The Correlation between Renal Color Doppler Indices and Pathological and Laboratory Parameters in Patients with Lupus Nephritis

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease affecting 20–50 per 100,000 people. This study aimed to assess the relationship between ultrasound indices and pathological and laboratory parameters in patients with lupus nephritis (LN).

 This cross-sectional, descriptive-diagnostic study was conducted on 32 patients and 32 healthy individuals. Sonographic indices, renal biopsy results, and laboratory parameters were assessed. A Receiver Operating Characteristic (ROC) curve was used to predict sensitivity and specificity. P-value <0.05 was considered significant.

 The mean GFR and anti-dsDNA levels in patients were 77.4±30.2 ml/min/1.73m² and 2.8±4.4 IU/ml, respectively. Abnormal C3, abnormal C4, and positive aPL were observed in 17 (60.7%), 9 (32.1%), and 8 (28.5%) patients, respectively. In terms of biopsy classification, most patients were in class II (32.1%). The mean biopsy activity index (bxAI) and biopsy chronicity index (bxCI) were 12.11±7.8 and 4.39±3.60, respectively. There was no significant association between the resistive index (RI) and pathological or laboratory parameters (P>0.05). However, a significant association was found between peak systolic velocity (PSV) and end-diastolic velocity (EDV) with GFR, and a negative association between PSV and EDV with aPL and bxCI in patients with LN(P<0.05). The sensitivity and specificity of the anti-dsDNA test for detecting bxCI using a cut-off value of 0.245 were 84% and 96%, respectively (area under the ROC curve = 0.92).

 This study found no association between RI and pathological or laboratory parameters. However, there was a negative association between PSV and EDV with the degree of chronic kidney damage in patients with LN. Anti-dsDNA appears to be a useful predictor of long-term renal outcomes in these patients.