Background
Methods
Design
Patients
Samples and blood tests
Biological parameters and data grouping
Index | Full name | Abbreviation | Reference range |
---|---|---|---|
1 | Carcinoembryonic antigen | CEA | 0-5 μg/L |
2 | Alpha fetoprotein | AFP | 0-20 μg/L |
3 | Carbohydrate antigen 125 | CA125 | 0.1-35 u/ml |
4 | Carbohydrate antigen 199 | CA199 | 0.1-37 u/ml |
5 | Carbohydrate antigen 153 | CA153 | 0.1-30 u/ml |
6 | Carbohydrate antigen 724 | CA724 | 0.1-10 u/ml |
7 | Cytokeratin fragment 21-1 | CYFRA21-1 | 0.1-4 ng/ml |
8 | Neuron specific enolase | NSE | 0-24 ng/ml |
9 | Squamous cell carcinoma related antigen | SCC | 0-1.5 ug/L |
10 | Glucose | Glu | 3.4-6.2 mmol/L |
11 | Total protein | TP | 55-80 g/L |
12 | Albumin | ALB | 35-50 g/L |
13 | Urea nitrogen | UN | 1.8-7.5 mmol/L |
14 | Creatinine | Cr | 30-110 μmol/L |
15 | Uric acid | Ua | 104-444 μmol/L |
16 | Total cholesterol | CH | 3.1-5.7 mmol/L |
17 | Triglyceride | TG | 0.4-1.7 mmol/L |
18 | High density lipoprotein cholesterol | HDL | 1-1.6 mmol/L |
19 | Low density lipoprotein cholesterol | LDL | 0-3.4 mmol/L |
20 | Potassium | K | 3.5-5.5 mmol/L |
21 | Sodium | Na | 130-150 mmol/L |
22 | Calcium | Ca | 2.25-2.75 mmol/L |
23 | Chloride | Cl | 94-110 mmol/L |
24 | Phosphorus | P | 0.97-1.62 mmol/L |
25 | Magnesium | Mg | 0.6-1.4 mmol/L |
26 | Carbon dioxide | CO2 | 20.2-30 mmol/L |
27 | Total bilirubin | TB | 0-21 μmol/L |
28 | Direct bilirubin | DB | 0-8.6 μmol/L |
29 | Alanine aminotransferase | ALT | 0-40 U/L |
30 | Aspartate aminotransferase | AST | 0-40 U/L |
31 | Lactate dehydrogenase | LDH | 40-250 U/L |
32 | Creatine kinase | CK | 2-200 U/L |
33 | γ-Glutamyltransferase | GGT | 0-50 U/L |
34 | Alkaline phosphatase | ALP | 0-130 U/L |
35 | International normalized ratio | INR | 0.8-1.2 |
36 | Fibrinogen | FIB | 2.0-4.0 g/L |
37 | Prothrombin time | PT | 11.0-15.0 s |
38 | Prothrombin activity | PA | 70-120% |
39 | Activated coagulation time of whole blood | APTT | 30-45 s |
40 | D-dimer | D2 | 0.0-0.5 μg/L |
41 | β2-microglobulin | B2MG | 0.07-0.18 mg/dl |
42 | Serum immunoglobulin A | sIgA | 70-180 mg/dl |
43 | Serum immunoglobulin G | sIgG | 700-1600 mg/dl |
44 | Serum immunoglobulin E | sIgE | 0-100 IU/ml |
45 | Serum immunoglobulin M | sIgM | 40-230 mg/dl |
46 | Complement 3 | C3 | 90-180 mg/dl |
47 | Complement 4 | C4 | 10-40 mg/dl |
48 | Prealbumin | PA | 20-40 mg/dl |
49 | Red blood count | RBC | Male:4.3-5.9 * 1012/L |
Female: 3.9-5.2 * 1012/L | |||
50 | Hemoglobin | HB | Male: 137-179 g/L |
Female: 116-155 g/L | |||
51 | White blood count | WBC | 3.5-10 * 109/L |
52 | Platelet | PLT | 100-300 * 109/L |
53 | Body mass index | BMI | 18-25 |
54 | Hypertension | HP | |
55 | Gender | Gender | |
56 | Age | Age |
Statistic analysis
Results
Patient characteristics
Modeling group | Validation group | |||
