From the Guidelines
To read an iron panel, first evaluate transferrin saturation (TSAT) and serum ferritin levels, as these are key indicators of iron status, with TSAT >45% and serum ferritin >200 μg/L (female) or >300 μg/L (male) suggesting potential iron overload 1. When interpreting an iron panel, it's essential to consider the following parameters:
- Transferrin saturation (TSAT), which is calculated from serum iron and transferrin or total iron binding capacity (TIBC)
- Serum ferritin, which reflects iron stores
- Full blood count and reticulocytes to exclude anemia and red cell disorders According to the most recent guidelines, a TSAT >45% combined with elevated serum ferritin levels (>200 μg/L for females, >300 μg/L for males) indicates potential iron overload 1. It's also important to note that ferritin levels can be influenced by inflammation, so clinical context and other parameters should be considered when interpreting results 1. Key points to consider when reading an iron panel include:
- Evaluating all parameters together rather than individually
- Considering the clinical context, including symptoms, medication use, and underlying conditions that might affect iron metabolism
- Being aware that acute inflammation can raise ferritin levels independently of iron status, potentially masking deficiency 1.
From the Research
Understanding Iron Panel Results
To read an iron panel, it's essential to understand the different components and their significance in diagnosing iron deficiency. The key elements of an iron panel include:
- Serum iron: measures the amount of iron in the blood
- Total iron-binding capacity (TIBC): measures the blood's capacity to bind iron
- Transferrin saturation: calculates the percentage of transferrin that is saturated with iron
- Ferritin: measures the amount of iron stored in the body
Interpreting Iron Panel Results
When interpreting iron panel results, consider the following:
- Low serum ferritin (<30 ng/mL) indicates iron deficiency, even if other parameters are normal 2
- Transferrin saturation (<20%) can also indicate iron deficiency, especially in patients with chronic inflammatory conditions 3
- Serum iron and TIBC have limited diagnostic value in iron deficiency, with low sensitivity and specificity 4, 5
- Ferritin is the most useful serum test for diagnosing iron deficiency, but may have limited sensitivity in certain populations 5
Diagnostic Criteria
The diagnostic criteria for iron deficiency vary, but generally include:
- Low serum ferritin (<30 ng/mL)
- Transferrin saturation (<20%)
- Serum iron (<11 μmol/L) and TIBC (>45 μmol/L) may also be used, but have limited diagnostic value 5
- The presence of symptoms such as fatigue, pica, or restless legs syndrome can also indicate iron deficiency 2
Clinical Utility
The clinical utility of iron panel results depends on the patient population and clinical context. For example:
- In patients with chronic inflammatory conditions, transferrin saturation may be a more useful diagnostic criterion than serum iron or TIBC 3
- In hospitalized patients, serum ferritin may be the most useful serum test for diagnosing iron deficiency, but bone marrow examination may be necessary for definitive diagnosis 5