A previously well-nourished patient with fever is admitted to the hospital. His laboratory tests reveal albumin 2.1 g/dL, C-reactive protein 30 mg/L, serum calcium 7.2 mg/dL. Which of the following is the most likely etiology of the hypoalbuminemia?

• A. Inflammatory response
• B. Caloric deficiency
• C. Hypocalcemia
• D. Protein deficiency

Answer: (A)

Hypoalbuminemia during acute illness is driven by the inflammatory response, not simply by a lack of intake. When fever and acute inflammation occur, cytokines signal the liver to reduce production of albumin and to increase production of positive acute‑phase proteins like CRP. Albumin is a negative acute‑phase reactant, so its synthesis falls while CRP rises, explaining the low albumin with an elevated CRP. Inflammation can also increase capillary permeability and cause albumin to move into the interstitial space, contributing further to lower circulating levels. The low calcium seen here is commonly related to the reduced albumin binding, and may not reflect true hypocalcemia of vitamin D or parathyroid issues. Since the patient was previously well nourished and now has fever with high CRP, the inflammatory response best explains the hypoalbuminemia.