Serum levels of circulating ICAM-1 are increased in Hodgkin's disease.

The intercellular adhesion molecule 1 (ICAM-1) is the ligand for the lymphocyte function-associated antigen 1 (LFA-1). The ICAM-1/LFA-1 complex mediates cell-cell and cell-matrix interactions and is believed to be crucial for several immunological functions, including non-MHC-restricted cytotoxicity. Recently, a circulating form of the surface ICAM-1 molecule, the 82 kDa cICAM, has been identified. Using enzyme-linked immunosorbent assay (ELISA) we have examined 82 kDa cICAM-1 levels in the sera of 45 age- and sex-matched healthy subjects and 130 consecutive patients with Hodgkin's disease (HD). The mean +/- SD concentration of the 82 kDa cICAM-1 was significantly higher (p < 0.001) in HD patients (725.6 +/- 141 ng/ml) than in healthy controls (403.5 +/- 54.5 ng/ml). Patients with B-symptoms (n = 66) had higher cICAM-1 levels than patients without systemic symptoms (n = 64) (825.1 +/- 202.9 ng/ml versus 671.7 +/- 164.9 ng/ml; p < 0.001). Serum levels of cICAM-1 were also significantly higher (p < 0.05) in patients with disseminated disease (stage III and IV) than in those with localized disease (stage I and II). The HD patients in stage III and IV with B-symptoms had significantly higher (p < 0.001 and p < 0.02, respectively) cICAM-1 levels then stage III/IV patients lacking B-symptoms. The increase of cICAM-1 concentrations was positively correlated to increases of soluble receptors for interleukin-2 (sIL-2R) (r = 0.69; p < 0.001). Since cICAM-1 is functionally able to bind to LFA-1, increased serum levels of this molecule could be a mechanism for promoting de-adhesion and inability of Hodgkin and Reed-Sternberg cells (H-RS) to be recognized by cytotoxic effector cells, and could thus represent a way for these cells to escape immunosurveillance and for progression and spreading of disease.