Differential Diagnosis for Decreased Iron Serum Level, Increased Ferritin, and Decreased Reticulocyte Count

Single Most Likely Diagnosis

• Anemia of Chronic Disease (ACD): This condition is characterized by a decrease in iron serum levels due to inflammation, which leads to increased ferritin levels as the body sequesters iron in storage sites. The decreased reticulocyte count indicates a lack of adequate erythropoiesis, which is common in ACD due to the body's prioritization of inflammation over erythropoiesis.

Other Likely Diagnoses

• Chronic Kidney Disease (CKD): CKD can lead to a decrease in erythropoietin production, resulting in a decreased reticulocyte count. Inflammation associated with CKD can increase ferritin levels, and iron deficiency is common due to blood losses during dialysis or decreased iron absorption.
• Hypothyroidism: Although less common, hypothyroidism can lead to decreased iron absorption and utilization, resulting in low serum iron levels. Ferritin can be elevated due to inflammation or as a acute phase reactant. The decreased reticulocyte count may reflect decreased erythropoiesis due to the metabolic slowdown associated with hypothyroidism.

Do Not Miss Diagnoses

• Hemophagocytic Lymphohistiocytosis (HLH): A rare but potentially fatal condition where the immune system produces too many activated immune cells called macrophages and lymphocytes. These cells can infiltrate various tissues and lead to the destruction of blood cells, including red blood cells, which could explain the decreased reticulocyte count. Ferritin levels are often markedly elevated in HLH, and iron levels can be low due to consumption.
• Sepsis: In the context of sepsis, inflammation can lead to increased ferritin levels, and iron can be sequestered away from the circulation, leading to low serum iron levels. The decreased reticulocyte count may indicate bone marrow suppression or failure in response to the severe infection.

Rare Diagnoses

• Gaucher's Disease: A genetic disorder that leads to the accumulation of glucocerebroside in cells and certain organs. It can cause anemia, low serum iron, and elevated ferritin due to the body's response to the accumulated substance. The decreased reticulocyte count could be due to bone marrow infiltration by Gaucher cells.
• Porphyria Cutanea Tarda: A disorder that affects the production of heme, a vital molecule for all of the body's organs. It can lead to iron overload in tissues but paradoxically low serum iron levels, elevated ferritin due to iron storage, and a decreased reticulocyte count due to ineffective erythropoiesis.