Erythropoietin production in patients with malignant lymphoma.

Lymphomas are a heterogenous group of malignant diseases. 30-50% of patients, even before chemo- and radiotherapy are begun have anemia. The pathogenesis of this anemia is multifactorial and still not completely clear. Newer investigations refer to a causality between the anemia in patients with lymphoma and the inappropriate erythropoietin production for the degree of anemia. Based on this finding, the aim of the study was to evaluate the erythropoietin production in patients with malignant lymphoma in order to define the clinical conditions of Epo deficiency and thereby enable rational use of this expensive drug. 27 patients with malignant lymphoma were examined. The control group consisted of 25 patients with iron deficiency anemia. 14 healthy volunteers represented the so-called "normal" control. The adequacy of Epo production was estimated from the graphic representation of the linear regression between Epo and hemoglobin (Hb) in the control group, as well as from the O/PEpo ratio as a measure of the degree of adequacy of Epo production (O - observed Epo value, P-predicted Epo value from the regression equation of the control group). The erythropoietic activity was estimated from the graphic representation of the linear regression between soluble transferrin receptors (sTfR) and Hb in the control group, as well as from the O/PsTfR ratio, as a measure of the degree of adequacy of erythropoietic activity (O - observed sTfR value, P - predicted sTfR value from the regression equation of the control group). Significant inverse correlation between Epo and Hb was found in patients with malignant lymphoma (r= -0.76, p < 0.001). 33% of patients had inadequate Epo response to anemia. O/PEpo in patients with malignant lymphoma is significantly lower in comparison to the control group, which also points to the inadequacy of erythropoietin production. There was a significant negative correlation between sTfR and Hb in patients with malignant lymphoma (r= -0.056, p < 0.001). Inadequate sTfR response to anemia have 76% of patients. The positive correlation between O/PEpo and O/PsTfR (r=0.79, p < 0.001) points out to a causality between the inadequacy of erythropoietin production and the inadequate erythropoiesis. In conclusion, results from this study show unambiguously that anemia in patients with malignant lymphoma appears because of decreased erythropoiesis as a consequence of bone marrow infiltration with lymphoma cells as well as inadequate Epo production. Most probably, the inadequate Epo production in patients with malignant lymphoma is as that seen in the anemia of chronic diseases whose mechanism is not clear.