Serum protein electrophoresis abnormalities in adult solid organ transplant patients with post-transplant lymphoproliferative disorder*

Post-transplant lymphoproliferative disorder (PTLD) is an Epstein-Barr virus (EBV) associated malignancy that occurs in the setting of pharmacologic immunosuppression used after organ transplantation. The presence of monoclonal gammopathy (MG) after organ transplantation is a risk factor for the development of PTLD. We retrospectively explored the characteristics of serum protein electrophoresis (SPEP) in 38 adult solid organ transplant patients with biopsy proven PTLD and SPEP. Twenty-three (61%) had MG with nine (24%) showing multiple MG. Background gammaglobulin levels were abnormal in 13 (34%) patients with five (13%) and eight (21%) having polyclonal hypergammaglobulinemia or hypogammaglobulinemia, respectively. Hypogammaglobulinemia was correlated with the presence of MG (p = 0.01) and polymorphic B-cell hyperplasia histology (p = 0.01). No correlation between SPEP findings and overall survival were noted. With median follow-up of 116 wk (range 2-261 wk), 21 (55%) patients are alive with 20 (53%) in complete remission. Response to reduction in immunosuppression was correlated with improved overall survival (262 wk vs. 68 wk, p = 0.003). Persistence of MG after complete response of the PTLD did not predict relapse. There is a high incidence of MG and gammaglobulin abnormalities in patients with PTLD.