Interobserver agreement of scoring of histopathological characteristics and classification of lupus nephritis

• Published in: Nephrology, dialysis, transplantation Vol. 23; no. 1; pp. 223 - 230
• Main Authors: Grootscholten, Cecile, Bajema, Ingeborg M., Florquin, Sandrine, Steenbergen, Eric J., Peutz-Kootstra, Carine J., Goldschmeding, Roel, Bijl, Marc, Hagen, E. Christiaan, van Houwelingen, Hans C., Derksen, Ronald H. W. M., Berden, Jo H. M.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.01.2008; Oxford Publishing Limited (England)
• Subjects: Adult; agreement; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Biopsy - statistics & numerical data; Emergency and intensive care: renal failure. Dialysis management; Female; Humans; Intensive care medicine; kidney biopsy; lupus nephritis; Lupus Nephritis - classification; Lupus Nephritis - pathology; Male; Medical sciences; Middle Aged; observer; Observer Variation; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; systemic lupus erythematosus; observer; lupus nephritis; systemic lupus erythematosus; agreement; kidney biopsy; Kidney disease; Immunopathology; Connective tissue disease; Skin disease; Urinary system disease; Hemodialysis; Autoimmune disease; Extrarenal dialysis; Histopathology; Biopsy; Systemic disease; Classification; Renal failure; Observer; Lupus erythematosus
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfm555

Background. Assessing renal biopsies from patients with lupus nephritis (LN) is a difficult task and it is subject to interobserver variability. In this study the interobserver agreement amongst five nephropathologists was analysed. Methods. Five specialized nephropathologists scored 126 biopsies, comprising 87 first and 39 repeat biopsies from 87 patients with biopsy-proven proliferative LN, included in a randomized controlled trial. The interobserver agreement [expressed as intraclass correlation coefficients (ICC)] of the scored histopathological items was calculated. Also, the WHO1995 and ISN/RPS2003 classification systems for LN were compared, with extra attention being given to the comparison between patients with diffuse proliferative LN with either segmental (IV-S) or global (IV-G) lesions. Results. There was a wide range of agreement. A good interobserver agreement (ICC > 0.6) was present in 15%, and a moderate interobserver agreement (ICC 0.4–0.6) in 31% of the scored items. The activity index for LN showed a good (ICC 0.716) and the chronicity index a moderate (ICC 0.494) interobserver agreement. Both classification systems showed low agreement, although consensus was easily reached. Patients classified as IV-S (n = 15) had more favorable clinical parameters at study entry than those with class IV-G (n = 57). Although suggested by others, we found no differences in outcome between these two subclasses. Conclusions. This study shows that, although definitions were agreed upon beforehand, even specialized on nephropathologists have difficulties with scoring histopathological characteristics of LN, particularly with SLE the classification systems.