Iron status, menarche, and calcium supplementation in adolescent girls

The effects of growth, menstrual status, and calcium supplementation on iron status were studied over 4 y in 354 girls in pubertal stage 2 who were premenarcheal at baseline (x+/-SD age: 10.8+/-0.8 y). Girls were randomly assigned to placebo or treatment with 1000 mg Ca/d as calcium citrate malate. Anthropometric characteristics, bone mass, and nutritional status were measured biannually; ferritin was measured annually; and red blood cell indexes were determined at 4 y. The simultaneous effects of iron intake and menstrual status on serum ferritin, after change in lean body mass (LBM) was controlled for, were evaluated in subjects in the upper and lower quartiles of cumulative iron intake. The average maximal accumulation of LBM (386 g/mo; 95% CI: 372, 399) occurred 0.5 y before the onset of menarche. Change in LBM was a significant predictor of serum ferritin (P < 0.0001), with a negative influence on iron status (t ratio=-4.12). The 2 fitted mathematical models representing ferritin concentrations of subjects in the upper and lower quartiles of cumulative iron intake were significantly different (P < 0.018). The regression line of the ferritin concentration in menstruating girls with high iron intakes had a less negative slope than the line fit to serum ferritin concentrations in girls with low iron intakes (NS). Serum ferritin concentrations at 0, 1, 2, 3, and 4 y were not significantly different between groups. In addition, there was no significant difference between groups in any of the red blood cell indexes. In summary, growth spurt and menstrual status had adverse effects on iron stores in adolescent girls with low iron intakes (<9 mg/d), whereas long-term supplementation with calcium (total intake: approximately 1500 mg/d) did not affect iron status.     

Effects of calcium supplementation and lactation on iron status

Calcium has been shown to inhibit iron absorption. The consequences of chronic calcium supplementation on iron status are unclear, however. As part of a randomized calcium-supplementation trial in lactating and nonlactating women in the postpartum period, we determined whether long-term calcium supplementation and lactation status affected iron stores as measured by serum ferritin concentrations. Subjects (95 lactating and 92 nonlactating) were enrolled at approximately 6 mo postpartum and then randomly assigned to receive either 500 mg Ca as calcium carbonate or a placebo twice daily with meals for 6 mo. Lactating women weaned their infants approximately 2 mo after enrollment (ie, approximately 8 mo postpartum). Calcium supplementation had no effect on serum ferritin concentrations. At the end of the study, geometric mean serum ferritin concentrations were 28.4 microg/L in the calcium-supplemented group and 27.5 microg/L in the placebo group (P > 0.5). Lactation status was significantly related to serum ferritin concentrations. At baseline, serum ferritin concentrations were higher in lactating women than in nonlactating women (47.7 compared with 31.5 microg/L, P < 0.001). In lactating women, serum ferritin concentrations decreased by a mean of 17 microg/L after weaning. By 12 mo postpartum, mean serum ferritin concentrations in women who were previously lactating were not significantly higher than those of nonlactating women (30.5 compared with 25.5 microg/L). These findings provide reassurance that long-term calcium supplementation does not impair iron stores. Furthermore, lactation status should be considered when assessing iron nutriture of women and determinants of iron status in populations.     

Changes in biochemical indicators of iron status during iron repletion and depletion in monkeys

Different modes of iron depletion and repletion were studied in monkeys to understand the sequential changes in and the relative importance of different biochemical indicators of iron status. Six control monkeys were divided into two groups, one was fed an iron-deficient diet (group 1) and the other underwent phlebotomy in addition to receiving an iron-deficient diet (group 2). Previously iron-depleted monkeys were subdivided into 4 groups of 3 animals each. While one group was continued on the iron-deficient diet (group 3), the second group received parenteral iron (group 4), the third group (group 5) received a sufficient-iron-containing diet, and the fourth group was fed 50% of the iron requirement. All indicators of iron status like hemoglobin (Hb), erythrocyte protoporphyrin (EPP), serum transferrin saturation and serum ferritin were monitored periodically, in addition to liver and bone marrow iron. all the indicators except serum ferritin and liver iron showed a decrease in group 2. On the other hand, animals receiving parenteral iron (group 4) showed an increase in all the parameters except serum ferritin. The dietary supplementation produced an increase in Hb and a decrease in EPP only (groups 5 and 6). There was a significant positive correlation between changes in bone marrow iron and Hb concentration depending on the severity of depletion and repletion. Both serum ferritin and liver iron did not respond to changes in dietary iron. Another parameter which responded to repletion was EPP. Serum ferritin and liver iron did not respond to changes in dietary iron or was not sensitive to subclinical iron deficiency. The results indicate that change in Hb is more sensitive to detect the deficiency of iron. It was also observed that different parameters respond variably under different modes of depletion and repletion.     

