Immune and mono- and oligoclonal abnormalities in patients with renal transplantation

Serum from 115 HIV negative renal transplant recipients having more than 6 months follow-up was tested for the presence of mono- or oligoclonal immuno globulins (molg) by immunoelectrophoresis or immunofixation. Mono/oligoclon al gammapathy was detected in 16 patients (13.9 %). Eight of these patients had only one monoclonal band, whereas the other eight had two or more band s. Thirteen of the 16 patients (81.3%) were IgG kappa positive, nine (56.3% ) were IgG lambda positive, four (25.0%) were IgM lambda positive and only one (6.3%) was IgM kappa positive. Six monoclonal patients (37.5%) were IgG kappa positive and two monoclonal patients (12.5%) were IgG lambda positiv e. The oligoclonal combination IgG kappa lambda was present in three patien ts (18.8%), the combination IgG lambda +IgM lambda was present in two patie nts (12.5%) and IgG lambda +IgM lambda was present in one patient. The trip le combination IgM kappa lambda +IgG kappa lambda and IgM lambda +IgG kappa lambda was found in two patients (12.5%). Ninety percent of these molg did not exceed 2 g/L. Molg appeared between 1 acid 28 months after the kidney transplantation (mean value:8.5 5.9 months) but were often transient, disap pearing within 1 to 19 months in 13 patients (81.3%). Nine of the 16 cases (56.3%) disappeared before the end of the first year after detection. Risk factors for the appearance of these immunoglobulins have been identified as : the patient's age, the duration of haemodialysis, the occurrence of prior (anti-cytomegalovirus [CMV]) infection, and therapy with cyclosporin A (Cs A). The persistence of monoclonal gammapathy was associated with acute or r eactivated Epstein-Barr virus (EBV) infection and inability to convert IgM to IgG CMV antibodies. Futhermore, no association was established with prev ious hepatitis B or C infection or the number of rejection episodes. Kaposi 's sarcoma was found in one patient (6.3%) but had no correlation with the presence of molg. We recommend carefull follow up of renal transplant patie nts in whom molg have been discovered. (C) 2000 Editions scientifiques et m edicales Elsevier SAS.