CD38 on B-cell chronic lymphocytic leukemia cells has higher expression in lymph nodes than in peripheral blood or bone marrow

CD38 expression levels in chronic lymphocytic leukemia B cells are associated with activation marker expression and differential responses to interferon stimulation

“…Of interest, recent reports state that CD38 expression is higher in bone marrow and lymphoid tissues, the presumed sites of CLL proliferation and cell activation, compared to peripheral blood. 8,39 These findings suggest that upon CLL B-cell emigration from a lymphoid compartment into blood, the expression of CD38 begins to decrease. In summary, we believe that it is possible that all B-CLL tumorigenic founders are CD38 pos and the CD38 B-cell percentage in peripheral blood is directly proportional to the turnover rate with low turnover favoring the presence of CD38 neg CLL-B cells, since CD38 expression is associated with a higher activation state.…”

Highly purified CD38+ and CD38− sub-clones derived from the same chronic lymphocytic leukemia patient have distinct gene expression signatures despite their monoclonal origin

“…Several recent studies have shown that CD38 expression is higher in CLL cells in the bone marrow and lymphoid tissues when compared to peripheral blood. 8,45 This implies that once CLL cells leave these compartments they begin to lose CD38 expression and by inference, the higher the level of CD38 in the peripheral blood, the higher the degree of renewal/turnover from bone marrow and lymph nodes. Although this is a possibility, it cannot fully explain the consistently high Mcl-1 expression found in CD38 þ CLL cells as Mcl-1 is a labile protein with a half-life of only 1-3 h. 46 Moreover, our data suggest that Mcl-1 expression is actively maintained in peripheral blood CD38 þ CLL cells and that these peripheral blood CLL cells are not merely shadows of a more vibrant counterpart in the bone marrow or lymph nodes.…”

Regulation of CD38 in proliferating chronic lymphocytic leukemia cells stimulated with CD154 and interleukin-4

“…Flow cytometry shows that the expression of CD38 on CLL cells in lymph nodes is greater than that on peripheral blood cells. 18 CLL lymph nodes contain proliferation centers, containing T cells and dendritic cells as well as proliferating CLL cells and this suggests that CD38 expression is regulated by the lymph node microenvironment.…”