P-glycoprotein and multidrug resistance-associated protein-1 expression in acute myeloid leukemia: Biological and prognosis implications.

BACKGROUND: Despite the advances in the cure rate for acute myeloid leukemia (AML), a considerable number of patients die from the disease due to the occurrence of multidrug resistance (MDR). Overexpression of the transporter proteins, such as P-glycoprotein (Pgp) and multidrug resistance-associated protein (MRP), confers resistance to the treatment of these leukemias. METHODS: To analyze the expression of the Pgp and MRP1 in patients with AML and determine their correlation between expression and demographic, clinical, and laboratorial variables, bone marrow and peripheral blood samples from 346 patients with a diagnosis of AML were assessed for the expression of Pgp and MRP1 by flow cytometry. RESULTS: The expression of Pgp and MRP1 was found in 111 (32.1%) and 133 (38.4%) patients, respectively, with greater prevalence in older patients and lower in children, while also observing a high incidence in patients with refractory, recurrence, and secondary disease in comparison with the cases of de novo AML. Regarding the laboratory findings, we observed an association between the expression of Pgp and MRP1 and CD34, CD7, and also M7, M5a, and M2-AML of French-American-British classification. CONCLUSIONS: The results showed that the detection of MDR phenotype by flow cytometry can be a molecular marker for prognosis of patients with AML.

Analysis of HFE genes C282Y, H63D, and S65D in patients with hyperferritinemia from northeastern Brazil.

BACKGROUND: Hereditary hemochromatosis (HH) is a genetic disease caused by the high absorption and deposition of iron in several organs. This accumulation results in several clinical complications such as cirrhosis, arthritis, cardiopathies, diabetes, sexual disorders, and skin darkening. The H63D and C282Y mutations are well defined in the HH etiology. The objective of this article is identification of the H63D and C282Y mutations in the HFE protein gene and the frequency assessment of these mutations in patients with persistent increase of serum ferritin in patients from Natal City from state of Rio Grande do Norte, located in northeastern Brazil. RESULTS: Of the 299 patients studied for C282Y and H63D, 48.49% showed absence of mutation and 51.51% showed some sort of mutation: heterozygous C282Y mutation in 4.35% patients, homozygous C282Y mutation in 2.67% patients, heterozygous H63D mutation in 31.44% patients, homozygous H63D mutation in 8.03% patients, and heterozygous for the mutation in both genes (C282Y/H63D) in 5.02% patients. The S65C mutation was studied in 112 patients and heterozygous mutation (S65D/WT) in 2.67% of patients and double mutation (H63D/S65C) in 1.78% of patients were observed. CONCLUSION: Due to the high prevalence of hemochromatosis, its genetic diagnosis has become a challenge, especially in the high-risk group.

Banding cytogenetic analysis in pediatric patients with acute lymphoblastic leukemia (ALL) in a Brazilian population.

BACKGROUND: Cytogenetic studies in Brazilian population about childhood acute lymphoblastic leukemia (ALL), the most common childhood malignancy, are scarce. Moreover, Brazilian race is very heterogeneous and is made by the confluence of people of several different origins, from the original Native Brazilians, with the influx of Portuguese colonizers, Black African slaves, and recent European, Arab and Japanese immigration. The purpose of this prospective, multicentric study was to assess the sociodemographic, clinic and cytogenetic characteristics of the children treated for ALL in the Northeast region of Brazil. RESULTS: This study includes thirty patients between 4 months and 17 years old treated for ALL from January 1st, 2009 to November 30th, 2010. Cytogenetic analysis showed that in nineteen out of thirty patients (64%) presented some chromosome abnormalities, in which 53% corresponds to numerical abnormalities, 21% structural and numerical abnormalities, and 26% only structural changes. Moreover, seven patients presented complexes karyotype not yet described in the literature. Taken together these results show the importance of the cytogenetic analysis in ALL pediatric patients and illustrates that the studied population presented unexpected complexes karyotypes which were correlated to poor outcome. CONCLUSION: The results demonstrate the importance of banding cytogenetics for ALL diagnosis despite the use of most modern techniques such as FISH and aCGH, and provide reliable insight into the ALL in Brazil.

Flow cytometry immunophenotyping evaluation in acute lymphoblastic leukemia: correlation to factors affecting clinic outcome.

The authors conducted a flow cytometry immunophenotyping study in patients with acute lymphoblastic leukemia (ALL) from Natal, Rio Grande do Norte, Brazil. The patients (n = 126) were newly diagnosed using a panel of monoclonal antibodies: CD1a, CD2, CD3, CD4, CD7, CD8, CD10, CD13, CD33, CD14, CD19, CD22, CD79a, CD117, CD34, anti-IgM, anti-TdT, anti-HLA-Dr, and anti-human kappa and lambda light chains. Additional data, such as patients' age and gender, clinical and laboratory findings such as presence of tumor masses, lymphadenopathy, hepatomegaly, splenomegaly, leukemic infiltration in the central nervous system (CNS) were also investigated. Results showed that 56.7% of the cases were B-lineage ALL and 55% were T-cell ALL. Also, we found that males were more affected by the disease, regardless of immunological classification. The correlation between age and immunological subtypes showed that the B-lineage ALL occurred more frequently in patients aged under 15 while the T-cell ALL subtype was more frequent in adults. Immunophenotypic profiles and morphological subtypes showed a direct correlation between L3 subtype and B-lineage ALL, while L1 and L2 subtypes correlated more often with B-cell lineage and T-cell ALL, respectively. Correlation analysis between immunophenotypic and clinical profiles showed that T-cell ALL was more associated with a higher incidence of lymphadenopathy, hepatomegaly, splenomegaly and CNS leukemic infiltration, also showing a greater blast cell count in peripheral blood than the other subgroups. The presented data suggest that immunophenotyping is an important method in the diagnosis, monitoring and prognostic assessment in determining the pathological mechanisms of evolution of ALL.