Management of Microcytic Anemia with Leukopenia

Initial Diagnostic Approach

The American Society of Hematology recommends completing iron deficiency workup immediately, including serum ferritin and transferrin saturation, to confirm iron deficiency anemia, especially in patients with microcytic anemia and leukopenia 1, 2
Serum ferritin is the single most powerful test for iron deficiency, with ferritin <30 μg/L confirming iron deficiency in the absence of inflammation, and ferritin <15 μg/L being diagnostic of iron deficiency 3, 4, 5
Transferrin saturation (TSAT) is used to assess iron available for erythropoiesis, with TSAT <15-20% supporting iron deficiency, and is less affected by inflammation than ferritin 1, 2, 4
Absolute reticulocyte count is used to evaluate bone marrow response, with low or normal reticulocyte count indicating impaired red cell production 1, 2, 4
Vitamin B12 and folate levels should be checked to exclude combined deficiency 1, 2

The presence of anemia and leukopenia represents abnormalities in two cell lines and mandates hematology consultation, as it raises concern for bone marrow dysfunction beyond simple nutritional deficiency 1, 2
Abnormalities in two or more cell lines should be evaluated carefully and likely warrant discussion with a hematologist, and do not presume iron deficiency alone explains both cytopenias without excluding more serious pathology 1, 6

Adolescent females, such as the 17-year-old female in this case, are at high risk for iron deficiency due to menstrual blood loss, and heavy menstrual bleeding should be specifically assessed 7
Dietary history is important, particularly restrictive diets, but do not presume borderline deficient diets as the sole cause without full investigation 3, 7

The management algorithm involves confirming iron deficiency with serum ferritin and TSAT, and if confirmed, initiating oral iron supplementation with ferrous sulfate 325 mg (65 mg elemental iron) 1-3 times daily between meals 2, 4
Expect hemoglobin increase of approximately 1-2 g/dL every 2-4 weeks, and continue iron for 3-6 months after hemoglobin normalizes to replenish stores 4
Investigate underlying cause of iron deficiency, including detailed menstrual history, dietary assessment, and consideration of gastrointestinal evaluation if menstrual losses and diet do not explain severity 3, 7

Do not accept ferritin alone in patients with inflammation; use TSAT to confirm iron deficiency, and do not rely on MCV alone, as iron deficiency can present with normal MCV in early stages 2, 4
Do not overlook the leukopenia—this is not explained by iron deficiency alone and requires separate evaluation, and do not presume dietary insufficiency as the sole cause without confirming with iron studies and excluding other pathology 1, 2, 3