Direct Immunization with Pathologic Urine Samples: A New Approach to Monoclonal Antibody-Based Urinary Assays of Renal Disorders

Gerhard A. Müller, Medical University Clinics, Department 3, University of Tübingen, D-7400 Tübingen (FRG) Dear Sir, Diagnosis of kidney disorders so far mainly relies on proteinuria measurements, changes in serum creatinine levels, urine output and release of various serum proteins or renal enzymes into the urine following renal injury. However, these routine tests are rather unspecific and often renal biopsy is required to verify diagnosis. Urinary shedding of renal tissue constituents, specific for distinct renal structures, could be a reliable indicator of kidney damage. Establishing a highly specific urinary assay using monoclonal antibodies (Moabs) detecting renal antigens would constitute a simple noninvasive system for diagnosing renal tissue injury. The development of a Moab-based sandwich enzyme immunoassay which reveals a 120-kd glycoprotein, the adenosine desaminase binding protein, mostly associated with proximal tubular epithelial cells, has been reported [1]. So far, Moabs