Effect of iron supplementation on platelet count in adult patients with iron deficiency anemia

Abstract

Iron deficiency anemia (IDA) affects more than 1.2 billion individuals globally. In addition to anemia, reactive thrombocytosis is also a common clinical hematological condition in patients with IDA. However, some case reports have described the thrombotic complications in association with IDA-induced thrombocytosis. Patients with a high risk of thrombosis need prompt identification and effective treatment to prevent thrombotic complications. While iron replacement treatment has been shown to decrease platelet count in this context, there is limited published evidence on how iron supplementation affects the thrombocytosis caused by IDA. We retrospectively examined the clinical records of 440 patients with IDA from an RCT completed from 1 January 2016, to 30 December 2017, and data obtained from this study was used for post hoc analysis to examine the effect of iron on platelet count in IDA-induced thrombocytosis.

The mean ± standard deviation (SD) platelet counts of the 440 patients with IDA was 310.23 ± 98.72 × 10⁹/L. With baseline platelet counts>450 × 10⁹ /L as the cutoff for thrombocytosis, patients were divided into 2 groups: 36 (8.1%) in the IDA with thrombocytosis group (mean ± SD platelet count, 521.67 ± 73.85 × 10⁹/L) and the remaining 404 in the IDA without thrombocytosis group (mean ± SD platelet count, 291.39 ± 76.11 × 10⁹/L).

Differences were found in baseline characteristics including white blood cell (WBC) count, hemoglobin (Hb) level, mean corpuscular volume (MCV), transferrin saturation (TSAT), serum iron (SI) level, and total iron-binding capacity (TIBC) between the two groups (P < .05). From baseline to 8 weeks of continuous iron supplementation treatment, the mean platelet counts in both groups were decreased at 2-week treatment intervals. And in the IDA with thrombocytosis group, half of the patients resolved thrombocytosis after 2 weeks of iron supplementation, and the counts of all patients with thrombocytosis decreased below 450 × 10⁹ /L within 6 weeks.

In conclusion, the rate of reactive thrombocytosis in patients with IDA was 8.1%. IDA patients with thrombocytosis showed more severe anemia, lower ferritin, and more advanced iron deficiency than those without thrombocytosis. Platelet counts of half of the patients with thrombocytosis reduced below cut off of 450 × 10⁹/L for thrombocytosis after 2 weeks of treatment, and all patients resolved thrombocytosis after 6 weeks. Our study provided clinical evidence for more effective and individualized iron management in the future. IDA patients with thrombocytosis should take active iron treatment and increase follow-up frequency to prevent thrombotic events. For patients with persistent thrombocytosis, a concomitant clonal process should be considered.

P lain l anguage s ummary

What is the context?

• Iron deficiency anemia, as its name implies is due to insufficient iron that results in a defect in hemoglobin synthesis. Iron deficiency anemia is the most common type of anemia worldwide and is characterized by microcytic red blood cells and decreased amount of hemoglobin.

• Thrombocytosis is a condition with a platelet count above 450 × 10⁹ /L, and can be classified as primary (clonal) or secondary (reactive). Reactive thrombocytosis may occur in various situations such as infections, inflammatory diseases, and iron deficiency anemia.

• Some studies have reported that iron deficiency-associated thrombocytosis may contribute to thrombotic complications (blood clots block veins or arteries).

• Iron supplementation has been proven to reduce platelet count in several diseases such as inflammatory bowel disease and chronic kidney disease.

What is new?

• Limited studies suggest the effect of iron supplementation on platelet count in adult patients with iron deficiency anemia.

• In this study, we examined clinical records of 440 consecutive adults with iron deficiency anemia from 1 January 2016, to 30 December 2017, and found that 36 (8.1%) had thrombocytosis at their first evaluation and that all patients could resolve thrombocytosis after 6 weeks of iron supplementation.

What is the impact?

• Our study provided clinical evidence for more effective and individualized iron management in the future to reduce thrombotic complications.

Keywords:

• Iron-deficiency anemia
• iron supplementation
• platelet count
• thrombocytosis
• thrombosis

Disclosure statement

This article does not have any conflict of interest.

Author contributions

Dr. Wang conceived and designed the study, had full access to all of the data in the study, and takes responsibility for the integrity of the data and the accuracy of the data analysis. Zhao collected the data. Xue Li performed the statistical analysis and drafted the manuscript. Nianyi Li critically revised the manuscript. All authors reviewed the manuscript.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.