Is serum transferrin receptor useful for detecting iron-deficiency in anaemic patients with chronic inflammatory diseases?

We investigated whether determination of serum transferrin receptor (TfR) is useful for detecting iron-deficiency in patients with chronic inflammatory diseases and for differentiating between iron-deficiency anaemia and anaemia of inflammation. Using an immunofluorometric assay, serum TfR was measured in 34 anaemic patients. Of these patients, 23 had a chronic rheumatic disease, 13 with both inflammation and iron-deficiency and 10 with anaemia of inflammation only; the other 11 patients had iron-deficiency anaemia and no evidence of inflammation. Serum TfR concentrations were lower in patients with anaemia of inflammation (2.6 +/- 0.2 mg/l, mean +/- S.E.M.) than in patients with iron-deficiency anaemia (6.7 +/- 1.1 mg/l, P < 0.01) or those with both inflammation and iron deficiency (5.8 +/- 1.0 mg/l, P < 0.01). Among patients with inflammatory disease, correlations between TfR and ferritin concentrations (r = -0.62, P < 0.05) and TfR and erythropoietin concentrations (r = 0.69, P < 0.001) were observed in iron-deficient subjects only. TfR, though not superior to serum ferritin, can help to distinguish between anaemia of inflammation and iron-deficiency anaemia and to identify iron-deficiency in subjects with chronic inflammation.     

Source of dietary protein influences kinetics of plasma gut regulatory peptide concentration in response to feeding in preruminant calves

Anaemia in pregnancy in developing countries continues to be a public health problem of significant proportion. At least 50% of the anaemia has been blamed on iron deficiency. In populations where chronic inflammation and iron deficiency anaemia coexist, the criteria to accurately define iron status are not always clear. Similarly, in pregnancy, with marked physiological changes, cut-off points for biochemical parameters need to be re-examined. In this study we examined the diagnostic accuracy of iron parameters including mean cellular volume (MCV), serum iron, transferrin, total iron binding capacity (TIBC) and its saturation, zinc protoporphyrin (ZPP), ferritin and serum transferrin receptor (TfR) for the assessment of iron status in a population of anaemic pregnant women in Malawi. Stained bone marrow aspirates were used as the standard for comparison. Results show that for the purpose of screening, serum ferritin is the best single indicator of storage iron provided a cut-off point of 30 microg/l is used. A number of other commonly used parameters of iron status were shown to have limited diagnostic accuracy. Logistic regression was used to obtain mathematical models for the prediction of bone marrow iron status using a combination of available parameters.     

The role of serum transferrin receptor in the diagnosis of iron deficiency

BACKGROUND AND OBJECTIVE: Iron deficiency anemia (IDA) is often associated with inflammatory disorders. The most conventional parameters of iron metabolism are therefore affected, making the evaluation of iron status difficult. Serum transferrin receptor (sTfR) levels are raised in iron deficiency but are not influenced by inflammatory changes. The aim of this study was to investigate the role of sTfR in differentiating IDA with inflammatory features. DESIGN AND METHODS: A diagnostic study of sTfR measured by immunoassay was carried out in IDA and anemia of chronic disorders (ACD). The cut-off points of sTfR and the ratio of sTfR/serum ferritin, which were obtained after comparing IDA and ACD, were applied to a group of 64 patients with mixed iron patterns (MIX) (16 with ACD and 48 with IDA). RESULTS: The best cut-off point of sTfR between IDA and ACD was 4.7 mg/L. Applying this cut-off to the MIX group, an efficiency of 87% was obtained (sensitivity 92% and specificity 81%). This level of sTfR correctly classified 53 out of 64 cases of the MIX group (83%). Using the ratio of sTfRx 100/serum ferritin, the best cut-off point was 8 (efficiency 100%), which correctly classified 62 out of 64 cases of the MIX group (97%). INTERPRETATION AND CONCLUSIONS: This study demonstrates that sTfR in conjunction with other iron parameters is very useful in iron deficiency evaluation, especially in hospital practice. Iron treatment should be considered in patients with mixed patterns of iron status, in which the diagnosis of IDA versus ACD is difficult, when the levels of sTfR exceed the cut-off point.     

