Immunoglobulin G4-related disease presenting with nephrotic syndrome due to minimal change disease: a case report.

BACKGROUND: Immunoglobulin G4-related disease is an inflammatory disease affecting multiple organs including the kidney. Immunoglobulin G4-related kidney disease most commonly manifests as a tubulointerstitial nephritis and is associated with glomerular disease in a proportion of cases. Membranous nephropathy is the most frequent glomerular lesion. Herein, we report the first documented case of immunoglobulin G4-related disease presenting with nephrotic syndrome owing to minimal change disease. CASE PRESENTATION: A 67-year-old South Asian male presented to our service with systemic upset and leg swelling. He had heavy proteinuria (urine protein:creatinine ratio 1042 mg/mmol) and was hypoalbuminemic (17 g/L) and hypercholersterolemic (9.3 mmol/L), consistent with the nephrotic syndrome. His serum creatinine was 140 µmol/L, and he was hypocomplementemic (C3 0.59 g/L, C4 < 0.02 g/L) with raised immunoglobulin G4 subclass levels (5.29 g/L). Kidney biopsy demonstrated minimal change disease alongside a plasma-cell-rich tubulointerstitial nephritis with strong positive staining for immunoglobulin G4. A diagnosis of minimal change disease in the setting of immunoglobulin G4-related disease was made. He was commenced on oral prednisolone at 60 mg daily but suffered infectious complications, including necrotizing fasciitis within 3 weeks of starting treatment, ultimately resulting in his death 52 days after initial presentation. CONCLUSION: This case highlights the potential for immunoglobulin G4-related disease to be associated with a spectrum of glomerular pathologies including minimal change disease. It adds to the differential diagnosis of secondary causes of minimal change disease, and moreover, aids as an important reminder of the potential complications of high-dose steroids used in its treatment.

Clinicopathological features and outcome of secondary steroid resistant nephrotic syndrome: A retrospective analysis.

Objective: To determine the clinico-pathological features and long-term outcome of secondary steroid-resistant nephrotic syndrome treated with steroids and calcineurin inhibitors. METHODS: The retrospective cohort study was conducted at the Sindh Institute of Urology and Transplant, Karachi, in June and July 2023, and comprised data from January 1, 2008, to December 31, 2020, of children aged 1-18 years who developed steroid resistance after initial sensitivity to steroids with at least 1-year of follow-up. Demographics as well as time taken to secondary steroid response were documented. Renal biopsy of all patients with secondary steroid resistance had been performed. Eventual outcomes after treatment with calcineurin inhibitors based on the degree of proteinuria and serum albumin levels were used to categorise complete remission, partial remission and no response. Kidney function, as determined by estimated glomerular filtration rate, was recorded. Data was analysed using SPSS 22. RESULTS: Of the 1,000 patients who underwent renal biopsy for steroid resistance, 48(4.8%) had idiopathic steroid-resistant nephrotic syndrome; 32(66.7%) males, 16(33.3%) females and median age of 5 years (interquartile range: 4-7.3 years). Median age at diagnosis of nephrotic syndrome was 5 years (interquartile range: 3.6-7.3 years). The median time from nephrotic syndrome to secondary steroid-resistant nephrotic syndrome was 23 months (interquartile range: 8.75-44.5 months). Biopsy results at diagnosis showed that 27(56.3%) had minimal change disease. The mean follow-up time was 6.1±3.2 years. Of the 43(89.5%) patients who received cyclosporin for 1 year, 29(67%) obtained complete remission, 5(12%) attained partial remission and no response was seen in 9(21%) patients. Conclusion: Majority of the children had minimal change disease at the time of diagnosis of secondary steroid-resistant nephrotic syndrome. The long-term response with calcineurin inhibitors was favourable at 1 year.

Implication of acute tubular injury in minimal change nephrotic syndrome.

