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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The serum IgG subclass concentrations in 47 cases and specific IgG subclass antibodies against pneumococcal polysaccharides (PnPs) were measured in 18 cases with iron deficiency. IgG subclass deficiencies were found in 28 (59.6%) cases with the frequency in order as IgG4 (27.7%, 13/47), IgG1 (21.3%, 10/47), IgG3 (14.9%, 7/47), and IgG2 (2.1%, 1/47). Compared with age-matched healthy children, the mean concentration of serum IgG4 and IgG1, and PnPs specific IgG1, IgG2 antibodies were decreased in children with iron deficiency. Decreased CD4+ cells and CD4+/CD8+ ratio in peripheral blood, low interleukin-6 (IL-6) activity, reduced lymphocyte proliferative responsiveness and increased recurrent respiratory tract infections (RRTI) were found in iron deficiency children. These results suggested that serum IgG subclass and PnPs specific IgG subclass antibody deficiencies caused by dysfunction of the regulation of T lymphocyte on B lymphocyte may be related to the susceptibility to RRTI in children with iron deficiency.
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PMID:Influence of iron deficiency on serum IgG subclass and pneumococcal polysaccharides specific IgG subclass antibodies. 786 86

Systemic-onset juvenile chronic arthritis (SoJCA) is associated with high levels of circulating interleukin-6 (IL-6) and is frequently complicated by severe microcytic anemia whose pathogenesis is unclear. Therefore, we studied 20 consecutive SoJCA patients with hemoglobin (Hb) levels <12 g/dL, evaluating erythroid progenitor proliferation, endogenous erythropoietin production, body iron status, and iron supply for erythropoiesis. Hb concentrations ranged from 6.5 to 11.9 g/dL. Hb level was directly related to mean corpuscular volume (r = .82, P < .001) and inversely related to circulating transferrin receptor (r = -.81, P < .001) suggesting that the severity of anemia was directly proportional to the degree of iron-deficient erythropoiesis. Serum ferritin ranged from 18 to 1,660 microgram/L and was unrelated to Hb level. Bone marrow iron stores wore markedly reduced in the three children investigated, and they also showed increased serum transferrin receptor and normal-to-high serum ferritin. All 20 patients had elevated IL-6 levels and normal in vitro growth of erythroid progenitors. Endogenous erythropoietin (epo) production was appropriate for the degree of anemia as judged by both the observed to predicted log (serum epo) ratio 10.95 +/- 0.12) and a comparison of the serum epo-Hb regression found in these subjects with that of thalassemia patients. Multiple regression analysis showed that serum transferrin receptor was the parameter most closely related to hemoglobin concentration: variation in circulating transferrin receptor explained 61% of the variation in Hb level (P < .001). In 10 severely anemic patients, amelioration of anemia following intravenous iron administration resulted in normalization of serum transferrin receptor. Defective iron supply to the erythron rather than blunted epo production is the major cause of the microcytic anemia associated with SoJCA. A true body-iron deficiency caused by decreased iron absorption likely complicates long-lasting inflammation in the most anemic children, and this can be recognized by high serum transferrin receptor levels. Although oral iron is of no benefit, intravenous iron saccharate is a safe and effective means for improving iron availability for erythropoiesis and correcting this anemia. Thus, while chronically high endogenous IL-6 levels do not appear to blunt epo production, they are probably responsible for the observed abnormalities in iron metabolism. Anemia of chronic disease encompasses a variety of anemic conditions whose peculiar features may specifically correlate with the type of cytokine(s) predominantly released.
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PMID:Defective iron supply for erythropoiesis and adequate endogenous erythropoietin production in the anemia associated with systemic-onset juvenile chronic arthritis. 863 55

Anemia is one of the characteristics of the frailty phenotype and is often observed in elderly patients. Although anemia in people of advancing age can often be attributed to underlying etiologies such as iron deficiency or chronic disease, some cases do not have any identifiable cause. Therefore, it has been suggested that the aging process itself might be an intrinsic factor in the development of anemia, possibly through the age-related dysregulation of certain proinflammatory cytokines such as interleukin-6 (IL-6). Although the mechanism underlying the association between increased IL-6 and anemia has not been fully elucidated, it has been suggested that, like with other cytokines, it involves direct inhibition of erythropoietin production or interaction with the erythropoietin receptor.
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PMID:Biological interactions of aging and anemia: a focus on cytokines. 1258 68

