What is a common laboratory finding in patients with polyarteritis nodosa?

In patients with polyarteritis nodosa, a common laboratory finding is a high leukocyte count. This condition is characterized by vasculitis of medium-sized muscular arteries, leading to a range of systemic symptoms, including fever, malaise, and weight loss. The inflammatory process stimulates the bone marrow, leading to an increased production of white blood cells (leukocytosis).

The presence of high leukocyte counts reflects the underlying inflammation associated with polyarteritis nodosa. It is often accompanied by elevated inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), indicating ongoing inflammatory activity.

In contrast, low ESR would not be consistent with the inflammatory nature of the disease, as ESR typically rises in inflammatory states. Low protein levels are also not characteristic of polyarteritis nodosa, as the disease does not typically lead to significant protein loss or decreased synthesis. Lastly, normal blood counts would not align with the typical presentation of this condition, which often includes some degree of leukocytosis indicative of the inflammatory response.