ANA Should be Performed in Patients Without Previous History of SLE Who Underwent Kidney Biopsy

Lupus nephritis (LN) is the most common etiology of secondary glomerulonephritis. Several studies have identified the risk of LN in SLE patients. However, clinical factors predictive of LN in patients who underwent kidney biopsy for the first time was limited if there was no previous history of SLE.

This study aimed to investigate the clinical factors predictive of LN by kidney biopsy regardless of SLE history.

We conducted a retrospective study between January 2012 and May 2013. The inclusion criteria were adults over 18 years old who underwent the first kidney biopsy in their lives. Participants were divided into two groups according to renal pathology (LN and non-LN group). Predictors for LN in those without history of SLE were executed by using by logistic regression analysis.

In total, there were 205 patients included in the study. LN was defined in 68 patients (33.2%) and the other 137 patients (66.8%) were non-LN. The LN group had a significantly lower mean age (33.6 years vs. 44.2 years; P value < 0.01) and higher eGFR (79.0 vs. 62.3 mL/min; P value 0.05) than the non-LN group. After adjustment, only three factors were independently associated with LN, including eGFR, history of SLE, and RBC in urine > 10 cells/HP. Without history of SLE, ANA was the only independent factor in predicting LN with ORs (95% CI) of 14.5 (1.4, 150.8).

ANA should be tested in all patients who underwent kidney biopsy regardless of previous history of SLE.