Which test result is likely in a patient diagnosed with sarcoidosis?

In a patient diagnosed with sarcoidosis, an elevated C-reactive protein (CRP) level is consistent with the inflammatory nature of the disease. Sarcoidosis is characterized by the formation of noncaseating granulomas in various organs, most commonly the lungs. This granulomatous inflammation triggers an immune response, which can lead to elevated levels of inflammatory markers such as CRP in the blood.

CRP is a nonspecific marker, meaning it can be elevated in various inflammatory conditions, but in the context of sarcoidosis, it reflects the active inflammatory process taking place in the body. Elevated CRP is commonly seen in active disease states and can be useful for monitoring disease activity or response to treatment.

In contrast, positive sputum cultures are more associated with infections rather than the granulomatous disease process seen in sarcoidosis. A positive rheumatoid factor would suggest a different autoimmune process, while normal lung volumes can occur in sarcoidosis but do not represent the expected pulmonary changes, which often include restrictive lung disease due to interstitial involvement.