INCREASED BETA(2)-MICROGLOBULIN (B(2)M) IS USEFUL IN THE DETECTION OFPOSTTRANSPLANT LYMPHOPROLIFERATIVE DISEASE (PTLD)

This study examines whether changes in beta(2)-microglobulin (B(2)M) s erum levels are useful in the early detection of post-transplant lymph oproliferative disease (PTLD). Serum B(2)M is monitored daily post-tra nsplant at our center as a marker of change in lymphocyte activation. We identified 16 cases (16/1359; 1.2%) of PTLD from among 1359 kidney and kidney-pancreas transplants. Those with CNS lymphoma (two patients ) and titer change only (one) were not included in this review. Thirte en patients had serum titer and clinical evidence of EBV activity; 12 of these patients had histological evidence of PTLD (lymph node 6, kid ney 3, and generalized disease 3). Three patients died with disseminat ed PTLD infection. Nine are alive but only two have the original trans plant kidney. All patients received quadruple immunosuppression for in duction, and 11 were subsequently treated with OKT3 or ALG for rejecti on. The mean number of days of induction ALG therapy was 14.8 d (20 mg /kg/d). The mean number of days of OKT3 therapy for rejection was 14.4 d (5 mg/d). During rejection the highest mean creatinine level was 6. 8 mg/dL, and the highest mean B(2)M level was 16.4. With PTLD, the hig hest mean creatinine level was 7.0 mg/dL and the highest mean B(2)M le vel was 32.3 mg/L. The difference in creatinine levels was not signifi cant, but the difference in B(2)M levels was significant (p<0.01). We conclude that B(2)M levels are useful markers in differentiating rejec tion from PTLD.