Hematologic Abnormalities in Patients with Renal Diseases

Production of erythropoietin and multiple cytokines by metanephric adenoma results in erythrocytosis

This is the first report of direct evidence that metanephric adenoma cells produce erythropoietin and other types of cytokines, which may be the cause of the high incidence of erythrocytosis in patients with this tumor. The purpose of the study was to establish a metanephric adenoma cell line in vitro from nephrectomized tumor tissue in order to investigate the ability of metanephric adenoma cells to produce erythropoietin and other types of cytokines. The tumor tissue was obtained from a 16-year-old boy who had developed metanephric adenoma with erythrocytosis and was served for cell culture. Significantly high concentrations of erythropoietin, granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte-colony-stimulating factor (G-CSF), interleukin-6 (IL-6), and IL-8 were detected in the cell culture supernatant. Southern hybridization showed specific positive signals for GM-CSF, G-CSF, IL-6, IL-8 and erythropoietin. The number of chromosomes was 46-XY without any structural abnormalities in cytogenetic analysis of the cultured cells.

Enzymes that hydrolyze adenine nucleotides in chronic renal failure: relationship between hemostatic defects and renal failure severity

The activities of the enzymes NTPDase (E.C.3.6.1.5, apyrase, ATP diphosphohydrolase, ecto-CD 39) and 5'-nucleotidase (E.C.3.1.3.5, CD 73) were analyzed in platelets from patients with chronic renal failure (CRF), both undergoing hemodialysis treatment (HD) and not undergoing hemodialysis (ND), as well as from a control group. The results showed an increase in platelet NTPDase activity in CRF patients on HD treatment (52.88%) with ATP as substrate (P<0.0001). ADP hydrolysis was decreased (33.68% and 39.75%) in HD and ND patients, respectively. In addition, 5'-nucleotidase activity was elevated in the HD (160%) and ND (81.49%) groups when compared to the control (P<0.0001). Significant correlation was found among ATP, ADP and AMP hydrolysis and plasma creatinine and urea levels (P<0.0001). Patients were compared statistically according the time of hemodialysis treatment. We found enhanced NTPDase and 5'-nucleotidase activities between 49 and 72 months on HD patients. Our result suggests the existence of alterations in nucleotide hydrolysis in platelets of CRF patients. Possibly, this altered nucleotide hydrolysis could contribute to hemostasis abnormalities found in CRF.

Neuroblastoma with expression of erythropoietin resulting in erythrocytosis

We report the detection of erythropoietin mRNA in the tumor from a patient with neuroblastoma and erythrocytosis. A 2-year-old girl with neuroblastoma presented with hemoglobin 21.3 g/dL, red blood cells 8.03 x 1012/L, and hematocrit 0.641. The serum erythropoietin level was 26.54 mU/mL. The hemoglobin, hematocrit, and serum erythropoietin level were within normal ranges 3 months after surgical excision of the tumor. RT-PCR analysis showed that erythropoietin mRNA expression in the tumor tissue was as high as that of normal renal tissue. These results conclusively demonstrated that the tumor was the site of the ectopic erythropoietin production.

Hemostasis, platelet function and serotonin in acute and chronic renal failure

A pathogenetic role for fibrin deposition and platelet activation in the kidney is thought to play a role in the pathogenesis of acute renal failure (ARF). Thus, some fibrinolytic parameters and platelet function have been studied in 17 patients with ARF and compared to healthy volunteers and subjects with chronic renal failure (CRF). Since serotonin may participate in pathological processes resulting from platelet/vessel wall interactions, its level in the whole blood and plasma was also assayed. In ARF and CRF platelet aggregatory responses in both whole blood and in platelet rich plasma upon stimulation with various agonists (collagen, arachidonic acid, ADP, ristocetin) were lower than those obtained in healthy volunteers. Increased levels of lipoprotein (a), von Willebrand factor (vWF) and fibronectin were found in ARF relative to controls. Protein C activity was significantly lower in patients with ARF. Euglobulin clot lysis time was prolonged in ARF and CRF, reflecting a decreased overall fibrinolytic activity. Activity of tissue plasminogen activator (tPA) inhibitor (PAI) and PAI:Ag were higher in ARF, whereas tPA:Ag, urokinase, tPA/PAI complexes, thrombin-antithrombin complexes (TAT), plasmin-antiplasmin (PAP) complexes, fibrinogen, and F1+2 did not differ between ARF and controls. In CRF elevated levels of TAT, PAP, fibrinogen and prothrombin fragments F1+2 were found, whereas concentration of fibronectin was lowered when compared to controls. In both groups of renal failure patients increased levels of fibrin monomers and d-dimer were found relative to healthy volunteers. Whole blood serotonin was significantly lower, whereas plasma serotonin was significantly higher in patients with ARF and CRF relative to controls. Serotonin uptake and its release from platelets were markedly diminished in patients with ARF and CRF. Chronic renal failure exhibit a slightly different pattern of coagulopathies that acute renal failure.

Hemostasis in renal disease: pathophysiology and management

The hemostatic abnormalities commonly encountered in patients with renal disease can significantly threaten the well-being of the patient and pose difficult management issues for the clinician. In this review, we explore the pathophysiology underlying the bleeding diathesis and hypercoagulability that can occur. Current therapeutic interventions are also discussed.

Paraneoplastic erythrocytosis in a young adult with an erythropoietin-producing Wilms' tumor

Paraneoplastic erythrocytosis in patients with Wilms' tumors is exceedingly rare, with only three reported cases in the literature. We report a case of a young man with Wilms' tumor with a significant erythrocytosis but a normal serum erythropoietin level and a tumor that elaborated erythropoietin.