While acute tubular injury (ATI) is known to occur in a significant number of minimal change disease (MCD) nephrotic syndrome cases with acute kidney injury (AKI), the clinical significance is not certain, and AKI may also occur without ATI. This study aimed to evaluate whether the severity of AKI defined by Kidney Disease Improving Global Outcomes (KDIGO) criteria correlated with the presence or severity of ATI in a series of adult patients with MCD. We also looked at whether time to remission of nephrotic syndrome (NS) with treatment correlated with the presence of ATI in those with and without AKI. We excluded patients with secondary MCD. Of 61 patients, 20 had AKI (33%). ATI was significantly more likely to occur in those with AKI than in those without AKI (60 vs. 24%). Overall, the severity of AKI did not clearly correspond with the severity of ATI. Remission rates at 4 weeks were lowest (25%) in those with both AKI and ATI, while they were highest (100%) in those with neither AKI nor ATI. Patients with AKI but no ATI and those with no AKI but having ATI were intermediate in remission rates and similar to each other (60 and 62%, respectively). The time to remission in the group of those without AKI was significantly longer in those with ATI than in those without (p = 0.0027), but the numerical difference in remission did not reach statistical significance in the smaller group of AKI patients. Patients with ATI were older and more often male than those without ATI. It appears that having ATI may predict a slower remission rate in MCD though the reason for this is unclear. The different demographics of those with ATI may also play a role.

[Steroid-Dependent Nephrotic Syndrome Due to Minimal Change Glomerulonephritis Treated with Rituximab].

47-year-old woman suffering from minimal lesion glomerulonephritis previously undergone high-dose steroid therapy and subjected to exacerbations of nephrotic syndrome after therapy discontinuation. It was decided to initiate off-label treatment with Rituximab at a dosage of 375 mg/m2 administred at zero-time, one-month and three months with good therapeutic response and resolution of the clinical laboratory picture. The therapy was well tolerated and had no side effects. This scheme could be an alternative to the conventional therapeutic scheme with steroids or other classes of immunosuppressive drugs, especially in order to avoid problems related to prolonged exposure to steroid therapy.

Steroid-resistant minimal change nephrotic syndrome associated with thymoma treated effectively with rituximab following thymectomy and cyclosporine: a case report.

BACKGROUND: Minimal change nephrotic syndrome (MCNS) can be complicated by thymoma; however, no standard therapy for thymoma-associated MCNS has yet been established. We herein describe a case of steroid-resistant MCNS associated with thymoma, treated effectively with rituximab. CASE PRESENTATION: A 71-year-old Japanese man was referred to our department with severe proteinuria (20 g/gCr). Renal biopsy showed minimal change disease and computed tomography revealed an anterior mediastinal mass. Based on these findings, he was diagnosed with thymoma-associated MCNS. He was treated with oral prednisolone (50 mg/day) and cyclosporine, and underwent thymectomy and plasma exchange. However, no improvement in proteinuria was observed. He therefore received intravenous rituximab 500 mg, resulting in a marked decrease in proteinuria from 5328 to 336 mg/day after 1 week. CONCLUSIONS: This case suggests that rituximab might be an effective therapy in patients with steroid-resistant MCNS associated with thymoma.

Patients with primary focal segmental glomerulosclerosis with detectable urinary CD80 are more similar to patients with minimal change disease in clinicopathological features.

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is an important cause of refractory nephrotic syndrome (NS) in children and adults. Urinary CD80 is elevated in some patients with primary FSGS, however, its clinical value is not fully clarified. This study aims to evaluate the clinical and pathological significance of urinary CD80 in patients with primary FSGS. METHODS: Sixty-one adult patients with biopsy-proven primary FSGS, with standard treatment and long-term follow up, were enrolled retrospectively. Urinary CD80, on the day of kidney biopsy, was measured using commercial ELISA kits and adjusted by urinary creatinine excretion. Their associations with clinical and pathological parameters were investigated. RESULTS: Urinary CD80 was detectable in 30/61 (49.2%) patients, who presented with a higher level of proteinuria (10.7 vs. 5.8 g/24h; p = 0.01), a lower level of serum albumin (19.3 ± 3.9 vs. 24.2 ± 8.2 g/L; p = 0.005), a higher prevalence of hematuria (70.0 vs. 38.7%; p = 0.01), and showed a lower percentage of segmental glomerulosclerosis lesion [4.8 (3.7-14.0) vs. 9.1 (5.6-21.1) %; p = 0.06]. The cumulative relapse rate was remarkably high in these patients (log-rank, p = 0.001). Multivariate analysis identified that the elevated urinary CD80 was an independent risk factor for steroid-dependent NS (OR 8.81, 95% CI 1.41-54.89; p = 0.02) and relapse (HR, 2.87; 95% CI 1.29-6.38; p = 0.01). CONCLUSIONS: The elevated urinary CD80 is associated with mild pathological change and steroid-dependent cases of primary FSGS adults, which indicates these patients are more similar to minimal change disease (MCD) in clinicopathological features.

