Background: The most common and pernicious complication of Familial Mediterranean fever (FMF) is renal amyloidosis, usually affecting the kidneys, leading to end-stage renal failure. FMF-related renal amyloidosis needed to be diagnosed early. Optimal colchicine dose is effective in preventing and reversing renal amyloidosis. Galectin-3, profibrotic mediator, has regulatory functions in inflammation, fibrosis and tumorigenesis. Galectin-3 is a strong prognostic marker for heart failure. Galectin-3 plays role in diabetic nephropathy and chronic kidney disease. The aim of the study is to investigate whether galectin-3 is related to proteinuria and amyloidosis in FMF.
Methods: Seventy-five FMF patients who have no exclusion criteria and healthy controls (n = 36) were included. Serum galectin-3 was measured and morning spot urine was collected for determination of the protein/creatinine ratio (PCR).
Results: Serum Galectin-3 levels were significantly higher in FMF patients than the control group [969.66 (3825) pg/mL vs. 238 (921) pg/mL, respectively; P<0.001]. We classified into two groups: Group1 (n = 48) had FMF patients with proteniuria, Group2 (n = 27) had FMF patients without proteinuria. Group1 had higher levels of galectin-3 than Group2 [1106(3812) pg/mL vs. 867.3(1433) pg/mL, P < 0.001]. Galectin-3 levels were correlated with PCR in whole group and FMF group (r = 0.785, P < 0.001 and r = 0.803, P < 0.001). In ROC curve, best cutoff value = 581.50 pg/mL was used to detect proteinuria (sensitivity = 91.7 %, specificity = 71.4 %, AUC = 0.879) and optimal cutoff value = 1458.00 pg/mL was an indicator of nephrotic-range proteinuric (sensitivity = 100 %, specificity = 92.1 %, AUC = 0.983).
Conclusion: Galectin-3 is associated with proteinuria and renal amyloidosis in FMF. Galectin-3 may play role in pathogenesis of amyloidosis.
Keywords: FMF; Galectin-3; Proteinuria; Renal amyloidosis.