(TIF 3265 kb) Acknowledgements The authors wish to acknowledge all patients and their families for participating in this study. Funding This work was financially supported bythe project of cultivating young teachers in Sun Yat-sen University (No. score matched (PSM) to non-IgAN cases on the logit of the propensity score using nearest neighbor matching in a 1:1 fashion, with a caliper of 0.02 with no replacements, according to age, gender, BMI, proteinuria level, and estimated glomerular filtration rate (eGFR). Results We found that in both the full cohort and PSM cohort, the IgA/C3 ratio in the IgAN group was significantly higher than that of the non-IgAN group. The same results were also obtained with stratification by different levels of proteinuria and renal function. In the PSM cohort, there was no difference in IgA/C3 ratio in patients with IgAN between different proteinuria groups and different chronic kidney disease (CKD) groups. DL-alpha-Tocopherol methoxypolyethylene glycol succinate The area under the ROC curve (AUROC) of the IgA/C3 ratio in distinguishing IgAN among primary glomerular disease was 0.767 in the full cohort, and 0.734 in the PSM cohort. The highest AUROC of the IgA/C3 ratio was in the 1?g/d proteinuria group (0.801 in the full cohort, and 0.803 in the PSM cohort); however, there was no difference between all CKD groups. Meanwhile, the diagnostic accordance rate for the diagnosis of IgAN among all patients with an IgA/C3 ratio? ?3.5304 was as high RDX as 92.02% in the full cohort. IgAN was independently correlated with IgA/C3 ratio in the full cohort by multivariate logistic regression analysis. Conclusions The present study provides clear evidence that the IgA/C3 ratio is an effective predictor of IgA diagnosis, especially in patients with proteinuria 1?g/d. In order to study the effectiveness of this biomarker, and to determine a standardized cut-off value, additional multicenter large-scale studies are needed. Electronic supplementary material The online version of this article (10.1186/s12882-019-1331-0) contains supplementary material, which is available to authorized users. body mass index, complement 3, complement 4, chronic kidney disease, diastolic blood pressure, estimated glomerular filtration rate, high-density lipoprotein cholesterol, immunoglobulin A, immunoglobulin DL-alpha-Tocopherol methoxypolyethylene glycol succinate A nephrology, immunoglobulin G, immunoglobulin M, low-density lipoprotein cholesterol, propensity score matched, systolic blood pressure value for analysis of comparison between IgAN patients and non-IgAN patients The median proteinuria in the IgAN group was 0.88?g/d, which was much lower than that of the non-IgAN group (4.00?g/d). 53.10% of IgAN patients had proteinuria 1?g/d, 33.55% had proteinuria between 1 DL-alpha-Tocopherol methoxypolyethylene glycol succinate and 3.5?g/d, and only 13.34% had proteinuria ?3.5?g/d. Among non-IgAN patients, the percentage of patients within the three proteinuria classifications were 13.91, 29.29, and 56.80% for proteinuria 1?g/d, proteinuria 1C3.5?g/d, and proteinuria ?3.5?g/d, respectively (Table ?(Table11). Among the full cohort, compared to non-IgAN patients, DL-alpha-Tocopherol methoxypolyethylene glycol succinate patients with IgAN had a younger mean age, and were more likely to be female. They also had a longer disease course, a higher prevalence of hematuria and lower prevalence of proteinuria, and higher BP, serum albumin, serum globulin, serum cystatin C, BUN and Scr. IgAN patients also had lower BMIs, and lower levels of hemoglobin, cholesterol, triglycerides, HDL-C, LDL-C DL-alpha-Tocopherol methoxypolyethylene glycol succinate and eGFR (complement 3, complement 4, immunoglobulin A, immunoglobulin A nephrology, immunoglobulin G, immunoglobulin M, propensity score matched, receiver operating characteristic In the different proteinuria groups, the highest AUROC of the IgA/C3 ratio in predicting IgAN was in the proteinuria1?g/d group (full cohort: AUROC 0.801, sensitivity 70.75%, specificity 80.85%; PSM cohort: AUROC 0.803, sensitivity 66.67%, specificity 82.98%; all complement 3, immunoglobulin A, immunoglobulin A nephrology, propensity score matched, receiver operating characteristic There was no difference in the AUROC of the IgA/C3 ratio in predicting IgAN between all the CKD groups (all complement 3, chronic kidney disease, immunoglobulin A, immunoglobulin A nephrology, propensity score matched, receiver operating characteristic Prediction efficiency of specific cut-off points of the IgA/C3 ratio In the PSM cohort, the 95% cut-off point for the IgA/C3 ratio in the non-IgAN group was 3.5304, and the 5% cut-off point for the IgA/C3 ratio in the IgAN group was 1.0546. This cut-off assumes that patients with an IgA/C3 ratio? ?3.5304 are predicted to be IgAN, and patients with an IgA/C3 ratio? ?1.0546 are non-IgAN. In the full cohort, the diagnostic accordance rate of an IgAN diagnosis among all patients with an IgA/C3 ratio? ?3.5304 was as high as 92.02%, but the diagnostic accordance rate of a diagnosis of non-IgAN among all patients with an IgA/C3 ratio? ?1.0546 was only 63.34% (Fig.?4). Open in a separate window Fig. 4 Prediction efficiency of specific cut-off points of the IgA/C3 ratio Factors associated with IgAN In the full cohort, a multivariate logistic regression analysis was performed to clarify which factors were independently associated with IgAN. The analysis showed that the IgA/C3 ratio was.
(TIF 3265 kb) Acknowledgements The authors wish to acknowledge all patients and their families for participating in this study
