Description: Neutrophils are a type of white blood cell, specifically a type of leukocyte, that plays a crucial role in the immune system of the human body. They are characterized by their ability to phagocytize, that is, engulf and destroy pathogenic microorganisms such as bacteria and fungi. Neutrophils are the most abundant leukocytes in the blood, accounting for approximately 50-70% of all white blood cells. Their lifespan is relatively short, typically ranging from 5 to 90 hours, depending on their activation and the environment they are in. These white blood cells are produced in the bone marrow and released into the bloodstream, where they patrol for signs of infection or inflammation. When they detect a pathogen, neutrophils quickly mobilize to the site of infection, where they release enzymes and chemicals that help break down and eliminate the invaders. Additionally, they can form extracellular traps of DNA, known as NETs (neutrophil extracellular traps), which trap and kill pathogens. Their function is vital for the body’s defense, and their numbers can significantly increase in response to infections, resulting in a phenomenon known as neutrophilia.
History: The discovery of neutrophils dates back to the 19th century when different types of white blood cells began to be studied. In 1873, German physician Paul Ehrlich developed staining techniques that allowed for the identification and classification of leukocytes, including neutrophils. Over time, their role in the immune response has been investigated, and by the 1930s, their function as the primary phagocytes in the immune system was established.
Uses: Neutrophils are used in medicine to assess a patient’s immune response. An elevated neutrophil count can indicate an acute bacterial infection, while a low count may be a sign of immunosuppression or hematological diseases. They are also studied in research on autoimmune diseases and inflammatory disorders.
Examples: A practical example of the use of neutrophils in the clinic is in blood count analyses, where the neutrophil count is evaluated to diagnose infections. In the case of a patient with fever and an elevated neutrophil count, doctors may suspect a bacterial infection and proceed to perform cultures to identify the specific pathogen.
