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1.
Int J Mol Sci ; 25(3)2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38338786

RESUMO

In vivo iron levels can be adjusted through intestinal iron absorption to be maintained at a suitable level; however, optimal iron levels in hemodialysis (HD) patients are unclear. In this study, we investigated total body iron (TBI), calculated as the sum of red blood cell (RBC) iron and iron stores, during courses of low-dose oral iron replacement therapy, and evaluated in vivo iron sufficiency and its indicators in HD patients. We analyzed data on 105 courses of low-dose iron replacement therapy administered to 83 patients on maintenance HD over 7 months. We evaluated changes in TBI, RBC iron, and iron stores from the initiation of treatment to month 7 in two groups of patients, namely, iron-therapy responders and non-responders. TBI showed significant increases until month 4 and plateaued thereafter in iron-therapy responders, and tended to increase and then reached a similar plateau in non-responders (month 7: 1900 ± 447 vs. 1900 ± 408 mg). Steady-state TBI was strongly correlated with body surface area (y = 1628.6x - 791.91, R2 = 0.88, p < 0.001). We observed constant TBI during oral iron replacement therapy suggesting the activation of a "mucosal block". The results suggest that body surface area has utility for estimating the required TBI with regression equations.


Assuntos
Anemia Ferropriva , Eritropoetina , Falência Renal Crônica , Humanos , Ferro/metabolismo , Estudos Retrospectivos , Ferritinas , Diálise Renal/efeitos adversos , Anemia Ferropriva/tratamento farmacológico , Eritropoetina/metabolismo , Falência Renal Crônica/etiologia , Hemoglobinas/metabolismo
2.
Int J Mol Sci ; 24(18)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37762085

RESUMO

Oral ferric citrate hydrate (FCH) is effective for iron deficiencies in hemodialysis patients; however, how iron balance in the body affects iron absorption in the intestinal tract remains unclear. This prospective observational study (Riona-Oral Iron Absorption Trial, R-OIAT, UMIN 000031406) was conducted at 42 hemodialysis centers in Japan, wherein 268 hemodialysis patients without inflammation were enrolled and treated with a fixed amount of FCH for 6 months. We assessed the predictive value of hepcidin-25 for iron absorption and iron shift between ferritin (FTN) and red blood cells (RBCs) following FCH therapy. Serum iron changes at 2 h (ΔFe2h) after FCH ingestion were evaluated as iron absorption. The primary outcome was the quantitative delineation of iron variables with respect to ΔFe2h, and the secondary outcome was the description of the predictors of the body's iron balance. Generalized estimating equations (GEEs) were used to identify the determinants of iron absorption during each phase of FCH treatment. ΔFe2h increased when hepcidin-25 and TSAT decreased (-0.459, -0.643 to -0.276, p = 0.000; -0.648, -1.099 to -0.197, p = 0.005, respectively) in GEEs. FTN increased when RBCs decreased (-1.392, -1.749 to -1.035, p = 0.000) and hepcidin-25 increased (0.297, 0.239 to 0.355, p = 0.000). Limiting erythropoiesis to maintain hemoglobin levels induces RBC reduction in hemodialysis patients, resulting in increased hepcidin-25 and FTN levels. Hepcidin-25 production may prompt an iron shift from RBC iron to FTN iron, inhibiting iron absorption even with continued FCH intake.


Assuntos
Compostos Férricos , Hepcidinas , Humanos , Compostos Férricos/farmacologia , Ferritinas , Ferro , Estudos Prospectivos , Diálise Renal
3.
Int J Mol Sci ; 24(3)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36769359

RESUMO

The production of erythropoietin (EPO), the main regulator of erythroid differentiation, is regulated by hypoxia-inducible factor (HIF). HIF2α seems to be the principal regulator of EPO transcription, but HIF1α and 3α also may have additional influences on erythroid maturation. HIF is also involved in the regulation of iron, an essential component in erythropoiesis. Iron is essential for the organism but is also highly toxic, so its absorption and retention are strictly controlled. HIF also induces the synthesis of proteins involved in iron regulation, thereby ensuring the availability of iron necessary for hematopoiesis. Iron is a major component of hemoglobin and is also involved in erythrocyte differentiation and proliferation and in the regulation of HIF. Renal anemia is a condition in which there is a lack of stimulation of EPO synthesis due to decreased HIF expression. HIF prolyl hydroxylase inhibitors (HIF-PHIs) stabilize HIF and thereby allow it to be potent under normoxic conditions. Therefore, unlike erythropoiesis-stimulating agents, HIF-PHI may enhance iron absorption from the intestinal tract and iron supply from reticuloendothelial macrophages and hepatocytes into the plasma, thus facilitating the availability of iron for hematopoiesis. The only HIF-PHI currently on the market worldwide is roxadustat, but in Japan, five products are available. Clinical studies to date in Japan have also shown that HIF-PHIs not only promote hematopoiesis, but also decrease hepcidin, the main regulator of iron metabolism, and increase the total iron-binding capacity (TIBC), which indicates the iron transport capacity. However, concerns about the systemic effects of HIF-PHIs have not been completely dispelled, warranting further careful monitoring.


