Clinical And Laboratory Features To Predict Pathological Classifications Of Lupus Nephritis

Objective: To investigate the difference of clinical and laboratory features of lupus nephritis whose pathological classifications are distinct, establish predictive models of them.Methods: Collection of all clinical data of patients who underwent renal biopsy pathological and diagnosed LN in the Department of Nephrology of the First Affiliated Hospital of Fujian Medical University from Jan 2003 to Dec 2015, excluding without complete clinical data and small number of patients with class VI and II + IV(1 and 2, respectively). According to pathological classifications all qualified LN patients were divided into 3 groups: class II, class III/IV, class V. We used ANOVO, Kruskal-Wallis Test, Two-sided Fisher exact or chi-square test to investigate the difference of clinical and laboratory features of lupus nephritis, among groups. Binary Logistic Analysis was used to identify the independent predictors of histological class of Lupus Nephritis and establish predictive models.Results: 1. The mean age of LN patients is(30.47±10.81)years, the ratio of male and female is 1:7.75.There is no significant difference among groups on ages and sex.2. Class IV with the highest proportion(50.7%), which followed by class V(30.5%).3. As respect to the outer-renal symptoms, the incidence of facial erythema is the highest in class II and photosensitivity is highest in class V(P<0.05).4. Average hemoglobin, leukocyte and blood platelet are significantly lower in class III + IV versus all other types.The incidence of hematuresis and cylindruia is highest in class III + IV( P<0.05).5. The impairment of renal function of Class III + IV is the most serious,which has the highest serum creatinine. There is no significant difference among groups on 24 hours urine protein.6. The level of complement C3 and C4 is the lowest in class III + IV. The ds-DNA antibody and anti-nuclear antibody in each type are in general no significant difference.7. The independent predictors of class II are facial erythema and serum albumin. The independent predictors of class III + IV are photosensitivity, facial erythema, cylindruia and complement C3. Class Ⅴis the same as class III + IV.8. The predictive model of class II: P = 5.506 + 2.161 ×(facial erythema)- 0.128 ×(serum albumin); The predictive model of class III + IV: P = 0.971- 2.140 ×(photosensitivity) + 1.488 ×(facial erythema) + 1.309 ×(cylindruia)- 3.015 ×(complement C3); The predictive model of class V: P = 0.358 + 1.635 ×(photosensitivity)- 1.109 ×(facial erythema)- 0.082 ×(cylindruia) + 2.468 ×(complement C3).9. When receiver operating characteristic curves for the predictive models are fitted, area under the curve is 0.839, 95%CI(0.753-0.926) for class II. Sensitivity and specificity of class II model is 100% and 63.0%, respectively. And its positive predictive value(PPV) and negative predictive value(NPV) is 20.3% and 100%, respectively. When receiver operating characteristic curves for the predictive models are fitted, area under the curve is 0.797, 95%CI(0.722-0.871) for class III + IV. Sensitivity and specificity of class III + IV model is 83.1% and 66.7%, respectively. And its PPV and NPV is 74.6% and 77.0%, respectively. Area under the curve is 0.769, 95%CI(0.692-0.846) for class V. Sensitivity and specificity of class V model is 97.9% and 46.6%, respectively. And its PPV and NPV is 51.7% and 97.4%, respectively.Conclusions: 1. There are significant differences of clinical and laboratory features of lupus nephritis whose pathological classifications are distinct. Patients of class III + IV is with the most prominence.2. We can establish predictive models for each type LN by independent predictors. And the models can help identify pathological classifications of LN and provide guidance for treatment.