The presence of which of the following is indicative of osteoarthritis?

The presence of bony enlargement of joints is characteristic of osteoarthritis, a degenerative joint disease. In this condition, the cartilage that cushions the ends of the bones deteriorates over time, leading to pain, swelling, and changes in the structure of the bone itself. This degradation often results in the formation of osteophytes, or bone spurs, which contribute to the visible enlargement of the affected joints.

In osteoarthritis, these bony enlargements can often be palpated and observed, particularly in weight-bearing joints like the knees and hips, as well as in the hands. The development of such bony changes is a key diagnostic feature of osteoarthritis as opposed to other types of joint disorders.

The other options provided do not align with the pathology of osteoarthritis. For instance, the presence of antibodies may indicate autoimmune conditions such as rheumatoid arthritis, while high levels of uric acid are typically associated with gout, and presence of infection would suggest septic arthritis. Hence, bony enlargement is the hallmark feature of osteoarthritis, confirming the diagnosis.