Changes in RDW according to prognostic predictors in newly diagnosed multiple myeloma.

RDW is an erythrocyte index that increase in multiple myeloma, in which it appears to have an important role in predicting outcome. For this reason, we performed a retrospective analysis to evaluate the relationships of RDW with some important prognostic predictors. Specifically, in a cohort of 190 newly diagnosed multiple myeloma patients, we have examined the behaviour of RDW and its trend in relation to the ISS stage and other prognostic factors, such as albumin, beta-2 microglobulin, LDH and bone marrow plasma cell infiltration. We performed the analysis in the entire cohort of patients and in the three different disease isotypes (Light chain, IgA, and IgG multiple myeloma). The evaluation of RDW in the different isotypes was made with the Kruskal-Wallis test, integrated by the Dunn test. The comparison between the subgroups allocated above and below the median value of each prognostic factor, was made with the Mann-Whitney test. From our analysis, we observed that RDW is higher in the IgA multiple myeloma, and it increases significantly from ISS I to III. Moreover, RDW increases in the presence of lower albumin values, higher levels of beta2-microglobulin and LDH and in the presence of a greater bone marrow plasma cell infiltrate.

Techniques to evaluate erythrocyte deformability in diabetes mellitus.

Using several rheological techniques, we examined erythrocyte deformability in different groups of diabetic subjects. The macrorheological techniques used for this evaluation were respectively whole-blood filtration, filtration of erythrocyte suspensions, polyviscosimetry and diffractometry. Whole-blood filterability, at a negative pressure of 20 cm water, was decreased in type 2 diabetics; no difference was evident at a negative pressure of 10 cm water. The filtration of erythrocyte suspensions at low haematocrit (5%) did not show differences between normal and diabetic subjects. Polyviscosimetry, which explores the filterability of erythrocyte suspensions at high haematocrit (80%) through wide pores, demonstrated an impaired behaviour especially in type 2 diabetics. Diffractometry, which measures erythrocyte elongation induced by a defined shear stress through the diffraction pattern of a laser beam, showed an alteration in type 1 diabetic subjects. The microrheological methods employed for this evaluation were those based on fluorescence spectroscopy. Labeling intact red blood cells with fluorescent probes, we determined the membrane dynamic properties and using these techniques we found a reduction of erythrocyte membrane fluidity and a decrease of red cell membrane protein lateral mobility.