Mild mesangial proliferative IgA nephropathy with and without minimal change disease.

Mild mesangial proliferative IgA nephropathy with minimal change disease (MCD-IgAN) and mild mesangial proliferative IgA nephropathy without minimal change disease (Non-MCD-IgAN) have similar characteristics on light microscopy. Nevertheless, their discrepancies in clinicopathological features and prognosis remain unknown. A total of 589 patients with biopsy-proven mild mesangial proliferative IgA nephropathy (M-IgAN) combined with light microscopy and immunofluorescence were enrolled. Firstly, the diagnoses of the patients by electron microscopy were recorded and used as the gold standard. We calculated the sensitivity and specificity using nephrotic syndrome (NS) as the diagnostic criteria to identify MCD-IgAN. Then, excluding patients with a 24-h urinary total protein less than 0.5 g/day, incomplete clinical data, or less than the six-month follow-up, we included 184 cases of non-MCD-IgAN and 98 cases of MCD-IgAN. The patients' clinicopathological and outcome data were collected and compared. Among the 589 patients, according to electron microscopy, 381 were diagnosed with non-MCD-IgAN, 167 with MCD-IgAN, and 41 with M-IgAN complicated by other glomerular diseases. Using NS as the diagnostic criteria to distinguish non-MCD-IgAN and MCD-IgAN, the sensitivity and specificity were 83.8% and 99.5%, respectively. The patients in the MCD-IgAN group tended to be younger, hypotensive, with lower urinary erythrocytes, and more likely to achieve complete remission, and fewer patients progressed to the endpoint than those in the non-MCD-IgAN group (all P < 0 .05). NS appears to be an objective indicator for differentiating MCD-IgAN from non-MCD-IgAN. Non-MCD-IgAN varies greatly from MCD-IgAN in clinicopathology and treatment response, with a poorer prognosis.

Glomerular parietal epithelial expression of CD44 in minimal change nephrotic syndrome and primary focal segmental glomerulosclerosis: A clinico-pathological study.

Introduction: Minimal change nephrotic syndrome (MCNS) and focal segmental glomerulosclerosis (FSGS) are the two common causes of nephrotic syndrome (NS) in both children and adults with overlapping clinical features, but with distinct prognostic and therapeutic implications. The distinction between these relies entirely on histopathology, which can sometimes be difficult. CD44 is expressed by activated parietal epithelial cells, plays a role in matrix deposition and thus in the pathogenesis of FSGS. Aims: To assess the expression of CD44 in MCNS and FSGS and to evaluate its association with the known clinical and histopathological prognostic factors. Materials and Methods: Thirty cases each of MCNS and FSGS were studied. The clinical, laboratory, histopathological, and CD 44 immunohistochemical data were recorded. The findings were analyzed and correlated. A P value of < 0.05 was considered statistically significant. Results: Statistical association was noted between CD44 positivity and serum creatinine (p = 0.031), estimated glomerular filtration rate (p = 0.040), segmental sclerosis (p < 0.001), tubular atrophy (p = 0.027), interstitial fibrosis (p = 0.027), and histological diagnosis (p < 0.001). The sensitivity, specificity, positive predictive, and negative predictive values were 90%, 76.67%, 79.41% and 88.46%, respectively. Conclusions: CD44 immunostain can effectively distinguish MCNS from FSGS. The congruent results of CD44 positivity with known prognostic factors support the possibility of using the CD44 marker as a predictive tool in selecting high-risk patients and offering appropriate therapeutic measures.

Outcomes of minimal change disease without nephrotic range proteinuria.

