Outcome of reclassification of World Health Organization (WHO) class III under International Society of Nephrology-Renal Pathology Society (ISN-RPS) classification: retrospective observational study

Abstract

The outcome of systemic lupus erythematosus (SLE) is largely influenced by the existence of lupus nephritis (LN), and its histologic classification guides the treatment and prognosis of SLE. International Society of Nephrology-Renal Pathology Society (ISN-RPS) announced a revised classification of LN in 2004. The present study investigated the differential outcome of World Health Organization (WHO) class III LN when reclassified according to ISN-RPS classification. Forty-three patients with biopsy-proven WHO class III LN at a single tertiary hospital were included in the study. Baseline characteristics at the time of renal biopsy and clinical data during follow-up were obtained from medical records. Renal response to treatment at one-year follow-up was analyzed in three ways; complete response (CR), partial response (PR), and no response (NR). Of 43 patients with previous WHO class III LN, 12 cases were reclassified into ISN-RPS class IV (9 cases of class IV-S and 3 cases of IV-G). Baseline characteristics at the time of renal biopsy were not different between the reclassified class IV and remaining class III LN group except activity index on renal histology, which was significantly elevated in the reclassified class IV group (4.90 vs. 6.75; P = 0.02). Significantly higher number of patients with remaining class III LN achieved CR to treatment than those with reclassified class IV LN at one-year follow-up since initial biopsy (CR: PR: NR; 16:7:7 vs. 3:1:8; P = 0.032). Our study suggests that the ISN-RPS classification is more advantageous in predicting renal outcome and guiding treatment when evaluating previously classified WHO class III LN.

Classifying Lupus Nephritis: An Ongoing Story

“…We summarized the findings of interobserver validation studies in the literature in Table 3 . Standardization of the definitions for each class with clear discriminating criteria and a well-defined approach in the handling of sclerotic glomeruli improved both intraobserver and interobserver reproducibility and enabled reliable comparison of different cases from various centers [ 13 , 22 – 26 ]. Moreover, the morphologic parameters indicative of prognostic value and outcome contributed to the medical literature.…”

The correlation of urinary podocytes and podocalyxin with histological features of lupus nephritis

“…6 There are a number of reports showing that ISN/RPS classifications correlate well with renal prognosis in LN. [7][8][9][10][11][12] While ISN/RPS classifications principally depend on glomerular pathology, extra-glomerular lesions such as interstitial fibrosis, tubular atrophy and vasculopathy are risk factors for renal outcome. 13,14 Therefore, recent guidelines recommend that all patients with clinical evidence of active LN undergo renal biopsy to obtain information necessary for making decisions on treatment and management of nephritis.…”

Outcomes of the Re-classification of WHO Class IV Lupus Nephritis Using the ISN/RPS Classification: a Single Center Retrospective Observational Study from the JUDE Study

“…However, no significant group differences in outcomes were detected. Similarly, Hwang and coworkers reported that among 43 patients with WHO class III LN, 12 patients were reclassified into ISN/RPS class IV (class IV-S, n = 9; class IV-G, n = 3) 8) . At one-year follow-up, there were no group differences in the response to treatment.…”

“…PR was defined as sCr<1.4 mg/dl and urinary protein decreased by 50% or more from baseline or 1+ to 2+ by dipstick test. NR was defined as a deterioration in renal function exclusive of other causes (such as sepsis or nephrotoxic agents), a reduction in urinary protein with failure to reach PR, or the persistence of active urinary sediments (<10 RBC/HPF) 8) . Renal flare was defined as an increase in urinary protein of 1 g/gCr associated with an increase in serological activity.…”

“…Thus, the International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003 classification of LN was designed 7) . The most common classswitching events have been reported to be from WHO class III to ISN-RPS class IV 8) . Moreover, using this new classification system for LN, numerous studies have examined the differential outcomes of classes IV-S and IV-G.…”