Which of the following blood tests is likely to be elevated in a patient with an acute inflammatory response?

C-reactive protein (CRP) is an acute-phase reactant produced by the liver in response to inflammation. When there is an acute inflammatory response, such as infection, trauma, or autoimmune conditions, levels of CRP in the blood increase significantly as part of the body's defense mechanism. The elevation of CRP serves as a biomarker for inflammation and is often used in clinical settings to assess the severity and extent of inflammatory processes.

In contrast, lymphocyte counts may not necessarily increase during an acute inflammatory response, as different types of white blood cells respond variably depending on the nature of the inflammation. Serum calcium levels typically remain stable or may even decrease during acute inflammation due to alterations in metabolism and distribution of calcium within the body. Albumin levels often decrease in acute inflammatory states because it is a negative acute-phase protein, meaning its production is downregulated during inflammation. Therefore, CRP remains the most relevant indicator for identifying an acute inflammatory response in blood tests.