Secondary polycythaemia associated with high plasma erythropoietin concentrations in a dog with a necrotising pyelonephritis

Abstract

An 11-year-old mixed breed dog was presented with anorexia, apathy and intermittent macrohaematuria, absolute polycythaemia (packed cell volume, 80 per cent; red blood cell, 12.2 x 10(6)/microl) and elevated erythropoietin concentrations. A renal mass was detected by ultrasonography and, following total nephrectomy, diagnosed as necrotising pyelonephritis. After surgery, the haematological parameters and erythropoietin values returned to normal, suggesting that the pyelonephritis was the cause of the polycythaemia. While secondary polycythaemia because of a non-neoplastic condition of the kidneys occasionally occurs in human beings, it has only extremely rarely been reported in dogs. This is the first case report of a unilateral pyelonephritis causing secondary polycythaemia in a dog.

Persistent reticulocytosis in a case of poodle macrocytosis

“…Enhanced erythropoiesis and reticulocytosis occur in response to renal hypoxia and increased erythropoietin secretion. Erythropoietin is produced primarily by renal interstitial cells in response to reduced renal oxygen tension, usually as the result of a low HCT or renal disease affecting renal perfusion . Rarely, congenital or acquired conditions with hemoglobin oxygen‐carrying capacity reductions, such as methemoglobinemia or carboxyhemoglobinemia, can stimulate erythrogenesis .…”

Renal adenocarcinoma-associated erythrocytosis in a cat: Clinicopathological features and immunohistochemical results

“…The latter mechanism is supported by the evidence that nonneoplastic kidney diseases (e.g. cysts, hydronephrosis, and pyelonephritis) or metastatic renal involvement have been associated with SIE in humans and dogs (Hirsch and Leiter, 1983;Kessler, 2008;Pejcic et al, 2011). Primary renal cell carcinoma often overproduces EPO in humans, even if epithelial tubular cells are unable to secrete EPO in normal conditions.…”

“…Secondary appropriate erythrocytosis arises in response to persistent systemic hypoxia, which is absent in the inappropriate form (Nitsche, 2004). Secondary inappropriate erythrocytosis (SIE) occurs in association with different neoplasms and renal diseases (Kessler, 2008). In particular, a link between renal neoplasia and SIE has been widely reported in humans and dogs (Hodges et al, 2007;Durno et al, 2011;Osumi et al, 2013;), but has only occasionally described in cats (Hasler and Giger, 1996;Henry et al, 1999;Yuki et al, 2005;Klainbart et al, 2008;Noh et al, 2013).…”

“…Phlebotomy could also stabilize patients with SIE before the definitive treatment (e.g. surgical removal of the underlying neoplasia or the renal lesion) is performed (Nitsche, 2004;Kessler, 2008;Klainbart et al, 2008;Liu et al, 2013). Repeated phlebotomies to treat absolute erythrocytosis may lead to hypovolemia, hypoalbuminemia and coagulation factor deficiency (Nitsche, 2004;Liu et al, 2013).…”

“…In the case here presented, the CBC returned within RI shortly after surgery, and remained stable at the rechecks performed through the following months. Variable time rates for normalization of RBC parameters, ranging from few days to weeks after surgery, have been noticed in veterinary patients (Kessler, 2008;Klainbart et al, 2008;Noh et al, 2013). Several factors including the degree of surgical bleeding, inflammation, timing of phlebotomies, frequency of monitoring and presence of chronic kidney disease may account for the reported variability, making comparisons hard to perform.…”