Renal histology before and after effective enzyme replacement therapy in a patient with classical Fabry's disease.

BACKGROUND

Iron-deficiency anaemia (IDA) commonly presents with reactive thrombocytosis. A less recognized, paradoxical decline in platelets may occur shortly after iron repletion. This phenomenon is most notably seen with intravenous (IV) formulations and termed the platelet steal effect.

CASE REPORT: We describe a 68-year-old man with severe IDA (haemoglobin 6.6 g/dl; mean corpuscular volume 53.4 fl; ferritin 8.7 ng/ml; iron saturation 3.4%) who developed marked thrombocytopenia after initiation of IV iron. The platelet count trended down from 290 ×103/μl on admission to a nadir of 39 ×103/μl by hospital day 5 without bleeding. Other causes of thrombocytopenia were systematically excluded. Iron therapy was continued and transitioned to oral supplementation; platelets stabilized by day 10 and recovered thereafter in parallel with haemoglobin improvement.

CONCLUSION

Transient thrombocytopenia following iron repletion is likely under-recognized. Awareness of its timing and benign course may prevent unnecessary testing or interruption of definitive IDA therapy.

LEARNING POINTS: Transient thrombocytopenia may occur shortly after intravenous iron repletion in severe iron deficiency anaemia, despite the usual association with thrombocytosis.The "stem cell steal" phenomenon reflects a temporary shift of bone marrow progenitors toward erythropoiesis once iron becomes available.Recognizing this benign, self-limiting response prevents unnecessary investigations or interruption of essential iron therapy.