Assuntos
Anemia , Eritropoetina , Inibidores de Prolil-Hidrolase , Insuficiência Renal Crônica , Humanos , Inibidores de Prolil-Hidrolase/farmacologia , Prolil Hidroxilases , Anemia/metabolismo , Ferro/metabolismo , Eritropoetina/metabolismo , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia , Hipóxia , Insuficiência Renal Crônica/metabolismo
4.
Acta Haematol ; 145(4): 412-418, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35051929

RESUMO

INTRODUCTION: Hypoxia-inducible factor prolyl hydroxylase domain inhibitors (HIF-PHI) are a new treatment for renal anemia. HIF-PHI is believed to increase iron usage to improve availability of iron for erythropoiesis. Therefore, there is concern that HIF-PHI might be prone to iron deficiency and that thrombosis might be induced by increased platelet and transferrin levels due to this iron deficiency. METHODS: Relationship of iron-related factors with platelet count (PLT) and total iron-binding capacity (TIBC; which reflects the transferrin level) were examined in 29 patients who were treated with darbepoetin alfa (DA) and then switched to roxadustat (Rox). To determine how changes in PLT and TIBC related to changes in iron-related factors, univariable and multivariable linear regression models were applied. To examine what iron-related factors on Day 0 influenced change in PLT, we used receiver operating characteristic (ROC) curves and logistic regression analysis for a rate of change in PLT ≤0% as the endpoint. Logistic regression analysis was performed with the reference group having serum ferritin (s-ft) or Transferrin saturation below the corresponding cutoff value (low vs. high). RESULTS: Multivariable analysis showed significant positive correlations between the rate of change in PLT and the change in s-ft and red blood cells (RBC) count {ß-coefficients; 0.40 [95% confidence interval (CI): 0.17-0.62], p = 0.001} (ß-coefficients; 30.45 [95% CI: 10.90-50.00], p = 0.004). The rate of change in TIBC was significantly positively correlated with only the change in RBC count. The ROC showed a significant cutoff value for s-ft of 77.2 ng/mL (sensitivity 63.6%, specificity 83.3%, area under the curve 0.76, 95% CI 0.55-0.96). Multivariable logistic regression also showed that only high s-ft was significantly elevated (9.46, 95% CI 1.42-63.30, p = 0.020). CONCLUSIONS: This study showed that changes in PLT were correlated with s-ft and amount of hematopoiesis. This suggests that an increase in PLT due to iron levels is less likely when s-ft is 77.2 ng/mL or higher at the time of switching from DA to Rox. In contrast, TIBC was only related to hematopoiesis in these patients. Control of s-ft before initiation of HIF-PHI treatment and gradual hematopoiesis might reduce the risk of thrombosis when switching from erythropoiesis-stimulating agents to HIF-PHI.


Assuntos
Inibidores de Prolil-Hidrolase , Insuficiência Renal Crônica , Darbepoetina alfa , Ferritinas , Humanos , Hipóxia , Ferro , Prolil Hidroxilases , Inibidores de Prolil-Hidrolase/uso terapêutico , Insuficiência Renal Crônica/terapia , Transferrinas
5.
Nutrients ; 15(1)2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36615783

RESUMO

Western guidelines recommend the use of intravenous iron supplementation for hemodialysis patients. However, in Japanese patients with well-controlled inflammation, iron replacement may be achieved with oral iron supplementation. This study involved 108 courses in 77 outpatient hemodialysis patients who received low-dose oral iron replacement therapy. Data from baseline to week 28 of treatment were analyzed to identify factors associated with effectiveness. Changes over time in erythrocyte- and iron-related parameters and erythropoiesis-stimulating agent (ESA) dose were investigated in the effective group. A total of 84 courses (77.8%) satisfied the effectiveness criteria. Compared with the effective and ineffective groups, only C-reactive protein (CRP) was significantly different (p < 0.01). ROC curve analysis with efficacy as the endpoint showed a CRP cut point value of ≤0.1 mg/dL (area under the curve, 0.69; 95% confidence interval, 0.57−0.81). The relationship between serum ferritin and hemoglobin fluctuation by reducing the ESA dose showed a positive correlation (p < 0.001). In the ESA maintenance group, the serum ferritin gradually increased and then remained constant at about 60 ng/mL. Our data suggest that patients with CRP ≤ 0.1 mg/dL may benefit from low doses of oral iron supplementation. Approximately 60 ng/mL serum ferritin may be sufficient during stable hematopoiesis.


