Final answer:
In cases of cystitis, neutrophils can be associated with the condition as they are an indicator of an active bacterial infection which is often detected with a urine test for leukocyte esterase.
Step-by-step explanation:
Cystitis is often caused by urease-positive bacteria such as Escherichia coli and Proteus vulgaris. It is characterized by symptoms like pain during urination and presence of pus in the urine (pyuria). These infections can be identified by the presence of nitrites and leukocyte esterase on a urine dipstick test. Leukocyte esterase specifically indicates the presence of neutrophils, which are a part of the body's immune response to active bacterial infections. Therefore, among the options provided, neutrophils can be associated with the condition of cystitis as they play a role in the immune response to such infections.