Immunochemical characterization of human liver and heart ferritins with monoclonal antibodies.

A library of 27 murine monoclonal antibodies was obtained by using human liver and heart ferritins as immunogens. The specificity of the antibodies for the two ferritins and their subunits was studied with five different methods. The antibodies elicited by the liver ferritin bound preferentially the immunogen and were specific for the L subunit. Some antibodies elicited by the heart ferritin had characteristics similar to the anti-liver antibodies, other ones bound preferentially the heart over the liver ferritin and were specific for the H subunit. Only two antibodies were able to bind both ferritins and subunits. Some anti-H and anti-L chain antibodies were used to develop and compare four types of immunoassay to quantitate isoferritins. The results indicate that heart ferritin is immunologically more heterogeneous than liver, the H and L subunits having large immunological differences with few, if any, identical epitopes; and that that the architecture of the immunoassays have a strong influence on the crossreactivity of the antibodies with the two isoferritins, probably because H and L chains are not arranged randomly in the assembled protein.

Ferritins in malignant and non-malignant lymphoid cells.

Lymphoid cells from peripheral blood, thymus, malignant and non-malignant lymph nodes were analysed for ferritin content using radioimmunoassays specific for the 'acidic' H-subunit-rich and for 'basic' L-subunit-rich isoferritins, and the data were compared with the immunological characteristics of the cells. All tissues with high proportion of T or 'null' cells contained the lowest concentration of L-subunit-rich isoferritins, while the H-subunit-rich forms increased from low levels in the quiescent peripheral blood lymphocytes (PBL), to higher values in the immature and proliferating thymocytes and lymphoblasts, malignant or not. B-cell lymphomas contained concentrations of both ferritin types higher than those found in PBL. No significant difference was found in the isoferritin concentrations between non-malignant lymph nodes and tissues involved in Hodgkin's disease. These findings indicate that maturation stage, proliferative status and anatomical localization affect isoferritin expression in lymphoid cells.

Serum ferritin in type I diabetes.

The concentration and degree of glycosylation of serum ferritin was evaluated in type I male diabetic patients at different levels of glycaemic control. Serum ferritin did not appear to be affected by hyperglycaemia, but some patients undergoing photocoagulation had abnormally high levels of serum ferritin. The glycosylated, (concanavalin A binding), proportion of serum ferritin was essentially the same in the control and diabetic groups. The finding that hyperglycaemia does not affect the degree of enzymatic glycosylation of this serum protein is discussed.