What type of white blood cells are indicative of interstitial nephritis when significant?

Mononuclear cells, which include lymphocytes and monocytes, are indicative of interstitial nephritis when found in significant numbers in the urine or kidney tissue. In interstitial nephritis, there is an inflammatory response that primarily involves these types of cells, which are associated with chronic inflammation in the renal interstitium.

This reaction often occurs due to various causes, including drug reactions, infections, and autoimmune disorders, leading to the infiltration of lymphocytes and monocytes into the renal interstitium. The presence of these mononuclear cells serves as a critical marker for diagnosing interstitial nephritis, as they reflect the underlying pathological changes and immune responses in the kidney.

In contrast, neutrophils are more closely associated with acute inflammation and bacterial infections, while basophils play a minor role in kidney pathology and are generally not significant in interstitial nephritis. Lymphocytes are a component of mononuclear cells, but the term "mononuclear cells" more accurately encompasses the overall picture of the immune response in this condition.