Serum transferrin receptor concentration is not indicative of erythropoietic activity in chronic hemodialysis patients with poor response to recombinant human erythropoietin

BACKGROUND: Serum transferrin receptor (sTfR) is a transmembrane glycoprotein derived from erythroid precursors in the bone marrow. Its concentration provides a quantitative measure of total erythropoietic activity and an indication of functional iron deficiency. This study was conducted to investigate whether sTfR is a useful index of erythropoietic activity in chronic hemodialysis patients with poor response to maintenance recombinant human erythropoietin (rHuEPO) therapy. METHODS: Using an enzyme-linked immunosorbent assay, sTfR concentration was measured in 67 uremic patients who had been on hemodialysis for a mean of 42 months (3-242 months). rHuEPO was administered three times a week to keep the hematocrit above 30%. Hemoglobin, red blood cell indices, serum ferritin, serum total iron binding capacity and unsaturated iron binding capacity were determined. Of the 67 patients, 35 who responded favorably to rHuEPO with hematocrits above 30% were categorized as Group I and 32 who did not attain the target hematocrit were categorized as Group II. As a control group, 31 healthy subjects were also investigated. RESULTS: The serum iron, ferritin, transferrin iron saturation, dialysis efficiency and nutritional state were not different between groups of hemodialysis patients. The mean sTfR concentration was 2.1 +/- 0.6 micrograms/ml (range, 1.15-3.53 micrograms/ml) in Group I patients, compared with 1.9 +/- 0.9 micrograms/ml (range, 1.03-2.65 micrograms/ml) in Group II. The difference was not significant. In addition, the mean sTfR concentration of 1.8 +/- 0.4 micrograms/ml (range, 0.86-2.76 micrograms/ml) in the healthy controls was not significantly different from Groups I and II. CONCLUSIONS: sTfR concentration cannot be used to distinguish good from poor rHuEPO responders among chronic hemodialysis patients who have elevated serum ferritin (> 300 micrograms/l) and transferrin iron saturation (> 25%) during the course of maintenance rHuEPO therapy.     

Functional iron deficiency in adults with cystic fibrosis

Functional iron deficiency (transferrin saturation < 16%) was found in 44 (62%) of 71 adult cystic fibrosis (CF) patients. Haemoglobin concentration and mean cell volume were lower in iron-deficient patients, in whom there was a non-significant trend for lower serum ferritin. Ten iron-deficient patients and two patients with transferrin saturation > = 16% (normal iron) were anaemic. There were no significant differences between iron-deficient and normal-iron patients in intake of calories, protein, iron and vitamin C as determined by 4-day records of dietary intake. Dietary iron deficiency is not an important factor in functional iron deficiency in adult CF patients. Impairment of absorption by exogenous pancreatic enzyme supplements is unlikely to be significant as enzyme intake was the same in the two groups. Iron-deficient patients had lower Shwachman-Kulczycki scores and lower percent predicted forced expiratory volume in 1 s (FEV1% predicted) and forced vital capacity (FVC% predicted). There was a non-significant trend for higher values of white cell count and plasma viscosity in the iron-deficient group. Chronic inflammation is likely to be the primary cause of functional iron deficiency in adult CF patients. Fifteen patients completed 3-month courses of oral iron replacement with no deterioration in pulmonary function, but with no effect on haemoglobin concentration.     

Iron reserves in the female body and susceptibility to colds

Levels of temporary invalidity because of catching cold were analyzed in 101 working women over two years and these women's levels of serum iron, total iron-binding capacity of the serum, transferrin saturation with iron, serum ferritin, and red cell ferritin measured. Women with stable iron reserves in the body virtually have no sick leaves because of catching cold, whereas in those with iron deficiency susceptibility to catching cold is increased, and if iron metabolism intensity in the body grows, invalidity periods are much longer. Normalization of not only iron reserves in the body, but correction of iron metabolism as well should be regarded as a factor exerting a favorable effect on body resistance to catching cold.     

