Expression of CD29 on lymphoma cells and/or CD36 on microvascular endothels correlates with high serum LDH level in diffuse large B-cell lymphomas (DLBCLs) and is frequent in de novo CD5-positive DLBCLs.

Our previous study demonstrated that CD29 and CD36 mRNAs were overexpressed in de novo CD5-positive diffuse large B-cell lymphomas (CD5+ DLBCLs) compared with CD5-negative (CD5-) DLBCLs. CD29 was expressed on lymphoma cells, and CD36 on microvascular endothels. In the present study, we analyzed the clinicopathological significance of CD29 and microvascular CD36 (mvCD36) expression in many cases of DLBCLs. CD29 and CD36 expression was examined by immunohistochemistry on frozen sections of 159 specimens, consisting of 120 cases of CD5-DLBCL, 14 cases of de novo CD5+ DLBCL, 11 cases of follicular lymphoma, 8 cases of mantle cell lymphoma, and 6 cases of reactive lymphoid hyperplasia. Three cases of CD5- intravascular large B-cell lymphomas (IVLs) with hepatic intrasinusoidal infiltration were also examined. CD29+ and/or mvCD36+ DLBCL cases had significantly higher serum LDH levels compared with CD29- mvCD36- DLBCL cases. The number of CD29+ and mvCD36+ cases, and the number of CD29+ or mvCD36+ cases, were significantly higher in de novo CD5+ DLBCLs than in CD5- DLBCLs. The frequencies of CD29 and mvCD36 expression were low in follicular lymphomas, and mvCD36 was negative in reactive lymphoid hyperplasias. Liver biopsies of three IVL cases showed that CD29 was positive on lymphoma cells, and, that CD36 was expressed on hepatic sinusoids. The present study supports the notion that CD29 and/or mvCD36 expression manifests the aggressive feature of a subset of DLBCLs because of its correlation with high serum LDH levels. Furthermore, CD29 and mvCD36 expression should be evaluated in relation to the intravascular growth pattern of lymphoma cells.