Minimal change disease (MCD) is characterized by edema and nephrotic range proteinuria (NS). However, the fate of MCD without nephrotic proteinuria requires elucidation. We retrospectively reviewed 79 adults diagnosed with primary MCD at their initial renal biopsy at a tertiary hospital between May 2003 and June 2017. Clinicopathologic features were compared between patients with and without NS. The frequency of flaring to nephrotic proteinuria and renal outcomes were assessed during follow-up. There were 20 and 59 patients in the Non-NS and NS groups, respectively. The Non-NS group had a lower frequency of acute kidney injury (AKI) during the follow-up period [5.0% vs. 59.3%, p <0.001]. The response rate to steroid treatment was 100% in the Non-NS group and 92.3% in the NS group (p = 1.000). Except for one patient, the Non-NS group was treated with steroids when their proteinuria increased to a nephrotic level. There were no differences in the frequency of the first relapse or the number of relapses among patients with initial remission from nephrotic range proteinuria. At the final visit, the complete remission rate was 73.4%. The estimated glomerular filtration rate during follow-up was significantly better in the NS group than the Non-NS group, given the higher rates of AKI at renal biopsy. The rates of renal events, end-stage renal disease, and mortality did not differ between the groups. Adult MCD patients with nephrotic and non-nephrotic range proteinuria showed similar outcomes. Accordingly, this population must be carefully managed, regardless of the amount of proteinuria at renal biopsy.

Is kidney biopsy necessary in children with idiopathic nephrotic syndrome?

AIM: To investigate the need, in the Northern European setting, to perform kidney biopsy in children with steroid-sensitive nephrotic syndrome. METHODS: In this retrospective study 124 individuals aged 1-18 years with idiopathic nephrotic syndrome, followed in the paediatric hospitals in southern Sweden from 1999 to 2018, were included. RESULTS: There was a median follow-up time of 6.5 (0.2-16.8) years. The majority (92%) of children were steroid-sensitive and of them, 60.5% were frequently relapsing or steroid-dependent. Microscopic haematuria was found at onset in 81.1% and hypertension in 8.7%. At least one kidney biopsy was performed in 93 (75%). The most common indication was a steroid-dependent or relapsing course (58.4%). One of 79 steroid-sensitive children had another histological diagnosis than minimal change nephropathy 1.3%, 95% confidence interval (0.002, 0.068). Bleeding occurred after eight biopsies (6.6%). Twenty individuals (30.7%) were transferred to adult units, 18 still on immunosuppression. CONCLUSION: We have in our cohort of unselected children with idiopathic nephrotic syndrome confirmed that a kidney biopsy rarely gives important medical information in steroid-sensitive children without any other complicating factor and that the liberal policy of kidney biopsy in the Nordic countries safely can be changed.

Minimal change disease with papillary thyroid carcinoma: a report of two adult cases.

BACKGROUND: Minimal change disease (MCD), a pathological type of nephrotic syndrome (NS), can occur in patients with tumors. We report two adult cases of MCD associated with papillary thyroid carcinoma (PTC), known to be extremely rare in adults. CASE PRESENTATION: A 35-year-old female patient was simultaneously diagnosed with MCD and PTC. The MCD was effectively treated with thyroidectomy and prednisone.In addition, a 50-year-old male patient, who had been diagnosed with PTC three years prior, had MCD confirmed by renal biopsy. The patient achieved complete remission following treatment with tacrolimus and rituximab. CONCLUSIONS: The present case report describes and discusses the diagnostic and treatment processes employed in these two patients. Clinicians need to be aware of the renal effects of treating patients with solid tumors.

IgA nephropathy with minimal change disease associated with primary Sjögren's syndrome: A case report.

RATIONALE: Only 1 case of IgA nephropathy (IgAN) with minimal change disease (MCD) associated with primary Sjögren's syndrome (SS) has been reported. We additionally describe IgAN with MCD associated with primary SS. PATIENT CONCERNS: A 80-year-old woman visited our hospital complaining of generalized edema that had started 4 weeks prior. She reported a sense of thirst and dry eye for the last 5 years. DIAGNOSES: Her initial laboratory findings were compatible with nephrotic syndrome; both the antinuclear antibody (1:80) and anti-SS-A (Ro) antibody (200 U/mL) tests were positive. A salivary gland scan revealed markedly decreased uptake for both the parotid and submandibular glands. The Schirmer test was positive. The random urine protein/creatinine ratio was 10 mg/mg. Renal biopsy was compatible with IgAN with superimposed MCD. INTERVENTIONS: Furosemide was intravenously administered with intermittent albumin infusion for her edema control. She was started on prednisone 40mg daily for 6 weeks, which was tapered to 5 mg for another 6 months after starting prednisolone. OUTCOMES: Over the next 6 months, her edema improved and the proteinuria decreased significantly. LESSONS: Physician should suspect IgA with MCD when patient with SS clinically showed nephrotic syndrome, and perform renal biopsy for pathologically diagnosis and appropriate treatment.