Multicenter study of penile cancer

The objective was to examine the relationships between serum ferritin, alcohol intake, and socioeconomic factors (school education, occupational education, occupation, income, marital status, cohabitation status, housing, social class) in a population survey performed in Copenhagen County during 1982-1984. The participants were selected at random from the census register and comprised 2235 healthy Danish individuals, non-blood donors (1044 men, 1191 women) in cohorts being 30, 40, 50, and 60 years old. The participants gave a detailed social and medical history and had a clinical examination including blood samples. In all age-groups, men had significantly higher serum ferritin and alcohol intake than women. In men, there was no relationship between serum ferritin and social class. Significant relationships were observed between ferritin and occupation (unemployed and self-employed men had higher ferritin than those with other occupations) and ferritin and income (in younger men, ferritin displayed a steady increase with income). None of the social variables were related to the prevalence of iron deficiency or iron overload. Alcohol intake was related to occupation and income, but not to social class. In women, none of the social variables showed any significant relationship to ferritin levels or iron overload. The prevalence of small iron stores (serum ferritin < or = 30 micrograms/l) was lower and the intake of alcohol was higher in women from high social classes. In both men and women, serum ferritin displayed highly significant positive correlations with alcohol intake. Likewise, the prevalence of iron overload (serum ferritin > 90th percentile) was closely correlated to alcohol intake. In conclusion, socioeconomic factors per se had a minor influence on serum ferritin levels and iron status in Danes. The distinct association between alcohol intake and serum ferritin levels should be considered in future iron status surveys.     

Severe chronic iron deficiency in a 17-year-old student

A 17 year old male suffered from iron deficiency of undetermined cause for 2 years. Iron substitution was able to correct it for short periods. With the exception of fatigue and recurring abdominal pain attributed to oral iron therapy no further symptoms were present. The physical status on admission was unremarkable. The laboratory detected intestinal disorders, an anemia of the chronic type without evidence for malignancy or renal failure suggested an inflammatory gastro-intestinal disorder. In spite of a twice negative noninvasive test for gluten-intolerance the clinician favored in his differential diagnosis non tropical sprue over inflammatory bowel disease (IBD, Crohn's disease, Whipple's disease). Histopathology of small bowel specimens did not indicate sprue. An ileo-colonoscopy revealed severe ulcerating ileitis and mild chronic colitis. The histologic specimen revealed a severe ileal inflammation with cosinophilia and the colon specimens epitheloid microgranuloma. These findings are highly compatible with the diagnosis of Crohn's disease. Iron deficiency anemia is common in Crohn's disease. In the current case it is due to disturbed iron uptake. Iron deficiency anemia as sole symptom of Crohn's disease is extremely rare.     

The relationship of haemoglobin to serum erythropoietin concentrations in the anaemia of rheumatoid arthritis: the effect of oral prednisolone

Previous studies of the erythropoietin response to anaemia in RA have yielded conflicting findings. Some have found the response to be impaired and others have found a normal response. We have compared erythropoietin (EPO) levels measured by radioimmunoassay, in 54 anaemic rheumatoid patients and 55 patients with iron deficiency anaemia but no inflammatory disease. The erythropoietin response in the rheumatoid patients was impaired compared with the control group (P < 0.025) but only seven rheumatoid patients showed a response which fell below the 95% confidence intervals predicted for the control group. Rheumatoid patients who fell within the highest quartile for serum ferritin concentrations (i.e. those most likely to have anaemia of chronic disease) had significantly lower EPO levels compared with the control group (P < 0.01). EPO levels in rheumatoid patients within the lowest quartile for ferritin (i.e. those with iron deficiency anaemia) were not significantly different from the control group (P = 0.670). The difference in EPO response between the RA patients in the upper and lower quartile for ferritin approached but did not achieve significance (P = 0.056). In a second study 15 anaemic RA patients were given a 5-day course of oral prednisolone 1.5 mgkg-1. Hemoglobin did not rise significantly until day 4 but EPO levels fell by day 1 (P < 0.005) and remained lower than pretreatment values throughout the study. Thus, in RA patients, anaemia of chronic disease is associated with inappropriately low EPO concentrations but this does not appear to be the major cause of the anaemia and Hb response to prednisolone does not depend upon an increase in EPO concentration.     

25-hydroxycholecalciferol serum levels in patients with Crohn's disease

In 37 patients with Crohn's disease the 25-hydroxycholecalciferol (25-HCC) serum level, serum concentration of calcium and inorganic phosphate, and the enzyme activity of alkaline phosphatase were measured. Furthermore the activity index of Crohn's disease was determined in every patient. There was no statistically significant difference of 25-HCC serum levels in these patients compared to a healthy control group. Correspondingly most patients showed normal alkaline phosphatase enzyme activity and normal serum concentration of calcium and inorganic phosphate. No correlation between 25-HCC concentration and site of inflammation or activity index was found.     

