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1.
Rev Clin Esp (Barc) ; 220(1): 31-42, 2020.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31783987

RESUMO

Iron deficiency due to blood loss, absorption disorders and dietary deficiencies causes iron-deficiency anaemia, whose treatment seeks to eliminate the underlying cause and restore haemoglobin and iron deposits. Typically, the latter 2 of these objectives can be achieved through oral iron therapy. Intravenous iron administration (IIA) should be limited to those patients refractory or intolerant to oral preparations or who require rapid repletion. The indiscriminate use of IIA can increase morbidity and mortality due to iatrogenic overload. This fact, coupled with the growing popularity of IIA and the lack of reference guidelines in Spanish, led the Spanish Erythropathology Group of the Spanish Society of Haematology and Haemotherapy to develop this study, which presents the main recommendations on the optimal use of IIA in iron deficiency and attempts to constitute reference guidelines on good practices for the clinical management of these conditions.

2.
Int J Lab Hematol ; 37(5): 641-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25959209

RESUMO

INTRODUCTION: The relationship between iron deficiency and vitamin B12 and folate was recognized several decades ago. Combined deficiency is important in clinical practice owing to its relationship with malabsorption syndromes. By contrast, iron deficiency and low levels of serum vitamin B12 with normal metabolic markers were often found mostly in young adults. In this work, vitamin B12/folate changes were investigated during treatment of iron deficiency anaemia (IDA) with pharmacological iron in young adult women. METHODS: A cohort of 35 young adult women with IDA was treated with oral iron. An haematological response was obtained in 97.2% at 4-month follow-up. Changes in serum vitamin B12, serum folate and other biochemical parameters were monitored. RESULTS: Treatment with iron increased significantly serum folate and vitamin B12 from baseline. This increase was also observed in vitamin B12 levels ≤200 pmol/L (six patients, 17.1%), in whom serum vitamin B12 was above 200 pmol/L at the end of the study in all cases. Other biochemical parameters also changed. Significant increases were seen for glucose (P = 0.012), uric acid (P < 0.001), total cholesterol (P = 0.023), HDL cholesterol (P = 0.026) and bilirubin (P < 0.001). Urea decreased significantly (P = 0.036). CONCLUSIONS: Data from our work suggest that iron deficiency could affect many metabolic pathways, including vitamin B12, folate and lipids. These changes normalize after iron therapy, even in women with baseline low levels of serum vitamin B12. Healthcare practitioners should be aware of these changes in IDA management. The mechanisms controlling these changes remain to be explained, but they are probably related to the control of iron homeostasis (iron deficiency mediated stimuli).


Assuntos
Anemia Ferropriva/sangue , Ácido Fólico/sangue , Vitamina B 12/sangue , Adolescente , Adulto , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/tratamento farmacológico , Biomarcadores , Contagem de Células Sanguíneas , Análise Química do Sangue , Estudos de Casos e Controles , Ingestão de Energia , Feminino , Compostos Ferrosos/uso terapêutico , Seguimentos , Humanos , Masculino , Resultado do Tratamento , Adulto Jovem
3.
Int J Lab Hematol ; 36(1): 92-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23998297

RESUMO

INTRODUCTION: Patients with persistent high levels of serum vitamin B12 were often referred to Hematology departments. In this study, characteristic of patients with serum vitamin B12 levels higher than 2500 pmol/L (high B12) were studied. METHODS: Prevalence of high B12 was evaluated during a 10-month period. Samples with high B12 were incubated with polyethylene glycol (PEG) and a new measurement of vitamin B12 was carried out using the supernatant. As a pilot study, 26 frozen samples with high B12 were evaluated for changes in vitamin B12 after PEG. Moreover, a prospective study was carried out during three consecutive months. Size exclusion chromatography was employed to demonstrate the presence of immune complexes (ICs) with plasma vitamin B12-binding proteins in some serum samples with high B12. RESULTS: Prevalence of high B12 was 1.3%. Results from 26 frozen samples and from a prospective study (28 cases) showed that undergoing vitamin B12 treatment was the main cause of high B12. However, ICs were detected in 10 frozen samples and in seven cases (25%) of the prospective study, respectively. Serum vitamin B12 decreased to normal values after precipitation with PEG, and size exclusion chromatography confirmed ICs. An association with autoimmune or hematological disorders was observed. CONCLUSIONS: In patients with repeatedly high B12 levels, ICs were detected in approximately 25% of samples. Precipitation with PEG is an easy method to confirm the presence of ICs and to evaluate serum vitamin B12 levels in these patients.


