[Indoleamine 2, 3-dioxygenasase (IDO) as a prognostic factor of hematological malignancies]

Indoleamine 2,3-dioxygenase (IDO) catalyses tryptophan degradation in the kynurenine pathway, and plays an important role in immune tolerance by regulating antigen-presenting cells. We introduce the results of our investigations of IDO for hematological malignancies. Serum L-kynurenine (KYN) for diffuse large B cell lymphoma (DLBCL): The Complete remission (CR) rates of patients with lower KYN and higher KYN were 83% and 61%, respectively (p < 0.05). The 3-year overall survival (OS) rates for patients with lower KYN and higher KYN were 89% and 58%, respectively (p < 0.005). IDO expression for DLBCL: CR rates in patients with IDO-positive DLBCL and IDO-negative DLBCL were 55.3% and 79.0% (p = 0.008), while 3-year overall survival rates were 49.8% and 78.8%, respectively (p = 0.0003). Serum KYN and IDO expression for DLBCL: Three-year OS rates were 55% and 78% for patients with higher KYN and lower KYN, respectively (p = 0.027), and 44% and 75% for patients with IDO-positive and IDO-negative DLBCL, respectively (p = 0.0017). Patients with low KYN and IDO-negative showed the best outcomes, while patients with high KYN and IDO-positive showed the poorest outcome. Serum KYN for T-cell lymphoma: The 5-year OS rates for patients with lower KYN and higher KYN were 77% and 38%, respectively (p < 0.005). Serum KYN and IDO expression for AML: The 5-year OS rates for patients with lower KYN and higher KYN were 68% and 11%, respectively (p < 0.05). The 5-year OS rates for patients with IDO mRNA expression and without IDO mRNA expression were 64% and 41%, respectively (p < 0.05). IDO activity might play an important role in the disease activity of hematological malignancies.