Commentary on Severe Thrombocytopenia Complicating Iron Deficiency Anemia: A Diagnostic Challenge?

Iron deficiency anemia (IDA) is the most common cause of anemia globally and is usually associated with normal platelet count or thrombocytosis. The authors here present a case of severe thrombocytopenia in an adult patient with IDA. Thrombocytopenia secondary to IDA has been described and documented in the pediatric population as far back as the 1960s; however, thrombocytopenia secondary to IDA in adults is much less common. The absence of clinical signs of bleeding despite severe thrombocytopenia is a common finding in these patients (1). Pancytopenia has also been reported secondary to IDA. The mechanism of iron deficiency–induced thrombocytopenia (or thrombocytosis) is largely unknown, although several mechanisms have been proposed. This points to the fact that IDA goes beyond red blood cells and that there is a complex relationship between iron metabolism, thrombopoiesis, and leukopoiesis. Thrombocytopenia secondary to IDA must be differentiated from immune thrombocytopenia. A noninvasive test useful for this differentiation is the immature platelet fraction (or reticulated platelets), which is now available on most automated hematology analyzers. Immature platelet fraction is increased in immune thrombocytopenia and decreased in IDA, as seen in this case. The patient in this case was on long-term rivaroxaban therapy. There are a few reports of this drug causing thrombocytopenia shortly after initiation of therapy, with return of platelet counts after discontinuation of the medication (2); however, the rapid improvement in this patient’s counts post iron therapy rules this out. Thrombocytopenia may occur in uncomplicated IDA; therefore, a thorough clinical assessment and basic laboratory investigations should save such a patient from very extensive investigations and bone marrow biopsy. A trial of iron therapy would be more beneficial than the use of steroids or platelet transfusions. In these cases, the increase in platelet count would precede that of reticulocytes or hemoglobin after iron therapy. Author Contributions: The corresponding author takes full responsibility that all authors on this publication have met the following required criteria of eligibility for authorship: (a) significant contributions to the conception and design, acquisition of data, or analysis and interpretation of data; (b) drafting or revising the article for intellectual content; (c) final approval of the published article; and (d) agreement to be accountable for all aspects of the article thus ensuring that questions related to the accuracy or integrity of any part of the article are appropriately investigated and resolved. Nobody who qualifies for authorship has been omitted from the list. Authors’ Disclosures or Potential Conflicts of Interest: Upon manuscript submission, all authors completed the author disclosure form. O.O. Oladipo (Investigation, Writing—original draft, Writing—review & editing [lead]). Research Funding: None declared. Disclosures: O.O. Oladipo has received honoraria from Diagnostica STAGO Inc. for service on a clinical advisory committee and for a book chapter in Stago Practical Manual.