The peripheral blood (PB) monocytes and monocyte-derived macrophages (MDM) of SS and SLE patients manifest significantly impaired ApoCell-phagocytosis.

<p>The aberrant uptake of apoptotic cells by blood-borne phagocytes largely resides in the patients' sera. <b>A.</b> Significantly decreased ApoCell-phagocytosis by PB monocytes in SS and SLE patients, but not in RA. <b>B–C.</b> The ApoCell-phagocytosis index values observed in SS and SLE patients correlated inversely with the disease activity indices of these diseases. <b>D.</b> Decreased ApoCell-phagocytosis by MDM in SS and SLE patients. <b>E.</b> Cross-admixture experiments illustrating the significantly reduced capacity of sera from SS and SLE patients to support ApoCell-phagocytosis by normal peripheral blood (PB) monocytes, in contrast to sera from HBD and from RA patients. In panels A, C and D the horizontal lines indicate the median levels in each group, whereas the numbers in boxes indicate the percentages of individuals with decreased ApoCell-phagocytosis, as defined by the presence of ApoCell-PhI values that were two standard deviations below the corresponding mean of HBD. Statistically significant comparisons of patient groups to HBD are shown. In panel B, the mean ApoCell-PhI values of SS-derived MDM were marginally different compared to MDM (p = 0.06).