Presence of CD34+ in Megakaryocytes in Association With p53 Expression Predicts Unfavorable Prognosis in Low-risk Myelodysplastic Syndrome Patients.

BACKGROUND/AIM: Although risk stratification using the Prognostic Scores Systems (IPSS, WPSS and IPSS-R) incorporate key information about prognosis of patients with Myelodysplastic syndromes (MDS), patients classified as low-risk may evolve rapidly and aggressively, despite a "favorable" prognostic stratification. The aim of this study was to identify biomarkers for predicting prognosis, and for better stratification and management of these patients. MATERIALS AND METHODS: Expression of CD34 and p53 in megakaryocytes was examined by immunohistochemistry in 71 MDS patients classified as low-risk. RESULTS: CD34 staining in megakaryocytes was associated with p53 expression (p=0.0166). CD34 and p53 expression were associated to worse overall survival in patients (p=0.0281). CONCLUSION: The presence of CD34 in megakaryocytes is associated with p53 expression and an adverse prognosis for MDS patients.

The Effect of a Selective Inhibitor of Phosphodiesterase-9 on Oxidative Stress, Inflammation and Cytotoxicity in Neutrophils from Patients with Sickle Cell Anaemia.

The aim of the study was to investigate the possible anti-inflammatory and antioxidant effects of BAY 73-6691 on neutrophils from SCA patients. This study included 35 patients with a molecular diagnosis of SCA, whose neutrophils were isolated and treated with BAY 73-6691 at the concentrations 100, 10, 1.0 and 0.1 µg/mL. LDH release and MTT assays were performed to verify cell viability. To evaluate oxidative stress, the following parameters were determined by spectrophotometric assays: NO and malondialdehyde (MDA) levels and activity of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx). As inflammatory markers, myeloperoxidase (MPO) levels were evaluated by colorimetric assay and TNF-α by enzyme immunoassay. The results showed that neutrophils from SCA patients not treated with hydroxyurea (HU) had significantly lower NO levels and catalase and SOD activity, as well as significantly higher MDA, MPO and TNF-α levels when compared with neutrophils from SCA patients treated with HU and neutrophils from control group. Treatment of SCA neutrophils with BAY 73-6691 resulted in 94%, 200% and 168% increase in NOx levels, SOD and catalase activity, respectively. In addition, there was a reduction of approximately 46% and 45% in TNF-α and MPO levels, respectively. In SCAHU neutrophils, there was a 30% and 44% increase in NOx levels and SOD activity, respectively, and a 28% and 37% decrease in TNF-α and MPO levels, respectively. However, these effects were observed at cytotoxic doses only. The results of this study are original and demonstrate that inhibition of phosphodiesterase-9 in neutrophils from SCA patients with BAY 73-6691 was able to increase the NO bioavailability and attenuate oxidative stress and inflammation in neutrophils from patients not treated with HU.

Tumor suppressor p53 protein expression: prognostic significance in patients with low-risk myelodysplastic syndrome.

BACKGROUND: At the time of diagnosis, more than 50% of patients with myelodysplastic syndrome have a normal karyotype and are classified as having a favorable prognosis. However, these patients often show very variable clinical outcomes. Furthermore, current diagnostic tools lack the ability to look at genetic factors beyond karyotyping in order to determine the cause of this variability. OBJECTIVE: To evaluate the impact of p53 protein expression at diagnosis in patients with low-risk myelodysplastic syndrome. METHODS: This study enrolled 38 patients diagnosed with low-risk myelodysplastic syndrome. Clinical data were collected by reviewing medical records, and immunohistochemical p53 staining was performed on bone marrow biopsies. RESULTS: Of the 38 participants, 13 (34.21%) showed p53 expression in their bone marrow. At diagnosis, this group of patients also presented clinical features characteristic of a poor prognosis more often than patients who did not express p53. Furthermore, patients expressing p53 had a shorter median survival time compared to those without p53 expression. CONCLUSION: This study shows that the expression of p53 at diagnosis is a useful indicator of distinct clinical characteristics and laboratory profiles found in low-risk myelodysplastic syndrome patients. These data indicate that the immunohistochemical analysis of p53 may be a prognostic tool for myelodysplastic syndrome and should be used as an auxiliary test to help determine the best therapeutic choice.