Cell surface proteoglycan expression during maturation of human monocytes-derived dendritic cells and macrophages.

Cell surface proteoglycans play an important part in the functional and metabolic behaviour of leucocytes. We studied the expression of cell surface proteoglycans in human monocytes, in monocyte-derived immature and mature dendritic cells and in macrophages by metabolic labelling with [(35)S]-sulphate, reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. Immature dendritic cells had the highest metabolic activity for the synthesis of cell surface proteoglycans. The major part of these proteoglycans was in phosphatidylinositol-anchored form and was released after treatment with phospholipase C. A minor part was released by trypsin. Digestion with chondroitinase ABC and mild HNO(2) treatment showed that cell surface proteoglycans had a higher proportion of chondroitin sulphate, both in the phospholipase C and trypsin fractions, suggesting that at least some glypicans contained chondroitin sulphate chains. RT-PCR detected the transcripts of glypicans 1, 3, 4 and 5 and all syndecans. Immature dendritic cells expressed a most complex spectrum of glypicans and syndecans, glypican-1 and syndecan-1 being expressed preferentially by this type of cells. Mature dendritic cells expressed glypican-3, which was not present in other lineages. These results suggest that different mononuclear cells synthesize cell surface proteoglycans actively with characteristic expression of different syndecans and glypicans genes, depending on the degree of cell differentiation and/or maturation.

[The value of erythrocytic protoporphyrin measurement for screening blood donors for iron deficiency: a decision analysis]. / Intérêt de la mesure de la protoporphyrine érythrocytaire pour le dépistage de la carence en fer chez le donneur de sang: analyse de la décision.

Blood donors are considered as a group with increased risk of iron deficiency. Therefore it seems particularly useful to have a simple screening test at one's disposal in blood centers to detect easily early iron deficiency. Erythrocyte protoporphyrin assay on an hematofluorometer is very easy and of a low cost. So we studied its diagnostic value on a sample of 285 blood donors (131 men and 154 women). Prevalence of iron deficiency, defined by the coexistence of, at least, two abnormal indicators (serum ferritin, transferrin saturation, erythrocyte protoporphyrin, mean corpuscular volume), was 5.6% in this sample; sensitivity of erythrocyte protoporphyrin used alone was 75% and its specificity was 91.5%. We used a decision analysis to evaluate the opportunity of screening with this test, accompanied where indicated by iron supplements. The results, though preliminary, suggest that erythrocyte protoporphyrin measurement could be of interest in screening blood donors for iron deficiency.