A retrospective study has revealed that iron therapy is associated with a reduction in platelet count in patients with non-dialysis chronic kidney disease (ND-CKD) independent of erythropoiesis-stimulating agent (ESA) use. Iron therapy may therefore reduce the risk of relative thrombocytosis in this patient population.
Thrombocytosis associated with iron deficient anaemia, may lead to cerebrovascular and thrombotic events and an increase in mortality rates in ND-CKD patients1,2. The mechanism of thrombocytosis in iron deficient anaemia is not completely understood. However, erythropoietin has been shown to have a positive effect on platelet production, therefore suggesting that ESA treatment may increase platelet count3. The study evaluated the effect of intravenous iron administration on platelet count in patients with iron deficient ND-CKD.
In this retrospective study, patients received a once-monthly dose of low molecular weight iron dextran (LMWID) either with a concomitant dose of darbepoetin alpha (DA, n=94) or without (n=14). DA and iron doses had been determined via a computerised programme targeting a haemoglobin level of 10.5–12.5 g/dl. The primary end-point was the change in platelet count 60 days after infusion of LMWID.
Following administration of LMWID, haemoglobin, ferritin, and iron saturation increased significantly at 60 days (p<0.0001). There was a statistically significant decrease in platelet count at 60 days post infusion of LMWID (305.72 ± 108.86 vs 255.58 ± 78.97 x 103/mm3, p≤0.0001). The decrease was independent of concomitant DA use and iron dose. There was also a negative correlation between baseline platelet count and transferrin saturation (p=0.0007).
The authors conclude that concomitant treatment of intravenous iron therapy with ESAs may reduce the risk of thrombocytosis and mortality in ND-CKD patients. However, they highlighted that adequately powered studies are needed to establish an association between thrombocytosis, iron deficiency and thromboembolic events in this patient population.
The full article is available in the July 2014 issue of BMC Nephrology. For information on iron deficiency in chronic kidney disease, please click here.