Induction therapy with low-dose intravenous cyclophosphamide, oral mizoribine, and steroids for severe lupus nephritis in children

Do we really need cyclophosphamide for lupus nephritis?

A 14-year-old patient presents with hematuria and proteinuria. Clinical evaluation reveals a positive anti-nuclear antibody titer, positive anti-double stranded DNA antibody and hypocomplementemia. Systemic lupus erythematosus (SLE) is diagnosed based on the 2019 EULAR/ACR (European League Against Rheumatism/American College of Rheumatology) classification criteria (Aringer et al. Arthritis Rheumatol 71:1400-1412, 2019). A kidney biopsy is performed that confirms the presence of immune complex glomerulonephritis, ISN-RPS (International Society of Nephrology/Renal Pathology Society) class IV (Bajema et al. Kidney Int 93:789-796, 2018). According to the latest clinical practice guidelines (Rovin et al. Kidney Int 100:753-779, 2021; Fanouriakis et al. Ann Rheum Dis 83:15-29, 2023), there are alternatives to treating this patient with cyclophosphamide. But what if this patient also presented with oliguria and volume overload requiring intensive care and dialysis? What if this patient also presented with altered mental status and seizures, and was diagnosed with neuropsychiatric lupus? What if this patient was also diagnosed with a pulmonary hemorrhage and respiratory failure? The clinical practice guidelines do not address these scenarios that are not uncommon in patients with SLE. Moreover, in some countries worldwide, patients do not have the privilege of access to biologics or more expensive alternatives. The purpose of this review is to evaluate the contemporary options for initial treatment of nephritis in patients with SLE.

Renal disease in pediatric rheumatology

PURPOSE OF REVIEW

This review will provide updates in the outcomes in the common rheumatologic diseases with kidney involvement. Covered are also advances in therapeutics for the use of pediatric rheumatologic diseases with kidney involvement, as well as the potential kidney complications from other rheumatologic diseases and their medications.

RECENT FINDINGS

Two of the more common rheumatologic diseases with kidney involvement, lupus and vasculitis, continue to show inadequate response to initial therapy of renal disease and practice continues to be driven by results of adult studies.

SUMMARY

There is a continued need for pediatric specific studies in rheumatologic diseases with kidney involvement as outcomes continue to be inadequate. Despite recently approved treatments for adults with rheumatic diseases and kidney involvement, therapeutic options in pediatrics remain limited, contributing to the overall morbidity and mortality.

Renal Response Outcomes of the EuroLupus and National Institutes of Health Cyclophosphamide Dosing Regimens in Childhood-Onset Proliferative Lupus Nephritis

OBJECTIVE

We compared clinical characteristics and renal response in patients with childhood-onset proliferative lupus nephritis (LN) treated with the EuroLupus versus National Institutes of Health (NIH) cyclophosphamide (CYC) regimen.

METHODS

A retrospective cohort study was conducted at 11 pediatric centers in North America that reported using both CYC regimens. Data were extracted from the electronic medical record at baseline and 3, 6, and 12 months after treatment initiation with CYC. To evaluate the adjusted association between CYC regimen (EuroLupus vs NIH) and renal response over time, generalized estimating equations with a logit link were used. An interaction between time and CYC regimen was included, and a contrast between CYC regimens at 12 months was used to evaluate the primary outcome.

RESULTS

One hundred forty-five patients (58 EuroLupus, 87 NIH) were included. EuroLupus patients were on average older at the start of current CYC therapy, had longer disease duration, and more commonly had relapsed or refractory LN compared with the NIH group. After multivariable adjustment, there was no significant association between CYC regimen and achieving complete renal response at 12 months (odds ratio [OR] of response for the EuroLupus regimen, reference NIH regimen: 0.76; 95% confidence interval [CI] 0.29-1.98). There was also no significant association between CYC regimen and achieving at least a partial renal response at 12 months (OR 1.35, 95% CI 0.57-3.19).

CONCLUSION

Our study failed to demonstrate a benefit of the NIH regimen over the EuroLupus CYC regimen in childhood-onset proliferative LN. However, future prospective outcome studies are needed.

Treatment of pediatric-onset lupus nephritis: a proposal of optimal therapy

Lupus nephritis (LN) is one of the major clinical manifestations of systemic lupus erythematosus (SLE) which occurs frequently in the early stages of pediatric-onset cases. Since SLE is a chronic disease associated with frequent disease flares and effective and safe maintenance therapy is required for achieving a favorable outcome, optimal treatment for LN in pubertal patients is a great challenge that remains to be overcome. Although its etiology remains unclear, it has been reported that the innate and adaptive immune systems have been reported to play an important role in the pathogenesis of SLE. However, studies of drugs that have been useful in controlling inflammatory pathways mediated by the innate and adaptive immune systems are now underway. In clinical practice, recent advances in the management of LN, together with earlier renal biopsy and selective use of aggressive immunosuppressive therapy, have contributed to a favorable outcome in children and adolescents with LN. However, the balance of the efficacy of treatment in terms of long-term prognosis and its adverse effects should be weighed in determining the treatment strategy.

