Idiopathic membranous glomerulopathy preceding the emergence of systemic lupus erythematosus in two children

Lupus-like membranous nephropathy during the postpartum period expressing glomerular antigens exostosin 1/exostosin 2 and phospholipase A2 receptor: a case report

Recently, several target antigens of membranous nephropathy (MN), such as phospholipase A2 receptor (PLA2R) and exostosin 1/exostosin 2 (EXT1/2), have been discovered. A 30-year-old woman was referred to our hospital with nephrotic range proteinuria and microscopic hematuria. She was first noted to have proteinuria before pregnancy, and her proteinuria worsened in the postpartum period. A renal biopsy showed MN. Immunofluorescence microscopy showed IgG, IgA, IgM, C3, C4, and C1q depositions in the mesangial area and glomerular capillary walls (GCWs). Regarding the IgG subclass, IgG1 and IgG3 were detected on glomeruli. Electron microscopy showed subepithelial electron-dense deposits (EDDs). EDDs were also detected in paramesangial and subendothelial areas. The diagnosis of membranous lupus nephritis (MLN) was suspected, but she did not fulfill the criteria for systemic lupus erythematosus. Neither anti-nuclear antibody nor hypocomplementemia were detected. We further evaluated glomerular EXT1/2 expressions, which were evident on GCWs. In addition, PLA2R was also detected on GCWs, although serum antibody for PLA2R was negative. She responded to immunosuppressive therapy with decreased proteinuria. In the present case, glomerular PLA2R expression implied the possibility of primary MN. However, pathological findings with a full-house staining pattern and glomerular EXT1/2 expressions were very similar to those of lupus-associated MN. Glomerular PLA2R expression appeared not to reflect immunocomplexes of PLA2R and autoantibody when considering the results for glomerular IgG subclass and the absence of serum anti-PLA2R antibody. Collectively, it is plausible that this was a case of a relatively young postpartum female who developed latent MLN rather than primary MN.

Clinicopathologic features of non-lupus membranous nephropathy in a pediatric population

BACKGROUND

Membranous nephropathy is an uncommon cause of nephrotic syndrome in pediatrics.

METHODS

We reviewed our kidney biopsy records for patients ≤ 20 years of age with membranous nephropathy without evidence of systemic lupus erythematosus within 6 months of biopsy (January 1995-September 2020). Staining for PLA2R, NELL1, THSD7A, SEMA3B, EXT2 (3 biopsies), and IgG-subclass were performed.

RESULTS

Sixteen children (≤ 12 years) and 25 adolescents (13-20 years) were identified. Four children and 15 adolescents showed autoantigen positivity: PLA2R+/SEMA3B- (13), SEMA3B+/PLA2R+ (2), SEMA3B+/PLA2R- (1), NELL1 (1), EXT2+ (2), and THSD7A (0). Co-morbidities associated with PLA2R positivity included IPEX syndrome, active hepatitis B, Von Hippel Lindau syndrome, solitary kidney, type 1 diabetes, hyperuricemia, pregnancy (1), obesity (3), type II diabetes, H. pylori, viral prodrome, and nephrolithiasis. The SEMA3B+/PLA2R- adolescent was pregnant, the NELL1+ adolescent was obese, and the two EXT2+ adolescents eventually met the clinical criteria for lupus (4, 9 years post-biopsy). Co-morbidities among the remaining 24 patients included remote hepatitis B (2), Down's syndrome, lysinuric protein intolerance, recurrent UTIs, hypothyroidism, pregnancy (3), and obesity (2). Follow-up data was available for 12 children and 16 adolescents. Of the 12 children, 6 achieved complete remission, 4 achieved partial remission, and 2 had no response to treatment (1 transplant). Of the 16 adolescents, 4 achieved complete remission, 4 achieved partial remission, and 8 had no response to treatment (3 transplants). A child with "full-house" immunofluorescence staining achieved spontaneous disease remission.

CONCLUSION

Our non-lupus membranous nephropathy cohort represents one of the largest pediatric studies to date. A higher resolution version of the Graphical abstract is available as Supplementary information.

Idiopathic membranous nephropathy preceding membranous lupus nephritis: a case report

Membranous nephropathy is one of the most common causes of nephrotic syndrome in the adult population. According to the underlying etiology, membranous nephropathy is classified as either primary or secondary. Systemic lupus erythematosus is an autoimmune disease that can affect the kidneys in 50% of patients in the course of the disease. Renal disease may be the first manifestation of systemic lupus erythematosus and the development of systemic findings may be delayed for about 1-5 years following the diagnosis of lupus nephritis. We present a 59-year-old male patient who had a diagnosis of idiopathic membranous nephropathy since 2007 and developed membranous lupus nephritis during the 12-year follow-up without any extrarenal systemic lupus erythematosus findings.

