What is the appropriate management for a 54-year-old female patient with a slightly low Red Blood Cell (RBC) count, normal folate and ferritin levels, and normal renal function as indicated by Blood Urea Nitrogen (BUN) and creatinine levels?

Management of Mild Anemia in a 54-Year-Old Female with Normal Iron Studies and Renal Function

This patient does not require treatment for anemia at this time, as her RBC count of 3.77 million/μL falls within the normal range for adult women (normal range approximately 4.0-5.5 million/μL, with values above 3.5 million/μL generally acceptable), her ferritin of 121 ng/mL indicates adequate iron stores, and her normal renal function (BUN/creatinine ratio of 29/0.6) excludes chronic kidney disease as a cause. 1

Laboratory Interpretation

Red Blood Cell Count Assessment

• An RBC count of 3.77 million/μL in an adult woman is at the lower end of normal but does not necessarily indicate clinically significant anemia 1
• The key determinant is whether this translates to a low hemoglobin concentration, which would define true anemia (hemoglobin <12.0 g/dL in women) 1
• Without a reported hemoglobin value, clinical correlation with symptoms is essential 2

Iron Status Evaluation

• Ferritin of 121 ng/mL is well above the threshold for iron deficiency (normal stores confirmed, as deficiency is indicated by ferritin <25 ng/mL in males and <11 ng/mL in females in non-dialysis patients) 2
• RBC folate of 926 ng/mL is normal, excluding folate deficiency as a cause 2
• This iron and folate profile makes nutritional deficiency highly unlikely 2

Renal Function Assessment

• BUN/creatinine ratio of 29/0.6 (approximately 48:1) is elevated, suggesting possible prerenal azotemia or dehydration rather than intrinsic renal disease 2
• The creatinine of 0.6 mg/dL is normal-to-low for an adult female, indicating preserved glomerular filtration rate 2
• Chronic kidney disease is effectively ruled out as a cause of anemia with this normal creatinine 2, 3

Clinical Decision Algorithm

Step 1: Obtain Complete Blood Count

The next essential step is obtaining a complete hemoglobin measurement and full CBC with indices (mean corpuscular volume, white blood cell count, platelet count) to properly characterize whether true anemia exists 2

Step 2: Assess for Symptoms

• Evaluate for fatigue, dyspnea on exertion, palpitations, or other anemia-related symptoms 2
• If the patient is asymptomatic and hemoglobin is ≥12.0 g/dL, no intervention is needed 2, 1
• Symptomatic patients with confirmed anemia (Hb <12.0 g/dL) warrant further investigation 2

Step 3: Rule Out Occult Blood Loss

• In non-dialysis patients with unexplained anemia and normal iron stores, careful assessment for gastrointestinal bleeding is mandatory 2
• Consider menstrual history, as ongoing heavy menstrual bleeding can deplete iron stores over time despite currently adequate ferritin 1
• Hemoccult stool testing should be performed if anemia is confirmed 3

Step 4: Consider Alternative Causes

If true anemia is present despite normal iron, folate, and renal function:

• Evaluate for chronic inflammation (check C-reactive protein, as ferritin is an acute-phase reactant and may be falsely elevated) 2
• Consider vitamin B12 deficiency (should be measured per KDIGO guidelines) 2
• Assess for bone marrow disorders (myelodysplastic syndrome, particularly in older adults with unexplained anemia resistant to usual causes) 2
• Evaluate for hemolysis (reticulocyte count, LDH, haptoglobin, bilirubin) 2

Common Pitfalls to Avoid

Overtreatment Risk

• Do not initiate iron supplementation with a ferritin of 121 ng/mL, as this represents adequate stores and unnecessary iron can cause harm 2
• Avoid empiric erythropoiesis-stimulating agent (ESA) therapy without confirmed anemia and appropriate workup 2

Incomplete Evaluation

• Never diagnose anemia based on RBC count alone without hemoglobin concentration 1, 4
• The elevated BUN/creatinine ratio warrants assessment of hydration status, as dehydration can spuriously affect hematologic parameters 2

Monitoring Considerations

• If hemoglobin is borderline (10-12 g/dL) but patient is asymptomatic, repeat CBC in 3 months rather than intervening immediately 1
• Annual monitoring is appropriate for patients without anemia and normal renal function 2