Incidence of idiopathic nephrotic syndrome during the Covid-19 pandemic in the Paris area (France) and in the Netherlands.

BACKGROUND: The aetiology of idiopathic nephrotic syndrome (INS) remains partially unknown. Viral infections have been associated with INS onset. Since we observed fewer first onset INS cases during the Covid-19 pandemic, we hypothesised that lower INS incidence was the result of lockdown measures. Therefore, the aim of this study was to evaluate the incidence of childhood INS before and during the COVID-19 pandemic in two independent European INS cohorts. METHODS: Children with new INS in the Netherlands (2018-2021) and Paris area (2018-2021) were included. We estimated incidences using census data for each region. Incidences were compared using two proportion Z-tests. RESULTS: A total of 128 and 324 cases of first onset INS were reported in the Netherlands and Paris area, respectively, corresponding to an annual incidence of 1.21 and 2.58 per 100,000 children/year. Boys and young children (< 7 years) were more frequently affected. Incidence before and during the pandemic did not differ. When schools were closed, incidence was lower in both regions: 0.53 vs. 1.31 (p = 0.017) in the Netherlands and 0.94 vs. 2.63 (p = 0.049) in the Paris area. During peaks of hospital admissions for Covid-19, no cases were reported in the Netherlands or Paris area. CONCLUSIONS: Incidence of INS before and during the Covid-19 pandemic was not different, but when schools were closed during lockdown, incidence was significantly lower. Interestingly, incidences of other respiratory viral infections were also reduced as was air pollution. Together, these results argue for a link between INS onset and viral infections and/or environmental factors. A higher resolution version of the Graphical abstract is available as Supplementary information.

A Case of Lupus Nephritis Preceded by Minimal Change Disease and Membranous Glomerulonephritis.

BACKGROUND Lupus nephritis (LN) is the most common and serious complication of systemic lupus erythematosus (SLE). Minimal change disease (MCD) and primary membranous nephropathy (PMN) are the 2 most common causes of primary nephrotic syndrome. Our purpose in publishing this case report is to introduce an unusual clinical course and initial renal biopsy revealed MCD and then PMN in second renal biopsy. Subsequently, a third renal biopsy resulted in a final diagnosis of LN. To the best of our knowledge, this is the first such report. CASE REPORT The 31-year-old male patient was initially diagnosed with MCD after the first renal biopsy in 2004. He improved with initial management and had a complete remission for 9 years. After 9 years, the patient again presented with heavy proteinuria without systemic lupus erythematous finding and he was diagnosed with MN following the second renal biopsy. Seven years later, he again developed proteinuria alone with concurrent systemic symptoms of systemic lupus erythematosus, and a third biopsy was performed, leading to final diagnosis as LN. He was well managed with the methylprednisolone and cyclophosphamide (CTX) regimen, which improved renal function and spared the patient from continuous hemodialysis. CONCLUSIONS In rare case, MCD may represent an early phase of lupus nephritis, which may subsequently develop into severe lupus nephritis.

Repetitive administration of rituximab can achieve and maintain clinical remission in patients with MCD or FSGS.

Minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are glomerulopathies associated with nephrotic syndrome. Primary forms of these diseases are treated with various regimes of immunosuppression. Frequently relapsing or glucocorticoid-dependent courses remain challenging. Here, a B-cell-depleting strategy with rituximab represents a salvage option although data are sparse in the adult population. In particular, there is limited evidence on the efficacy of restoring remission after initial successful treatment with rituximab and whether patients benefit from an individualized, relapse-based approach. We identified 13 patients who received multiple therapies with rituximab from the FOrMe-registry (NCT03949972), a nationwide registry for MCD and FSGS in Germany, or from the University Hospital of Cologne. Disease status, changes in serum creatinine, proteinuria, and time to relapse were evaluated. Relapse-free survival was compared to the patients' previous therapy regimens. Through all treatment cycles, an improvement of disease activity was shown leading to a complete remission in 72% and partial remission in 26% after 3 ([Formula: see text]0.001) and 6 months ([Formula: see text]0.001). Relapse-free survival increased from 4.5 months (95%-CI 3-10 months) to 21 months (95%-CI 16-32 months) ([Formula: see text]0.001) compared to previous immunosuppression regimens with no loss in estimated glomerular filtration over time (p = 0.53). Compared to continuous B-cell depletion, an individualized relapse-based approach led to a reduced rituximab exposure and significant cost savings. Relapse-based administration of rituximab in patients with MCD/FSGS with an initial good clinical response did not result in a decreased efficacy at a median follow-up duration of 110 months. Thus, reinduction therapies may provide an alternative to continuous B-cell-depletion and reduce the long-term side effects of continuous immunosuppression.

