[Iron deficiency anaemia--interpretation of biochemical and haematological findings]. / Jernmangelanemi--tolking av biokjemiske og hematologiske funn.

BACKGROUND: Iron deficiency and iron deficiency anaemia are frequent problems in both the primary and the specialist health services. It is important to detect iron deficiency and to determine the causal relationship because iron deficiency may be secondary to a serious disease. The diagnosis of iron deficiency is largely based on biochemical and haematological laboratory findings, but there is no standardisation or consensus on the interpretation of these findings. METHOD: Non-systematic search in the PubMed database with a discretionary selection of articles, based on the authors' knowledge of the field. RESULTS: Ferritin measurement is the most important analysis in the study of iron deficiency, but there is no consensus on the diagnostic cut-off. It is usual in Norway today to use a ferritin level of < 12-20 µg/L, but at this low level the sensitivity for detecting iron deficiency is very low. A number of studies show that if the diagnostic cut-off is increased to the order of 30 µg/L the sensitivity is significantly higher for only a small reduction in specificity. INTERPRETATION: When studying iron deficiency as a cause of anaemia, the diagnostic cut-off for detecting deficiency should be higher than that used today. The ferritin level increases with inflammation and ought in practice to be considered in conjunction with the CRP level. The level of transferrin receptor in plasma increases with iron deficiency without being influenced by inflammation and is therefore a good supplement to ferritin measurement. Measurement of iron, transferrin and transferrin saturation provides little information additional to that provided by ferritin in iron deficiency studies.

Validation of the Hemo_Control instrument for determination of B-haemoglobin concentration in primary health care.

OBJECTIVE: The aim of this study was to evaluate the analytical performance of a new portable haemoglobinometer, Hemo_Control (EKF-diagnostic, GmbH, Germany), which measures haemoglobin concentration in venous and capillary samples. METHOD: The within series and between series imprecision of the Hemo_Control instrument were calculated after measuring the concentration of venous samples under standardized conditions; by experienced laboratory technicians in a hospital laboratory, and venous and capillary samples under conditions similar to where the instrument is intended for use; by personnel at two primary health care centres. The bias of the Hemo_Control instrument was calculated as the difference between its results and results obtained with a Coulter LH 750 instrument traceable to the ICSH reference method. RESULTS: The uncertainty of the Hemo_Control instrument for venous samples was lower than the quality goal of +/- 5% considered acceptable for patient care. High within series imprecision (5.5%) was observed for measurements of capillary blood samples in one of the primary care centres, whereas adequate analytical performance was obtained at the other centre. The Hemo_Control instrument showed negligible bias of +0.8 g/L for both venous and capillary samples in primary health care. CONCLUSION: The observed uncertainty indicates that Hemo_Control is appropriate for near patient testing using venous samples. Capillary samples may be used if sampling skills are adequate.

[Hemoglobinopathies and patients with foreign names]. / Hemoglobinopatier og fremmedartede navn.

BACKGROUND: The diagnosis of haemoglobinopathies is of growing importance in Norway because of increasing immigration from countries where haemoglobinopathies are prevalent conditions. The aim of this study was to investigate the relationship between mean corpuscular volume (MCV) and the various haemoglobinopathies diagnosed in Norway. MATERIAL AND METHODS: For a period of three years, all samples with MCV lower than 70 fl were also examined for beta-thalassaemia and haemoglobin variants HbS, HbC, HbE and HbD. A total of 263 samples with low MCV were analysed by high-pressure liquid chromatography. RESULTS AND INTERPRETATION: In 18% of the samples, a variant of haemoglobinopathy was found, mainly beta-thalassemia minor. 119 of the samples were from persons with an ethnic background from a country in which these diseases are common; all observed haemoglobinopathies were found in this group. 35% of persons with low MCV and a mainly African or Asian ethnic origin had a heterozygous haeomglobinopathy. Low MCV in patients with a foreign ethnic origin is a useful first step in the diagnosis of haemoglobinopathies.