LM Evers

CD27, a transmembrane disulfide-linked 55-kD homodimer, belongs to the nerve growth factor-receptor family, a group of homologous molecules involved in lymphocyte differentiation and selection. It is expressed on mature thymocytes, peripheral blood T cells, and a subpopulation of B cells. We investigated the expression of CD27 on malignant B cells representative for a broad range of stages in physiologic antigen-independent and -dependent B-cell development. In normal lymphoid tissue CD27+ B cells were only found in the peripheral blood (29.8% +/- 10.8%, n = 13) and in germinal centers. With the exception of pro-B and the majority of pre-pre-B acute lymphocytic leukemias and of myelomas, CD27 expression of variable intensity was detected on almost all immature and mature malignant B cells tested. Moreover, using a sandwich enzyme-linked immunosorbent assay we could show the presence of sometimes very high (up to 6,000 U/mL; normal values < 190 U/mL) amounts of the soluble 28- to 32-kD form of CD27 (sCD27) in the sera of patients with B-cell malignancies. The highest levels of sCD27 were observed in patients with chronic lymphocytic leukemia and low-grade non-Hodgkin's lymphomas. Most importantly, both in transversal and longitudinal studies, we found a strong correlation between sCD27 levels in the serum and tumor load, indicating that sCD27 can be used as a disease-marker in patients with acute and chronic B-cell malignancies.

Diagnosis of meningeal localization of lymphoid malignancies by means of cytologic examination of the cerebrospinal fluid (CSF) can be difficult. Thus far no reliable CSF tumor markers have been identified. CD27 is a transmembrane disulfide-linked 55-kD homodimer present on most peripheral blood T cells and on a subset of B cells. CD27 is also expressed on human malignant B cells and high levels of soluble CD27 can be present in the serum of patients with B-cell malignancies. The aim of this study is to determine prospectively the diagnostic value of CSF sCD27 as a tumor marker in patients with meningeal localization of lymphoid malignancies. CSF sCD27 levels were determined by sandwich enzyme-linked immunosorbent assay. The optimal cut-off value using receiver operator characteristics curves was found to be 10 U/mL. sCD27 levels were normal in all 50 control patients (lumbar disc protrusion) and in 39 of 40 samples obtained from patients with either solid tumors or acute myeloid leukemia. Of 104 CSF samples from 70 children with acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL) undergoing routine central nervous system (CNS) staging, sCD27 was false positive and false negative in only one sample each. In 70 samples from 45 patients suspected of meningeal localization of ALL or NHL, the sCD27 test had an excellent sensitivity (100%) and specificity (82%). In 7 patients with positive CSF studied longitudinally, sCD27 levels correlated very well with remission and relapse. sCD27 levels were not nonspecifically increased by the administration of cytostatic drugs. Finally, sCD27 was also elevated in the 4 patients studied with primary central nervous system lymphoma (PCNSL). CSF sCD27 is a promising tumor marker in patients with either meningeal localization of lymphoid malignancies or PCNSL, and can be useful in the differential diagnosis of CNS involvement by either lymphoid malignancies or solid tumors.

Diagnosis of meningeal localization of lymphoid malignancies by means of cytologic examination of the cerebrospinal fluid (CSF) can be difficult. Thus far no reliable CSF tumor markers have been identified. CD27 is a transmembrane disulfide-linked 55-kD homodimer present on most peripheral blood T cells and on a subset of B cells. CD27 is also expressed on human malignant B cells and high levels of soluble CD27 can be present in the serum of patients with B-cell malignancies. The aim of this study is to determine prospectively the diagnostic value of CSF sCD27 as a tumor marker in patients with meningeal localization of lymphoid malignancies. CSF sCD27 levels were determined by sandwich enzyme-linked immunosorbent assay. The optimal cut-off value using receiver operator characteristics curves was found to be 10 U/mL. sCD27 levels were normal in all 50 control patients (lumbar disc protrusion) and in 39 of 40 samples obtained from patients with either solid tumors or acute myeloid leukemia. Of 104 CSF samples from 70 children with acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL) undergoing routine central nervous system (CNS) staging, sCD27 was false positive and false negative in only one sample each. In 70 samples from 45 patients suspected of meningeal localization of ALL or NHL, the sCD27 test had an excellent sensitivity (100%) and specificity (82%). In 7 patients with positive CSF studied longitudinally, sCD27 levels correlated very well with remission and relapse. sCD27 levels were not nonspecifically increased by the administration of cytostatic drugs. Finally, sCD27 was also elevated in the 4 patients studied with primary central nervous system lymphoma (PCNSL). CSF sCD27 is a promising tumor marker in patients with either meningeal localization of lymphoid malignancies or PCNSL, and can be useful in the differential diagnosis of CNS involvement by either lymphoid malignancies or solid tumors.

The glycocalyx is an important anti-inflammatory and anti-adhesive barrier at the luminal side of endothelial cells. Glycocalyx volume was significantly reduced in sickle cell patients (HbSS/HbSbeta(0)-thalassemia median 0.47L, IQR 0.27-0.66, HbSC/HbSbeta(+)-thalassemia 0.23L, 0.0-0.58) compared with controls (1 x 10(9)L, 0.52-1.77) (p=0.03). Reduced glycocalyx may be a new factor in the pathophysiology of sickle cell disease.

CD27, a transmembrane disulfide-linked 55-kD homodimer, belongs to the nerve growth factor-receptor family, a group of homologous molecules involved in lymphocyte differentiation and selection. It is expressed on mature thymocytes, peripheral blood T cells, and a subpopulation of B cells. We investigated the expression of CD27 on malignant B cells representative for a broad range of stages in physiologic antigen- independent and -dependent B-cell development. In normal lymphoid tissue CD27+ B cells were only found in the peripheral blood (29.8% +/- 10.8%, n = 13) and in germinal centers. With the exception of pro-B and the majority of pre-pre-B acute lymphocytic leukemias and of myelomas, CD27 expression of variable intensity was detected on almost all immature and mature malignant B cells tested. Moreover, using a sandwich enzyme-linked immunosorbent assay we could show the presence of sometimes very high (up to 6,000 U/mL; normal values &lt; 190 U/mL) amounts of the soluble 28- to 32-kD form of CD27 (sCD27) in the sera of patients with B-cell malignancies. The highest levels of sCD27 were observed in patients with chronic lymphocytic leukemia and low-grade non-Hodgkin's lymphomas. Most importantly, both in transversal and longitudinal studies, we found a strong correlation between sCD27 levels in the serum and tumor load, indicating that sCD27 can be used as a disease-marker in patients with acute and chronic B-cell malignancies.