Differential Expression Of MiR-155 In Urine And Serum Of Patients With IgA Nephropathy And Its Clinical Significance

Objective:IgA nephropathy(IgAN)is the most common primary glomerulonephritis in the world.About 20-40% of patients diagnosed with IgAN progress to end-stage renal disease after 10-20 years.However,the pathogenesis of IgA nephropathy has not been clarified yet,and the diagnosis and evaluation of IgA nephropathy mainly rely on renal biopsy.However,renal biopsy is a kind of invasive examination and cannot be repeated.Therefore,we need to find non-invasive examination indicators to evaluate the progress and prognosis of IgA nephropathy.The existing research shows that microRNAs(miRNAs)may participate in the pathogenesis of IgA nephropathy,More and more clinical and basic studies suggest that the expression of miR-155 is closely related to renal diseases?By detecting the differential expression of miR-155 in urine and serum of patients with IgA nephropathy(IgAN)and healthy control group,and analyzing its relationship with clinical and pathological indicators,Furthermore,the feasibility of miR-155 as a noninvasive index to evaluate the severity of renal damage was discussed.Methods:Urine and blood samples(IgAN group)of 30 patients with IgA nephropathy diagnosed by renal biopsy in the First Affiliated Hospital of Nanchang University from August 2018 to September 2019 were collected.Also besides urine and blood samples(healthy control group)of 20 healthy volunteers were collected.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect the expression level of miR-155 in urine and blood of the two groups,and to compare the expression difference of miR-155 in serum and urine between the IgAN group and the healthy control group.The clinical and renal pathological indexes of IgAN group were collected and the relationship between the expression of miR-155 in serum and urine and the clinical and renal pathological indexes of IgAN group was analyzed.Results:1.Compared with the control group,the expression of miR-155 in urine sediment of IgAN group was up-regulated(P < 0.05),but there was no significant difference in the expression of miR-155 in the serum of IgAN group(P = 0.647).there was a positive correlation between the expression of miR-155 in urine sediment and urine protein of IgAN patients(r = 0.429),P = 0.018),negative correlation with eGFR(r =-0.417,P = 0.022),suggesting that urinary sediment miR-155 is closely related to urinary protein excretion and renal function in patients with IgA nephropathy,but the expression level of serum miR-155 in IgAN has no correlation with urinary protein and eGFR(all P > 0.05).2.The expression level of miR-155 in urine sediment of IgAN patients was correlated with renal pathological damage.The higher the Lee and Oxford classification grades were,the higher the expression level of miR-155 in urine sediment was(all P < 0.05).The expressi on of miR-155 in urine sediment of IgAN patients was positively correlated with the proportion of glomerulosclerosis(r = 0.367,P = 0.042),but not with the formation of crescent(r = 0.349,P = 0.059).3.There was no significant difference in the expression of miR-155 between Lee and Oxford classification(all P > 0.05).There was no correlation between the expression of miR-155 and glomerulosclerosis and crescent formation(all P > 0.05)Conclusion:1.The expression level of miR-155 in urine sediment of patients with IgAN is significantly increased,which may be related to renal function and urinary protein level.2.The expression level of miR-155 in urine is related to the degree of renal pathological damage,which may have a certain predictive value for the degree of renal tissue damage in patients with IgAN,but it still needs to be further verified by expanding the sample size and long-term follow-up to determine its clinical application value.