Assuntos
Hematínicos , Falência Renal Crônica , Humanos , Proteína C-Reativa/metabolismo , População do Leste Asiático , Ferritinas , Hemoglobinas/metabolismo , Ferro , Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Japão
6.
PLoS One ; 16(6): e0252439, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34143801

RESUMO

BACKGROUND: Hypoxia-inducible factor (HIF) prolyl hydroxylase domain inhibitors, which have recently become clinically available for treating renal anemia, are attracting attention for their novel mechanisms of action. METHODS: Relationships of reticulocyte hemoglobin content (CHr), which reflects recent Hb synthesis, with serum ferritin (s-ft) and transferrin saturation (TSAT) were examined in 30 patients on hemodialysis after switching from darbepoetin alfa (DA) to roxadustat (Rox). Iron deficiency was defined as CHr < 32.0 pg. Cutoff values of s-ft and TSAT were determined using receiver operating characteristic curves for the endpoint CHr ≥ 32.0 pg. Logistic analysis was performed with the reference group having s-ft or TSAT below the corresponding cutoff value (low vs high). RESULTS: With the endpoint CHr ≥ 32.0 pg on Day 0, cutoff values for s-ft and TSAT were respectively 49.7 ng/mL and 21.6% on Day 0 and 35.5 ng/mL and 16.2% on Day 28. With the endpoint CHr ≥ 32.0 pg on Day 28, cutoff values for s-ft and TSAT on Day 0 were 81.6 ng/mL and 23.9%, respectively. According to multivariable logistic analysis, the odds ratios of CHr ≥ 32.0 pg on Day 0 were significantly higher for high TSAT on Day 0 [34.7 (95% CI 2.42-131.0), p<0.003] and Day 28 [24.8 (95% CI 2.75-224.0), p = 0.004]. There were no significant differences by s-ft. Odd ratios of CHr ≥ 32.0 pg on Day 28 were also significantly higher for high s-ft on Day 0 [16.0 (95% CI 1.57-163.0), p = 0.019] and high TSAT on Day 0 [13.5 (95% CI 1.24-147.0), p<0.033]. CONCLUSIONS: Our results suggest Hb synthesis was maintained with lower TSAT and s-ft during Rox therapy compared with DA therapy. To avoid iron deficiency during the 4 weeks after switching DA to Rox, ideal s-ft and TSAT levels before the switch are 81.6 ng/mL and 23.9%, respectively.


Assuntos
Darbepoetina alfa/sangue , Ferritinas/sangue , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Idoso , Feminino , Hemoglobinas/metabolismo , Hepcidinas/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores de Prolil-Hidrolase/uso terapêutico , Transferrina/metabolismo
7.
Int J Mol Sci ; 21(19)2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32998272

RESUMO

Roxadustat (Rox), a hypoxia-inducible factor (HIF) stabilizer, is now available for the treatment of anemia in hemodialysis (HD) patients. To investigate hematopoietic effect and iron metabolism, this study involved 30 HD patients who were initially treated with darbepoetin (DA), a conventional erythropoietin-stimulating agent, and then switched to Rox. We measured erythrocyte, reticulocyte indices, and iron-related factors at every HD during the first two weeks after the treatment switch (Days 0-14) and again on Days 21 and 28. We measured erythropoietin (EPO) concentration every week and examined their changes from Day-0 values. The same variables were measured in 15 HD patients who continued DA at every HD for one week. Iron-related factors were also measured on Days 14 and 28. In the Rox group, hepcidin significantly decreased from Day 2. The reticulocyte hemoglobin content (CHr) significantly increased on Day 4, but decreased with a significant increase in reticulocyte count from Day 7. Log10(serum ferritin) significantly decreased after Day 11. Log10(EPO concentration) was lower at all time points. Compared with the DA group, the Rox group showed significant differences in all variables except CHr. These results suggest that Rox improves hematopoiesis and iron metabolism early after administration independent of EPO concentration.