Sex differences in the relation of visceral adipose tissue accumulation to total body fatness

With a newly developed short term enzyme linked immunosorbent assay kit (TOYOBO Co.), in which 2 kinds of anti-EPO monoclonal antibodies were used, we assayed EPO concentration in sera from patients with renal failure and hematological disorders. In this report, the EPO data were analysed in relation to serum iron concentrations, with ferritin and UIBC. In the patients with renal failure, there was no significant correlation between EPO concentration and serum iron, ferritin, nor UIBC concentration. On the other hand, in the patients with hematological disorders, there were two types. One was in patients with iron deficiency anemia, whose serum EPO was negatively correlated to serum iron (r = -0.64) and ferritin (r = -0.59), but positively related to UIBC (r = 0.27). The another was the pattern in patients with aplastic anemia, leukemia and MDS, whose serum EPO positively correlated to iron and ferritin but negatively correlated to UIBC. In the patients with aplastic anemia serum EPO had good correlation to serum iron (r = 0.62), ferritin (r = 0.60) and UIBC (r = -0.46). The relationship of EPO to iron in the patients with leukemia (r = 0.54), and EPO to ferritin in the patients with MDS (r = 0.42) show significantly positive correlation coefficient.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum ferritin as a control parameter for oral iron therapy (author's transl)

Ferrritin can be measured in blood serum radioimmunometrically. Serum ferritin is directly correlated to body iron stores. In comparison to other parameters of storage iron (bone marrow iron, intestinal iron absorption) this quantitative diagnostic parameter is easily available. Thus it can be used to judge body iron status. In 20 patients with chronic haemorrhagic and 7 patients with posthaemorrhagic iron deficiency anaemia as well as nine blood donors with latent iron deficiency serum ferritin was used to control oral iron therapy. The continuous determination of serum ferritin during therapy gives a quantitative value of the relevant level of body iron stores. This value shows whether therapy was effective and when iron stores are replenished. The results demonstrate that oral iron therapy should be continued for at least 3 months from the time of normalisation of haemoglobin to obtain a sufficient restoration of iron depots.     

The effect of interferon and desferrioxamine on serum ferritin and hepatic iron concentrations in chronic hepatitis B

BACKGROUND/AIMS: Recent reports indicate that an individual's iron status might affect the response rate achieved with Interferon therapy for the treatment of chronic viral hepatitis. METHODOLOGY: Forty individuals, 29 men and 11 women, with chronic viral hepatitis B, who had elevated serum ferritin levels, were randomized to receive either Interferon (IFN) 5 MU TIW SQ for 6 months alone (n=21) or Interferon in combination with repetitive cycles of desferrioxamine infused at a dose of 80 mg/kg per cycle (n=19) over 3 consecutive days in an effort to reduce their metabolically active iron pool during the course of IFN treatment. These cycles were continued until a serum ferritin level of less than 250 ng/ml (normal values <220 ng/ml) was achieved. Additionally, all desferrioxamine treated subjects were placed on a low iron containing diet. An interferon response was defined as normalization of the serum ALT and seroconversion from eAg positive to eAb positive. All other responses were defined as failures. RESULTS: The mean ages of the subjects in the 2 groups were 39+/-6 and 38+/-5 years. The initial serum ALT levels were 150+/-27 and 151+/-13 IU/l. The hepatic iron concentrations were 916+/-29 and 896+/-15 microg/g/dry liver weight. The serum ferritin levels were 386+/-12 and 393+/-18 ng/ml. None of these values differed significantly between the 2 treatment groups. The desferrioxamine treated group consisted of 14 men and 5 women. This group experienced a reduction in their serum ferritin to a level of 237+/-13 ng/ml as a result of the desferrioxamine treatment (p<0.05). Additionally, a reduction in their hepatic iron concentration, to a level 766+/-29 microg/g/dry liver weight, occurred with treatment (p<0.05). Twelve of the 19 (63%) desferrioxamine-treated subjects and 8 of the 21 (38%) control subjects experienced a normalization of their serum ALT levels with treatment (p<0.05). Thirteen of 19 (68%) of the desferrioxamine-treated subjects but only 8 of 21 (38%) of the IFN alone treated group seroconverted to anti-e positive (p<0.05). Moreover, a greater improvement in the hepatic histologic score and rate of HBV-DNA loss occurred in the desferrioxamine-treated group. CONCLUSIONS: Based upon these data, it can be concluded that desferrioxamine infusion to achieve a normal serum ferritin level enhances the likelihood of an individual with chronic hepatitis B responding to IFN therapy. The precise mechanism responsible for this phenomenon is not clear, but would appear to be due to a reduction in the hepatic free iron pool as reflected by sequential changes in the serum ferritin and hepatic iron concentrations.     

