Current issues in pediatric lupus nephritis: role of revised histopathological classification

Childhood-onset systemic lupus erythematosus (SLE) has an unpredictable natural history with variable clinical manifestations. The prognosis of SLE is linked closely to renal involvement with lupus nephritis (LN), which is more severe in patients with childhood-onset compared with adult-onset disease. The histopathological classification of LN facilitates treatment decisions, protocols, and clinical research. After the World Health Organization and modified WHO classifications of LN from 1974 to 1995, the International Society of Nephrology and Renal Pathology Society Working Group revised the histopathological classification of LN. The reclassification was published in 2004 after their consensus conference held at Columbia University in New York in May 2002. The aims of the reclassification were to standardize definitions, emphasize clinically relevant lesions, and encourage uniform and reproducible reporting among centers. Although the revised classification is time-consuming, it is important for future international collaboration on multicenter trials of disease-modifying agents. The prognosis of SLE and LN is linked to the histopathology of the renal lesion, but the clinical manifestations of LN, including nephrotic syndrome and hypertension, cannot predict the degree of renal involvement. However, we are many years away from completely understanding the etiopathogenesis of LN and the predictive role of the revised histological classification for direction of patient management.