Assuntos
Anemia/tratamento farmacológico , Darbepoetina alfa/uso terapêutico , Glicina/análogos & derivados , Hematínicos/uso terapêutico , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Ferro/metabolismo , Isoquinolinas/uso terapêutico , Insuficiência Renal Crônica/terapia , Idoso , Idoso de 80 Anos ou mais , Anemia/etiologia , Anemia/genética , Anemia/patologia , Contagem de Células , Substituição de Medicamentos , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Eritropoetina/genética , Eritropoetina/metabolismo , Feminino , Ferritinas/genética , Ferritinas/metabolismo , Regulação da Expressão Gênica , Glicina/uso terapêutico , Hematopoese/efeitos dos fármacos , Hematopoese/genética , Hemoglobinas/genética , Hemoglobinas/metabolismo , Hepcidinas/genética , Hepcidinas/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/agonistas , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Pessoa de Meia-Idade , Diálise Renal , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/fisiopatologia , Reticulócitos/efeitos dos fármacos , Reticulócitos/metabolismo , Transferrina/genética , Transferrina/metabolismo , Resultado do Tratamento
8.
PLoS One ; 15(9): e0238763, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941454

RESUMO

BACKGROUND: Recent studies have found hypomagnesemia is linked to a heightened risk of cardiovascular events and mortality in hemodialysis (HD) patients; however, the level of serum magnesium (s-Mg) necessary for promoting overall health in these patients and the effects of s-Mg in diabetes HD patients remains to be clarified. METHODS: HD outpatients (n = 148 under, age ≤ 70 y) were followed over a 6-y period. They were divided into four groups according to their average s-Mg during the first year (L; low level, H; high level) and if they had DM or not (non-DM). The endpoint was mortality and hospitalization for decline of Activities of Daily Living (death/hospitalization). A receiver operating characteristics curve was used in diagnostic tests to identify s-Mg associated with this endpoint. Kaplan-Meier, log-rank test, and a Cox proportional hazards model were used to evaluate prognoses. Fisher's exact test and multiple regressions examined the causes of the endpoints between the four groups and the factors predictive of s-Mg. RESULTS: s-Mg at 2.7 mg/dL was associated with death/hospitalization. The 5-y survival rate was 38.1%, 86.7%, 73.2% and 87.5%, in the DM/Mg(L), DM/Mg(H), non-DM/Mg(L) and non-DM/Mg(H) groups, respectively (P < 0.001). The Cox proportional hazards model showed significantly lower risk in other groups compared with that in the DM/Mg(L) group [DM/Mg(H); hazard ratio (HR): 0.22, 95% confidence interval (CI): 0.05-0.97, P = 0.046, non-DM/Mg(L); HR: 0.32, 95% CI: 0.15-0.68, P = 0.003, non-DM/Mg(H); HR: 0.17, 95% CI: 0.06-0.44, P < 0.001]. The frequency of the different causes of the endpoints for each group was not significant; s-Mg only associated with age in the DM group. CONCLUSIONS: s-Mg greater than 2.7 mg/dL associated with a favorable prognosis in HD patients with DM, suggesting that s-Mg is a factor independent of diabetes.


Assuntos
Diabetes Mellitus/sangue , Diabetes Mellitus/diagnóstico , Magnésio/sangue , Diálise Renal , Atividades Cotidianas , Diabetes Mellitus/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Estudos Retrospectivos , Análise de Sobrevida
9.
Semin Dial ; 33(2): 170-177, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32180272

RESUMO

Laparoscopic findings have been used to confirm peritoneal degenerations in peritoneal dialysis (PD) therapy. This study evaluated morphological changes in the peritoneum and their clinical relevance in patients undergoing PD. Laparoscopic findings at the rectovesical peritoneum were evaluated and scored using an imaging system at the time of PD catheter removal in this multicenter study. Angiogenesis evaluated by the vascular score (VS), color changes score (CCS), plaque score (PS), PD duration, history of peritonitis, dialysate/plasma creatinine (D/P Cr) levels, and age at PD termination were statistically analyzed. The VS of patients with PD duration more than 96 months was significantly decreased compared with that of the other patients and was negatively correlated with D/P Cr levels at PD termination. The CCS for patients with PD duration more than 96 months were significantly higher than those for the other patients and positively correlated with D/P Cr levels at PD termination. The PS of patients with recurring peritonitis were significantly higher than those of the other patients. Diminished vascularity and increased color changes in the peritoneum may be predictive of D/P Cr levels with peritoneal degradation. Laparoscopic evaluation of the abdominal cavity can provide detailed information about peritoneal injury.


