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Guillermo J Ruiz-Argüelles

Publications and source records attributed to Guillermo J Ruiz-Argüelles.

At least 19 recordsLinked to original sources
PubMed2007

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.

Biomarkers↗
PubMed2006

Allografting in patients with severe, refractory aplastic anemia using peripheral blood stem cells and a fludarabine-based conditioning regimen: the Mexican experience.

We studied the effectiveness of a fludarabine/cyclophosphamide-based conditioning regimen without anti-thymocyte globulin in 23 aplastic anemia patients who had no response to previous conventional pharmacologic treatment. Patients received oral busulphan 4 mg/kg/day/2 days, IV cyclophosphamide 350 mg/m(2)/day/3 days, and fludarabine 30 mg/m(2)/day/3 days. For GVHD prophylaxis, patients received MTX 5 mg/m(2) days +1, +3, +6, and +11 and oral cyclosporin A (CyA) 5 mg/kg/day, starting on day -1. Peripheral blood stem cell products were used with a median dose of 5.5 x 10(6) CD34(+)/kg. The patients were followed for an average of 25 months. By a median of day +11, an ANC > 0.5 x 10(9)/L was reached; and by day +12, the platelet count had reached >20,000 x 10(9)/L. Acute grade I-II GVHD occurred in 4 patients, whereas limited chronic GVHD presented in 6 cases. Twenty-one patients (91.3%) achieved engraftment. Two patients failed to engraft, and 4 developed late rejection; 2 of these individuals died, 2 have survived with high transfusion requirements, whereas 2 received a second peripheral blood stem cell infusion and achieved sustained engraftment. Currently 21 (91%) of the 23 patients are alive, whereas 19 of 21 (90%) remain in complete remission. The average cost was about USD 15,000 for this kind of reduced-intensity allotransplant. Reduced-intensity stem cell transplantation represents an affordable alternative to traditional more cytotoxic conditioning for severe aplastic anemia (SAA) patients. Long-term effects however, remain to be evaluated.

Adolescent↗
PubMed2006

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. These data are not different from those observed in normal controls, where the allele frequencies were 0.062 and 0.013 for the H63D and C282Y HFE gene mutations, respectively. CONCLUSIONS: These HFE gene mutations are not risk factors for the development of leukemia in Mexican mestizos.

Adolescent↗
PubMed2006

Altered functional status of the hypothalamic dopaminergic tone in patients with chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation: a pilot study.

We compared the functional status of the hypothalamic dopaminergic tone in patients given an allogeneic hematopoietic stem cell transplantation (allo-HSCT) with chronic graft-versus-host disease (GVHD) with that observed in patients with allo-HSCT without chronic GVHD and in healthy controls. The effect of acute dopaminergic blockade with intravenous metoclopramide on serum prolactin (PRL) concentrations was evaluated. Twenty volunteers, 20 to 52 years of age, seronegative for both hepatitis C virus and the human immunodeficiency virus, were studied: (1) 10 clinically healthy men (group 1), and (2) 9 patients with leukemia, and 1 patient with refractory aplastic anemia who underwent allo-HSCT, 5 of whom (3 men and 2 women) developed chronic GVHD (group 2), and 5 (3 men and 2 women) who did not develop chronic GVHD (group 3). Serum PRL concentrations were measured both fasting and after intravenous administration of metoclopramide (10-mg bolus). The area under the PRL curve was calculated. Patients in group 2 were older than those in groups 1 and 3 (P<.018), but their body mass index was similar. Fasting serum PRL concentrations were similar among the 3 groups; however, group 2 had higher PRL concentrations throughout the test (P<.001) and a greater area under the PRL curve than groups 1 and 3 (P<.001), without differences between the last 2 groups. The differences remained significant after adjustment for age (P<.01). Our results in a small group of patients with chronic GVHD after allo-HSCT suggest the existence of an increased functional level of their hypothalamic dopamine tone, which would favor a tendency toward a diminished endogenous production, release of pituitary PRL, or both. This could represent an adaptive mechanism aiming to maintain circulating PRL concentrations within a physiological range.

