The invention relates to methods, compositions, and kits for detection of biomarkers. In one embodiment, the invention relates to a method for detecting AMR biomarkers in a biological sample. In another embodiment, the invention relates to a method for detecting, monitoring, diagnosing and predicting antibody mediated rejection. In yet another embodiment, the invention relates to a method for monitoring a subject for antibody mediated rejection comprising detecting BAFF or a BAFF variant in a biological sample. In still another embodiment, the invention relates to a kit for detecting BAFF in a urine sample.
