The American College of Rheumatology (ACR) has released its first guidelines for the screening, treatment and management of lupus nephritis (LN). The guidelines, published in the June 2012 issue of Arthritis Care & Research, were originally presented at the 2011 ACR Annual Meeting. The 2012 guidelines for lupus nephritis are a major step forward because they explain the overall treatment of LN, not just the short-term treatment,” said Bevra H. Hahn, MD, PhD, lead author of the guidelines and professor of medicine and chief of the Division of Rheumatology at the University of California School of Medicine, Los Angeles. Introduction: Approximately 35% of adult SLE patients in the United States have clinical manifestations of LN at the time of diagnosis, approximately 50%-60% of SLE patients develop LN within 10 years, and up to 30% of LN cases progress to end-stage renal disease within 15 years of diagnosis. 88%). Impaired renal function remains the most important predictor of mortality in SLE patients. METHODS: Through a collaborative team consisting of task force, working group, and core research expert group at three levels, various RCT clinical trials, meta-analyses, and expert consensus on LN since 1966 were systematically and extensively discussed and studied, and after multiple voting discussions at multiple levels, 11 recommendations were finally formulated: I Definition of lupus nephritis As required by the recommendations, lupus nephritis was defined as clinical and laboratory manifestations meeting ACR A review of ACR criteria recommended replacing 24-hour urine protein measurement with an immediate urine protein/creatinine ratio >0.5 and replacing cellular tubularity with a positive urine sediment (>5 red blood cells/high magnification, >5 white blood cells/high magnification, >5 white blood cells/high magnification). >5 leukocytes/high magnification field in the absence of infection, or a cellular tubular pattern of red cells or leukocytes only) (1). An additional and perhaps best criterion is a kidney biopsy specimen confirming immune complex-mediated glomerulonephritis consistent with lupus nephritis presentation. Finally, for these recommendations to be implemented, the core executive group agreed that the diagnosis of lupus nephritis must be appropriate in the opinion of a rheumatologist or nephrologist. II Renal Biopsy and Histology The Task Force recommends that all patients with evidence of active and untreated lupus nephritis need to have had a renal biopsy (unless strongly counter-indicated) to type the glomerular lesions according to current ISN/RPS staging (level of evidence C) (13,14) (Table 1). In addition, biopsy allows for assessment of disease activity, degree of chronicity, and tubular and vascular lesions. Finally, biopsy can identify other additional or alternative renal diseases, such as tubular necrosis associated with medication use, hypovolemia, or hypotension. Renal biopsy is highly recommended for patients with the features in Table 2. The Task Force recommends treatment to a large extent based on ISN/RPS LN staging (13C15). Therefore, the following recommendations are based on the histologic typing of lupus nephritis. The Task Force agreed that type I (immunofluorescence showing mild thylakoid immune complex deposition with normal light microscopy) and type II (increased cellularity or stromal widening in the thylakoid region on light microscopy with immunofluorescence detection showing immune complex deposition confined to the thylakoid region) do not usually require treatment with immunosuppressive agents (Level of Evidence C). Typically, type III (subendothelial immune complex deposition with <50% of glomeruli showing proliferative changes domestically seems to tend to be described as involvement) and type IV (subendothelial immune complex deposition with >=50% of glomeruli showing proliferative changes) require aggressive treatment with glucocorticoids and immunosuppressive agents. When type V (subepithelial immune complex deposition with glomerular capillary basement membrane thickening) is present along with type III or IV changes treatment is required as for type III or IV. Type V alone (pure membranous lupus nephritis) presents with some differences, as described in Section VI below. Histological staging for type VI (>=90% glomerulosclerosis) usually recommends the preparation of renal replacement therapy rather than the application of immunosuppressive therapy.A and C refer to lesions that manifest as active or chronic; the higher the degree of chronic changes, the less likely the nephritis will respond to immunosuppressive therapy (15,16). However, in the LN trials published so far, A or C classification was not among the inclusion criteria and, therefore, was not considered in the recommendations.