RESUMO
The aim of the present study was to determine whether there is an association between serum free light chains (sFLC) quantification and the development of post-transplant lymphoproliferative disorder (PTLD), using serum samples from a nested case-control cohort of patients with renal transplant. Ten new cases of PTLD and 46 controls were enrolled. Additional comparison groups consisted of five human immunodeficiency virus (HIV)-infected individuals, five with untreated Hodgkin lymphoma and six normal individuals. Serum κ and λ FLC concentrations were measured by nephelometry and compared with reference ranges (normal and renal ranges). κ and/or λ were above the normal range in 90% of cases and in 65% of matched controls. There was no statistically significant difference between all groups, except for λ FLC concentrations between cases of PTLD and normal individuals (p = 0.016). The κ/λ sFLC ratios of cases and controls were within the renal range and normal range. Our results suggest that sFLC are not useful to predict PTLD development in renal transplant recipients.