Assuntos
Anemia Ferropriva/sangue , Complexo Antígeno-Anticorpo/isolamento & purificação , Artrite Reumatoide/sangue , Autoanticorpos/sangue , Neoplasias Hematológicas/sangue , Vitamina B 12/sangue , Idoso , Idoso de 80 Anos ou mais , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/imunologia , Complexo Antígeno-Anticorpo/sangue , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/epidemiologia , Artrite Reumatoide/imunologia , Feminino , Congelamento , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/epidemiologia , Neoplasias Hematológicas/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Polietilenoglicóis/química , Prevalência , Estudos Prospectivos , Espanha/epidemiologia , Vitamina B 12/administração & dosagem , Vitamina B 12/imunologia
4.
Ann Hematol ; 93(4): 565-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24057896

RESUMO

Plasma holotranscobalamin (holoTC) transports active cobalamin. Decreased levels of holoTC have been considered to be the earliest marker of cobalamin (Cbl) deficiency. In this work, holoTC was evaluated in low or borderline serum Cbl (LB12) and a concordance analysis was carried out with methylmalonic acid (MMA) and homocysteine (Hcy). Levels of Cbl, holoTC, MMA, and Hcy were investigated in a reference group in 106 patients with LB12 (≤200 pmol/l) and in 27 with folate deficiency (FOL). HoloTC levels were evaluated by an automated immunoassay (Active B12, Abbott Lab, Abbott Park, IL, USA). Lower levels of holoTC were observed in both LB12 and FOL groups (reference group vs LB12; p < 0.0001. Reference group vs FOL; p = 0.002). HoloTC levels were lower in LB12 than in FOL (p = 0.001). In LB12, concordance between Hcy and MMA was 82.1 % (chi-square test, p < 0.001; Kappa Index, 0.64, p < 0.0001). Concordance between Hcy and holoTC was 62 % (chi-square test, p = 0.006; Kappa index, 0.245, p = 0.006). Concordance between holoTC and MMA was 55.6 % (p = 0.233). Some cases with LB12 and elevated MMA did not show decreased holoTC. By contrast, MMA and Hcy were not increased in some patients with low holoTC and LB12. In conclusion, levels of holoTC were decreased in LB12 and FOL. In LB12 patients, holoTC concordance with MMA was poor. MMA/Hcy levels were not increased in a significant number of subjects with LB12 and low holoTC. This profile was found in iron deficiency. The significance of these changes remains to be clarified.


Assuntos
Homocisteína/sangue , Ácido Metilmalônico/sangue , Transcobalaminas/metabolismo , Deficiência de Vitamina B 12/sangue , Deficiência de Vitamina B 12/diagnóstico , Vitamina B 12/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
Curr Med Res Opin ; 27(5): 951-60, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21381892

