Purpose: The transcription factor CCAAT/enhancer binding protein α, encoded by the CEBPA, is crucial for the differentiation of immature granulocytes. Mutation of the CEBPA may play an important role in leukemogenesis and prognosis. We sought to characterize the CEBPA mutation in acute myeloid leukemia (AML) and to clarify if there is a distinct immunophenotype for leukemic cells with the mutation. Experiment Design: One hundred and four patients with de novo AML were evaluated for the CEBPA mutation and immunophenotype of the leukemic cells. Results: Twenty-two distinct mutations were identified in 16 (15%) of 104 AML patients. Fourteen patients had biallelic mutations, mostly involving both the NH2-terminal TAD1 region and the COOH-terminal basic leucine zipper domain (bZIP). The mutations in the bZIP region were always tandem duplications and were located at hot-spot regions for topoisomerase II sites. Sequential study of the CEBPA mutations showed that the mutations disappeared at complete remission but the same mutations reappeared at relapse. None of the patients developed novel mutations during the follow-up period. Patients with CEBPA mutations had significantly higher incidences of CD7 (73%), CD15 (100%), CD34 (93%), and HLA-DR (93%) expression on the leukemic cells. Conclusion: These data revealed that most AML with CEBPA mutations were associated with an immunophenotype of HLA-DR+CD7+CD13+CD14−CD15+CD33+CD34+. The close relationship of CEBPA mutations with the leukemia status of the patients and the concordance of mutation in presenting and relapse samples implicate the CEBPA mutation as a potential marker for monitoring minimal residue disease.

Nucleophosmin (NPM) mutations have been found in a significant proportion of adults with de novo acute myeloid leukemia (AML), especially in those of a normal karyotype. These results provide a basis for studies of the pathogenesis in this specific subgroup of AML. In this study, NPM mutations were analyzed in 173 Chinese patients of de novo AML, including adults and children. We found that NPM mutations were present in 19.1% of the overall population and 40.3% of those with a normal karyotype. Adults had a significantly higher incidence of NPM mutations than children [32 of 126 (25.4%) versus 1 of 47 (2.1%), P < 0.001]. NPM mutations were closely associated with normal karyotype (P < 0.001) and internal tandem duplication of FLT3 (P = 0.002), but negatively associated with CEBPA mutations (P = 0.032) and expression of CD34 (P < 0.001) and HLA-DR (P = 0.003). Serial analyses of NPM mutations showed the mutation disappeared at complete remission, but the same mutation reappeared at relapse, except for one who lost the mutation at the second relapse, when new cytogenetic abnormalities emerged. None acquired novel mutations during the follow-up period. In conclusion, NPM mutations occur in an age-dependent fashion. Moreover, the findings that NPM mutations are stable during disease evolution and closely associated with disease status make it a potential marker for monitoring minimal residual disease. (Cancer Res 2006; 66(6): 3310-6)

Summary: CD4⁺ CD25⁺ regulatory T cells (Tregs) are critical in maintaining self‐tolerance and preventing organ‐specific autoimmunity. Their role in paediatric systemic lupus erythematosus (SLE), an autoimmune disease characterized by inappropriate regulation of hyperactivated B and T cells, has not been clearly defined. Using flow cytometry to determine cell populations and real‐time polymerase chain reaction to assay mRNA expression for FOXP3, CTLA‐4, and GITR, we characterized CD4⁺ CD25⁺ T cells in paediatric SLE patients and healthy subjects. The frequency of CD4⁺ CD25⁺ Tregs was significantly decreased in patients with active SLE compared with patients with inactive SLE and with controls (7·27% ± 2·50%, 9·59% ± 2·80% and 9·78% ± 2·11%, respectively; P = 0·027 and P < 0·001, respectively), and was inversely correlated with disease activity, as assessed with the Systemic Lupus Erythematosus Disease Activity Index 2000 scores (r = −0·59, P = 0·001) and serum anti‐double‐stranded DNA levels (r = −0·65, P < 0·001). Our preliminary investigations found elevated surface expression of GITR in CD4⁺ CD25⁺ T cells, elevated mRNA expression of CTLA‐4 in CD4⁺ T cells and higher amounts of mRNA expression for FOXP3 in CD4⁺ cells in patients with active SLE compared with patients with inactive disease and controls. We demonstrated reduced CD4⁺ CD25⁺ Treg levels were inversely correlated with disease activity, indicating a defective Treg population in paediatric SLE patients. The differences in the expression of FOXP3, CTLA‐4 and GITR imply the possible role of CD4⁺ Tregs in the pathogenesis of SLE.

Purpose: To investigate the possible prognostic factors of survival outcomes in patients with granulocytic sarcoma (GS). Methods: We retrospectively investigated the prognostic factors determining survival in 24 patients with GS using Kaplan-Meier survival analysis followed by log rank tests. We evaluated gender, age, location, GS antedating leukemia, underlying disorders, treatment type and stem cell transplantation. Results: The 5-year survival rate for the patients with GS was 21%. The patients undergoing chemotherapy had a significantly longer survival time compared to those who did not (p = 0.0009). We found no difference in the 5-year survival rate among the patients undergoing chemotherapy combined with radiation or surgery. Patients with chronic myelogenous leukemia and myelodysplastic disorders had worse survival rates (p = 0.0028). Conclusion: Early diagnosis with biopsy and early chemotherapy can improve survival outcome. Local radiation or surgery can improve symptoms but does not influence survival outcomes.

Summary. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were demonstrated to have important implications in the progression and invasiveness of many malignant disorders. In contrast, the biological significance of these molecules in human leukaemias is not clear. We determined the levels of MMP‐2, MMP‐9, TIMP‐1 and TIMP‐2 in the bone marrow of 37 patients with acute myelogenous leukaemia (AML) and 18 patients with acute lymphoblastic leukaemia (ALL) before chemotherapy. Nineteen bone marrow donors served as normal controls. After chemotherapy, sequential measurements were done during the course in 19 AML patients. The levels of TIMP‐1 and TIMP‐2 were significantly higher and MMP‐9 levels were significantly lower in the AML and ALL patients than in the normal controls. MMP‐2 levels were higher in ALL, but not AML patients, compared with controls. Moreover, the levels of marrow MMP‐2 and MMP‐9 did not parallel the numbers of leukaemic blasts in the peripheral blood. MMP‐9 levels were significantly lower in the AML patients who achieved a complete remission (CR) than in those who did not (8·71 ± 8·15 ng/ml vs 26·13 ± 27·75 ng/ml, P < 0·05). The AML patients with lower MMP‐9 levels (≤ 4·4 ng/ml) tended to have longer survival time than those with higher levels (> 12 months vs 4 months, P = 0·12). In addition, MMP‐9 levels in the AML patients at CR rose to the same range as the controls, but dropped again at relapse, demonstrating a close relationship of marrow MMP‐9 with disease status of AML. Therefore, we conclude that the level of marrow MMP‐9 may be a useful surrogate marker for monitoring disease status in AML and propose it as a potential prognostic factor.