Simultaneous use of multiplex ligation-dependent probe amplification assay and flow cytometric DNA ploidy analysis in patients with acute leukemia.

Background: The aim of this work was to simultaneously use multiplex ligation-dependent probe amplification (MLPA) assay and flow cytometric DNA ploidy analysis (FPA) to detect aneuploidy in patients with newly diagnosed acute leukemia.

Methods: MLPA assay and propidium iodide FPA were used to test samples from 53 consecutive patients with newly diagnosed acute leukemia referred to our laboratory for immunophenotyping. Results were compared by nonparametric statistics.

The mutation profile of JAK2, MPL and CALR in Mexican patients with Philadelphia chromosome-negative myeloproliferative neoplasms.

Context And Objective: By using molecular markers, it is possible to gain information on both the classification and etiopathogenesis of chronic myeloproliferative neoplasias (MPN).

Methods: In a group of 27 Mexican mestizo patients with MPNs, we studied seven molecular markers: the BCR/ABL1 fusion gene, the JAK2 V617F mutation, the JAK2 exon 12 mutations, the MPL W515L mutation, the MPL W515K mutation, and the calreticulin (CALR) exon 9 deletion or insertion. Patients with the BCR/ABL1 fusion gene were excluded.

Pharmacogenetic selection of volunteers increases stringency of bioequivalence studies; the case of clopidogrel.

Clinical response to clopidogrel varies widely due to under-dosing, drug interactions and intrinsic interindividual differences resulting from genetic polymorphisms. Cytochrome P450-2C19 is the principal enzyme involved in the activation of the prodrug and loss-of-function alleles have been described. Upon expiration of the pharmaceutical patent of clopidogrel, generic manufacturers have started to subject interchangeable formulations to bioequivalence studies.

Genetic selection of volunteers and concomitant dose adjustment leads to comparable hydralazine/valproate exposure.

What Is Known And Objective: Hydralazine is an inhibitor of DNA methyltransferases, whereas valproate interferes with histone deacetylation. In combination, they show a marked synergism in reducing tumour growth as well as development of metastasis and inducing cell differentiation. Hydralazine is metabolized by the highly polymorphic N-acetyltransferase 2.

Treatment of vitiligo with a chimeric monoclonal antibody to CD20: a pilot study.

Five patients with active disseminated vitiligo were given 1g of a chimeric (murine/human) monoclonal antibody to CD20 in a single intravenous infusion and followed-up for 6 months. Three of the patients showed an overt clinical and histological improvement of the disease, one presented slight improvement and the remaining patient showed no changes. Improvement was neither associated with changes in laboratory parameters nor to a specific human leucocyte antigen D-related (HLA-DR) phenotype.

[Dislocation and necrosis of the first, second and third wedges. Management with the Masquelet technique. A case report].

The induced membrane technique was first described by Masquelet in 1986. It was initially used for the reconstruction of long bone shaft defects, particularly of the femur and tibia. The technique consists of two stages.

Primary thrombophilia in Mexico IX: the glycoprotein IIIa PLA1/A2 polymorphism is not associated with the sticky platelet syndrome phenotype.

Introduction: The sticky platelet syndrome (SPS) seems to be a common cause of thrombosis, although no molecular substrate to explain platelet hyperaggregability has been found.

Objective: To analyze an association between the SPS phenotype and the platelet glycoprotein (GP) IIIa PL(A1/A2) (human platelet antigen [HPA]-1a/b) gene polymorphism.

Methods: Along an 18-month period, Mexican mestizo thrombophilic patients were prospectively accrued.

Primary thrombophilia in México VII: the V617F mutation of JAK2 is not a frequent cause of thrombosis.

The study of the V617F JAK2 gene mutation has been used to identify the presence of an underlying myeloproliferative disorder (MPD) as the cause of unexplained thrombosis. In a group of 77 consecutive Mexican patients with a clinical marker of a primary thrombophilic condition, we looked for this JAK2 mutation and did not find any individual displaying it. Given these results, we conclude that an undetected MPD is a very improbable cause of thromboses in Mexican mestizos, a population where the prevalence of these disorders has been found to be lower than that found in Caucasian populations.