A case of membranous nephropathy diagnosed with lupus nephritis 11 years after onset

A 34-year-old female patient presented to our hospital with lower extremity edema and proteinuria during pregnancy. Renal biopsy was performed and the patient was diagnosed with nephrotic syndrome due to lupus-like membranous nephropathy. This diagnosis was reached upon as laboratory findings upon admission, wherein both anti-nuclear and anti-double-stranded DNA antibodies revealed negative, did not fulfill the criteria for systemic lupus erythematosus (SLE) proposed by the American College of Rheumatology (ACR) and the patient did not reveal any typical physical manifestations of SLE. Methylprednisolone pulse therapy was started followed by oral administration of prednisolone. Urinary protein excretion diminished after 1 year of treatment. Eleven years later, the same patient was admitted to our hospital again with relapse of nephrotic syndrome. Laboratory findings upon second admission, wherein both anti-nuclear and anti-double-stranded DNA antibodies revealed positive, fulfilled the ACR criteria. Renal biopsy was performed again, resulting in a diagnosis of lupus nephritis. Steroid therapy combined with administration of mycophenolate mofetil led to an incomplete remission. Immunofluorescence studies confirmed the presence of IgG, IgM, C3, and C1q in renal biopsy specimens both at first and second admissions. Furthermore, immunofluorescence studies confirmed the presence of IgG1–4 in the first biopsy and tubuloreticular inclusions (TRIs) were revealed using electron microscopy. The present case represents the possibility that characteristic pathological findings of lupus nephritis, including TRIs, can reveal themselves before a diagnosis of SLE.

Clinical presentation and outcomes of childhood-onset membranous lupus nephritis

BACKGROUND

Best practices for managing childhood-onset membranous lupus nephritis (MLN) are not yet established. Most studies involve primarily or exclusively adult cohorts or pediatric cohorts with combinations of pure or mixed membranous and proliferative nephritis.

METHODS

We performed a single-center cohort study of consecutively diagnosed children with pure MLN from 1990 and 2016. Patients received care in Houston, Texas, one of the most diverse metropolitan areas in North America. Renal outcomes were obtained using consensus definitions from the Childhood Arthritis and Rheumatology Research Alliance (CARRA). Logistic regression was used to detect predictors of complete renal response.

RESULTS

A total of 56 children with MLN were identified (82% females, 44% black, 35% Hispanic) with a median follow-up time of 4.1 years. The mean age of MLN onset was 13.7 ± 3.4 years. On initial presentation 69% had nephrotic syndrome and 11% had acute kidney injury. Glucocorticoids were prescribed in 96% of patients and anti-malarials in 88%. Mycophenolate mofetil was the most common non-steroid immunosuppressive agent (69%), followed by rituximab (25%), cyclophosphamide (18%), and azathioprine (9%). Renin-angiotensin aldosterone system blocking agents were prescribed in 78% of patients. Of 37 patients with ≥2 years of follow-up, 74% achieved complete renal response at 24 months. No predictor variable of complete renal response was identified in this small cohort. Renal flares occurred in 48% of patients (86% proteinuric, 14% nephritic). On subsequent renal biopsy, 13% patients had developed proliferative nephritis.

CONCLUSIONS

This single-center cohort of childhood-onset MLN showed favorable outcomes. Utilizing pediatric renal outcomes definitions, we found that response rates were high, as were rates of renal flare.

An Overlapping Case of Lupus Nephritis and IgG4-Related Kidney Disease

We report a case of a 71-year-old Filipino female who was admitted to the hospital for abdominal pain, vomiting and diarrhea of 8 days duration. The patient was found to have marked acute kidney injury (AKI), which required hemodialysis in the next 3 days. Extensive workup revealed hematuria, subnephrotic range proteinuria, elevated anti-nuclear antibody (ANA) and elevated total immunoglobulin G (IgG) levels, with normal IgG4 and anti-dsDNA levels. On kidney biopsy, mild membranous glomerulonephritis was found, along with autoimmune tubulointerstitial nephritis (TIN) with a “full-house” pattern of immune deposits. These findings were suggestive of lupus interstitial nephritis. However, IgG4+ plasma cells were detected in the interstitium by immunostaining, favoring a diagnosis of IgG4-related kidney disease (IgG4-RKD). Our case highlights the difficulty in differentiating lupus nephritis (LN) from IgG4-RKD in some patients, raising the suspicion that these two entities can co-exist.

Lupus-like membranous nephropathy: Is it lupus or not?

BACKGROUND

Membranous glomerulonephritis is typically classified as idiopathic or secondary to systemic lupus erythematosus (SLE), hepatitis B, drugs, toxins, other infections, or malignancy. Not infrequently in some patients without a definite diagnosis of SLE, pathologic features of secondary membranous nephropathy are seen e.g., mesangial and/or subendothelial deposits, tubuloreticular inclusions, and full house immunofluorescence. In these patients, there is uncertainty about the etiology, response to therapy, and prognosis of membranous GN.

METHODS

We retrospectively reviewed the charts of 98 patients with membranous GN at San Francisco General Hospital and John Stroger Hospital of Cook County over a 10-year period. Data were collected and analyzed using SPSS.18.