RESUMO

BACKGROUND: Current guidelines support the use of erythropoiesis-stimulating agents for the treatment of anemia associated with low-risk myelodysplastic syndromes (MDS). DESIGN AND METHODS: Single-arm, open-label, multi-center, phase 2 trial that evaluated the efficacy and safety of darbepoetin alfa (DA) in patients with low or intermediate-risk MDS, hemoglobin <100 g/L, erythropoietin (EPO) levels <500 IU/L and transfusion requirements <2 units/month over the preceding 2 months. Erythroid response (major [MaR] or minor [MiR]) and fatigue (Functional Assessment of Cancer Therapy-Fatigue [FACT-F]) were evaluated at 8, 16 and 24 weeks. DA was initiated at 300 µg weekly. For patients who did not achieve MaR by 8 weeks, filgrastim 300 µg weekly was added. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01039350. RESULTS: Forty-four patients (72.7% transfusion independent) were included. Median age was 76.0 years (range 41.3-92.4), 54.5% were male, and 90.9% presented ECOG Status (0-1). Eighteen patients received filgrastim. An erythroid response was achieved by 31 of 44 patients (70.5%) at week 8 (47.7% MaR, 22.7% MiR), 31 of 44 patients (70.5%) at week 16 (61.4% MaR, 9.1% MiR), and 32 of 44 patients (72.7%) at week 24 (61.3% MaR, 11.4% MiR). Mean (95% CI) change in FACT-F at week 24 was 3.61 (0.72 to 6.51). Baseline EPO levels <100 IU/L were a predictive factor of response. DA was well tolerated. Four mild (two iron deficiencies, flu syndrome and headache) and one fatal (thromboembolic event) adverse events were considered related to darbepoetin alfa. CONCLUSIONS: A fixed dose of 300 µg of darbepoetin alfa weekly (with or without filgrastim) seems to be an effective and safe treatment for anemic patients with low or intermediate-risk MDS, low transfusion burden and EPO levels <500 IU/L. Results may not be extrapolable to unselected MDS patients.


Assuntos
Anemia/tratamento farmacológico , Eritropoetina/análogos & derivados , Hematínicos/administração & dosagem , Síndromes Mielodisplásicas/tratamento farmacológico , Adulto , Idoso , Anemia/sangue , Anemia/mortalidade , Darbepoetina alfa , Eritropoetina/administração & dosagem , Eritropoetina/efeitos adversos , Eritropoetina/sangue , Feminino , Hematínicos/efeitos adversos , Hemoglobinas/análise , Hemoglobinas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/mortalidade , Fatores de Risco
7.
Bone Marrow Transplant ; 34(6): 505-9, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15286693

RESUMO

Iron overload is associated with free radical generation and tissue damage. Our main objective was to ascertain the frequency and severity of iron overload in a group of 59 patients who died after conventional-intensity autologous (n=24) or allogeneic (n=35) haematopoietic stem cell transplantation (HSCT). A second objective was to investigate associations between liver-iron concentration and causes of transplant-related mortality. The median age was 41 years (range, 19-66), 41 were males and 18 females. In total, 26 patients had acute leukaemia or MDS, 10 CML, 17 lymphoma, four myeloma and two aplastic anaemia. The median hepatic iron concentration (HIC) was 138 micromol/g dry weight (7.7 mg/g; range 31-631 micromol/g). In total, 4/32 (12%) patients with HIC <150 micromol/g and 10/27 (37%) with hepatic iron > or =150 micromol/g showed invasive aspergillosis at autopsy (P=0.035). This was significant in multivariate analysis (RR 9.0; 95% CI 1.6-50.3, P=0.012). In conclusion, severe iron overload is frequent in patients who die following HSCT and is associated with invasive aspergillosis.


Assuntos
Aspergilose/epidemiologia , Sobrecarga de Ferro/epidemiologia , Hepatopatias/epidemiologia , Transplante de Células-Tronco/efeitos adversos , Adulto , Idoso , Aspergilose/complicações , Feminino , Humanos , Sobrecarga de Ferro/complicações , Leucemia/terapia , Hepatopatias/complicações , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/terapia , Estudos Retrospectivos , Espanha
8.
Histopathology ; 45(3): 268-74, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15330805

