Longitudinal testing of 266 renal allograft patients for HLA and MICA antibodies: Greenville experience.

1. From the analysis of 266 Greenville kidney recipients, we found that almost every patient who had graft failure had HLA antibodies (93%), while less than half of patients with currently functioning graft had antibodies (46%). 2. The difference between failed grafts and successful grafts was even greater for de novo antibodies (60% vs. 14%) and greatest for donor-specific antibodies (75% vs. 9%). 3. The incidence of HLA-DQ antibodies was surprisingly high, and the majority was donor-specific. Now that the improved detection beads are available, the effect of DQ antibodies on transplants should be further studied. 4. MICA antibodies were found in 12% of total 266 patients, and found to be more frequent (21%) in patients with graft failure than in patients with successful graft (7%). Almost all patients with MICA antibodies also had HLA antibodies. 5. From the sequential sera testing, we were able to see that, in most cases, antibodies are produced long before the failure and before the elevation of serum creatinine. 6. Periodic testing of sera by single antigen beads enable us to distinguish de novo antibodies from preformed antibodies and to determine whether they are donor-specific. This is important since de novo DSA are most detrimental to graft.