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Thank you for attending THSNA 2026. The virtual meeting is now closed.
Presentation Details
| Hematologic Evidence of Iron Deficiency Common Below Ferritin 50 ng/mL Lisa Baumann Kreuziger1, 2, Ryan Hanson3, Julie Kolinski2, Nathan Ledeboer2, Alexandra Harrington2, Robert Nerenz2. 1Versiti Blood Research Institute, Milwaukee, WI, USA.2Medical College of Wisconsin, Milwaukee, WI, USA.3Froedtert Hospital, Milwaukee, WI, USA |
Abstract
Background: Laboratory reference ranges are historically derived by finding the values that include 95% of healthy individuals within a sample population. However, iron deficiency is common in women with previous studies showing absent bone marrow iron in 24-50% of women. Due to the frequency of iron deficiency, many iron deficient women could be included in the “healthy population” used by test manufacturers to develop normal ranges. There is no physiologic reason that ferritin normal range should be lower in women than in men yet ferritin “normal” ranges differ between males and females. Objectives: We aimed to review laboratory parameters for evidence of iron deficiency in people with ferritin <50 ng/ml. Methods: We extracted all ferritin tests completed over a month in our hospital system (Roche Elecsys ferritin assay, performed on a cobas e801 module). People >14 years old with ferritin <50 ng/ml and CBC or iron panel within 14 days were included. The lower limit of normal ferritin was 12 ng/ml in females and 30 ng/ml in males. Anemia was considered hemoglobin <11.3 g/dl or hematocrit <34 in females and hemoglobin <13.7 g/dl or hematocrit <40 in males. We defined MCV <80 as low and RDW >=15% as high. Transferrin saturation <20% denoted iron deficiency. Descriptive statistics were calculated. Results: In total, 1036 people had ferritin tested in 31 days of which 876 people [732 females (83.6%) and 144 males (16.4%)] were included due to age, ferritin <50 ng/ml, and availability of other laboratory testing. 826 people would not have been flagged as having an abnormal ferritin. Of the 386 females with ferritin between 12-29.9 ng/dl, 26.2% were anemic by hemoglobin, 30.8% were anemic by hematocrit, 26.7% had low MCV, 39.4% had elevated RDW, 32.1% with transferrin sat <20% (Table 1). Overall, 93.5% had either anemia, low MCV, elevated RDW, or low transferrin saturation. Of the 346 females with ferritin 30-49.9, fewer were anemic (14.2% and 15.9% by hemoglobin and hematocrit), 13.6% had low MCV, 25.4% had elevated RDW, and 27.5% had low transferrin % saturation. Of the 94 males with ferritin 30-49.9 ng/dl, 50% were anemic by hemoglobin, 42.6% were anemic by hematocrit, 27.7% had low MCV, 37.2% had elevated RDW, and 22.3% had low transferrin % sat. All had one of the lab abnormalities. Conclusion: Most people with a ferritin between 12-30 ng/ml are female. Over 90% of people with ferritin <50 ng/ml have hematologic or transferrin saturation abnormalities suggestive of iron deficiency which supports eliminating sex-based differences in ferritin normal ranges.
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No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.