A DTT- AMELIORATED POSITIVE CROSSMATCH DOES NOT INFLUENCE RENAL GRAFT OUTCOME.
C.F. Bryan, J. Martinez, N. Muruve, P.W. Nelson, G.E. Pierce, G. Ross, C.F. Shield, B.A. Warady, M.I. Aeder, T.S. Helling, A.M. Luger. Midwest Organ Bank, Inc., Westwood, KS.

---

    A positive crossmatch that is rendered negative by treating the serum with the IgM-reducing agent dithiotreitol (DTT) is generally reported not to influence short-term renal graft outcome. Its effect on long-term (³ 3 years) function, however, is less clear. We evaluated the effect of a DTT-ameliorated positive crossmatch (DTT-APXM) on long-term renal graft outcome in 1,025 consecutive cadaveric renal transplants and 294 living-donor renal transplants from patients transplanted between 1990 and 1997. Graft survival data for the cadaveric transplants are in the following table.  

DTT-AmelioratedPositive Crossmatch	Graft Survival (Years)
	0.25	1	3	5
NO	94%	91%	85%	78%
(n=974)	(n=857)	(n=720)	(n=443)	(n=228)
YES	91%	87%	79%	70%
(n=51)	(n=44)	(n=39)	(n=24)	(n=10)

 

     The data show that short-term and long-term graft survival of cadaveric kidney transplants in patients with a DTT-APXM is not significantly different from patients who had a negative untreated crossmatch (Wilcoxon=0.2; log-rank=0.3). Similarly, no significant effect was seen with living-donor renal transplants with the DTT-APXM group (n=4) having 1-, 3- and 5-year survival of 100%, 100% and 75%, compared with the negative crossmatch group (n=290) having 94%, 87% and 83% 1-, 3- and 5-year survival (Wilcoxon=0.7; log-rank=0.8).
    Conclusion: The data show that long-term graft survival in renal transplantation is not influenced by the presence of donor-reactive lymphocytotoxic antibodies in the crossmatch if no reactivity is present after the serum is treated with DTT.