Alterations of the sugar moiety of Tamm-Horsfall protein in children with malignancies of lymphoid cells.

The aim of this study was to examine whether the sugar moiety of Tamm-Horsfall protein (THP) is affected by pathological processes caused by acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL). The carbohydrate part of THP was studied by monosaccharide analysis, N-glycan profiling, and reactivity with specific lectins. Our results have shown that THP of ALL or NHL patients, in comparison with healthy subjects, have modified sugar chains. This is expressed in lower contents of N-acetylgalactosamine, alpha2,6-linked sialic acid and alpha1,6-linked fucose as well as in altered proportions of various N-glycans. We have shown that pathological processes also affect the carbohydrate unit of human immunoglobulin G (IgG) isolated from sera of ALL or NHL patients. As compared with healthy subjects, in IgG of the patient group, lower amounts of sialic acid and fucose were observed. These changes did not influence the biological properties of THP as judged by their unaltered ability to bind with interleukin-1alpha, alpha1-acid glycoprotein, serum albumin, transferrin, IgG1 and the light and heavy chains of IgG. Neither the in vivo alterations of IgG caused by ALL or NHL nor its in vitro modifications influence the interaction between IgG and THP.