Preleukemia is different from CAA or a-PNH. It has its own clinical and laboratory features, which may be useful for prospective diagnosis.