Assuntos
Falência Renal Crônica/patologia , Falência Renal Crônica/terapia , Laparoscopia , Diálise Peritoneal , Peritônio/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo
10.
Clin Chim Acta ; 504: 138-145, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32014518

RESUMO

Iron deficiency leads to the suppression of hemoglobin (Hb) synthesis and induces metabolic disorders. In contrast, iron overload not only reduces the iron utilization efficiency but also induces oxidative stress. Iron metabolism in the body is closely regulated by hepcidin, a short peptide produced by the liver. Unfortunately, conventional iron indices may not always accurately reflect the iron status. For example, Hb concentration assessed using mature erythrocytes do not accurately reflect the real-time iron status due to their long lifespan. Reticulocytes are differentiated from erythroblasts after Hb synthesis and transform into mature erythrocytes in 1-2 days upon release into peripheral blood. Thus, Hb content in reticulocytes (Hb-ret) is more reflective of real-time Hb synthesis. Moreover, Hb-ret is affected only by the amount of iron intake as long as there is no hematopoietic disorder. Reticulocyte Hb content (CHr) can be accurately and inexpensively measured as Hb-ret by commercial H*3 or ADVIA hematology analyzers. CHr has been shown to be more effective than other indices of iron metabolism for the diagnosis of iron deficiency, for early detection of the therapeutic effects of iron therapy, and for differentiation of the beta thalassemia trait.


Assuntos
Anemia Ferropriva , Talassemia beta , Hemoglobinas/análise , Humanos , Ferro , Reticulócitos/química
11.
Hematology ; 25(1): 71-78, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32009585

RESUMO

Objectives: The optimal iron level in hemodialysis (HD) patients remains unclear. The hemoglobin content of reticulocytes (CHr) is a sensitive indicator of iron used for hematopoiesis. To identify the optimal iron content for HD patients, we investigated the relation between CHr levels and iron status, as well as the levels of hepcidin, a main regulator of iron metabolism.Methods: This study enrolled 181 HD outpatients treated with recombinant human erythropoietin (rHuEPO). A sensitivity analysis, using a generalized linear regression model that included the interaction term, was applied to determine the correlations between levels of CHr and those of serum ferritin (s-ft), transferrin saturation (TSAT), and hepcidin.Results: The greatest changes in correlation coefficients for levels of s-ft and TSAT with CHr levels indicated optimal cut-off points of 50 ng/mL (≤50 ng/mL, r = 0.47 vs >50 ng/mL, r = 0.22) and 24% (≤24%, r = 0.58 vs >24%, r = 0.08), respectively. The correlation coefficient for levels of CHr and hepcidin showed that the optimal lower and upper cut-off points were 20 ng/mL (≤20 ng/mL, r = 0.52 vs >20 ng/mL, r = -0.01) and 70 ng/mL (≤70 ng/mL, r = 0.36 vs >70 ng/mL, r = -0.45), respectively.Discussion: This study indicates that the amount of iron in HD patients is sufficient for hematopoiesis under conditions of low s-ft and moderate TSAT levels. High levels of hepcidin could induce negative iron metabolism in hematopoiesis.Conclusion: Therefore, controlling hepcidin levels to within approximately 20-70 ng/mL may prevent iron deficiency and reduced Hb synthesis, and may thus facilitate effective iron utilization in hematopoiesis.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Eritropoetina/uso terapêutico , Ferritinas/sangue , Hemoglobinas/análise , Reticulócitos/citologia , Transferrinas/sangue , Anemia Ferropriva/sangue , Hepcidinas/sangue , Humanos , Ferro/sangue , Proteínas Recombinantes/uso terapêutico , Diálise Renal , Estudos Retrospectivos
12.
Blood Purif ; 47 Suppl 2: 70-73, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30943480

RESUMO

Optimal iron level in hemodialysis patients remains a subject of debate. The reticulocyte hemoglobin content (CHr) is believed to reflect the concentration of iron required in the most recent hematopoiesis in the bone marrow. CHr is not influenced by any factors that measure direct hemoglobin (Hb) of reticulocytes and is considered a reliable indicator. The supply of iron for Hb synthesis is regulated by hepcidin-25 (Hep-25). However, CHr and Hep-25 measurements are not covered by the Japanese medical insurance system. Serum ferritin (s-ft) and transferrin saturation (TSAT) are used mainly as indicators of internal iron status. Therefore, we examined the relationships among CHr, s-ft, TSAT, and Hep-25 to determine the optimal iron level. This report presents the clinical significance of CHr, the potential use of CHr for the diagnosis of iron deficiency, and tests for optimal iron level using CHr as performed in our hospital.


