Urinary exosome isolation in fluorosis patients with early symptoms of nephrotoxicity

Abstract

Polyureic nephropathy, a kidney disease characterized by excess thirst & frequent urination, are established manifestations of non-skeletal fluorosis. This study aimed to isolate the urinary exosomes from fluorosis patients with early renal impairment. Fluorosis patients having urinary fluoride above 1ppm were recruited as test group (Group-1). The recruited fluorosis patients were sub-divided in two groups i.e., fluorosis patients with normal renal functions (G-1A) and fluorosis paints with renal impairments (G-1B). Healthy individuals having urinary fluoride up to 1ppm were included as control (Group-2). Urinary Exosomes were isolated and correlated with fluoride toxicity associated nephrotoxicity. A significantly (P = 0.002) higher urinary fluoride (G-1A: 2.62 ± 0.94 ppm and G-1B: 3.87±1.6 ppm) in fluorosis patients were observed compared to the normal control (G-2: 0.40±0.19 ppm), (P = 0.004).The serum creatinine levels was significantly increased in G-1B (3.33±0.76 mg/dL) compared to G-1A (1.11±0.89 mg/dL), (P = 0.003) and G-2, (0.64±0.17), (P = 0.005). A significant (P = 0.001) increase in BUN were observed in G-1B, compared to G-1A and control. The urinary protein was also significantly higher in G-1A (P = 0.005) and G-1B (0.001) compared to G-2. The number of exosomes per/ml of urine in G1-B was significantly higher (P = 0.05) than the G-1A and G-2. The number of urinary exosomes in G-1A and G-1B were also significantly higher than G-2 (P = 0.05). Chronic fluoride toxicity may induce renal impairments and increased urinary excretion of exosomes.