Differential Diagnosis
- Single most likely diagnosis
- Anemia of Chronic Disease (ACD): The patient has mixed connective tissue disease, which is a chronic inflammatory condition. The low TIBC (Total Iron Binding Capacity) and high iron saturation in the presence of low ferritin levels are characteristic of ACD. The body's inflammatory response leads to increased hepcidin levels, causing a decrease in iron release from stores, resulting in a functional iron deficiency despite adequate iron stores.
- Other Likely diagnoses
- Iron Deficiency Anemia (IDA) with Inflammation: Although the ferritin level is low, which typically indicates iron deficiency, the high iron saturation and low TIBC suggest an inflammatory component that could be masking a true iron deficiency state.
- Hemochromatosis: This genetic disorder leads to excessive iron absorption. However, the presence of mixed connective tissue disease and the specific pattern of iron studies (low TIBC, high iron saturation) make this less likely but still a consideration due to the potential for genetic predispositions.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Sideroblastic Anemia: A group of disorders characterized by the accumulation of iron in the mitochondria of red blood cell precursors. This condition can lead to increased iron saturation and could be a consideration, especially if there are other signs of myelodysplastic syndrome or if the patient has been exposed to certain toxins or medications.
- Thalassemia: Although less likely given the patient's hemoglobin level and the specific iron studies, certain forms of thalassemia can present with complex iron metabolism disturbances. It's crucial to consider this diagnosis, especially if there's a family history or if other diagnostic criteria are met.
- Rare diagnoses
- Aceruloplasminemia: A rare genetic disorder characterized by a lack of ceruloplasmin, leading to iron accumulation in tissues. This condition could potentially explain the high iron saturation but is extremely rare and would require specific diagnostic testing.
- Atransferrinemia: A rare condition where there is a deficiency of transferrin, the protein responsible for binding and transporting iron in the blood. This could lead to high iron saturation and low TIBC, but it is exceedingly rare and would need to be confirmed with specific tests.