Abstract 18092: Source of Galectin-3 in Human Heart Failure, Chronic Kidney Disease and Cardio-renal Failure

Abstract

Background: Galectin-3 (Gal-3) may promote cardiac and renal fibrosis in heart failure (HF). Plasma Gal-3 levels predict outcome in HF but are tightly correlated with renal function. The source of Gal-3 in human HF, chronic kidney disease (CKD) or cardio-renal failure (HF+CKD) is unclear. Objective: To assess Gal-3 presence and location in human heart or kidney tissue from patients with HF, CKD or HF+CKD. Methods: Plasma Gal-3 levels and LV tissue explanted at time of cardiac transplant in systolic HF (n=15) and autopsy renal sections from patients with normal kidneys (n=4), CKD (n=17) or CKD+HF (n=14) were examined (H&E, Masson’s trichrome and CD-68 and Gal-3 immunohistochemistry). In the systolic HF patients, we quantified the number of Gal-3+/CD-68+ cells per HPF in LV tissue and assessed the correlation with plasma Gal-3 levels. In autopsy renal tissue, we derived a Composite Gal-3 Score (CG3S) incorporating the % of Gal-3+ tubules per HPF, % of Gal-3+ cells/tubule per HPF, and intensity of Gal-3 staining and assessed the correlation of the CG3S with ante-mortem estimated glomerular filtration rate(eGFR). Renal macrophage Gal-3 staining was also assessed. Results: In systolic HF LV tissue, Gal-3 was present in macrophages rather than myocytes but Gal-3+/CD-68+ cells per HPF was not correlated with plasma Gal-3 levels (p> 0.9) which correlated inversely with eGFR (r = -0.89 for log Gal-3 vs eGFR, p<0.0001). In the kidney, Gal-3 was not present in macrophages but was localized to renal tubular cells (Figure). The CG3S increased exponentially as eGFR decreased (r = - 0.88 for log CG3S versus eGFR; p<0.0001) and this relationship was not different (p=0.44) in patients with or without HF (Figure). The log CG3S correlated with the degree of fibrosis (tubulointerstitial scarring) in the kidney (r=0.88; p<0.0001). Conclusion: Collectively, these data suggest that plasma Gal-3 is predominantly of renal tubular epithelial origin in human HF, CKD, and CKD+HF.