Detection of gammopathy by serum protein electrophoresis for predicting and managing therapy of lymphoproliferative disorder in 911 recipients of liver transplants.

Monitoring of posttransplantation lymphoproliferative disorder (LPD) is usually based on imaging, which lacks sensitivity. A prospective study in 911 consecutive recipients of liver transplants was conducted to assess the value of gammopathy monitoring by serum protein electrophoresis (SPE) and to compare it with conventional follow-up methods. Patients systematically underwent SPE testing just before transplantation, at least twice during the first year after transplantation, and once a year thereafter. Patients with LPD underwent SPE testing every month. Immunofixation was done if abnormalities were detected by SPE. Gammopathy was observed in 114 patients, 18 of whom had onset of LPD. In 3 other patients, LPD developed, but no gammopathy was detected before onset of LPD or while LPD was present. Multivariate analyses showed gammopathy (relative risk [RR], 65.3), more than one transplantation (RR, 7.5), and viral cirrhosis (RR, 2.8) to be independent prognostic factors associated with occurrence of LPD. LPD was treated by reducing immunosuppression, with or without chemotherapy, administration of anti-CD20 monoclonal antibody, or surgery. The mortality rate was 24% (5 of 21 patients). Remission, which occurred in 13 patients, was associated with disappearance of gammopathy in 10 patients. In 5 patients, normalization of SPE results preceded the diagnosis of remission based on imaging, by a mean of 4 months. For diagnosis of LPD remission, the positive and negative predictive values of disappearance of gammopathy were 91% and 100%, respectively; and gammopathy monitoring was more sensitive than imaging (100% and 38%, respectively). Gammopathy monitoring is an inexpensive, noninvasive, sensitive way to detect LPD and assess the efficacy of treatment. It could be used routinely in follow-up of recipients of transplants.