Iron Deficiency in Immune Thrombocytopenia: Are We Doing Enough?

Introduction

Iron deficiency (ID) is a common entity with a worldwide prevalence of 25%, but its prevalence is not known in patients with immune thrombocytopenia (ITP), and it may occur more frequently because of an increased risk of bleeding. Also, patients with ITP commonly use high-steroids and have Helicobacter pylori infection, which can increase the risk of ID. Both ITP and ID are associated with fatigue and a negative effect in quality of life. The recognition and treatment of ID in patients with ITP may improve hematologic responses and patient-related outcomes. Our main objective was to determine the prevalence of ID in patients with ITP and to describe the determinants of ID-related outcomes.

Methods

This is a retrospective cohort study that included patients with a newly diagnosed ITP between 2015 and 2022. Iron deficiency was defined as transferrin saturation < 20% and/or serum ferritin < 30 ng/mL. We collected clinical, demographic, and treatment values, and aimed to associate them with ID and both ITP and ID-related outcomes.

Results

Eighty-eight patients were included with a median age of 41 years (17-87), 68.2% were women; 92% required treatment for ITP, most commonly prednisone (54.3%) followed by dexamethasone (45.7%). Iron profiles were performed in 89.8% of cases. ID was diagnosed at any time in 65.8% of the patients (64.8% in women, and 68.0% in men). The diagnosis of ID was made during ITP initial workup in 44.3%, and this was more common in women (54.3% in women vs. 23.5% in men, OR for being male 0.26 [95% CI 0.07-0.95], p=0.043), and during follow-up in 55.8%. There was no association of H. pylori with ID (36.5% vs. 44.4%, p=0.628). With a median follow-up of 38 months, median number of iron profiles performed per patient was 2 (1-16), with a median of 50% (0-100%) showing ID. Etiology of ID was found in 52.9% of cases (57.9% in women and 43.8% in men, p=0.546), with the most common cause being abnormal uterine bleeding in women (80.0%), non-malignant gastrointestinal (GI) bleeding in men (42.8%), there were no cases of malignant GI bleeding, and the cause of iron deficiency was not found in 47.1% of all the patients. Endoscopic studies were performed in 34.6% and pelvic imaging in 35.3% of the women. ID during follow-up was found more frequent in men (76.5% vs. 45.7%, OR 3.86 [95% CI 1.05-14.21], p=0.043), in patients who received prednisone vs. dexamethasone (61.5% vs. 35.5%, OR 4.00 [95% CI 1.17-13.73], p=0.024), and although not statistically significant, in patients who had an ITP relapse (16.7% vs. 61.1%, OR 7.86 [95% CI 0.83-74.84], p=0.075). Only 61.5% of patients with ID received treatment, with oral iron being the most common in 71.9%. In 35.4% of cases iron studies never returned to normal values, and 51.1% had persistent ID during follow-up.

Conclusions

ID is a common condition found in patients with ITP, as it was diagnosed in more than half of these patients. At the time of ITP diagnosis, women are more commonly diagnosed with ID, and ID during follow-up was more common in men, in patients with ITP-relapse, and in those who received prednisone vs. dexamethasone. Although in nearly half of the patients the cause of ID is not known, diagnostic workup studies like endoscopy and ultrasound were only done in a third of patients. Only 61.5% patients received treatment, and in 35.4% ID did not correct. Our study highlights the need to aggressively screen and treat ID in ITP. The impact of ID diagnosis and treatment on patient reported outcomes of patients with ITP should be addressed in future studies.