Instability of immunoglobulins and complement (C3) as predictor of renal allograft rejection

Abstract

Ten renal allograft recipients were studied for a period of three months with weekly measurements of serum complement C3 including a baseline value before transplantation. Immunoglobulins (IgG, IgM, IgA) were studied in nine of these patients. Fifteen rejection episodes occurred, three patients losing their graft because of irreversible rejections. The patients were followed for 2.5 years. The degree of of change in serial C3 and immunoglobulin levels from baseline was determined by variability index s. Fourteen out of 15 rejections were preceded by si (C3) greater than .1, one to several weeks in advance. The si (Ig) was useful in week 1 and predicted the rejection missed by si (C3). We conclude that instability of immunoglobulins and complement as measured by s is not only associated with rejections but appears to be a precursor to rejection events. We suggest the following prognostic two-step procedure: (1) Week 1: If either si (C3) or si (Ig) greater than .1, predict rejection. (2) Cases that pass step 1 are monitored by C3 at weekly intervals. As soon as si (C3) greater than .1, predict rejection.