2167 Polyclonal immunoglobulin free light chains: an evidence of cardiac remodeling in patients with glomerular diseases

Abstract Background and Aims It was previously shown, that polyclonal immunoglobulin free light chains (FLC) are the independent predictor of mortality in patients with decompensated heart failure, chronic kidney disease (CKD) and also in general population. Mechanisms of this phenomenon are still unknown. The aim of our study is to reveal the possible relationships between FLC and cardiac remodeling in patients with glomerular diseases. Method We included 97 patients with biopsy-proven diagnosis of different immune-mediated glomerular diseases, 53% were men, mean age was 48 ± 14.6 years. Serum Freelite FLC levels were measured as well as standard clinical and laboratory investigation. At the time of biopsy transthoracic echocardiography was also performed. Glomerular filtration rate (eGFR) was estimated by “2021 CKD-EPI Creatinine” equation. Results Median of eGFR was 46.8 ml/min/1.73 m² (28.7-80.0), FLC-kappa level was 27.4 mg/l (16.8- 48.4), FLC-lambda level was 28.2 mg/l (20.8-43.3). FLC-kappa levels were above reference range in 65%, FLC-lambda levels – in 54%. LV diastolic dysfunction (DD) was present in 68%. Comparison in groups showed that the elevation of FLC-kappa more than 19.4 mg/l was associated with bigger LV mass index (LVMI) – 138.3 ± 30.2 g/m² vs 99.9 ± 31.2 g/m² р = 0.022, the parallel correlation was found between LVMI and levels of FLC-lambda higher than 26.3 mg/l (136.2 ± 64.8 g/m² vs 104.0 ± 36.6 g/m², р = 0.023). Spearman analysis has shown statistically significant correlations between FLC levels and E/e’- Rs = 0.501 p = 0.0001 for FLC-kappa, Rs = 0.343 p = 0.012 for FLC-lambda. Combined FLC level higher than 52.9 mg/l was a significant predictor of DD with area under the ROC curve (AUC) 0.703 (sensitivity 76.5%, specificity 62.5%). Conclusion Elevation of serum pFLC level could be a promising marker of cardiac remodeling, especially, of DD in patients with glomerular diseases. Possible pathogenic role of FLC in cardiorenal relationships may be revealed in further studies. Figure: Area under ROC curve, characterizing the combined pFLC as a predictor of left ventricle diastolic dysfunction.