Anemia is currently defined by the World Health Organization (WHO) as a hemoglobin (Hb) level <13 g/dL in men and <12 g/dL in women. While estimates vary widely, nearly one quarter of community-based octagenerians and one half of the chronically ill elderly have Hb levels that satisfy a diagnosis of anemia according to these criteria. A growing body of evidence has linked adverse events with even "mild" anemia or low-normal Hb in the elderly. Recent studies suggest strongly that aging is associated with dysregulation of pro-inflammatory cytokines, most notably interleukin-6 (IL-6), which may negatively impact hematopoiesis, either by inhibition of erythropoietin (EPO) production or interaction with EPO receptors. Anemia in older individuals is associated with a very wide range of complications, including increased risk for mortality, cardiovascular disease, cognitive dysfunction, longer hospitalization for elective procedures and comorbid conditions, reduced bone density, and falls and fractures. Not surprisingly, anemia also has a significant effect on quality of life (QOL) in the elderly. Most anemia in older individuals results from iron deficiency, chronic inflammation, or chronic kidney disease, or it may be unexplained. Future research on anemia in the elderly should focus on the age-related physiologic changes underlying this condition and whether anemia correction can reduce anemia-associated risks, and improve QOL.
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PMID:Anemia in the elderly: current understanding and emerging concepts. 1647 93

Iron homeostasis is maintained through meticulous regulation of circulating hepcidin levels. Hepcidin levels that are inappropriately low or high result in iron overload or iron deficiency, respectively. Although hypoxia, erythroid demand, iron, and inflammation are all known to influence hepcidin expression, the mechanisms responsible are not well defined. In this report we show that the inflammatory cytokine interleukin-6 (IL-6) directly regulates hepcidin through induction and subsequent promoter binding of signal transducer and activator of transcription 3 (STAT3). STAT3 is necessary and sufficient for the IL-6 responsiveness of the hepcidin promoter. Our findings provide a mechanism by which hepcidin can be regulated by inflammation or, in the absence of inflammatory stimuli, by alternative mechanisms leading to STAT3 activation.
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PMID:Interleukin-6 induces hepcidin expression through STAT3. 1683 72

There is a relationship between schistosomiasis and anemia, although the magnitude and exact mechanisms involved are unclear. In a cohort of 580 Schistosoma japonicum-infected 7- to 30-year-old patients from Leyte, The Philippines, we evaluated the impact of reinfection with S. japonicum after treatment with praziquantel on the mean hemoglobin level, iron-deficiency (IDA) and non-iron-deficiency anemia (NIDA), and inflammatory markers. All participants were treated at baseline and followed up every 3 months for a total of 18 months. At each follow-up, participants provided stools to quantify reinfection and venous blood samples for hemograms and measures of iron status and inflammation. After 18 months, reinfection with S. japonicum was associated with a lower mean hemoglobin level (-0.39 g/dl; 95% confidence interval [95% CI], -0.63 to -0.16) and 1.70 (95% CI, 1.10 to 2.61) times higher odds of all-cause anemia than those without reinfection. Reinfection was associated with IDA for high reinfection intensities only. Conversely, reinfection was associated with NIDA for all infection intensities. Reinfection was associated with serum interleukin-6 responses (P<0.01), and these responses were associated with NIDA (P=0.019) but not with IDA (P=0.29). Our results provide strong evidence for the causal relationship between S. japonicum infection and anemia. Rapidly reinfected individuals did not have the positive treatment effect on hemoglobin seen in nonreinfected individuals. The principle mechanism involved in S. japonicum-associated anemia is that of proinflammatory cytokine-mediated anemia, with iron deficiency playing a role in high-intensity infections. Based on the proposed mechanism, anemia is unlikely to be ameliorated by iron therapy alone.
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PMID:Schistosoma japonicum reinfection after praziquantel treatment causes anemia associated with inflammation. 1692 90

Epidemiological studies report that a third of the cases of anaemia in older persons is unexplained. We compared erythropoietin (EPO), inflammatory markers and major comorbidities between older subjects with normal haemoglobin levels and those with different aetiologic forms of anaemia, including unexplained anaemia. Participants were a representative sample of 964 persons aged > or =65 years, with no evidence of bleeding, complete blood tests, and a complete blood count within 6 h of phlebotomy. Anaemia was defined as haemoglobin <130 g/l in men and 120 g/l in women, and classified as a result of chronic kidney disease, iron deficiency, chronic disease and B12/folate deficiency anaemia, or unexplained anaemia based on standard criteria. Of the 124 anaemic participants, 42 (36.8%) had unexplained anaemia. Participants with anaemia of chronic diseases had significantly higher interleukin-6 (IL-6) and C-reactive protein (CRP) levels, while those with unexplained anaemia had significantly lower CRP than non-anaemic controls. Iron deficiency anaemia was characterised by significantly higher EPO levels compared with other types of anaemia and normal haemoglobin, B12 and/or folate deficiency. Unexplained anaemia was characterised by unexpectedly low EPO and low lymphocyte count. Unexplained anaemia is associated with reduced kidney EPO response, low levels of pro-inflammatory markers and low lymphocyte counts.
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PMID:Unexplained anaemia in older persons is characterised by low erythropoietin and low levels of pro-inflammatory markers. 1734 Dec 72