Assuntos
Anemia/sangue , Anemia/etiologia , Hemoglobinas/análise , Ferro/sangue , Insuficiência Renal Crônica/complicações , Reticulócitos/química , Anemia/terapia , Gerenciamento Clínico , Feminino , Ferritinas/sangue , Hepcidinas/sangue , Humanos , Deficiências de Ferro , Masculino , Diálise Renal , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/terapia , Transferrina/análise
13.
Contrib Nephrol ; 195: 62-73, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29734151

RESUMO

Normal iron metabolism is essential for effective hemoglobin (Hb) production in the management of renal anemia. Considering that studies regarding the optimal Hb levels predated the creation of the iron management indices found in the treatment guidelines for hemodialysis (HD) patients, an increase in the Hb levels caused by intravenous iron supplementation has been used as an iron management index. However, no consideration was given to iron metabolism or the long-term safety of intravenous iron supplementation. Although iron is a vital trace element in humans, it can also be toxic, and its metabolism is carefully controlled, with several factors affecting it. Considering that the details regarding the mechanisms underlying iron metabolism have been elucidated recently, a study regarding iron management that is safe and considers iron metabolism status effective for Hb production in patients with renal anemia is warranted. This study presents information regarding iron metabolism in patients on HD, the factors that influence iron metabolism in such patients, and the problems with existing treatment guidelines in Japan, apart from discussing the optimal iron levels and optimal Hb production indices.


Assuntos
Anemia/metabolismo , Hemoglobinas/metabolismo , Ferro/metabolismo , Falência Renal Crônica/metabolismo , Diálise Renal , Anemia/terapia , Ferritinas/metabolismo , Hematínicos/uso terapêutico , Hematopoese , Humanos , Absorção Intestinal , Intestino Delgado/metabolismo , Japão , Falência Renal Crônica/terapia , Modelos Logísticos , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Transferrina/metabolismo
14.
PLoS One ; 12(6): e0179608, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28662118

RESUMO

BACKGROUND: Optimal iron levels in patients on hemodialysis are currently unknown, and a higher level than that for the healthy population is usually set for such patients considering the use of erythropoiesis-stimulating agents or the occurrence of chronic inflammation. However, excessive iron causes oxidative stress and impairment of its utilization by cells. Therefore we investigated the relationship between hemoglobin (Hb) level and iron status in hemodialysis patients to identify the optimal iron levels for patients undergoing hemodialysis. METHODS: A total of 208 outpatients on maintenance hemodialysis were followed up between July 2006 and June 2007. Men accounted for 64.9% cases [mean age, 59.3 ± 13.1 years and median dialysis history, 7.7 (3.6-13.2) years], and diabetic nephropathy accounted for 25.0% cases. Hemoglobin level was measured twice a month and serum ferritin, serum iron, and total iron-binding capacity were measured once a month. The doses of recombinant human erythropoietin and low-dose iron supplement were adjusted to maintain a hemoglobin level of 10-11 g/dL, according to the guidelines of the Japanese Society for Dialysis Therapy. Hepcidin was measured at baseline. Using the mean values for 1-year period, the relationships among hemoglobin, serum ferritin levels, and transferrin saturation levels were investigated based on a receiver operating characteristic curve and a logistic regression model. In addition, the correlations among serum ferritin, transferrin saturation, and hepcidin levels were analyzed by Pearson product-moment correlation coefficient and linear regression model. RESULTS: By receiver operating characteristic curve, the cutoff point of serum ferritin and transferrin saturation levels with a hemoglobin ≥10 g/dL showed <90 ng/mL (sensitivity: 69.1%, specificity: 72.1%, p < 0.001) and ≥20% (sensitivity: 77.6%, specificity: 48.8%, p = 0.302). Upon logistic regression model analysis with a hemoglobin ≥10 g/dL as the endpoint, the analysis of odds ratios relative to a group with serum ferritin ≥90 ng/mL and transferrin saturation <20% revealed that the group with serum ferritin <90 ng/mL and transferrin saturation ≥20% had the highest ratio: 46.75 (95% confidence interval: 10.89-200.70, p < 0.001). In Pearson product-moment correlation coefficient, hepcidin showed a strong positive correlation with serum ferritin [r = 0.78 (95% confidence interval: 0.72-0.83, p < 0.001)] and a weak positive correlation with transferrin saturation [r = 0.18 (95% confidence interval: 0.04-0.31, p = 0.010)]. In the multivariable analyses of the linear regression model, a positive relationship was shown between hepcidin and serum ferritin [ß-coefficient of 0.30 (95% confidence interval: 0.27-0.34, p < 0.001)]; however, no relationship was shown with transferrin saturation [ß-coefficient of 0.09 (95% confidence interval: -0.31-0.49, p = 0.660)]. CONCLUSIONS: In this study, the iron status of serum ferritin <90 ng/mL and transferrin saturation ≥20% was optimal in hemodialysis patients receiving recombinant human erythropoietin for anemia therapy. This result indicates that the threshold values for the optimal iron status may be lower than those currently recommended in iron-level management guideline.


