Abnormal Expression Of Gd-IgA1 In Peripheral Blood And Urine Of Patients With IgAN

IgA Nephropathy(IgAN)is the most common primary glomerular disease after Focal segmental glomerulosclerosis(FSGS).Although the majority of IgAN patients have a good prognosis,about 30% of patients still progress to ESRD,and more than50% of IgAN patients relapse within 2 years after renal transplant treatment.Renal biopsy pathology is the gold standard for diagnosing IgAN and evaluating the severity,activity and prognosis of the disease.Urinalysis,such as proteinuria,is also one of the indicators for evaluating the severity and activity of IgAN disease.Both of these methods can be used to guide the treatment of IgAN,but they are insufficient in practical clinical application: Renal biopsy is an invasive test that may lead to serious complications such as bleeding or even life threatening;Proteinuria and other urinalysis are not accurate enough to evaluate the pathological changes of IgAN.As perhaps the most important link in the pathogenesis of IgAN,Gd-IgA1 in peripheral blood and urine may play an important role in the diagnosis and prediction of the disease progression of IgAN.Objective: To detect the concentrations of Gd-IgA1 in peripheral blood and urine of IgAN patients,non-IgAN patients and healthy people,and to explore the relationship between the concentrations of Gd-IgA1 in peripheral blood and urine and the clinical indicators and renal pathology(Oxford classification)of patients.Methods: In this study,patients with clinical and pathological diagnosis of IgAN in Jiangsu Subei People’s Hospital were selected as the experimental group,non-IgAN patients as the control group,and healthy people with physical examination at the same period were selected as the healthy control group.Peripheral blood and urine were collected from patients in the three groups,and the concentrations of Gd-IgA1 in peripheral blood and urine were determined by KM55 ELISA kit.We analyzed the distribution differences of peripheral blood and urine Gd-IgA1 in the three groups,and the correlation between peripheral blood Gd-IgA1 and urine Gd-IgA1 and clinical indicators and renal pathology in IgAN patients.Results:1.There were differences in peripheral blood Gd-IgA1 concentrations among IgAN,NC and HC groups(IgAN vs.NC;P=0.040;IgAN vs.HC P<0.001;NC vs.HC,P=0.004);There were differences in urinary Gd-IgA1 concentration between IgAN and NC,also between IgAN and HC,but there was no difference in the distribution of urinary Gd-IgA1 concentration between NC and HC(IgAN vs.NC,P=0.031;IgAN vs.HC,P=0.002;NC vs.HC,P=0.887).2.In IgAN patients,peripheral blood Gd-IgA1 was positively correlated with gross hematuria(r=0.318,P<0.05),but not with serum creatinine,urea nitrogen,24 h urinary protein,e GFR,CKD stage,urinary creatinine,NJIgAN-RSS(P>0.05);Urinary Gd-IgA1 was negatively correlated with serum creatinine(r=-0.542,P=0.004),urea nitrogen(r=-0.381,P=0.050),24 h urinary protein(r=-0.489,P=0.010),CKD stage(r=-0.489,P=0.010),and NJIgAN-RSS(r=-0.515,P=0.008),but not with gross hematuria,urinary creatinine(P>0.05).3.Peripheral blood Gd-IgA1 was positively correlated with C score(r=0.385,P=0.005),but not with M,E,S,T(P>0.05);Urinary Gd-IgA1 was negatively correlated with T(r=-0.054,P<0.001),but not with M,E,S and C(P>0.05).Conclusion: Gd-IgA1 is highly expressed in peripheral blood and urine of patients with IgAN.Urinary Gd-IgA1 concentration may play a greater role in assessing the severity,activity and disease progression of IgAN,and may be an effective biomarker for the diagnosis of IgAN.Compared with normal healthy people,peripheral blood Gd-IgA1 concentration >11.67ug/ml has high sensitivity in diagnosis of IgAN,while urinary GdIgA1 concentration >8.25ug/ml has high specificity in diagnosis of IgAN.