Free light chain and intact immunoglobulin abnormalities in heart transplant recipients: Two year follow-up timelines and clinical correlations
Abstract
Objectives: To assess the timelines of serum free light chain (sFLC) concentrations and the kappa/lambda light chain (K/L) ratio in heart transplant (HTX) recipients. To analyze the performance of serum protein electrophoresis (SPE), serum immunofixation (sIFE) and sFLC measurements for gammopathy detection following a HTX.
Methods: A total of 96 patients who underwent a HTX were analyzed during a two-year follow-up period. The relevant clinical data were obtained from patient medical records.
SPE, sIFE and 5FLC methods were used for the detection of free light chain and intact immunoglobulin gammopathies at 4 time points after HTX. Results: A statistically significant decrease in sFLC K and L (a decrease of 39.1% and 27.6%, respectively, when compared to pretransplant values) was found 9 months after the HTX (p <0.001, Friedman test).
We detected SPE or sIFE abnormalities in 23 (8.4%) samples, and sFLC K/L ratio abnormalities in 34 (12.4%) samples. All of the K/L ratio abnormalities had normal SPE/sIFE values, and 19% of the findings were persistent Conclusions: A significant and consistent dynamics in the sFLC concentration was found in the HTX patients during a 2-year follow-up period, which reflected changes in the immunosuppressant dosage.
A remarkable number of monoclonal and polyclonal gammopathies was identified with some persistdnt abnormalities, using the SPE/ sIFE and sFLC methods. Some of the detected abnormalities, which might possess a higher risk for PTLD if interpreted according to common practice in nonTX patients can only be detected by 5FLC methods.