The confirmation and monitoring of acute rejection by urine immunoglobulin determinations

The urinary excretion of increasing amounts of immunoglobulins by renal graft patients strongly suggests the presence of acute rejection. Grafts that do not undergo rejection exhibit no increase in immunoglobulinuria. If immunoglobulinuria persists at high levels, graft prognosis is poor. Immunosuppression should be stopped or tapered at this point before high-dose corticosteroid therapy harms the recipient. The return of urinary immunoglobulins to prejection levels suggests restoration of graft function and the subsidence of immunologic attack on the graft. A correlation also exists between the low levels of immunoglobulinuria and continued long-term function.