Intravenous Iron Repletion Does Not Significantly Decrease Platelet Counts in CKD Patients with Iron Deficiency Anemia

Iron Deficiency is Associated With Platelet Count Elevation in Patients With Dialysis-dependent Chronic Kidney Disease

OBJECTIVE

Iron deficiency is common in patients with end-stage renal disease (ESRD). Platelet count changes may reflect iron status, but the relationship between platelet count and iron indices is unclear in patients with ESRD.

METHODS

We conducted a retrospective study in 1,167 patients with ESRD from 2012 to 2017 in West China Hospital. Baseline data were used to analyze the relationship between the platelet count and iron indices. Patients were followed up for 3 years.

RESULTS

Patients with iron deficiency (both absolute and functional) had a higher platelet count than those without iron deficiency (174 ± 61 × 10⁹/L vs. 153 ± 58 × 10⁹/L, P < .001). Receiver operating characteristic analysis showed a weak predictive power of platelet count on absolute iron deficiency (area under curve 0.620; cutoff value > 137 × 10⁹/L, sensitivity 76%, specificity 43%) and functional iron deficiency (area under curve 0.540; cutoff value > 124 × 10⁹/L, sensitivity 77%, specificity 32%). Platelet count was negatively correlated with ferritin (Spearman's rho [ρ] -0.1547, P < .001), transferrin saturation (ρ = -0.1895, P < .001), and serum iron (ρ = -0.1466, P < .001). The abovementioned correlations remained significant in multivariate regression (β -0.7285, 95% confidence interval [CI] -1.0757 to -0.3814; β -.00347, 95% CI -0.0520 to -0.0174; β -0.0097, 95% CI -0.0159 to -0.0035, respectively). In unadjusted and adjusted Cox regression models, neither baseline platelet count nor relative thrombocytosis was associated with 3-year mortality.

CONCLUSION

There was a weak but significant platelet count elevation in patients with ESRD and with iron deficiency.

KEY WORDS

end-stage renal disease; iron deficiency; iron supplement; mortality; platelet count.

Intravenous iron administration is associated with reduced platelet counts in patients with chronic kidney disease

WHAT IS KNOWN AND OBJECTIVE

In the management of anaemia associated with chronic kidney disease (CKD), optimal use of intravenous (i.v.) iron has a central role. It minimizes reliance on erythropoiesis-stimulating agents (ESAs) and may be beneficial in reducing overall cardiovascular risks through its effects on platelet counts (PLT). We have examined the effects of i.v. iron on PLT in patients with CKD.

METHODS

Two hundred and three patients with CKD, referred to a single teaching hospital in UK for i.v. iron therapy, received low molecular-weight iron dextran at a median dose of 1000 milligrams given over a median time of 2 h and 40 min. PLT at baseline were compared with the measurements taken during a 4-month follow-up period post-infusion.

RESULTS

PLT were checked at various points following i.v. iron treatment. Compared with baseline, mean reduction in PLT ranged between 10.1 and 23.6 (×10(9) /L) during consecutive 15-days intervals post-treatment. At the reference point of 90-days post-infusion, the drop in PLT was statistically significant (P < 0.001).

WHAT IS NEW AND CONCLUSION

Low molecular-weight iron dextran in patients with CKD leads to reduction in PLT. This reduction appears soon after treatment and is maximal after 3 months. Prospective data are required to confirm these findings and examine whether this translates to a reduction in thrombotic episodes.

Iron repletion is associated with reduction in platelet counts in non-dialysis chronic kidney disease patients independent of erythropoiesis-stimulating agent use: a retrospective cohort study

Background

Iron deficiency is common in non-dialysis chronic kidney disease (ND-CKD) patients and, on occasion, requires parenteral iron therapy. We investigated the effect of intravenous iron repletion on platelet counts in ND-CKD patients with and without concomitant darbepoetin administration.

Methods

We conducted a retrospective analysis of ND-CKD patients with iron deficiency anemia treated with low molecular weight iron dextran (LMWID) between 2005 and 2009 at our CKD clinic. The primary end-point was change in platelet count 60 days post infusion of LMWID in those with and without concomitant darbepoetin administration. Secondary end-points were the correlations between changes in platelet count and iron indices.

Results

A total of 108 patients met inclusion and exclusion criteria. The decrease in platelet counts in response to iron repletion was statistically significant (305.72 ± 108.86 vs 255.58 ± 78.97, P = < .0001). The decrease in platelet count was independent of concomitant darbepoetin use. Bivariate regression analysis between baseline platelet count and transferrin saturation by iron (TSAT) showed a negative association (β_TSAT = −5.82, P = .0007) and moderate correlation (R = 0.32). Following iron treatment, the within individual changes in platelet count in 60 days were not related to changes in TSAT (β_ΔTSAT = −0.41, P = .399) and demonstrated a poor correlation (R = 0.10).

Conclusions

Parenteral iron treatment by LMWID is associated with reduction in platelet counts in iron deficient anemic ND-CKD patients. However, ESA use in the majority of patients prior to intravenous iron administration could have altered platelet production through bone marrow competition.