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.