| Objective:To investigate the correlation between serum IgG levels and the clinical manifestation,pathological changes and outcomes of IgA nephropathy.Methods:From January2010 to July 2017,a total of 602 IgA nephropathy(IgAN)patients were recorded m the database.According to the exclusion criteria,309 patients with IgA nephropathy were included in the study.Patients were divided into 3 groups on the basis of serum of IgG tertiles:<8.99,8.99-11.17 and>11.17g/L.The clinical indicators and the differences between the 3 groups were compared.Single factor and multivariate cox regression models were used to explore the independent influencing factors of kidney outcomes.A diagnostic model of renal survival is established by the ROC curve.Kaplan-Meier survival curve analysis was used to investigate the correlation between serum IgG and renal endpoint events according to different level of semrn IgG.Interaction and stratified analyses were conducted according to sex(men and women),body mass index(<23.5 and>23.5 kg/m2),hemoglobin(<120 and>120g/L),serum albumin(<40 and? 40 g/L),hypertension(yes and no),24-hour urine protein quantitation(<0.5 and?0.5g/d),estimated glomerular filtration rate(eGFR<60 and?60[mlˇmm-lˇ(1.73m2)]),whether or not had used RAS Inhibitors(yes and no),whether or not had used corticosteroids(yes and no),and whether or not had used immunosuppressants(yes and no).Results:(1)Clinical and medical records:309 patients with IgAN(154 male patients),103 patients(59 male patients)in the G1group,103 patients(49 male patients)in the G2group,and 104 patients(46 male patients)in the G3group.As the level of serum IgG increased,there was a decrease in diastolic blood pressure(P=0.03),serum creatinine(P=0.010),total cholesterol(P<0.001),triglyceride(P=0.006),low density lipoprotein(P=0.003),24-hour total urine protein(P<0.001)and a increase in serum albumm(P<0.001).And serum IgG levels was inversely correlated with serum creatinine level and proteinuria.Pathological records:interestingly,with increasing serum IgG,there was a tendency of a decrease in the proportion of glomerular sclerosis(P=0.003)and the ratio of crescent(P<0.001)(2)Univariate cox regression model:Diastolic blood pressure,cholesterol,24-hour urine protein quantitation,serum C3,the proportion of glomerular sclerosis and tubular atrophy/interstitial fibrosis may be risk factors for renal outcomes.Serum albumin and serum IgG may be protective factors for renal outcomes(3)Multivariate cox regression model:elevated sera creatinine level,tubular atrophy/interstitial fibrosis were independent risk factors for kidney outcomes.And a decreased serum IgG level was also a independent factor for unfavorable outcomes(4)Spline-transformed association:the spline-transformed association of serum IgG with time to renal endpoints(progression to ESRD;OR 30%decrease in eGFR;OR the doubling of baseline serum creatinine),and serum IgG tended to be linearly associated with renal endpoints.With increasing serum IgG,there was a tendency of decrease in the progression to renal outcomes.To quantify in a simple form the relationship between continuous variables and renal endpoints,we also carried out analyses where risk was computed separately for each tertile of continuous variables.Serum IgG was still independent factor for progression(5)Kaplan-Meier survival curve analysis:Patients in the lowest tertile of circulating IgG level had significantly lower renal survival(P<0.05)(6)The interaction analysis:It showed that 24-hour urine protein quantitation,eGFR and the use of immunosuppressants played an interactive role in the association between serum IgG and renal outcomes in IgAN patients.The participants with 24-hour urine protein quantitation>0.5g had higher HRs between serum IgG and renal outcomes(HR=0.80;95%CI,0.61-1.05)than those with 24-hour urine protein quantitation<0.5g(HR=0.24;95%CI,0.05-1.08).And the participants with eGFR<60[mlˇmin-1ˇ(1.73m2)]had higher HRs between serum IgG and renal outcomes(HR=0.88;95%CI,0.64-1.21)than those with eGFR>60[mlˇmin-1ˇ(1.73m2)](HR=0.44;95%CI,0.14-0.97).The participants with the use of immunosuppressants had higher HRs between serum IgG and renal outcomes(HR=0.85;95%CI,0.62-1.16)than those without use of immunosuppressants(HR=0.41;95%CI,0.22-0.76)Conclusions:(1)IgA nephropathy with low of serum IgG levels have more serious clinical manifestations and pathological manifestations(2)Low level of serum IgG is an independent risk factor for unfavorable outcomes in IgA nephropathy.The probability of renal endpoints increased with lower serum IgG(3)It showed that 24-hour urine protein quantitation,eGFR and the use of immunosuppressants played an interactive role in the association between serum IgG and renal outcomes in IgAN patients. |
PDF Full Text Request