Serum transferrin, estimated by total iron-binding capacity (TIBC), may be a marker of protein-energy wasting (PEW) in maintenance hemodialysis (MHD) patients. We hypothesized that low TIBC or its fall over time is associated with poor clinical outcomes. In 807 MHD patients in a prospective 5-year cohort, associations of TIBC and its changes over time with outcomes were examined after adjustment for case-mix and markers of iron stores and malnutrition-inflammation including serum interleukin-6, iron and ferritin. Patients with serum TIBC >or=250 mg/dl had higher body mass index, triceps and biceps skinfolds and mid-arm muscle circumference and higher serum levels of iron but lower ferritin and inflammatory markers. Some SF-36 quality of life (QoL) components were worse in the lowest and/or highest TIBC groups. Mortality was incrementally higher in lower TIBC levels (p-trend <0.001). Adjusted death hazard ratio was 1.75 (95% CI: 1.00-3.05, p = 0.05) for TIBC <150 compared to TIBC of 200-250 mg/dl. A fall in TIBC >20 mg/dl over 6 months was associated with a death hazard ratio of 1.57 (95% CI: 1.04-2.36, p = 0.03) compared to the stable TIBC group. Hence, low baseline serum TIBC is associated with iron deficiency, PEW, inflammation, poor QoL and mortality, and its decline over time is independently associated with increased death risk.
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PMID:Association of serum total iron-binding capacity and its changes over time with nutritional and clinical outcomes in hemodialysis patients. 1913 18

Hepcidin is a hormone that regulates the intestinal absorption of iron and its release from the reticuloendothelium. The objective of this study was to determine the use of hepcidin for kidney disease patients with a diagnosis of iron deficiency pretransplantation by evaluating the soluble transferrin receptor (sRTfR-F) index as a marker for iron deficiency. This transverse study of 164 pretransplant patients determined hematometry and conventional markers related to iron metabolism, as well as soluble transferrin receptor (sTfR), its index (sTfR-F), and serum hepcidin concentrations. The following markers of inflammation (MIF) were also assessed C-reactive protein (hs-CRP), interleukin-6 (IL-6), soluble IL-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), and soluble TNF-alpha receptor (s-TNF-alphaR). Among the studied patients, 11.4% showed an absolute iron deficiency with ferritin concentrations < 100 ng/mL, a mean hepcidin value of 120.7 +/- 38.5 ng/mL, and a mean sTfR-F value of 1.03 +/- 0.3; 18.2% of patients displayed a ferritin > 800 ng/mL with mean hepcidin and sTfR-F values of 147.5 +/- 36.6 ng/mL and 0.54 +/- 0.2, respectively. Iron deficiency was not observed in the other patients when considering the conventional markers: ferritin > 100 ng/mL and transferrin saturation (ST) > 20%. However, this study showed that determination of hepcidin concentrations together with M/F improved the identification of iron deficiency in pretransplant patients by 21.6%.
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PMID:Hepcidin and iron deficiency in pre-kidney transplant patients. 1971 36

In patients with overt inflammatory diseases, up-regulated hepcidin impairs iron absorption and macrophage release, causing anemia. Whether the mild proinflammatory state of aging is associated with increased hepcidin is unknown. We characterized the relationships between urinary hepcidin, iron status, anemia, and inflammation in 582 patients 65 years or older participating in the InCHIANTI (Invecchiare in Chianti, "Aging in the Chianti Area") study, a population-based study of aging in Tuscany, Italy. Compared with nonanemic persons, urinary hepcidin (nanograms/milligram of urinary creatinine) was significantly lower in iron deficiency and inflammation anemia compared with no anemia or other anemia types. Urinary hepcidin was positively correlated with log(ferritin) and negatively correlated with the soluble transferrin receptor/log(ferritin) ratio but not correlated with markers of inflammation: interleukin-6 (IL-6), IL-1beta, tumor necrosis factor-alpha, and C-reactive protein (CRP). Lower iron was significantly correlated with higher IL-6 and CRP. Adjusting for confounders, IL-6 and CRP remained significantly associated with serum iron, with no evidence that such a relationship was accounted for by variability in urinary hepcidin. In conclusion, elevated proinflammatory markers were associated with anemia and low iron status, but not with higher urinary hepcidin. Future studies should test whether hepcidin production becomes up-regulated only in situations of overt inflammation.
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PMID:Proinflammatory state, hepcidin, and anemia in older persons. 2044 17


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