Adult↗
PubMed2006

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. According to the French-American-British (FAB) morphological classification of leukemia, the morphology was M2 in four cases, M4 in three cases, M3 in one case and M0 in one. In addition to the myeloid markers, lymphoid markers were identified in 6 patients. Patients were induced to remission with combined chemotherapy and three subsequently underwent bone marrow transplantation (BMT). The median overall and disease-free survival has not been reached, being above 3390 days, the probability of survival at this time was 73%. In this single-center experience in México, we found that the t(8;21) (q22;q22) variant of leukemia was more frequent than in Caucasian populations, that the co-expression of lymphoid markers in the blast cells is very frequent and that this malignancy is associated with a relatively good prognosis.

Acute Disease↗
PubMed2006

Transient mixed chimerism after stem cell transplantation can induce durable molecular complete remissions in chronic myelogenous leukemia.

Three patients with BCR/ABL+ chronic myelogenous leukemia were allografted, two with unrelated compatible placental blood and one from a human leukocyte antigen compatible sibling. The patients engrafted successfully, achieved mixed chimerism and all cleared the BCR/ABL fusion transcript. Despíte the fact that the three patients lost the chimerism, they have remained in complete molecular remissions 9 months, 16 months and 5 years, respectively, after the allografts. It is possible that the transient induction of a graft-vs.-leukemia effect was able to control the malignancy despite the fact that the three patients lost the graft; however, other possible explanations are discussed. A longer follow-up of the patients is mandatory to further clarify these observations.

Adult↗
PubMed2005

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. In 5/42 patients with abnormal results (12%), a single abnormality was recorded, whereas in the remaining 37, two to five co-existing abnormalities were identified. We found 22 (48%) patients with the SPS, 11 (24%) with the aPCR phenotype, 5 (11%) with the factor V Leiden mutation, 7 (15%) with the prothrombin gene mutation, 29 (63%) with the MTHFR gene mutation, 11 (24%) with the factor V HR2 haplotype, 11 (24%) with antiphospholipid antibodies, 4 (9%) with PS deficiency, 6 (13%) with PC deficiency, one with the FV Hong Kong mutation, and one with AT-III deficiency. The results are consonant with the idea that most cases of thrombophilia in Mexico are multifactorial.

Adolescent↗
PubMed2005

Gilbert's syndrome disclosed during the treatment of hematological malignancies.

Gilbert's syndrome (GS) is a benign, familial condition characterized by recurrent asymptomatic non-hemolytic low-grade indirect hyper-bilirubinemia. Conditions related to fasting, stress or co-morbidity might reveal the disease in asymptomatic individuals. Seven patients who were treated for a hematological malignancy were identified with reversible indirect hyper-bilirubinemia. Liver function tests in all of them, including bilirubin levels were normal before the therapeutic maneuver, which was the delivery of combined chemotherapy in three cases and a bone marrow transplantation in four (three allografts and one autograft). Bilirubin levels returned to normal in all five patients following treatment. GS should not be overlooked in individuals exposed to these treatments who develop hyperbilirubinemia and jaundice.

Adolescent↗
PubMed2005

Extramedullary leukemic relapses following hematopoietic stem cell transplantation with nonmyeloablative conditioning.

Of a group of 149 patients who underwent allogeneic stem cell transplantation using the "Mexican approach", a nonablative preparative regimen, 49 individuals developed bone marrow relapse, and 8 patients developed extramedullary relapse (EMR). All EMR cases presented in patients who received allografts for myeloid malignancies. In contrast, bone marrow relapses presented in patients with myeloid or lymphoid malignancies. EMR presented 60 to 1010 days after the allograft and appeared in 3 cases as subcutaneous nodules in different parts of the body, in the vertebrae in 3 cases, and in the kidney and the breast in 1 case each. One patient had both subcutaneous nodules and epididymis EMR. When EMR was noted, acute graft-versus-host disease (GVHD) had presented in 4 patients, and limited forms of chronic GVHD were present in 3 patients. All but 1 of the patients were full chimeras when the EMR ensued, and the EMR preceded an overt hematologic relapse in all but 1 of the patients. Patients who experienced an overt hematologic relapse died 20 to 180 days (median, 40 days) after the EMR. The only individual alive 240 days after relapse shows no evidence of a full-blown hematologic relapse. An EMR after allogeneic hematopoietic stem cell transplantation usually has a bad prognosis and presents mainly in individuals with high-risk malignancies.

