Studies in polycythemia after kidney transplantation

Area of Science:

• Nephrology
• Hematology
• Stem Cell Biology

Background:

• Kidney transplantation can lead to polycythemia.
• The underlying mechanisms of post-transplant polycythemia are not fully understood.
• Distinguishing it from polycythemia vera is clinically important.

Purpose of the Study:

• To investigate the erythropoietin-dependent proliferation of mononuclear cells in patients with post-kidney transplant polycythemia.
• To compare these findings with polycythemia vera and normal controls.

Main Methods:

• Mononuclear cells from six kidney transplant recipients with polycythemia were cultured in methyl cellulose.
• Cultures were performed using fetal calf serum with/without erythropoietin and in synthetic medium.
• Results were compared to polycythemia vera and normal subjects.

Main Results:

• Erythropoietin-independent proliferation, characteristic of polycythemia vera, was not observed in kidney transplant patients.
• Erythroid colony formation was detected in fetal calf serum cultures without added erythropoietin.
• This suggests increased sensitivity or proliferation of erythropoietically determined stem cells.

Conclusions:

• Post-transplant polycythemia in kidney recipients differs from polycythemia vera in its proliferative characteristics.
• Evidence suggests an altered erythropoietin sensitivity or stem cell behavior in these patients.