Intercellular adhesion molecule-1(ICAM-1), CD44s expression and serum level of sICAM-1 in disseminated non-Hodgkin's lymphoma: correlation with overall survival.

BACKGROUND AND PURPOSE

Uncontrolled growth, invasion and distant spread are the characteristics of neoplastic cells. Changes in adhesion molecule expression, such as loss of expression, de novo expression or functional alterations, can be observed in each of these steps. The aim of the present work was to study the expression of two adhesion molecules [standard CD44 (CD44s) and intercellular adhesion molecule-1 (ICAM-1)] and the soluble form of ICAM-1(sICAM-1) in adult disseminated non-Hodgkin's lymphoma (D-NHL) and to correlate the findings with overall survival.

PATIENTS AND METHODS

The expression of CD44s and ICAM-1 adhesion molecules and the level of sICAM-1 were studied in 34 cases of (D-NHL). They included: 13 cases of lymphoblastic lymphoma (LBL), 5 cases of Burkitt's lymphoma (BL), one case of diffuse large cell lymphoma (DLCL), 14 cases of small lymphocytic lymphoma (SLL), one case of mantle cell lymphoma (MCL). Ten apparently healthy individuals were taken as a control group. CD44s expression was evaluated by direct immunofluoresence, ICAM-1 by immunoperoxidase on cyto-preps and serum level of sICAM-1 by ELISA.

RESULTS

ICAM-1 was positive in 6/34 cases (17.6%) of D-NHL. ICAM-1 was expressed in 2/15 (13.3%) of low-grade NHL and 4/19 (21%) of high-grade lymphoma with no significant difference between the two groups (p=0.6). CD44s was expressed in 13/34 cases (38.2%) of D-NHL; in 4/15 (26.6%) of low grade NHL and 9/19 (47.3%) of high grade lymphoma with no significant difference between the two groups (p=0.2). The serum levels of sICAM-1 were elevated in all patients with D-NHL compared to healthy controls with a statistically significant difference (p <0.001), (median 1160 ng/ml, range from 150 to 2500 ng/ml, and 375 ng/ml, range from 270 to 620 ng/ml, respectively). The median of sICAM-1 in patients with high-grade D-NHL was significantly (p=0.006) lower than that of those with low-grade D-NHL (median 890 ng/ml, range from 150 to 1540 ng/ml and 1440 ng/ml, range from 380 to 2500 ng/ml respectively). The median follow-up duration for all patients was 18 months. No statistical significant difference was achieved (p=0.8) on comparing overall survival pattern between D-NHL lymphoma patients with positive or negative expression of ICAM-1 or sCD44 expression. Also, no statistically significant difference (p=0.9) was found between patients with sICAM (above and below 600 ng/ml) at 18 months from diagnosis.

CONCLUSION

There is a marked heterogeneity in cell adhesion molecule (CAM) expression in NHL and this may correlate with degree of differentiation of malignant lymphocytes. However the exact significance of these findings will require functional studies to determine the role of these CAMs in each subtype of NHL.