Contribution of Clinically Indicated Repeat Renal Biopsy in Indian Patients with Lupus Nephritis

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

Kidney involvement in patients with lupus highly increases morbidity and mortality. In recent years, several reports have emphasized the dissociation between clinical and histological findings and highlighted the role of kidney biopsy as an instrument for diagnosis and follow-up of lupus nephritis. The kidney biopsy at initial diagnosis allows an early diagnosis, assessment of activity and chronicity, and detection of nonimmune complex nephritis. A kidney biopsy repeated months after treatment aids in the detection of persistent histological inflammation, which has been linked to the occurrence of future kidney relapses. A kidney biopsy at a relapse detects histological changes including chronic scarring. Finally, a kidney biopsy in patients with a clinical response undergoing maintenance immunosuppression may aid therapy tapering and/or suspension. The evidence supporting the use of a kidney biopsy in different scenarios across the course of lupus nephritis is heterogeneous, with most reports assessing the value for the diagnosis of a first or relapsing flare. In contrast, less evidence suggests additional therapeutic-modifying information derived from repeat posttreatment biopsies and biopsies to evaluate treatment tapering or suspension. In this clinical case-based review, we examine the role of kidney biopsy as a tool to improve clinical outcomes of patients with lupus nephritis.

Lupus Nephritis Risk Factors and Biomarkers: An Update

Lupus nephritis (LN) represents the most severe organ manifestation of systemic lupus erythematosus (SLE) in terms of morbidity and mortality. To reduce these risks, tremendous efforts have been made in the last decade to characterize the different steps of the disease and to develop biomarkers in order to better (i) unravel the pre-SLE stage (e.g., anti-nuclear antibodies and interferon signature); (ii) more timely initiation of therapy by improving early and accurate LN diagnosis (e.g., pathologic classification was revised); (iii) monitor disease activity and therapeutic response (e.g., recommendation to re-biopsy, new urinary biomarkers); (iv) prevent disease flares (e.g., serologic and urinary biomarkers); (v) mitigate the deterioration in the renal function; and (vi) reduce side effects with new therapeutic guidelines and novel therapies. However, progress is poor in terms of improvement with early death attributed to active SLE or infections, while later deaths are related to the chronicity of the disease and the use of toxic therapies. Consequently, an individualized treat-to-target strategy is mandatory, and for that, there is an unmet need to develop a set of accurate biomarkers to be used as the standard of care and adapted to each stage of the disease.

Epidemiology and Outcomes of Glomerular Diseases in Low- and Middle-Income Countries

Glomerular diseases account for a significant proportion of chronic kidney disease in low-income and middle-income countries (LMICs). The epidemiology of glomerulonephritis is characterized inadequately in LMICs, largely owing to unavailable nephropathology services or uncertainty of the safety of the kidney biopsy procedure. In contrast to high-income countries where IgA nephropathy is the dominant primary glomerular disease, focal segmental glomerulosclerosis is common in large populations across Latin America, Africa, Middle East, and South East Asia, while IgA nephropathy is common in Chinese populations. Despite having a high prevalence of known genetic and viral risk factors that trigger focal segmental glomerulosclerosis, membranoproliferative glomerulonephritis also is common in adults and children in some African countries. Treatment of glomerular diseases in adults and children in LMICs largely is dependent on corticosteroids in combination with other immunosuppressive therapy, which often is cyclophosphamide because of its ready availability and low cost of treatment, despite significant adverse effects. Partial and/or complete remission status reported from studies of glomerular disease subtypes vary across LMIC regions, with high rates of kidney failure, mortality, and disease, and treatment complications often reported. Improving the availability of nephropathology services and ensuring availability of specific therapies are key measures to improving glomerular disease outcomes in LMICs.

Clinical characteristics and long-term outcomes in patients with mixed Class III/IV + V and pure proliferative lupus nephritis: A single-center experience

OBJECTIVES

Proliferative lupus nephritis (LN) is a crucial complication in systemic lupus erythematosus (SLE). This study evaluated the clinical implications of coexistence of membranous LN in proliferative LN in terms of clinical characteristics and long-term outcome.

METHODS

We retrospectively reviewed the medical records of patients with SLE who underwent renal biopsy between 2005 and 2018. Patients with proliferative LN based on the 2003 International Society of Nephrology/Renal Pathology Society classification were subclassified into pure (Class III or IV only) and mixed (Class III or IV + Class V) proliferative LN. The clinical features at the time of renal biopsy, incidence of end-stage renal disease (ESRD), and all-cause mortality were compared between patients with mixed or pure proliferative LN.

RESULTS

Of the 171 patients, 30 and 141 were classified into mixed and pure proliferative LN groups, respectively. Patients with pure proliferative LN showed higher anti-dsDNA antibody and lower hemoglobin, platelet, and complement 3 levels than patients with mixed proliferative LN. The SLE disease activity index was also higher in patients with pure proliferative LN (p = 0.047). The pure proliferative LN group showed a higher proportion of Class IV and higher histologic activity index scores (p < 0.001 and p = 0.004, respectively). During the follow-up period of 58.3 months, 18 patients developed ESRD and 15 patients died. ESRD was exclusively observed in patients with pure proliferative LN, although the incidence of ESRD was not statistically different (p = 0.055). All-cause mortality was comparable between the two groups.

CONCLUSION

Pure proliferative LN was associated with higher clinical and histological activities and modestly increased risk of ESRD. Active immunosuppressive treatment would be required to control the renal inflammation in patients with proliferative LN, regardless of the coexistence of membranous LN.