Zinc protoporphyrin (ZPP) in diagnosis of anemia

In iron deficiency, zinc protoporphyrin (ZPP) is produced instead of heme, and the ZPP concentration in erythrocytes increased (normal value < 2.3 micrograms ZPP/g Hb). The ZPP level and comparison with the other normally used tests in iron deficiency in the group of the patients with iron deficiency, ACD, MDS, AML, plasmocytoma was investigated. The ZPP level was determined by hematofluorometry in samples from 96 patients. Thirty five patients with iron depletion showed decreased both serum ferritin (median 5.9 ng/ml), and hemoglobin level (median 9.8 g/dl) with significantly increased ZPP level (median 8.5 micrograms/gHb). An increased level of ZPP (median 3.95 micrograms/gHb) with normal level of ferritin (median 24 ng/ml) and iron (median 50 (g/dl) in the serum of patients with ACD was determined. Measurement of ZPP level in the combination with ferritin and peripheral blood morphology allows to classify the degree of iron deficiency. The ZPP levels higher than 4.55 micrograms/gHb confirms iron deficiency in the group of anaemic patients.     

Serum transferrin receptor and transferrin receptor-ferritin index identify healthy subjects with subclinical iron deficits

Despite the established utility of serum transferrin receptor (sTfR), serum ferritin, and the sTfR/log ferritin ratio (TfR-F Index) in the diagnosis of iron deficiency (ID) anemia, the numeric values of these parameters, which are indicative of subclinical ID, remain to be clearly defined. In this study, 65 apparently healthy nonanemic adults (22 men and 43 women) were treated with 3 months of oral iron supplementation to evaluate its effect on parameters reflecting iron status and to determine the prevalence of subclinical iron deficiency in apparently healthy adults. Significant supplementation-induced changes were observed in sTfR, ferritin, and TfR-F Index values in women, whereas in men, none of the studied parameters showed any significant change. Iron-deficient erythropoiesis (IDE) was not observed in men, but was found in 17 women (40%). Although individuals with a compromised iron status may be represented in substantial numbers in conventional reference populations, they can be readily identified using sTfR, ferritin, and TfR-F Index determinations.     

Percentage hypochromic red cells and the response to intravenous iron therapy in anaemic haemodialysis patients

INTRODUCTION: Iron deficiency is commonly encountered in haemodialysis (HD) patients and may be overcome by i.v. iron therapy. We have examined the percentage hypochromic red cells (%HRC) for predicting response to i.v. iron in subjects with a low serum ferritin. METHODS: Prospective study of i.v. iron saccharate (trivalent iron 200 mg/week for 8 weeks) in anaemic (Hb < 10 g/dl) HD patients with serum ferritin < 100 microg/l despite oral iron therapy. Response to i.v. iron was assessed by comparing Hb at 0 and 8 weeks according to %HRC at baseline (0-3%, 4-9%, > or = 10%). Results are mean+/-1 SD. RESULTS: For all subjects (n=82), Hb and ferritin increased between 0 and 8 weeks (8.9+/-1.0 to 10.1+/-1.4, P<0.0001; 55+/-24 to 288+/-126, P<0.0001). Patients were stratified into three groups according to %HRC at baseline (0-3%, 4-9%, > or = 10%). Hb increased significantly in all three groups. The mean increase in Hb was greater (0-3%, 0.6+/-1.2; 4-9%, 1.2+/-1.0; > or = 10%, 1.6+/-1.4; P=0.02) and the proportion of patients showing a > or = 1 g/dl increase in Hb was greater (0-3%, 27%; 4-9%, 57%; > or = 10%, 67%; P=0.02) in those with the largest %HRC pre-treatment. CONCLUSION: Intravenous iron therapy is effective in improving Hb in anaemic HD patients with a low ferritin. However, the magnitude of this response and the proportion of patients responding is related to the percentage hypochromic red cells prior to treatment.