---|---|---|---|---|
IgAN | Non-IgAN | IgAN | Non-IgAN | |
Number | 58 | 63 | 93 | 87 |
Age (years) | 35.6 ± 12.4 | 39.7 ± 15.3 | 32.8 ± 11.6 b
| 43.7 ± 15.7 b
|
Male : female | 39:19 | 33:30 | 53:40 | 48:39 |
Hypertension (%) | 28 (48.3%) | 28 (44.4%) | 45 (48.9%) | 50 (57.5%) |
Body mass index (kg/m2) | 24.9 ± 3.7 | 24.8 ± 4.0 | 24.1 ± 4.2 | 25.2 ± 4.3 |
Manifestation
| ||||
Chronic nephritis syndrome (%) | 44 (75.9%)a
| 23 (36.5%)a
| 75 (80.6%)a
| 31 (35.6%)a
|
Nephrotic syndrome (%) | 10 (17.2%)a
| 33 (52.4%)a
| 10 (10.8%)a
| 51 (58.6%)a
|
Isolated proteinuria or hematuria (%) | 4 (6.9%)a
| 7 (11.1%)a
| 8 (8.6%)a
| 5 (5.7%)a
|
Renal function
| ||||
Normal (%) | 43 (74.1%) | 48 (76.2%) | 67 (72.0%) | 69 (79.3%) |
Chronic renal insufficiency (%) | 15 (25.9%) | 11 (17.5%) | 25 (26.9%) | 14 (16.1%) |
Acute renal insufficiency (%) | 0 | 4 (6.3%) | 1 (1.1%) | 4 (4.6%) |
Univariate analysis
Parameter | Mean ± SD |
P-value | |
---|---|---|---|
IgAN | Non-IgAN | ||
FIBa
| 3.63 ± 1.00 | 5.00 ± 2.60 | 0.000 |
sIgGa
| 1018.5 ± 307.0 | 858.2 ± 352.7 | 0.020 |
TP b
| 66.2 ± 9.5 | 57.3 ± 12.7 | 0.000 |
ALB b
| 39.1 ± 6.5 | 31.7 ± 9.7 | 0.000 |
Ca b
| 2.22 ± 0.15 | 2.09 ± 0.18 | 0.000 |
D2a
| 0.70 ± 1.26 | 1.46 ± 2.99 | 0.019 |
sIgA a
| 331.3 ± 103.9 | 241.5 ± 102.3 | 0.000 |
CHa
| 4.84 ± 1.24 | 6.38 ± 2.79 | 0.002 |
DBa
| 3.1 ± 1.8 | 2.4 ± 1.3 | 0.029 |
LDLa
| 2.98 ± 1.00 | 4.14 ± 2.23 | 0.003 |
CA153a
| 11.9 ± 5.2 | 14.9 ± 7.7 | 0.038 |
TGa
| 1.7 ± 1.1 | 2.1 ± 1.0 | 0.013 |
ALPa
| 68.8 ± 40.2 | 81.0 ± 50.3 | 0.015 |
CA199a
| 12.0 ± 8.7 | 18.8 ± 20.3 | 0.046 |
UN a
| 6.6 ± 3.1 | 6.1 ± 3.4 | 0.048 |
Parameter | AUC | 95% Confidence lnterval |
P-value | |
---|---|---|---|---|
lower Bound | upper Bound | |||
CA199 b
| 0.605 | 0.505 | 0.706 | 0.046 |
CA153 b
| 0.609 | 0.509 | 0.709 | 0.038 |
TP a
| 0.703 | 0.611 | 0.796 | 0.000 |
ALB a
| 0.727 | 0.636 | 0.819 | 0.000 |
UN a
| 0.604 | 0.503 | 0.706 | 0.048 |
CH b
| 0.667 | 0.572 | 0.763 | 0.002 |
TG b
| 0.631 | 0.532 | 0.731 | 0.013 |
LDL b
| 0.657 | 0.560 | 0.753 | 0.003 |
Ca a
| 0.718 | 0.625 | 0.810 | 0.000 |
Cl b
| 0.628 | 0.528 | 0.729 | 0.015 |
DB a
| 0.615 | 0.514 | 0.717 | 0.029 |
ALP b
| 0.628 | 0.528 | 0.729 | 0.015 |
FIB b
| 0.712 | 0.621 | 0.804 | 0.000 |
D2 b
| 0.626 | 0.525 | 0.727 | 0.019 |
sIgA a
| 0.756 | 0.670 | 0.842 | 0.000 |
sIgG a
| 0.623 | 0.524 | 0.722 | 0.020 |
Correlation analysis of pre-selected parameters
Modeling with multiparameter analysis
Parameter | B | S.E. | Wald | df | Sig. | Exp(B) |
---|---|---|---|---|---|---|
FIB | 2.485 | 0.735 | 11.432 | 1 | 0.001 | 0.534 |
D2 | −0.242 | 0.161 | 2.275 | 1 | 0.132 | 0.785 |
sIgA | 0.009 | 0.002 | 16.440 | 1 | 0.000 | 1.009 |
sIgG | 0.001 | 0.001 | 6.396 | 1 | 0.011 | 1.001 |
UN | 0.049 | 0.057 | 0.740 | 1 | 0.390 | 1.051 |
ALB | 0.109 | 0.026 | 17.498 | 1 | 0.000 | 1.115 |