RESUMO

AIM: To determine the efficacy of flow cytometry (FC) in the assessment of bone marrow (BM) in B-cell non-Hodgkin lymphoma (B-NHL). FC is a common practice, but is far from being validated. METHODS AND RESULTS: Morphological analysis and FC immunophenotyping were performed on 421 samples. T-cell lymphomas, Hodgkin's disease, chronic lymphocytic leukaemia and hairy cell leukaemia were not included in the study. Clonality was assessed by the standard kappa/lambda/CD19 test. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. A double-step procedure was employed in all cases to increase the sensitivity of the FC procedure. Of 380 evaluable samples, 188 corresponded to follicular lymphoma (FL), 58 to diffuse large B-cell lymphoma (DLBCL), 57 to mantle cell lymphoma (MCL), seven to Burkitt's lymphoma and the remaining 70 samples to other low-grade lymphomas. Morphological marrow infiltration was found in 148 cases, and flow immunophenotyping identified 138 cases with BM involvement. A concordance between the two methods was detected in 298 cases (79%). There was a discordance in 82 cases (21%): morphology positive/FC negative in 46 cases and morphology negative/FC positive in 36 (61% of all cases with discordance were from FL). There was no difference in outcome when patients with discordances were compared with patients without discordances. CONCLUSIONS: Most samples showed concordance between morphological and FC results. FC identified BM involvement in the absence of morphological infiltration. Morphology/FC discordance seems to have no influence on the outcome of FL patients.


Assuntos
Medula Óssea/patologia , Citometria de Fluxo/métodos , Linfoma de Células B/patologia , Linfoma não Hodgkin/patologia , Medula Óssea/imunologia , Intervalo Livre de Doença , Humanos , Imunofenotipagem , Linfoma de Células B/imunologia , Linfoma não Hodgkin/imunologia , Análise Multivariada , Prognóstico
9.
J Immunol Methods ; 295(1-2): 89-99, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15627614

RESUMO

Soluble transferrin receptor (sTfR) has been proposed as an indirect biomarker of the misuse of recombinant human erythropoietin in sport. An extended validation of four commercially available immunoassays for its measurement in serum is presented. Two ELISA techniques (ELISA1: Orion Diagnostica; ELISA2: R&D Systems), an immunoturbidimetric technique (Turbid: Roche Diagnostics), and a nephelometric technique (Nephel: Dade Behring) were investigated. Intra-laboratory precision better than 3% and correct accuracies were obtained for the Turbid and Nephel techniques using autoanalysers. Slightly worse precision (but always better than 11%) and correct accuracies were also obtained in almost all cases for the two ELISA techniques. Inter-laboratory results showed higher concordances for the ELISA procedures (intraclass correlation coefficients of 0.848 for ELISA1 and 0.973 for ELISA2 which was clearly better). Inter-technique correlations were good for the four techniques with lower dispersions found for the techniques using autoanalysers, i.e. Turbid and Nephel. While Turbid and ELISA1 results (expressed in mg/l) were comparable, results obtained with Nephel were approximately 2.7 times lower. The relationship between those three techniques was maintained when compared with ELISA2, which uses different units (nmol/l). We conclude that ELISA2 and Nephel in our hands were the most suitable techniques in terms of sensitivity, precision and accuracy, and adequacy of the calibration curve for the measurement of sTfR in real serum samples. Discrepancies observed in the results obtained with the different sTfR techniques showed that different reference standards were used and harmonization is recommended in order to obtain comparable results.


Assuntos
Biomarcadores/sangue , Dopagem Esportivo , Eritropoetina/farmacologia , Imunoensaio , Receptores da Transferrina/sangue , Ensaio de Imunoadsorção Enzimática , Humanos , Receptores da Transferrina/efeitos dos fármacos , Proteínas Recombinantes , Sensibilidade e Especificidade
10.
Ann Hematol ; 82(2): 127-130, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12601495

RESUMO

Biochemical iron overload (IO) is a frequent metabolic abnormality. It may be caused by several diseases, and data regarding the relative frequency of these are scant. A single diagnostic protocol including clinical, biochemical, and genetic data was used to diagnose the cause of biochemical IO in a group of 150 patients referred by general practitioners. Severe alterations of the HFE gene (42 patients, 28%), hepatitis C virus infection (33 patients, 22%), and dysmetabolic syndrome with iron overload (DSIO) (22 patients, 15%) emerged as the main causes, and other single causes were found in 20 patients (13%). In 19 patients (13%), multiple causes of IO were found, and in 14 patients no cause was found, 5 of whom had classical criteria of genetic hemochromatosis (GH) without HFE mutations. Transferrin saturation index (TSI) had a very low positive predictive value (0.16) for GH among patients with biochemical IO in this setting. In conclusion, 90% of patients with biochemical IO were diagnosed with a specific disorder. GH, hepatitis C infection, and DSIO were the major causes, and a large group of patients had multiple causes of IO. TSI is not a useful indicator of GH in patients referred by general practitioners.


