Transferrin receptor expression in reactive and neoplastic lesions of lymphnodes

Transferrin, the major iron binding protein in human plasma transports iron to various tissues. The first step in cellular iron uptake is binding of transferrin complex to the cell surface membrane by specific molecule known as transferrin receptors. Transferrin receptors are found in limited sites in normal tissues, in contrast, the receptors are widely distributed in majority of carcinomas and sarcomas. Presence of increased transferrin receptors implies a stage of moderate or less differentiation corresponding to elevated proliferative activity and therefore, has a prognostic value. Demonstration of transferrin receptors and its distribution pattern within a tumour as well as its quantitative determination can provide data helpful for, both, an additional understanding of tumour biology and as an approach for planning therapy. In present study, we analysed 60 cases, 30 each of reactive lymphadenitis and lymphomas for transferrin receptors using immunohistochemical technique (DAKO, Code-K0673). Grade II and Grade III intensity was recorded in the germinal centers and the histiocytes in sinus histocytosis indicating the proliferating cells and activated histocytes. Most of the low grade non-Hodgkin lymphomas (83.66%) showed weak (Grade I) positivity for transferrin receptors. Intermediate grade lymphomas showed moderate (Grade II) to high intensity (Grade III) for transferrin receptors (57.14% and 42.85%) respectively. Seventy five percent of high grade lymphomas showed strong (Grade III) positivity. All the 9 cases of Hodgkin lymphoma (100%) showed grade III positivity. Proportion of the cells within a tumour expressing transferrin receptors in high density are therefore likely to represent the growth fraction of the tumour.