Methotrexate-induced mucositis in acute leukemia patients is not associated with the MTHFR 677T allele in Mexico.

Methylenetetrahydrofolate reductase (MTHFR) has two common variants with reduced activity due to polymorphisms at nucleotides 677 and 1298. Both affect folate metabolism and thus remethylation of homocysteine, but are also thought to affect nucleotide synthesis and DNA methylation. Methotrexate (MTX), which interrupts folate metabolism, is used in the treatment of a variety of diseases including acute lymphoblastic leukemia (ALL), but exerts in some patients toxic effects on fast dividing tissues such as mucosal epithelia.

The Janus Kinase 2 (JAK2) V617F mutation in hematological malignancies in México.

A new mutation (V617F) affecting the JAK2 gene has been recently described as acquired in patients with myeloproliferative disorders and other myeloid malignancies. Using an amplification refractory mutation system, we investigated this mutation in 70 Mexican mestizo patients with hematological malignancies: 28 cases of acute lymphoblastic leukemia, 17 cases of Ph1-positive chronic myelogenous leukemia, 8 patients with acute myelogenous leukemia, 6 patients with chronic lymphocytic leukemia, 6 patients with polycythemia vera (PV), two patients with essential thrombocythemia (ET), one patient with hypereosinophilic syndrome one patient with primary myelofibrosis (MF) and one patient with chronic myelomonocytic leukemia. The mutation was identified in 4 of 6 patients with PV, in one of 2 patients with ET and in the patient with MF.

t(8;21) (q22;q22) acute myelogenous leukemia in Mexico: a single institution experience.

We analyze the prevalence and clinical features of a group of patients with t(8;21) (q22;q22) acute myeloblastic leukemia, identified in a single institution in México over a 10-year period. Fifteen patients presented at the Centro de Hematología y Medicina Interna de Puebla from February 1995 to August 2005; only nine were treated and followed in the institution. Median age was 24 years, (range 7-49); there was only one male.

Clearance of the Janus kinase 2 (JAK2) V617F mutation after allogeneic stem cell transplantation in a patient with myelofibrosis with myeloid metaplasia.

A patient with myelofibrosis with myeloid metaplasia displaying the V617F mutation of the JAK2 gene was given an allogeneic stem cell transplantation using a reduced-intensity conditioning regimen. The patient engrafted, and as he became a chimera, the expression of the V617F mutation of the JAK2 gene decreased progressively until its disappearance. Accordingly, the concept of "molecular remission" of the myelofibrosis with myeloid metaplasia could be entertained and added to the categories of response to treatment which have been recently described.

Molecular characterization of alpha-thalassemia in the Mexican population.

Background: alpha-Thalassemia (alpha-Thal) has been poorly characterized at the molecular level in Mexico.

Methods: 106 consecutive individuals identified in Laboratorios Clínicos de Puebla, with either hypochromia (MCH < 24 pg) and/or microcytosis (MCV < 75 fl in women or < 80 fl in man), without iron deficiency, with or without anemia were investigated in this study, along a 16 month-period. alpha and beta-Thal were looked for, the former were characterized at the molecular level.

HFE-codon 63/282 (H63D/C282Y) gene variants in Mexican Mestizos are not risk factors for leukemia.

Background: In some Caucasian populations it has been found that the C282Y hemochromatosis (HFE) gene mutation is a risk factor for the development of leukemia and other malignancies.

Methods: In a group of 50 Mexican mestizo patients and 153 normal controls, the HFE gene mutations H63D and C282Y were studied by means of ARMS-PCR.

Results: In the group of patients with leukemia we found a heterozygote for the C282Y mutation, seven heterozygotes for the H63D mutation, a double heterozygote for the H63D / C282Y mutation and 41 normal homozygotes.

Treatment of acute promyelocytic leukemia: a single institution experience.

The results of the treatment of 14 patients with promyelocytic leukemia (PML) treated with all trans-retinoic acid (ATRA), combined chemotherapy (CT) and prophylactic prednisone are reported; the median age was 30 years (range 7 - 49). A complete remission (CR) was obtained in 13 / 14 patients (93%). All patients were given ATRA fully as outpatients; the CR was achieved after the administration of ATRA in five patients, whereas in the remaining eight, CT was required to achieve it.

