In bacterial infection, what is the characteristic predominance of leukocytes in the synovial fluid?

In the context of bacterial infections, the predominant leukocyte type in synovial fluid is neutrophils. This is because neutrophils are the primary responders to acute infections, especially those caused by bacteria. They play a crucial role in the immune response by phagocytosing pathogens and releasing enzymes that can help to eliminate bacteria.

In cases of bacterial arthritis, for instance, the synovial fluid analysis typically reveals a high number of neutrophils, often constituting more than 75% of the total leukocyte count. This neutrophilic predominance distinguishes bacterial infections from other types of joint inflammation, such as viral or autoimmune conditions, where lymphocytes or monocytes might be more prevalent.

Understanding the leukocyte profile in synovial fluid is critical for clinicians to direct appropriate treatment and manage joint-related infections effectively.