Assuntos
Sobrecarga de Ferro/etiologia , Adulto , Idoso , Estudos de Coortes , Feminino , Hemocromatose/complicações , Hemocromatose/genética , Proteína da Hemocromatose , Hepatite C/complicações , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Incidência , Distúrbios do Metabolismo do Ferro/complicações , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/epidemiologia , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Transferrina/metabolismo
11.
Ann Hematol ; 81(11): 616-21, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12454698

RESUMO

A number of studies have identified elevated levels of homocysteine (Hcy) as a risk factor for thrombosis. Given the relationship between Hcy and thrombosis, a high prevalence of thrombosis would be expected in patients with megaloblastic anemia. The aim of our study was to determine whether an acquired vitamin B12/folate deficiency is a risk factor for thrombosis. A retrospective case and control study was performed that included 193 cases with reduced levels of vitamin B12/folate. The cases were divided initially into two groups (105 with serum vitamin B12 < or =150 pmol/l and/or low red cell folate < or = 450 nmol/l and 88 with serum vitamin B12 between 150 and 200 pmol/l and/or red cell folate between 450 and 590 nmol/l). The control group consisted of 87 additional patients who had normal levels of serum vitamin B12, red cell folate, and normal renal function. Serum Hcy, thrombotic events, and risk factors were evaluated in all participants. Eight patients (9%) in the control group had had previous vascular events although only three of these events (37.5%) were observed between the vitamin study and 2 years prior to the study. In the case group, 20% of the patients had a history of thrombosis. In contrast with controls, 85% of cases suffered thrombosis between the time they were diagnosed and 2 years prior to the time they were diagnosed as showing a vitamin deficiency. Multivariate analysis demonstrated that vitamin deficiency was a significant risk factor for arterial thrombosis [adjusted odds ratio (OR) 3.3, confidence interval (CI) 1.1-10.2]. However, when hyperhomocysteinemia was included in the analysis, vitamin deficiency was no longer a risk factor, suggesting that hyperhomocysteinemia was responsible for arterial thrombotic risk in these patients (adjusted OR 2.5, CI 1.1-5.8). As a consequence of hyperhomocysteinemia, patients with acquired vitamin deficiency of vitamin B12/folate had a high risk of thrombosis. However, a more extensive study that controls risk variables and genetic factors is needed to sort out the various contributing factors.


Assuntos
Deficiência de Ácido Fólico/complicações , Hiper-Homocisteinemia/complicações , Trombose/etiologia , Deficiência de Vitamina B 12/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Deficiência de Ácido Fólico/epidemiologia , Humanos , Hiper-Homocisteinemia/epidemiologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prevalência , Análise de Regressão , Estudos Retrospectivos , Fatores de Risco , Trombose/sangue , Trombose/epidemiologia , Fatores de Tempo , Deficiência de Vitamina B 12/epidemiologia
12.
Bone Marrow Transplant ; 29(12): 987-9, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12098067

RESUMO

Iron overload (IO) is associated with free radical generation and tissue damage. Our main objective was to ascertain if very high levels (VHL) of ferritin (>/=3000 microg/l) and transferrin saturation (TS) >/=100% during conditioning had an impact on overall survival (OS) and transplant-related mortality (TRM) after a haematopoietic stem cell transplantation (HSCT). Levels of ferritin and TS were measured at days -7 and -4, respectively, in 25 patients who underwent HSCT after CY/TBI. The group consisted of 20 men and five women with a median age of 40 years. Fifteen patients were autotransplanted and 10 allotransplanted. Nine of them had a diagnosis of AL, six of CML and 10 of lymphoma. Thirteen of them were in early and 12 in advanced status of disease. VHL of ferritin and TS >/=100% were associated with a decreased OS (P = 0.001 and P = 0.006, respectively) and an increased TRM (P = 0.003 and P = 0.004, respectively) in univariate survival analysis. Both variables remained significant at multivariate analysis for OS (P = 0.03 and 0.02, respectively) and TS was an independent factor for TRM (P = 0.01). Ferritin was very close to achieving statistical significance for TRM (P = 0.06) in multivariate analysis. In conclusion, VHL of ferritin and TS >/=100% at conditioning are associated with an increase in toxic deaths after transplant.


