Human leukocyte antigen-class I (HLA-I) molecules are membrane-associated proteins that contain two separate polypeptide chains: an alpha heavy chain and a beta chain. The beta chain is the b-2 microglobulin (b2-M). Significant levels of free soluble HLA-I (sHLA-I) have been detected in serum and studied as a marker for immunomodulation in patients with infection and after transplant. Little is known about the role of sHLA-I as a tumor marker, despite the documentation of b2-M as a tumor marker. We measured the levels of sHLA-I and b2-M in the plasma of 205 patients with acute myeloid leukemia (AML) and 95 patients with myelodysplastic syndrome (MDS) and assessed the value of both markers in predicting clinical behavior. Both sHLA-I and b2-M were strong predictors of response to therapy (P = 0.03 and P = 0.001, respectively), overall survival (both P <0.0001), and remission duration (both P <0.001). The Multivariate Cox proportional hazards model incorporating cytogenetics, b2-M, and sHLA-I demonstrated that only b2-M was an independent predictor of survival. In patients with MDS, b2-M but not sHLA-I correlated with response to therapy, overall survival, and response duration. These data not only establish the role of sHLA-I as a tumor marker in AML, but also suggest that MDS disease is significantly different from AML. Because sHLA-I has been reported to be an immunomodulator that inhibits the cytotoxic effects of T-lymphocytes, its role as an immunomodulator in patients with MDS needs further investigation.

Figure
View largeDownload slide

Figure

Topics:
human leukocyte antigens, leukemia, myelocytic, acute, myelodysplastic syndrome, tumor marker, immunologic adjuvants, alpha heavy chains, antigens, disease remission, infections, membrane proteins

Author notes

Corresponding author

2005, The American Society of Hematology
2004
Sign in via your Institution