The use of low-dose cyclophosphamide followed by AZA/MMF treatment in childhood lupus nephritis

Cyclophosphamide (CYC) has been the landmark in the treatment of lupus nephritis. However, long-term treatment with CYC is associated with significant side effects. We aimed to evaluate the efficacy of short-term intravenous (IV) CYC treatment as a remission induction treatment followed by azathioprine (AZA) or mycophenolate mofetil (MMF) as a maintenance treatment. Twenty patients (18 girls) with biopsy-proven class III (5) and IV (15) lupus nephritis were included in to the study. Detailed clinical and laboratory data and patient outcomes were evaluated. All patients received three methylprednisolone (MP) IV pulses, followed by oral prednisone 0.5-1 mg/kg per day and one IV pulse of CYC per month for 6 months. Azathioprine was started as a remission-maintaining treatment. In ten of 20 patients, treatment was switched to MMF. The mean age at the time of diagnosis was 16.11 +/- 3.49 years, and the mean duration of follow-up was 49.6 +/- 27 months. Fourteen patients (70%) had complete remission, three (15%) had partial remission, one (5%) continued to have active disease, and two (10%) progressed to end-stage renal disease. Nine of the patients (45%) with complete remission had received AZA, and switching to MMF increased complete remission rate (additional five patients; 25%). In conclusion, short-term (6-month) IV bolus CYC treatment followed by AZA is a safe and effective treatment in children with severe lupus nephritis, and using MMF increases remission rate in resistant cases.

Maintenance therapy with mycophenolate mofetil for children with severe lupus nephritis after low-dose intravenous cyclophosphamide regimen

Although recent studies on adults with lupus nephritis indicate that mycophenolate mofetil (MMF) may be effective in maintaining remission for patients who previously received short-term intravenous cyclophosphamide (IVCY) induction therapy, the experience with the new immunosuppressive agent in children with severe lupus nephritis has not been as satisfactory thus far. To assess the efficacy and safety of maintenance therapy with MMF, we prospectively analyzed four patients with biopsy-proven severe lupus nephritis (three girls, one boy; mean age 12 years; two with class IIIA, two with class IVG(A); mean duration of lupus nephritis 7 months) receiving MMF for at least 6 months after induction treatment. These patients had been treated previously with 6 months of low-dose IVCY combined with oral mizoribine and steroids for induction, followed by therapy with MMF adjusted to maintain predose mycophenolic acid (C0-MPA) levels at 2-5 mcg/ml. Mean follow-up after staring MMF was 27.5 months (range 6-41). The mean MMF dose required was 405 +/- 49 mg/m(2) per 12 h, which maintained mean C0-MPA levels of 3.3 +/- 0.41 mcg/ml. No patient experienced renal flares during maintenance therapy with MMF, which permitted a significant reduction in mean prednisolone dose from 11.9 +/- 1.3 to 3.9 +/- 2.6 mg/day (P = 0.003). No significant gastrointestinal or hematologic side effects of MMF were noted. This preliminary study demonstrates that maintenance therapy with MMF after a low-dose IVCY regimen appears to be a promising intervention without adverse effects in children with severe lupus nephritis. These data should be confirmed by a prospective randomized multicenter clinical trial.

Evaluation of activity, chronicity and tubulointerstitial indices for childhood lupus nephritis

Few data exist on use of the National Institutes of Health (NIH) activity index (AI) and chronicity index (CI) in childhood lupus nephritis (LN). A tubulointerstitial activity index (TIAI) has been derived but not validated. We evaluated clinicopathologic correlations of the AI, CI and TIAI in children with LN who had undergone initial renal biopsy (n=25, age 12.4+/-2.7 years, biopsy 1) and 1 year after treatment (n=15, biopsy 2). The TIAI correlated with the AI at biopsy 1 (r=0.76, P=0.001) and biopsy 2 (r=0.52, P=0.05), but not with CI scores. Mean AI and CI scores changed substantially from biopsy 1 to biopsy 2 (P<0.05), but TIAI scores did not. Higher AI and TIAI scores correlated with proteinuria at both biopsies (r=0.51-0.76, P<0.05); CI scores correlated with estimated creatinine clearance (r=0.46-0.58, P<0.05). Improved AI score from biopsy 1 to biopsy 2 was associated with decrease in proteinuria. These results suggest that the AI and CI are useful in childhood LN. The TIAI may be a valid measure to evaluate the tubulointerstitium, but research is needed to define its responsiveness to change with therapy.

Pathogenesis and treatment of systemic lupus erythematosus nephritis

PURPOSE OF REVIEW

Glomerulonephritis is a challenging complication of systemic lupus erythematosus that still results in kidney loss in up to 30% of patients. In this review we highlight the development of integrated efforts to link pathogenesis with disease definition and new therapeutics.

RECENT FINDINGS

Immune complex deposition in the kidney initiates an inflammatory cascade that causes glomerular disease but there are many modulating factors including genetic predisposition, products of the innate immune system, cytokines, complement and activated cells (both renal and immune). Animal models can help dissect potential disease mechanisms but the study of multiple models will be required since there are multiple subsets of human disease. Recent therapeutic studies in humans address the distinction between therapies for remission induction and remission maintenance. Multiple studies confirm the therapeutic equivalence of mycophenolate mofetil and cyclophosphamide in induction of remission but results are still far from ideal. The next few years should see the testing of new biologic reagents in humans. Another area of interest is the search for noninvasive measures of disease and disease response.

SUMMARY

Although there has been remarkable progress in our understanding of the immunology and phenotype of lupus nephritis current therapies have insufficient efficacy. As new therapies emerge, improved clinical design coupled with mechanistic studies will be needed to identify agents that may be effective only in some patient subpopulations.