Assuntos
Transplante de Células-Tronco Hematopoéticas/mortalidade , Sobrecarga de Ferro/mortalidade , Adolescente , Adulto , Transplante de Medula Óssea/mortalidade , Ciclofosfamida/uso terapêutico , Feminino , Ferritinas/sangue , Neoplasias Hematológicas/sangue , Neoplasias Hematológicas/mortalidade , Neoplasias Hematológicas/terapia , Humanos , Sobrecarga de Ferro/sangue , Masculino , Pessoa de Meia-Idade , Transplante de Células-Tronco de Sangue Periférico/mortalidade , Estudos Prospectivos , Fatores de Risco , Análise de Sobrevida , Irradiação Corporal Total
13.
Blood ; 97(4): 1106-14, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11159544

RESUMO

Cytochrome b(5) reductase (b5R) deficiency manifests itself in 2 distinct ways. In methemoglobinemia type I, the patients only suffer from cyanosis, whereas in type II, the patients suffer in addition from severe mental retardation and neurologic impairment. Biochemical data indicate that this may be due to a difference in mutations, causing enzyme instability in type I and complete enzyme deficiency or enzyme inactivation in type II. We have investigated 7 families with methemoglobulinemia type I and found 7 novel mutations in the b5R gene. Six of these mutations predicted amino acid substitutions at sites not involved in reduced nicotinamide adenine dinucleotide (NADH) or flavin adenine dinucleotide (FAD) binding, as deduced from a 3-dimensional model of human b5R. This model was constructed from comparison with the known 3-dimensional structure of pig b5R. The seventh mutation was a splice site mutation leading to skipping of exon 5 in messenger RNA, present in heterozygous form in a patient together with a missense mutation on the other allele. Eight other amino acid substitutions, previously described to cause methemoglobinemia type I, were also situated in nonessential regions of the enzyme. In contrast, 2 other substitutions, known to cause the type II form of the disease, were found to directly affect the consensus FAD-binding site or indirectly influence NADH binding. Thus, these data support the idea that enzyme inactivation is a cause of the type II disease, whereas enzyme instability may lead to the type I form.


Assuntos
Substituição de Aminoácidos , Redutases do Citocromo/genética , Metemoglobinemia/genética , Mutação Puntual , Adulto , Sequência de Aminoácidos , Sítios de Ligação , Criança , Consanguinidade , Redutases do Citocromo/química , Citocromo-B(5) Redutase , DNA Complementar/genética , Éxons/genética , Feminino , Flavina-Adenina Dinucleotídeo/metabolismo , Genótipo , Humanos , Masculino , Metemoglobinemia/classificação , Metemoglobinemia/enzimologia , Modelos Moleculares , Dados de Sequência Molecular , NAD/metabolismo , Linhagem , Conformação Proteica , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
14.
Haematologica ; 85(12): 1324-5, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11114141

RESUMO

Hereditary hemochromatosis is related to mutations of the HFE gene. The role of the S65C mutation of this gene was evaluated in a Spanish population, consisting of 100 controls and 41 patients who had resulted positive to screening for iron overload. Only one patient was heterozygous for the S65C mutation, so the S65C mutation is infrequent in our area. Nevertheless, it is advisable to search for this mutation in cases with iron overload and heterozygosity for the C282Y or H63D mutations of the HFE gene.


