Clinical and Laboratory Predictors of Distinct Histopathogical Features of Lupus Nephritis

The authors aimed to explore whether distinct clinical, serological, and urinalysis findings are associated with specific histological classes of lupus nephritis. Clinical and laboratory features were recorded at the time of clinical diagnosis from 297 consecutive patients with biopsy-confirmed lupus nephritis. Univariate and logistic regression analyses were performed and a risk score was developed to estimate the risk for developing different classes of lupus nephritis. Variables independently associated with class II included absence of malar rash, negative anti-dsDNA, and ≤5 urine leucocytes/high power field (hpf); with III/IV: age at nephritis diagnosis ≤32 years old, presence of musculoskeletal features, new-onset hypertension, positive anti-dsDNA, >5 urine leucocytes/hpf, creatinine >1.2 mg/dL, cellular casts >1/hpf, and absence of nephrotic range proteinuria; with V: age at nephritis diagnosis >32 years, malar rash, absence of musculoskeletal complaints or serum C3 hypocomplementemia, nephrotic range proteinuria, and ≤9 urine erythrocytes/hpf. A risk predictive score of specific histological classes was calculated for each patient. Associations between 2, 3 or more risk factors with specific histological classes were also revealed [Odds ratios (95% confidence interval) (≥2 risk factors) was 6.7 (2.8-17.4) for class II nephritis, 15.6 (5.1-47.8), and 8.2 (3.6-19.0) for classes III/IV and for class V, respectively (≥3 risk factors)]. The identification of independent factors associated with specific classes of lupus nephritis can provide guidance in selecting specific therapeutic modalities, particularly in cases in which renal biopsy is contraindicated.