Serum ferritin and the iron status of Canadians.

Serum ferritin concentration was determined in 1105 Canadians aged 1 to 90 years. Geometric mean values (ng/ml) were as follows: children 1 to 4 years old, 12; children 5 to 9 years old, 15; adolescent girls, 17; adolescent boys, 18; women 20 to 39 years, 23; women 65 years and older, 52; men 20 to 39 years, 93; and men 40 and older, 92. Ranges were side in all age groups, reflecting variations in size of body iron stores. From analysis of the ferritin values it is highly probably that iron stores were greatly reduced in approximately 25% of children, 30% of adolescents, 30% of menstruating women, 60% of pregnant women and 3% of men. Iron-deficiency anemia was noted in only 2% of subjects. If "normality" requires more than small amounts of storage iron to meet physiologic demands, the study results suggest a high probability of iron deficiency in 60% of the pregnant women and in 19% of the other subjects; but if normality is defined as maintenance of adequate iron stores for erythropoiesis, the prevalence of iron deficiency was zero in the pregnant women and 2% in the other subjects.     

Serum ferritin,cobalt excretion and body iron status.

Serum ferritin concentration was measured by immunoradiometric assay in 64 subjects. It was closely related to the size of body iron stores measured by hemosiderin content of bone marrow in all subjects and by the deferoxamine test in 10 patients with iron overload. Urinary cobalt excretion, an indirect measure of iron absorption, was inversely related to hemosiderin content of bone marrow in 34 patients aged 18 to 72 with or without liver disease, but this relation did not hold in a group of 20 student volunteers aged 17 to 30, indicating that the test is unreliable in young people. A strong inverse correlation was demonstrated between values for cobalt excretion and serum ferritin in the 34 patients and between those for iron absorption and serum ferritin in the 20 students. Serum ferritin concentration appears to reflect accurately the iron status of the healthy individual but high values in liver disease must be interpreted with caution.     

Cost-benefit analysis of long-term haemodialysis for chronic renal failure.

A cost-benefit analysis of long-term maintenance haemodialysis indicates that there is a large gulf between the cost of the service and "economic" benefit. The difference may be considered to represent one estimate of the price society is prepared to pay to maintain life. Using "best estimates" from available data we found the implicit social value of maintaining a patient on haemodialysis to be approximately pounds 4720 per annum in hospital or pounds 2600 at home. The analysis would suggest that society must look carefully at alternative uses for health expenditure before extending indiscriminately to large sections of the population these treatment programmes or other similarly expensive.     

Serum ferritin in iron overload

Even with uncomplicated iron overload, serum ferritin which can be identified in the circulating blood by sensitive immunochemical methods has a direct and quantitative correlation to the iron stored in the organism. The relation of stored iron and serum ferritin is not linear, but has an exponential character. The diagnostic function of serum ferritin as an indicator of stored iron, however, is virtually not influenced by it. The indications listed in Tab. 3 can be demarcated for diagnostic application in cases of iron overload. Hitherto, the molecular microheterogenicity of serum ferritin has exercised no essential impact on its diagnostic application. High ferritin concentrations may arise in the circulating blood by a number of disease processes listed in Tab. 4, without the simultaneous existence of a respective iron overload of the tissue. These correlations have to be observed in the diagnostic application of determining serum ferritin as well as in methodical possibilities of fault (high dose hook effect), thus limiting the use of serum ferritin as an indicator of stored iron both in case of iron overload and iron deficiency. As in all isolated laboratory investigations, all other clinical and chemical laboratory information available about the individual patient has to be taken into account in each case for interpreting the serum ferritin concentration.     

Ocular findings in patients with chronic renal failure undergoing haemodialysis

The aim of this paper was to evaluate the ocular findings in patients with chronic renal failure (CRF) undergoing haemodialysis (HD). In 64 patients undergoing haemodialysis (30 female and 34 male), aged 24-83 years (mean 58 years) on haemodialysis 1-213 months (mean 47 months) complete ocular examination were performed: visual acuity (VA), intraocular pressure (IOP), biomicroscopic examination and fundoscopy. On right eye sixty-nine percent of patents had VA 0.6 or better, and on left eye 84% of patients had VA 0.6 or better. Mean IOP before dialysis was 15 mmHg and after dialysis was 14 mmHg. In 9 patients (14%) we found corneo-conjunctival calcium deposits. No correlation of ocular calcification and parathyroid hormone (PTH) level or calcium and phosphate product were observed. 39 (60%) patients had cataract. Hypertensive vascular changes were seen in 44 (68%) patients and in 6 (7%) patients age-related macular degeneration. Seven patients had diabetes mellitus and in 5 diabetic retinopathy was observed. Patients with CRF or who are receiving HD represent unique group of patients. Pathologic change could be found in many tissue and organs, therefore we suggest ocular examination more frequently in dialysis patients.     

Regular short haemodialysis in end-stage renal failure.

A study was made of thrice weekly haemodialysis of 3-3 1/2 hours'' duration using a large surface area dialyser in patients with end-stage renal failure. Body water, potassium, and blood pressure control were satisfactory and comparable with the more widely used long dialysis schedules (6-9 hours thrice weekly). Patient rehabilitation was improved overall and the regimen enabled the dialysis unit to treat more patients despite a reduction in technical and nursing staff. The technique proved inadequate, however, in two patients with an intercurrent infection, and more intensive dialysis in recommended in such cases.     

Serum beta-N-acetyl hexosaminidase levels in chronic renal failure

Serum beta-N-acetyl hexosaminidase (beta-NAH) levels, the indirect indicators of hepatic endothelial and Kupffer cell function, were examined in 16 anuric chronic hemodialysis patients, and in 11 patients in different stages of chronic renal failure (serum creatinine 2-8.8 mg/dl). They were found to be lower than those of the healthy controls, contrary to expectation. It might be concluded that nonparenchymal liver cells are functioning well in chronic renal failure. However, the possibility that production of beta-NAH in these patients is abnormally reduced cannot be excluded.     

Serum iron, serum ferritin and tissue ferritin during development in ducks

Serum ferritin and tissue ferritin from kidney, heart, small intestine, spleen and liver from ducks during development from 16 to 112 days of age were measured by radioimmunoassay using rabbit anti-duck liver ferritin antibodies and goat second antibody. Serum iron concentration and tissue ferritin iron content are given. Serum ferritin concentration, tissue ferritin and ferritin iron content increase gradually during development. The decrease in all these parameters at 8 weeks of age might be due to molting.     

Assessment of iron stores in inflammation by assay of serum ferritin concentrations.

A serum ferritin concentration of below 15 microgram/l is accepted as indicating diminished iron reserves in an otherwise normal person. In patients with inflammatory disease this lower limit of normality may be inappropriate as inflammation may directly stimulate the production of ferritin protein. Results obtained in a survey of 150 patients with early inflammatory joint disease suggest that a ferritin concentration of 55 microgram/l is a more appropriate lower limit of normality.