1.1000
#2
THE USE OF DTT IN FLOW CYTOMETRIC CROSSMATCHES.
B. Blair and C. Murphey. San Antonio TX, SW Immunodiagnostics.

---

Flow cytometric crossmatching provides increased sensitivity leading to improved renal transplant graft survival. Specificity still remains an issue, however, especially when testing patients with immune complex diseases. SLE patients, in particular, continue to be problematic during periods of increased disease activity. We report on 6 patients that were evaluated after an unexpectedly positive allogeneic flow cytometric crossmatch (i.e. 0mm donor and/or 0% IgG PRA). Four of the 6 were known to have IgM antibodies. Crossmatches were repeated with untreated and DTT-treated recipient sera and pronase-treated donor lymphocytes. Autologous crossmatches were performed when possible. In 5 of 6 patients, the weak non-specific T cell reactivity was reduced in the DTT-treated sera. The same trend was seen in the auto crossmatches although they tended to have higher negative control values. We believe that DTT is useful in select patients to reduce non-specific T cell reactivity that might otherwise contraindicate transplantation.