Assuntos
Ferritinas/sangue , Hemoglobinas/metabolismo , Diálise Renal , Transferrina/metabolismo , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
Artigo em Inglês | MEDLINE | ID: mdl-27895933

RESUMO

BACKGROUND: Hyperphosphatemia is one of the common complications in patients undergoing hemodialysis. Although calcium carbonate (CaC) is often used to control serum inorganic phosphorus level in dialysis patients, co-administration of gastric acid reducers (ARs) may interfere with the phosphate binding effect of CaC. We performed a retrospective medical chart review to study whether ARs attenuate the hypophosphatemic effect of CaC in patients undergoing hemodialysis. METHODS: One hundred and eight chronic hemodialysis patients receiving either CaC alone or CaC concomitant with one of the ARs (proton pump inhibitors and histamine H2-receptor antagonists) were retrieved from the medical charts in Juntendo University Nerima Hospital. The patients were subdivided according to the interval between hemodialysis sessions (interdialysis interval of 48 or 72 h). A multivariate analysis was performed to identify clinical covariates associated with the variability of serum inorganic phosphorus levels. The study protocol was approved by the Institutional Review Board before the study was begun. RESULTS: Among patients on hemodialysis with a 72-h interdialysis interval, the magnitude of increase in serum inorganic phosphorus concentration in patients receiving CaC and AR was significantly greater than in those receiving CaC alone. While a similar trend was observed among patients with a 48-h interdialysis interval, the difference did not reach a significant level. A multivariate regression analysis revealed that concomitant administration of ARs with CaC and a longer interdialysis interval (72 h) were significantly and independently associated with the magnitude of increase in serum phosphorus concentration between dialysis sessions. No significant differences in albumin-corrected serum calcium concentrations and incidence of pathological fractures were observed between patients receiving CaC alone and those receiving CaC with ARs. CONCLUSIONS: Concomitant use of ARs with CaC may attenuate the hypophosphatemic effect of CaC in patients undergoing chronic hemodialysis. When hemodialysis patients require prescription of ARs for the prevention of upper gastrointestinal mucosal diseases (such as peptic ulcer), it may be prudent to choose a phosphate binder other than CaC.

16.
Case Rep Rheumatol ; 2016: 6571621, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27699076

RESUMO

A patient with severe lupus nephritis developed thrombocytopenia during treatment with high-dose steroids. In addition to viral- or disease-induced cytopenia, the pathology was believed to arise from diverse contributing factors, such as thrombotic microangiopathy and heparin-related thrombocytopenia (HIT). By combining plasma exchange therapy and intravenous cyclophosphamide, we successfully controlled the SLE activity and improved the thrombocytopenia. An antecedent bacterial infection or SLE activity is believed to have contributed to the concurrent HIT.

17.
Semin Dial ; 27(4): E42-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24262039

RESUMO

Peritoneal dialysis (PD) catheters often become severely dislocated, which may lead to malfunction. With the aim of preventing this complication, we have developed a simple method of fixing the catheter downwards in the peritoneal cavity (fixation technique), a technique that does not require a laparoscope. Sixteen patients were implanted using the conventional placement technique and 25 patients were implanted using the fixation technique. The location of the catheter tip was classified from grade 1 (downward, normal) to 5 (dislocated). The frequency of dislocation (defined as the extended time and/or decrease in volume when draining the PD solution) was measured for both the fixation technique and conventional placement technique. There was a significant difference in grade between the fixation technique (2.72 ± 1.01) and conventional technique (3.92 ± 1.31). The time until first dislocation was significantly different between the fixation technique (59.3 ± 48.1 days) and conventional technique (8.8 ± 14.6 days). The time until any dislocation was significantly different between the fixation technique (69.2 ± 41.9 days) and conventional technique (12.9 ± 13.7 days). Complications were not significantly different between the fixation technique and conventional technique. The fixation technique appears to be simple, safe, and useful for preventing severe dislocation and for lengthening the time until dislocation in PD patients.