TG | −0.326 | 0.186 | 3.068 | 1 | 0.080 | 0.722 |
CH | −0.429 | 0.131 | 10.673 | 1 | 0.001 | 0.651 |
DB | 0.308 | 0.126 | 5.970 | 1 | 0.015 | 1.361 |
ALP | −0.007 | 0.005 | 1.883 | 1 | 0.170 | 0.993 |
CA199 | −0.041 | 0.019 | 4.855 | 1 | 0.028 | 0.960 |
CA153 | −0.071 | 0.031 | 5.293 | 1 | 0.021 | 0.931 |
Parameter | B | S.E. | Wald | df | Sig. | Exp(B) | 95% CI for EXP(B) | |
---|---|---|---|---|---|---|---|---|
Lower | Upper | |||||||
Manifestation | −1.089 | 0.423 | 6.637 | 1 | 0.010 | 0.336 | 0.147 | 0.771 |
FIB | −0.326 | 0.165 | 3.918 | 1 | 0.048 | 0.722 | 0.522 | 0.997 |
sIgA | 0.011 | 0.003 | 16.724 | 1 | 0.000 | 1.011 | 1.006 | 1.016 |
Constant | −0.648 | 0.858 | 0.569 | 1 | 0.450 | 0.523 |
Variables in the analysis | ||||
---|---|---|---|---|
Step | Tolerance | Sig. of F to Remove | Wilks' Lambda | |
1 | ALB | 1.000 | 0.000 | |
2 | ALB | 1.000 | 0.000 | 0.839 |
sIgA | 1.000 | 0.000 | 0.834 | |
3 | ALB | 0.601 | 0.123 | 0.702 |
sIgA | 0.974 | 0.000 | 0.810 | |
Manifestation | 0.593 | 0.020 | 0.722 | |
4 | sIgA | 0.986 | 0.000 | 0.846 |
Manifestation | 0.986 | 0.000 | 0.839 | |
5 | sIgA | 0.967 | 0.000 | 0.829 |
Manifestation | 0.803 | 0.003 | 0.733 | |
FIB | 0.789 | 0.045 | 0.702 |
Validation of the two models
Model | Cut-off point of of predicted probability | Predicted membership | Biopsy diagnosis | Sensitivity | Specificity | Accuracy | |
---|---|---|---|---|---|---|---|
IgAN | Non-IgAN | ||||||
Logistic regression model PRE-1 | 0.50 | IgAN | 64 | 12 | 68.8% | 86.2% | 77.5% |
Non-IgAN | 29 | 75 | |||||
0.40 | IgAN | 77 | 18 | 82.8% | 79.3% | 81.1% | |
Non-IgAN | 16 | 69 | |||||
Discriminant analysis model PRE-2 | 0.50 | IgAN | 64 | 13 | 68.8% | 85.1% | 77.0% |
Non-IgAN | 29 | 74 | |||||
0.40 | IgAN | 77 | 20 | 82.8% | 77.0% | 79.9% | |
Non-IgAN | 16 | 67 |
Predicted membership of the models | IgAN | Non-IgAN | Sensitivity | Specificity |
---|---|---|---|---|
Logistic regression model PRE-1
| ||||
IgAN | 54 | 7 | 85.7% | 88.5% |
Non-IgAN | 9 | 54 | ||
Discriminant analysis model PRE-2
| ||||
IgAN | 51 | 6 | 85.0% | 90.0% |
Non-IgAN | 9 | 54 |
Analysis of the net reclassification improvement (NRI)
Order | Parameter | Logistic regression model | Discriminant analysis model | ||
---|---|---|---|---|---|
NRI |
P-value | NRI |
P-value | ||
1 | sIgA | 0.290 | 0.001 | 0.308 | 0.000 |
2 | ALB | 0.023 | 0.157 | 0.000 | -- |
3 | FIB | 0.168 | 0.003 | 0.169 | 0.001 |
4 | CH | -0.022 | 0.334 | -0.034 | 0.184 |
5 | TG | -0.108 | 0.037 | -0.130 | 0.017 |
6 | ALP | -0.012 | 0.762 | 0.019 | 0.640 |
7 | D2 | -0.011 | 0.317 | 0.011 | 0.581 |
8 | sIgG | -0.022 | 0.726 | 0.003 | 0.962 |
9 | DB | 0.022 | 0.157 | -0.011 | 0.646 |
10 | CA153 | 0.001 | 0.985 | -0.022 | 0.593 |
11 | CA199 | -0.011 | 0.317 | 0.011 | 0.775 |
12 | sUN | -0.024 | 0.384 | 0.022 | 0.334 |