Assuntos
Hemocromatose/epidemiologia , Hemocromatose/genética , Sobrecarga de Ferro/genética , Proteínas de Membrana , Estudos de Casos e Controles , Testes Genéticos , Antígenos HLA/genética , Hemocromatose/diagnóstico , Proteína da Hemocromatose , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Mutação Puntual , Espanha/epidemiologia
17.
Haematologica ; 84(12): 1058-64, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10586205

RESUMO

BACKGROUND AND OBJECTIVE: Anemia leading to transfusion is probably the most important problem in patients with myelodysplastic syndromes (MDS). Human recombinant erythropoietin (rHuEpo) and granulocyte colony-stimulating factor (G-CSF) have been used to treat patients with anemia of MDS, but fewer than 50% respond. The aim of this work was to evaluate the benefit of rHuEpo +/- G-CSF treatment and to isolate the response predictive variables in a group of selected patients with MDS. DESIGN AND METHODS: A non-randomized multicenter trial was carried out in 32 patients with MDS. The inclusion criteria were age >= 18 years, refractory anemia (RA) or refractory anemia with ringed sideroblasts, Hb <= 100 g/L or receiving transfusions and serum erythropoietin <= 250 U/L. These patients were treated with subcutaneous rHuEpo (300 U/kg) three times a week for 8 weeks. In the case of partial response (PR) or no response (NR) subcutaneosly administered G-CSF (1 microg/kg) three times a week was added to the rHuEpo for 8 more weeks. If the patient achieved complete response (CR) or PR in the second phase, he was included in a follow-up phase of 24 weeks in which the dose of growth factors was tapered down. Several variables, including the score published by the Scandinavian-American group, were used as possible predictive variables. RESULTS: An erythroid response was observed in 16 patients (50%); in 12 it was a CR and in 4 it was a PR. During the period of rHuEpo administration, 7 CR and 4 PR (34.4%) were documented. Of the 14 patients in whom G-CSF was added to rHuEpo, 7 (50%) responded (3 CR and 4 PR). No major side-effects associated with growth factors were observed. The multivariate analysis showed that of the different variables evaluated only the Scandinavian-American response score was significant with a relative probability of response of 11.8 (95% confident intervals: 2.5-53) when this score was > +1 (77% of cases responded). In contrast, when this score was <= 1 only 15 % of the cases responded. INTERPRETATION AND CONCLUSIONS: Use of the Scandinavian-American response score is to be recommended in a patient-oriented approach to treating MDS cases with the Epo and G-CSF. Treatment with rHuEpo and G-CSF is safe, its main drawback being its cost. However, a long-term study evaluating the regimen's cost-benefit ratio is warranted.


Assuntos
Eritropoetina/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Síndromes Mielodisplásicas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Valor Preditivo dos Testes , Proteínas Recombinantes/uso terapêutico
20.
Semin Hematol ; 36(1): 75-87, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9930570

RESUMO

Serum vitamin B12 levels are often low in human immunodeficiency virus (HIV)-infected patients. However, only a few patients appear to have actual vitamin B12 deficiency. A low red cell folate level accompanying the low vitamin B12 level makes the presence of vitamin B12 deficiency more likely. Our experience suggests that a low red cell folate level always indicates deficiency, but does not differentiate between vitamin B12 and folate deficiency. The deoxyuridine suppression test and the assay of serum or plasma total homocysteine and/or of methylmalonic acid levels can also be useful in the identification of patients with true vitamin B12 deficiency. HIV-positive patients frequently have absorption disorders, including vitamin B12 malabsorption. However, the correlation between vitamin B12 malabsorption and serum vitamin B12 and plasma homocysteine levels is poor. Abnormalities in vitamin B12-binding proteins, which are often found in HIV-positive patients, may explain many cases of low vitamin B12 levels. Current evidence suggests that low vitamin B12 levels are more common as the HIV disease progresses. The results of vitamin B12 treatment have been disappointing thus far, including the prevention of toxicity induced by azidothymidine. The possible role of vitamin B12 treatment in the long-term survival of HIV-infected patients is at present unknown. However, it is important to identify those patients who have real vitamin B12 deficiency to treat or prevent their hematologic and/or neurological symptoms.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Deficiência de Vitamina B 12/complicações , Eritrócitos/metabolismo , Ácido Fólico/sangue , Homocisteína/sangue , Humanos , Síndromes de Malabsorção/complicações , Doenças do Sistema Nervoso/complicações , Prognóstico , Deficiência de Vitamina B 12/epidemiologia
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