Assuntos
Cateteres de Demora , Falência Renal Crônica/terapia , Diálise Peritoneal/instrumentação , Peritônio/cirurgia , Feminino , Seguimentos , Humanos , Laparoscopia/métodos , Masculino , Reprodutibilidade dos Testes , Estudos Retrospectivos
18.
ISRN Nephrol ; 2013: 351364, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24967224

RESUMO

Purpose. To explore factors contributing to chronic kidney disease (CKD) progression and change in estimated glomerular filtration rate over time (ΔeGFR) as a risk factor in predialysis patients under multidisciplinary managements. Methods. Among 113 CKD patients, eGFR, serum creatinine, total protein, albumin, urea nitrogen, uric acid, calcium, inorganic phosphate, total cholesterol, urinary creatinine, urinary protein (UP), hemoglobin A1c, hemoglobin, and hematocrit were analyzed. Results. ΔeGFR analysis in the first six months presented a positive slope (remission group) in 43 patients (38%) and a negative slope (no-remission group) in 70 patients (62%). Three-year dialysis-free rate was 89.4% in the remission group and 39.3% in the no-remission group, with a significant difference (P < 0.0001). To explore factors contributing to dialysis initiation by stepwise Cox regression, baseline eGFR (HR 0.706, P < 0.0001) and ΔeGFR in the first six months of treatment (HR 0.075, P < 0.0001) were identified. To investigate factors affecting remission and no remission by stepwise logistic regression, age (odds ratio 1.06, P = 0.018) and UP excretion (odds ratio 1.223, P = 0.045) were identified. Conclusion. Monitoring of ΔeGFR and UP is not only useful in suppressing CKD 3 progression, but also in deciding strategies to achieve remission in individual patients.

19.
Kaohsiung J Med Sci ; 22(5): 207-10, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16793554

RESUMO

The objective of the present study was to investigate whether InBody 2.0 might be useful in measuring the dry weight of chronic hemodialysis (HD) patients. Thirty-five HD patients (22 males and 13 females; mean age 62.6 +/- 14.0 years; mean HD duration 101.0 +/- 118.06 months) were examined. Multifrequency bioelectric impedance analysis was used to estimate the ratio of extracellular water (ECW) to total body water (TBW). The body resistance was measured at frequencies ranging from 1 kHz to 1 MHz. The impedance index was determined at a low frequency (5 kHz) and correlated closely with ECW, using sodium bromide dilution as standard comparison. The levels of serum albumin, prealbumin, total cholesterol (TC), triglycerides (TG), transferrin, and human atrial natriuretic peptide (hANP) were measured by routine methods in our hospital. The ECW/TBW ratio was significantly associated with the levels of hANP (p < 0.05). However, no associations between the levels of serum albumin, TC, TG, or transferrin and the ECW/TBW were observed. It appears that the body composition analyzer, InBody 2.0, may be useful for estimating the dry weight in chronic HD patients.


Assuntos
Composição Corporal , Diálise Renal , Adulto , Idoso , Fator Natriurético Atrial/sangue , Doença Crônica , Impedância Elétrica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Nephrology (Carlton) ; 11(1): 29-35, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16509929

RESUMO

BACKGROUND: In type 2 diabetic nephropathy, there is no animal model which has been completely matched with humans. Advanced glycation end products (AGE) and transforming growth factor-beta (TGF-beta) are closely related to hyperglycaemia and their pathobiochemistry could explain diabetic nephropathy. The objective of the present study was to evaluate the KK-A(y)/Ta mouse as a suitable model for type 2 diabetic nephropathy including pathological changes and immunohistochemical analyses of AGE and TGF-beta, compared with the non-diabetic BALB/cA mouse. METHODS: The urinary albumin/creatinine ratio (ACR), body weight (BW), fasting and casual blood glucose, blood haemoglobin A(1c) (HbA(1c)), creatinine clearance (Ccr) and blood pressure were measured for phenotypic characterisation. The pathological changes of glomeruli were evaluated by light microscopy, immunofluorescence and electron microscopy. AGE and TGF-beta accumulation were evaluated by immunoperoxidase staining. RESULTS: The mean levels of ACR, casual blood glucose, blood HbA(1c) and Ccr in KK-A(y)/Ta mice were higher than those in age-matched non-diabetic BALB/cA mice after 12 weeks of age. There were no significant changes in the levels of systemic blood pressure among all groups. The pathological changes of glomeruli in KK-A(y)/Ta mice were consistent with those in the early stage of human diabetic nephropathy. AGE and TGF-beta protein appeared to be localised in the glomerular mesangial matrices. CONCLUSION: It appears that KK-A(y)/Ta mice, especially in terms of histopathological findings, are a suitable animal model for the early stage of type 2 diabetic nephropathy.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas , Modelos Animais de Doenças , Glomérulos Renais/patologia , Animais , Produtos Finais de Glicação Avançada/análise , Glomérulos Renais/química , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fator de Crescimento Transformador beta/análise
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