LAUSR

Iron deficiency anemia (IDA) is often associated with mild to moderate thrombocytosis, and iron deficiency–associated thrombocytopenia (IDAT) is much more uncommon and often misdiagnosed as immune thrombocytopenia (ITP). To better describe the features of IDAT, we conducted a retrospective multicenter case-control study. We identified 10 patients (9 women) with a definite diagnosis IDAT, with a median age of 43.5 [range, 16–72] years and a median platelet count of 30.5 × 109/L [range, 21–80], and 7 patients with a possible diagnosis of IDAT. Bleeding manifestations were absent in all patients but one. All the patients recovered (platelet count ≥ 150 × 109/L) upon iron therapy ± red blood cell transfusion after a median time of 6 [4–39] days. When compared with 30 randomly newly diagnosed ITP patients matched on age, the baseline platelet count was significantly lower in ITP (median = 7 × 109/L [4–59], p < 0.001) whereas MPV was higher (10.5 fL [9,4–13,8] vs 8.2 fL, for IDAT p < 0.001). The median platelet count on day 7 was 337 × 109/L [113–1000] for IDAT cases vs 72 × 109/L [13–212] for ITP controls (p < 0.001). IDAT is potentially an under-recognized cause of thrombocytopenia that may be easily managed with iron therapy.