Adult↗
PubMed2004

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. Before transplant, IgG anti-CMV antibodies were found in 11 patients and in 10 donors; in 8 cases, both donor and patient had IgG anti-CMV antibodies. In only one case (6%) was CMV mRNA identified 30 days after the allograft during grade IV acute graft-versus-host disease. CMV reactivation, disease, and mortality were very low using our non-myeloablative stem cell transplantation schedule, which has been shown to be useful for allografting with minimal toxicity and reduced costs.

Adolescent↗
PubMed2004

Allogeneic hematopoietic stem cell transplantation with non-myeloablative conditioning in patients with acute myelogenous leukemia eligible for conventional allografting: a prospective study.

Using a non-myeloablative stem cell trasplantation (NST) program, 25 allografts were prospectively given to 24 patients with acute myelogenous leukemia (AML) eligible for conventional allografting; 2 individuals had secondary forms of AML. The median age of the patients was 35 years, with a range of 12 to 56. All patients engrafted; median time to achieve an absolute neutrophil count > 0.5 x 10(9)/1 was 12 days (range 0-26), whereas the median time to a platelet count > 20 x 10(9)/1 was 13 days (range 0-26). Patients developed mixed chimerism 15 to 100 (median 30) days after the allograft. The follow-up periods range between 33 and 2670 days (median 450). The median post-transplant overall survival of the patients has not been reached and is above 89 months, whereas the 683 days both overall and progression-free survival is 66%. In 14 grafts (56%) acute GVHD ensued; in 12 cases grades I-II and in 2 cases grade IV which was fatal in both. In 9/19 patients (47%) limited chronic GVHD developed. In 22 cases (88%), the procedure could be completed fully on an outpatient basis. The 100-day and the transplant-related mortality were both 8%. NST appears to be an effective additional therapeutic option for patients with AML in remission and a matched donor available.

Adolescent↗
PubMed2004

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 9.3% whereas the bcr3 27.9%. The prevalence of the bcr1 subtype is significantly higher than that informed in Caucasians and similar to that in Asians; these data are consonant with those described in other Latin-American patients with APL. Since other Asian genetic markers have been found in the Indian component of the Mexican mestizos, it is possible that the Asian immigration into the Americas through the strait of Behring 12,000 years ago may account for a possible genetic susceptibility to suffer certain forms of APL.

Asia↗
PubMed2004

Breaking dogmata to help patients: non-myeloablative haematopoietic stem cell transplantation.

Various dogmata have been broken as a consequence of the evolution of knowledge in the area of allogeneic haematopoietic stem cell (HSC) transplantation. The following is now clear: for the successful engraftment of allogeneic HSC, bone marrow ablation of the recipient is not required; HSCs create their own space through graft-versus-host reactions; several malignancies can be eradicated by the graft-versus-tumour effect; HSC allografting can be conducted on an out-patient basis; HSC allografting can be done in aged or debilitated individuals; HSC allografting can be achieved without transfusion of blood products; and the costs of the allografting procedures can be substantially diminished. Despite the fact that HSC allografting with reduced intensity conditioning may be related to several disadvantages, such as mixed chimaerism and relapse of the malignancy, breaking these dogmata has resulted in availability of HSC allografting to a larger number of individuals worldwide, thus offering true curative therapeutic options to patients who otherwise would not qualify to be given these opportunities.

Animals↗