Development of an instrument to predict proliferative histological class in lupus nephritis based on clinical and laboratory data

Abstract

Objectives To compare the correlations of histological class inferences based on clinical manifestations and laboratory tests between rheumatologists and nephrologists, to determine the associations of clinical and laboratory data with histological classes and to develop an instrument that can assist histological class identification in lupus nephritis (LN). Methods Retrospective study based on medical records of 80 systemic lupus erythematosus patients (SLICC criteria classification, 2012) who underwent kidney biopsy between 2010 and 2017. Two rheumatologists and two nephrologists received clinical and laboratory data and answered questions regarding which histological class was expected on kidney biopsy. Kappa (K) coefficient was used to assess agreement between evaluators. A decision tree was constructed using the chi-square interaction detector and logistic regression was performed for the development of the proliferative histological class predictor instrument . Results The mean age and disease duration were 33 ± 10.3 years and 11.5 ± 6.7 years, respectively. The level of agreement between the evaluators and kidney biopsy was poor (global K 0.364 ± 0.029; p < .001). Analyzing clinical and laboratory variables as predictors of proliferative histological class, patients with abnormal urinary sediment and positive anti-dsDNA antibodies presented 13.96 and 4.96 times higher risks of presenting class III or IV, respectively ( p < 0.001). Our instrument has a sensitivity of 87.8% and specificity of 80%, using abnormal urinary sediment, anti-dsDNA antibodies, and serum creatinine as variables. Conclusions Rheumatologists and nephrologists with experience in treating LN generated evaluations that correlated weakly with kidney biopsy. When kidney biopsy is unavailable or is contraindicated for medical reasons, instruments based on clinical and laboratory predictors may be helpful.

Kidney Biopsy in Management of Lupus Nephritis: A Case-Based Narrative Review

“…A significant inflammatory disease may be observed in patients with proteinuria below this threshold and even in patients without any evidence of clinical involvement. 16 , 26 , 27 , 28 , 29 In most of these series, the additional finding of low complement C3 and/or positive anti-dsDNA antibodies was associated with a higher degree of inflammatory activity in the kidney biopsy or a higher risk of progressive disease. 26 , 27 , 28 , 29 …”

“…Nevertheless, several reports have demonstrated the agreement between clinical presentation and histopathologic findings in the kidney biopsy is moderate to poor. 14 , 15 , 16 Hence, patients with low proteinuria and inactive urinary sediment may present with class III, IV, or V LN in kidney biopsy. 17 Moreover, nephrotic syndrome, which is usually thought to predict an underlying class V LN in the kidney biopsy, is more frequently found in class IV LN.…”