Cerebral venous thrombosis in an adult with relapsing minimal change disease.

Minimal change disease (MCD) is a well-known cause of fulminant acute nephrotic syndrome (NS) and has been associated with thrombotic complications. We report the case of a 51-year-old woman with previous biopsy-proven MCD in remission who presented with worsening headache and acute confusion shortly after a relapse of the NS and was diagnosed with cerebral venous thrombosis (CVT) complicated by intracranial hemorrhage and midline shift. One month prior, she had been initiated on an oral contraceptive agent during remission of the NS. After initiation of systemic anticoagulation, her condition rapidly deteriorated, and she passed away before being able to undergo catheter-based venous thrombectomy. We conducted a systematic literature review and identified 33 case reports of adults with NS-associated CVT. The most common symptoms were headache (83%), nausea or vomiting (47%), and altered mental status (30%). 64% of patients presented at time of initial diagnosis of the NS and 32% during a relapse. Mean urinary protein excretion was 9.32 g/day and mean serum albumin was 1.8 g/dL. 91% of patients received systemic anticoagulation, and 19% died. The outcome in the remaining cases was favorable with only one report (5%) of residual neurological deficit. Of the available kidney biopsy results, MCD was the most common diagnosis (70%), raising the hypothesis that the fulminant acute onset of the NS might be a predisposing factor for this serious thrombotic complication. Clinicians should have a high index of suspicion for CVT in patients with the NS who present with new-onset neurological symptoms, including headache and nausea.

Minimal change nephrotic syndrome diagnosed with acute femoral thromboembolism and successfully salvaged limb: a case report.

A 64-year-old man visited the outpatient department of our hospital for the first time due to bilateral lower limb edema, which he noticed 1 week before the visit. Pain suddenly developed in the left lower limb while the patient was in the waiting room. Nephrotic syndrome was suspected based on blood and urine test results. Acute arterial thromboembolism in the left lower limb associated with hypercoagulation due to nephrotic syndrome was suspected, and a diagnosis was made using computed tomography angiography. Arterial thrombectomy was urgently performed, and the limb was salvaged without sequelae. Based on renal biopsy, minimal change nephrotic syndrome was diagnosed, and the patient underwent remission induction with steroid therapy. Heparin was drip infused and apixaban was orally administered to prevent recurrent thrombosis. Nephrotic syndrome in the acute phase is often complicated by thrombosis. Particularly, arterial thromboembolism requires prompt treatment, and prophylactic anticoagulation therapy needs to be considered.

A case of minimal change nephrotic syndrome complicated by Kimura disease treated with rituximab.

Kimura disease (eosinophilic granuloma of the soft tissue) is a benign granulomatous disease complicated by nephrotic syndrome. Herein, we report a case of recurrent minimal change nephrotic syndrome (MCNS) complicated by Kimura disease that was successfully treated with rituximab. A 57-year-old man presented to our hospital with relapsed nephrotic syndrome with worsening swelling of the right anterior ear and elevated serum IgE. MCNS was diagnosed on renal biopsy. Treatment with 50 mg of prednisolone rapidly placed the patient in remission. Therefore, RTX 375 mg/m2 was added to the treatment regimen, and steroid therapy was tapered. Early steroid tapering was successful, and the patient is currently in remission. In this case, the nephrotic syndrome flare-up was accompanied by worsening Kimura disease. Rituximab reduced the worsening of symptoms related to Kimura disease, including head and neck lymphadenopathy and elevated IgE levels. Kimura disease and MCNS may share a common IgE-mediated type I allergic condition. Rituximab effectively treats these conditions. In addition, rituximab suppresses Kimura disease activity in patients with MCNS, enables early tapering of steroids, and reduces the total dose of steroids.