Zinc protoporphyrin assays in patients with alpha and beta thalassaemia trait.

Abstract

Aims-To determine the value of the red cell distribution width (RDW) and erythrocyte zinc protoporphyrin (ZPP) concentration in discriminating between iron deficiency, and /1 and a thalassaemia in a mixed urban Asian population. Methods-The RDW and ZPP concentrations were measured in 1412 subjects attending for The red cell distribution width (RDW) and erythrocyte zinc protoporphyrin (ZPP) concentration have both been proposed as simple tests for identifying iron deficiency and distinguishing it from other causes of microcytosis, including a and fi thalassaemia. The RDW is the coefficient of variation of the mean cell volume (MCV)-that is, (SD/MCV) x 100-and is derived from the red cell histogram on Coulter automated cell counters. It reflects anisocytosis, and is increased in many types of anaemia, including iron deficiency. ZPP is formed in the final reaction in the biosynthetic pathway of haem when zinc is incorporated into protoporphyrin IX by the enzyme ferrochelatase, rather than the usual substrate iron. Concentrations of zinc protoporphyrin rise in iron deficiency and in other conditions where the transfer of iron to or within the bone marrow is limited, such as lead poisoning or the anaemia of chronic disease.As part of an investigation into the prevalence of iron deficiency and haemoglobinopathies in a mixed Asian population,5 we compared RDW and ZPP in normal subjects and those with iron deficiency of different grades and a and ,8 thalassaemia, to determine the diagnostic value of these parameters, and their value as screening tests. MethodsSubjects were referred by general practitioners, hospital outpatient, and antenatal clinics to the local phlebotomy service for routine blood tests. They were about 80% female, of whom one quarter were pregnant, and 20% male. Ages ranged from 14 to 85 years. The study was approved by the local ethics committee and informed consent obtained. An additional 5 ml of blood was taken when necessary.A total of 1412 subjects (1256 South Asian and 156 Caucasian) were studied and 1233 subjects had both RDW and ZPP measured. Thirty eight subjects did not have the RDW measured, and are included only in the ZPP analysis, while none of the Caucasians, who were added as a small control group to the original survey, had ZPP measured, and these are included only in the RDW data.All subjects had a full blood count (including haemoglobin, red blood count, mean red cell volume (MCV) and mean red cell haemoglobin (MCH) using a Coulter S + VI automated cell counter: when the MCH was less than 27-0 pg, HbA2 was quantified using an inhouse column method. Haemoglobin electrophoresis was performed on cellulose acetate (pH 8 6) (Helena Laboratories): when a structural variant was found, electrophoresis was repeated at pH 6-0 on citrate agar (Beckman Paragon Gel). A sickle solubility test was performed when a band was identified in the S/D region. Plasma ferritin was measured using the Becton-Dickinson immunoradiometric assay. RDW was obtained from the red cell profile on the Coulte...

A direct and simultaneous detection of zinc protoporphyrin IX, free protoporphyrin IX, and fluorescent heme degradation product in red blood cell hemolysates

“…The observed hemolysate fluorescence at 626 nm (directly obtained from the emission peak shown in Figure 2 [20][21][22]. All these data validate the method of the direct determination of relative total erythrocyte porphyrin and ZPP levels in hemolysates.…”

A transgenic mouse model expressing exclusively human hemoglobin E: Indications of a mild oxidative stress

“…Thal mice, known to exhibit ineffective erythropoiesis due to globin chain imbalance [79], show greatly elevated levels of ZPP compared to the C57 and HbE mice (data not shown). This is consistent with elevated ZPP reported in human β-thal patients [18; 89]. …”

Non-invasive detection of iron deficiency by fluorescence measurement of erythrocyte zinc protoporphyrin in the lip

“…Increases in red blood cell zinc protoporphyrin also may be produced by conditions other than iron deficiency. These disorders include lead or other heavy metal exposure 33 34 , some haemoglobinopathies 35 36 37 38 39 and a variety of uncommon or rare genetic and acquired disorders, including certain porphyrias 40 and a variety of sideroblastic and inherited microcytic anaemias 41 . Generally, these conditions are not a barrier to the use of red blood cell zinc protoporphyrin to screen for iron deficiency, but the procedures used will need to take account of their prevalence in the specific population examined (see Supplementary Note 3 for a more detailed description of these conditions).…”