urinemarkers

Urine markers, or urinary biomarkers, are molecules found in urine that reflect normal physiology or disease processes in the body. They are used for detection, prognosis, and monitoring of health conditions, often offering a noninvasive alternative to blood tests or imaging.

Markers can be categorized by what they indicate. Protein and peptide markers, such as albumin, are commonly used to assess kidney function and detect proteinuria or microalbuminuria. Tubular injury markers, including neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and interleukin-18 (IL-18), help identify acute kidney injury. Metabolic and small-molecule markers, sometimes normalized to urinary creatinine, can reflect disorders in metabolism or renal concentration. Nucleic acid and RNA markers, including cell-free DNA and microRNA panels, are being explored for cancer detection and other diseases. Infectious and inflammatory conditions are monitored with markers detected by dipstick tests (such as leukocyte esterase and nitrites) and more specific laboratory assays. In bladder cancer, urinary biomarkers such as certain proteins and DNA-based tests (including FISH and related panels) have been used alongside cytology.

Collection and analysis methods vary. Dipstick tests provide rapid screening in clinics; laboratory assays such as enzyme-linked immunosorbent assays (ELISA), immunoassays, chromatography, mass spectrometry, and PCR-based tests enable more precise measurement. Results often require normalization (for example, to urinary creatinine) and interpretation within clinical context, as no single biomarker is universally definitive.

Urine markers represent a growing field of noninvasive diagnostics, with ongoing validation and standardization needed to maximize clinical utility.