High endothelial venules and cell adhesion molecules in B-cell chronic lymphocytic leukaemia and related low grade B-cell lymphoma/leukaemia: I. High endothelial venules and lymphocyte migration.

The high endothelial venule (HEV)-content and the lymphocyte migration index (LMI) of reactive lymph nodes and lymph nodes from patients with B-cell chronic lymphocytic leukaemia (B-CLL), as well as some related B-cell malignancies (lymphocytic lymphoma -LL-, prolymphocytic leukaemia -PLL-) were determined and statistically analyzed. The HEV-content and the LMI were significantly higher in reactive lymph nodes than in the low grade B-cell lymphomas and leukaemias (p < 0.001). The number of HEVs among lymphoma/leukaemia cases was the highest in LL independently of the maturation. However, the maturation of the process seems to determine the intensity of lymphocyte migration; i.e. a significantly higher LMI was found in mature (B-CLL, PF, mature; M and LL, M) than in immature subtypes (B-CLL, PF, immature -IM-; diffuse -D- and LL, IM) subtypes (levels of significance varied from p < 0.05 to p < 0.001). Based on these findings, a more intense migration of lymphocytes from blood to peripheral lymph nodes may be supposed in LL than in B-CLL, thus explaining the nodal sites of involvement in LL and the peripheral blood in B-CLL. Within the same histological categories the morphometric features in mature subtypes may implicate an enhanced HEV-lymphocyte interaction when compared to the immature subtypes.