Urinary Detected Renal Antigens in the Early Diagnosis of Kidney Graft Rejection

Abstract

The determination of renal antigens in the urine with an immunoassay, based on monoclonal antibodies (moabs), is a noninvasive test system for the analysis and monitoring of renal injury. New moabs allowing an immunohistologic dissection of the human nephron were generated by a direct intrasplenic immunization of mice with pathologic urine samples. A sandwich enzyme immunoassay was developed to quantitate renal cell membrane antigens in the urine. While antigen excretion in healthy individuals is low, preliminary data of a clinical investigation suggest the usefulness of these assay systems in diagnosis of tubular injury in human kidney transplant recipients. The immunoassay can provide very early hints of renal graft rejection prior to the appearance of clinical symptoms or the detection by routine clinical laboratory investigations.

Non-Invasive Monitoring of Graft Dysfunction after Renal Transplantation

“…However, these parameters are also upregulated by other causes such as CMV infections [26]. A set of monoclonal antibodies against surface proteins or high-molecular breakdown products derived from tubular epithelial cells was used by Mueller et al in a sandwich enzyme immunoassay to quantitate antigen excretion [27]. In the 9 recipients of a kidney graft involved in this study, high excretion values were found in clinical situations of tubular damage such as ischaemia/reperfusion injury or rejection.…”

Expression of human minor histocompatibility antigen on cultured kidney cells

“…The cells were allowed to grow to confluency in a humidified atmosphere of 5% COz at 37°C. The cultured tubular epithelial cells were characterized by FACS analyses using specific mAb detecting antigens of either proximal or distal tubular epithelial cells [14]. The HLA types of these cells were as fOllOWS: TK126 (HLA-AlUA11, B7/B35, C W~/ C W~) , TK128 (HLA-A2/A3, B35/B39, CW~/CW-), S1387 (HLA-A3/A32, B35/B-, CW~/CW-).…”