Frequencies of the breakpoint cluster region types of the BCR/ABL fusion gene in Mexican Mestizo patients with chronic myelogenous leukemia.

There is little information about the breakpoint cluster regions of the BCR/ABL fusion gene in Mexican Mestizos with Philadelphia chromosome positive chronic myelogenous leukemia; in a small study a different distribution of these as compared with Caucasians was recently described. We have now prospectively analyzed the breakpoint cluster regions of the BCR/ABL fusion gene in a group of 238 Mexican Mestizos patients with Philadelphia chromosome positive chronic myelogenous leukemia and found a prevalence of 54.2% for the b3/a2 subtype, 43.

Primary thrombophilia in Mexico. V. A comprehensive prospective study indicates that most cases are multifactorial.

Over a 36-month period, 46 consecutive Mexican mestizos with a clinical marker associated with a primary hypercoagulable state were prospectively assessed by searching for the sticky platelet syndrome (SPS), the activated protein C resistance (aPCR) phenotype, coagulation protein C activity and antigen, coagulation protein S, antithrombin III, plasminogen, tissue-type plasminogen activator activity, plasminogen activator inhibitor activity, plasminogen activator inhibitor type 1, IgG and IgM isotypes of antiphospholipid antibodies, homocysteine levels, the factor V gene Leiden, Cambridge, Hong Kong, and Liverpool mutations, the 677 C-->T mutation in the 5,10-methylenetetrahydrofolatereductase (MTHFR), and the G20210A polymorphism in the 3'-untranslated region of the prothrombin gene. Of the 46 consecutive patients prospectively accrued in the study, only 12 (26%) were males, the median age being 38 years (range 10-63 years). In only four individuals (8%) could we not record any abnormality.

More on geographic hematology: the breakpoint cluster regions of the PML/RARalpha fusion gene in Mexican Mestizo patients with promyelocytic leukemia are different from those in Caucasians.

Acute promyelocytic leukemia is characterized the PML/RARalpha chimeric fusion gene, transcript and protein; the breakpoint cluster regions (bcr) in the PML gene may occur in 3 different sites: Intron 6 (bcr1), exon 6 (bcr2) or intron 3 (bcr3). In a 10-year period in a single institution, we studied prospectively the breakpoint cluster regions of the PML/RARalpha fusion gene in 43 Mexican Mestizo patients with APL, and found that the bcr1 represented 62.7%, the bcr2 9.

The Mexican schedule to conduct allogeneic stem cell transplantation is related to a low risk of cytomegalovirus reactivation and disease.

The prevalence of cytomegalovirus (CMV) reactivation and disease after non-myeloablative stem cell transplantation is largely unknown. Using fludarabine combined with alemtuzumab or antithymocyte globulin in the conditioning regimen, some authors have found increased prevalences of CMV disease, whereas other authors using different schedules have observed decreased prevalences. In a group of 17 individuals allografted using the Mexican conditioning regimen, which employs fludarabine, cyclophosphamide, and busulfan, we assessed CMV reactivation, morbidity, and mortality.

[National evaluation of the diagnosis of activated protein C resistance].

Thrombophilia or prothrombotic state appears when activation of blood hemostatic mechanisms overcomes the physiological anticoagulant capacity allowing a thrombotic event. Thrombosis is the leading worldwide mortality cause and due to its high associated morbidity and mortality, it should be insisted in the opportune identification of a thrombophilic state. The study of thrombophilia identifies individuals at high risk for thrombosis.

Follow up of hemopoietic chimerism in individuals given allogeneic hemopoietic stem cell allografts using an immunosuppressive, non-myeloablative conditioning regimen: a prospective study in a single institution.

Thirty consecutive patients were given non-myeloablative stem cell transplants (NST) and posttransplant chimerism was studied by several methods. In 16 individuals definitive proofs of chimerism have been shown: In 10 cases sex chimerism, in 7 cases chimerism shown by means of microsatellites, in 4 cases ABO chimerism, in two cases Rh chimerism and in one HLA-DR chimerism. In addition, in 9 individuals the disappearance of the molecular marker of the leukemia is an indirect evidence of the chimerism, as well as the presence of graft versus host disease (GVHD) in 17 allografted patients.