Serum Erythropoietin and Erythropoiesis in Primary and Secondary Hyperparathyroidism: Effect of Parathyroidectomy

Abstract

Primary as well as secondary hyperparathyroidism may be associated with anemia, and parathyroidectomy (PTx) may improve or even heal it. The precise link between the two conditions is still matter of dicussion. The purpose of the present study was to investigate possible effects of PTx on serum immunoreactive erythropoietin (iEPO) in secondary (group I, n = 23), and primary (group II, n = 16) hyperparathyroidism patients, and in 3 patients undergoing cervicotomy for thyroid mass removal (group III). In group I patients, circulating iEPO levels rose from 23.1 ± 4.8 mU/ml before PTx to 28.2 ± 5.0 and 245 ± 125 mU/ml (mean ± SEM) at day 7 (p = NS) and 14 after PTx (p < 0.003), respectively. Reticulocyte count increased 2 weeks after PTx: from 61,000 ± 13,317 to 86,533 ± 13,462/mm³ (p < 0.05, n = 23). In 4 of these patients serum iEPO levels could be measured again 12–24 months after PTx. They were slightly higher than those determined before PTx: 37.0 ± 8.4 versus 31.8 ± 13.5 mU/ml. Their hematocrits were also higher than before PTx: 12.8 ± 0.9 versus 11.0 ± 0.9 g/dl. In group II patients, serum iEPO levels remained unchanged after PTx: 17.5 ± 2.0 mU/ml before PTx and 20.0 ± 3.0 mU/ml 14 days after PTx. The reticulocyte count, however, increased significantly 2 weeks after PTx: from 25,103 ± 3,000 to 40,827 ± 4,080/mm³ (p < 0.01). In group III patients, serum iEPO, reticulocyte count, and hemoglobin remained stable after surgery. Since all group I patients had received vitamin D supplementation after PTx, we studied an additional group of 14 chronic dialysis patients (group IV) who received either calcitriol (1 μg/day, n = 7) or placebo (n = 7) during 14 days. The patients on calcitriol treatment, but not those on placebo, had a significant decrease of serum iEPO: 18.6 ± 4.9 versus 16.0 ± 4.2 mU/ml (p < 0.03). In conclusion, PTx led to a striking increase of serum iEPO and blood reticulocytes in uremic patients with secondary hyperparathyroidism, and an increase of reticulocyte count, but not of iEPO, in patients with primary hyperparathyroidism. Marked changes of circulating PTH, extra- or intracellular calcium and phosphorus concentrations as well as of tissue sensitivity to EPO after PTx could all be responsible. In contrast, the surgical procedure and the therapeutic increase in plasma calcitriol do not appear to be involved.

Cinacalcet Hydrochloride (Sensipar) in Hemodialysis Patients on Active Vitamin D Derivatives with Controlled PTH and Elevated Calcium × Phosphate

“…SHPT generally is associated with abnormally high rates of bone resorption and is often accompanied by pain and fractures (14 -16). Extraskeletal manifestations of the disease include vascular calcification, hypertension, anemia, pruritus, and sexual dysfunction (17)(18)(19)(20)(21)(22)(23)(24)(25). Analyses of data from large hemodialysis cohorts (1-3) have demonstrated significant relations among elevated PTH, Ca, and P and mortality and morbidity.…”

Risk factors associated with secondary hyperparathyroidism in patients with chronic kidney disease

“…In the present study, it was observed that the serum PTH expression levels were negatively correlated with blood hemoglobin expression levels in patients with CKD. PTH is considered to be a uremic toxin, as it directly inhibits the hematopoietic function of bone marrow, increases the fragility of erythrocytes and shortens the life expectancy of erythrocytes (38). SHPT can also increase erythropoietin resistance (39).…”

Hyperparathyroidism and Anemia in Uremic Subjects

“…Two interesting studies appeared during the last decade: Urena et al (18) described the follow-up after surgery in patients who had primary (n ϭ 16) and secondary (n ϭ 23) hyperparathyroidism. The results related to the latter group are summarized in Table 2.…”