Final answer:
A UA positive for proteinuria is the lab value that may indicate Systemic Lupus Erythematosus (SLE), since protein in the urine suggests possible kidney damage, which is a symptom of SLE.
Step-by-step explanation:
The lab value that may indicate Systemic Lupus Erythematosus (SLE) in a 25-year-old female patient with a maculopapular butterfly-shaped rash on the face is UA positive for proteinuria. The presence of protein in the urine can be a sign of kidney involvement, which is one of the common symptoms of SLE. In contrast, a UA positive for leukocytes might indicate an infection, not necessarily SLE. A negative result for both proteinuria and leukocytes would be less likely to suggest SLE. Systemic lupus erythematosus is characterized by its autoimmune nature, causing a wide array of symptoms across different parts of the body due to the production of autoantibodies—including ANAs, anti-ds-DNA, and anti-Sm—which can lead to type III hypersensitivity reactions and subsequent tissue damage.