**7. Conflict of interest**

106 Progress in Hemodialysis – From Emergent Biotechnology to Clinical Practice

Preliminary studies in our laboratory have shown an interesting trend in the reduction of total MVs in a cross-over clinical study when patients shifted from high-flux HD to on-line

Fig. 7. Total MVs count in patients on maintenance HD. In a cross-over design, 8 patients were started on bicarbonate HD (black columns) and 8 patients on on-line HDF (grey columns). MVs were counted by cytofluorimetry. MVs were also characterized (data not shown) by the following specific markers: CD62P, CD41, CD42, CD31, for platelets; CD45, for leukocytes; CD31, CD146, CD144 for the endothelium: CD235 and CD242 (ICAM 4), for

More studies are needed to better assess the relevance of these observations and to better characterize the type and biological effects of the MVs. It is still to be fully elucidated whether MVs are a consequence or a cause of disease. Increasing evidence for their pathophysiologic role in other human diseases such as sepsis and tumors (Camussi et al., 2011) is rapidly accruing. Many points require further investigation. i. The stimuli and the molecular pathways that regulate the assembly within MVs of the biological active molecules that they shuttle. ii. The stimuli that trigger their release. iii. The surface receptors that may confer selective specificity. iv. The full diagnostic potential of MVs in different pathological conditions. v. The strategy to inhibit formation or to remove from circulation potentially harmful MVs. The recognition of MVs has opened a new era and new

perspectives of investigation also in biocompatibility of extracorporeal treatments.

The outlook of more biocompatible and physiological dialysis is today confronted with a older and sicker population in need of maintenance HD. The knowledge of biological mechanisms operating at the system level will be approached with the help of improved technologies hopefully able to reduce the deleterious effect of the repetitive contact with a foreign surface and to insure optimal performances for the elimination of small and middle molecule solutes. Advances in dialyzer membranes and geometries, as well as blood tubings

**5.2.3 MVs in treatment modalities** 

HDF (**Figure 7**).

erythrocytes.

**6. Conclusions** 

Ciro Tetta and Emanuele Gatti are full-time employees of Fresenius Medical Care.
