Elevated serum endostatin levels is associated with favorable outcome in acute myeloid leukemia

INTRODUCTION

Endostatin is the C-terminal antiangiogenic fragment of the extracellular matrix protein collagen XVIII, and is generated by tumor-derived proteases. The levels and the prognostic relevance of serum endostatin in AML patient is not fully clear.

AIM

To evaluate serum levels of endostatin in acute myeloid leukemia patients before chemotherapy and after achieving complete remission and to correlate endostatin levels with patients outcome.

MATERIALS AND METHODS

Serum samples from 30 adult patients (22 males and 8 females, median age 37, range 19-66 years) with AML had been taken before chemotherapy was administered. In addition 20 out of 30 patients were reinvestigated again at complete remission (CR). Ten samples from healthy normal persons of matched age and sex were evaluated as a reference control group. Serum endostatin levels were determined using enzyme linked immune sorbent assay (ELISA).

RESULTS

Endostatin serum levels were not significantly different in the pretreatment AML patients as compared to that in normal controls (P>0.05). In AML patients the baseline endostatin levels were significantly lower than at CR (P=0.001). No significant correlation were detected between pretreatment serum endostatin levels and age, peripheral blood white cell counts, platelet counts, bone marrow blast cell counts, blast cell distribution ratio. The prognostic value of sE was also evaluated by dividing AML patients into high and low sE groups using the 75 percentile sE levels of the patients group as cutoff. The authors found that patients group in the high sE group survived for significantly longer time than those patients in the low sE group.

CONCLUSIONS

Elevated endostatin levels at AML diagnosis is a good prognostic marker for patients' outcome. Wide scale study is recommended in order to establish the clinical value of this study.

Angiogenesis factor pattern differs in acute lymphoblastic leukemia and chronic lymphocytic leukemia

Angiogenesis is an important event in the survival and progression of solid tumors. The angiogenic status and the exact role of the angiogenic cytokines in lymphoid leukemia has not been fully elucidated. We have investigated the profile of the systemic components of angiogenic regulation in B-lineage acute lymphoblastic leukemia (B-ALL) and B-chronic lymphocytic leukemia (B-CLL), namely vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), endostatin and matrix metalloproteinase-9 (MMP-9) using enzyme-linked immunosorbent assay (ELISA). In B-ALL patients, sVEGF, and MMP-9 were significantly lower than control levels at diagnosis (p < 0.001) and increased to near control levels in remission (p>0.05). Both serum TNF-alpha and endostatin levels showed no significant difference at diagnosis (p>0.05) and in remission (p>0.05) compared to control levels. VEGF, TNF-alpha, MMP-9 and endostatin levels were not significantly correlated with peripheral white cell count or bone marrow blast cell count, but were positively correlated with platelet count. In B-CLL patients, serum VEGF, MMP-9 and TNF-alpha were significantly higher (p < 0.001 = 0.009, 0.007, respectively) and decreased to near control levels in remission (p>0.05 for all). Serum endostatin levels showed no significant difference at diagnosis and in remission compared to control levels (p>0.05). A significant positive correlation between VEGF, TNF-alpha, MMP-9 and peripheral white cell counts, bone marrow lymphocytic count and platelets count were found. In conclusion, our data suggest that the driving forces of angiogenic factors (VEGF, TNF-alpha and MMP-9) in adult B-ALL appears different from that in B-CLL patients.

Pneumococcal antigen in pneumonia. A post-mortem study with the histological and bacteriological findings

Pneumococcal capsular antigens can be detected in lung tissue by counter-current immunoelectrophoresis even when, following antibiotics, post-mortem bacterilogy suggests that Escherichia coli has replaced pneumococci. The results suggest that antipneumococcal therapy would benefit at least 55% of patients critically ill with lung infection and that the potentially toxic drugs directed at coliform bacteria may be unnecessary.

Counter-current immunoelectrophoresis for the diagnosis of pneumococcal chest infection

Counter-current immunoelectrohporesis is a rapid sensitive method for detecting pneumococcal capsular antigens in sputum. A result can be obtained within 45 minutes. The optimum conditions for performing the test are given. Counter-current immunoelectrophoresis works with all the 33 pneumococcal antigens tested except type 14. Better precipitin lines are obtained when the gel-support is acid (pH 6-6) than when it is alkaline (pH 8-6). Omniserum is as effective as group-specific sera for the identification of pneumococcal capsular antigens. The findings suggest that pneumococcal infection was present in 44% of 300 unselected suspected chest infections. Culture for pneumococci was positive in only 15% of these cases. The clinical importance of these findings is still being studied but our experience has shown that patients with chest infections should have effective antipneumococcal antibiotics as part of their regimen and that the laboratory diagnosis may be made quickly and accurately by counter-current immunoelectrophoresis.