Expression of Inhibitory Molecules (Arginase-1, IDO, and PD-L1) by Myeloid-Derived Suppressor Cells in Multiple Myeloma Patients in Remission.

We studied suppressor potential of myeloid-derived suppressor cells (MDSC) in multiple myeloma patients, including before and after mobilization of hematopoietic stem cells (HSC), by evaluating the expression of arginase-1 (Arg1), indolamine-2,3-dioxygenase (IDO), and PD-L1 in MDSC subsets. The study included 20 multiple myeloma patients in remission, 5 patients with progression, as well as 10 sex-and age-matched healthy donors. The expression of Arg1, IDO, and PD-L1 in circulating granulocytic MDSC (G-MDSC, Lin-HLA-DR-CD33+CD66b+), monocytic MDSC (M-MDSC, CD14+HLA-DRlow/-), and early-stage MDSC (E-MDSC, Lin-HLA-DR-CD33+CD66b-) was evaluated by flow cytometry. Multiple myeloma patients in remission were characterized by reduced expression of Arg1 in M-MDSC in comparison with donors. The expression of Arg1 in M-MDSC depended on the number of induction therapy lines performed and was significantly lower in patients who received ⩾2 lines and responded with remission. Patients with multiple myeloma progression (resistant to therapy) showed significantly increased expression of Arg1 and PD-L1 in M-MDSC, as well as increased expression of Arg1 in E-MDSC. After G-CSF-induced mobilization of HSC, the content of circulating Arg1-expressing M-MDSC increased significantly. Considering the presence of MDSC in apheresis products, MDSC suppressive activity is discussed as a factor affecting the outcomes of autologous HSC transplantation in multiple myeloma patients.

[A case of chronic Budd-Chiari syndrome].

The Budd-Chiari syndrome is a rare disease associated with occlusion of the hepatic vein by a tumor or a thrombus. It develops due to progressive narrowing or occlusion of the hepatic veins and may occasionally proceed through the chronic disease within months, rarely years as individual recurrences, with pains, enlarged liver, and mild jaundice. These patients generally have partial hepatic vein occlusion. The paper describes a long (more than 20 years) course of the Budd-Chiari syndrome in which only a special angiographic study could verify the presumptive diagnosis and reveal the cause of evolving liver cirrhosis.