From the Guidelines
For a 60-year-old patient with anemia and a negative occult blood test, a comprehensive workup is essential to determine the underlying cause of anemia, and I recommend starting with a complete blood count with differential, reticulocyte count, iron studies, vitamin B12, folate, and a comprehensive metabolic panel, as well as gastrointestinal evaluation with upper endoscopy and colonoscopy, despite the negative occult blood test, as suggested by 1. The workup should include:
- Complete blood count with differential
- Reticulocyte count
- Iron studies (ferritin, iron, TIBC, transferrin saturation)
- Vitamin B12 and folate levels
- Comprehensive metabolic panel
- Hemoglobin electrophoresis
- LDH and haptoglobin levels
- Peripheral blood smear examination Gastrointestinal evaluation is crucial, even with a negative occult blood test, as bleeding can be intermittent or minimal, and upper endoscopy and colonoscopy should be performed to rule out slow bleeding lesions, as recommended by 1. Additional testing, such as bone marrow examination, may be necessary if initial testing is inconclusive, particularly to evaluate for myelodysplastic syndrome, which becomes more common in this age group, as noted in 1. Inflammatory markers like ESR and CRP should be checked to screen for chronic disease anemia, and thyroid function tests and screening for celiac disease may also be appropriate, as suggested by 1. Treatment will depend on the underlying cause identified through this systematic approach, ranging from iron supplementation for iron deficiency to more specific interventions based on diagnosis, and iron repletion is necessary to improve quality of life and decrease the risk of complications related to anemia, as emphasized by 1.
From the Research
Initial Evaluation
- The laboratory evaluation of anemia begins with a complete blood count and reticulocyte count, as stated in the study 2.
- The anemia is then categorized as microcytic, macrocytic or normocytic, with or without reticulocytosis.
Categorization of Anemia
- Microcytic anemia can be further evaluated with serum iron level, total iron-binding capacity, serum ferritin level, and hemoglobin electrophoresis to separate the microcytic anemias 2.
- The erythrocyte size-distribution width may be particularly helpful in distinguishing iron deficiency from thalassemia minor.
Diagnostic Strategy for Unexplained Anemia with Iron Deficiency
- A diagnostic strategy is recommended for unexplained anemia with iron deficiency, including serological celiac disease screening and bidirectional endoscopy (gastroscopy and colonoscopy) 3.
- Bidirectional endoscopy is not required in premenopausal women < 40 years of age.
- Small intestine investigation is not recommended routinely after negative bidirectional endoscopy but should be conducted if there are red flags indicating malignant or inflammatory small bowel disease.
Consideration of Occult Gastrointestinal Bleed
- Occult gastrointestinal bleeding may present with a positive fecal occult blood test or iron deficiency anemia, and a stepwise approach to evaluation is recommended after negative upper and lower endoscopy 4.
- This approach includes repeat endoscopies if warranted, followed by video capsule endoscopy (VCE) if no obstruction is present.
Specific Considerations for a 60-year-old Patient
- Anemia should not be accepted as an inevitable consequence of aging, and a cause is found in approximately 80 percent of elderly patients 5.
- The most common causes of anemia in the elderly are chronic disease and iron deficiency.
- Serum ferritin is the most useful test to differentiate iron deficiency anemia from anemia of chronic disease.
Negative Occult Blood Test (OBT)
- In the case of a negative OBT, the focus should be on evaluating for other causes of anemia, such as chronic disease, vitamin B12 deficiency, and folate deficiency 5.
- A diagnostic workup, including a complete blood count, reticulocyte count, and serum iron level, should be performed to guide further evaluation and management.