RESULTS

Thirty-nine (40 %) had idiopathic membranous GN (Group 1), thirty-six (37 %) had lupus membranous GN (Group 2) and twenty-three (23 %) had some pathological features of secondary membranous GN, but no definite etiology of membranous GN (Group 3). At baseline (at time of renal biopsy) and after mean follow-up of 3.5 years, the average serum creatinine (in mg/dL) in Group 1 was (1.6 ± 1.0 versus 1.6 ± 1.7), Group 2 was (1.8 ± 2.5 versus 1.2 ± 0.9) and Group 3 was (1.1 ± 0.4 versus 1.27 ± 0.83), respectively. For the same time points, the average urine protein to creatinine ratio (g/g) in Group 1 was (9.8 ± 7.1 versus 5.7 ± 6.7), Group 2 was (4.2 ± 3.9 versus 1.7 ± 2.2), and Group 3 was (7.4 ± 5.7 versus 3.1 ± 3.8). In addition, during the follow-up period, eleven of 39 (28 %) in Group 1, two of 36 (6 %) in Group 2, and three of 23 (13 %) in Group 3 progressed to end-stage renal disease and were started on dialysis.

CONCLUSIONS

It appears that patients with lupus membranous GN have better renal prognosis than patients with idiopathic membranous GN. The renal prognosis for patients with pathological features of lupus membranous but no diagnosis of systemic lupus (lupus-like membranous GN) falls in between. Further studies are needed to determine if Group 3 patients can (a) definitively be classified as true idiopathic membranous GN or lupus membranous GN or (b) they have a separate disease from either M-type phospholipase A2 receptor membranous nephropathy or systemic lupus-induced membranous nephropathy.

Membranous glomerulonephritis: treatment response and outcome in children

The aim of this study was to characterize clinical features, treatment response, and outcome of idiopathic membranous glomerulonephritis (MGN) in a single-center cohort of children. A retrospective review of biopsy-proven idiopathic MGN in 12 children (mean age 11.9 years) was undertaken. Presentation was nephrotic syndrome (NS) (75%), hematuria/proteinuria (17%), and asymptomatic proteinuria (8%). Ten patients (83%) with NS and nephrotic range proteinuria (NRP) were treated with prednisone, and two patients with non-NRP were not treated with immunosuppressive medications. Steroid response in the treated patients was complete (10%), partial (40%), and absent (50%), respectively. Oral cyclophosphamide was used in seven patients of whom five were steroid resistant, one was steroid dependent, and one was partially responsive. At the mean follow up of 27 months, outcome parameters included an estimated glomerular filtration rate of 128 cc/min per 1.73 m(2), albumin of 4.2 gm/dL, and a urine protein/creatinine ratio of 0.87 [median 0.16 (range 0.02-6.52)]. Remission was complete in 75% of the patients and partial in 17%. One patient (8%) with chronic kidney disease (stage 2) was unresponsive to therapy. Complete remission was significantly associated with the absence of chronic histological changes (p = 0.03). In conclusion, children with NS and/or NRP associated with MGN appear to have a good prognosis when treated with a combination of corticosteroids and cyclophosphamide.

Idiopathic membranous nephropathy in children

Idiopathic membranous nephropathy (MN) is a rare cause of asymptomatic proteinuria (AP) or nephrotic syndrome (NS) in childhood. To improve our understanding of its clinical course, we retrospectively reviewed 19 cases of idiopathic MN seen in our hospital over a period of 28.5 years, i.e., from January 1977 to July 2005. Eight patients (39%) had AP and 11 (61%) presented with NS. All eight AP patients achieved remission, regardless of treatment modality. Oral corticosteroid was given to all 11 NS patients, but only three of them responded to corticosteroid. Of the eight steroid non-responders, three achieved remissions with the addition of cyclosporine, and the five who were not administered additional immunosuppressive drugs had persistent NS. At the latest evaluation, all six NS patients that achieved remission remained free of proteinuria and had a normal renal function. Moreover, two of the 5 steroid non-responders showed persistent nephrotic-range proteinuria but a stable renal function. The remaining three steroid non-responders progressed into chronic renal insufficiency, and this progression was preceded by renal vein thrombosis (RVT) in two of the three patients. Presentation with NS (P=0.045) and the development of RVT (P=0.010) were identified as poor prognostic factors.

Full-house nephropathy in a patient with negative serology for lupus

A 10-year-old girl presented with a complaint of recurrent abdominal pain. Physical examination findings were unremarkable. Laboratory investigations revealed BUN of 17 mg/dl and creatinine of 1 mg/dl, and complement levels were normal. She had neither hematuria nor proteinuria, and glomerular filtration rate was 60.9 ml/min/1.73 m(2). ANA, anti-DNA, p-ANCA and c-ANCA were all negative. Renal biopsy revealed findings of class III lupus nephritis in light, "full-house" nephropathy in immune fluorescent and tubuloreticular inclusions in electron microscopic examinations. After 17 months of treatment, her last creatinine is 2.5 mg/dl and GFR is 17.9 ml/min/1.73 m(2) and ANA and anti-DNA remain still negative. This case presents an example that decreased GFR can be the first presenting symptom of full-house nephropathy. Those patients who have negative lupus serology and renal biopsy findings of full-house nephropathy and tubuloreticular inclusions may behave and should be treated as lupus nephritis.

Prognosis of lupus membranous nephropathy in children

The occurrence of membranous nephropathy in pediatric series of systemic lupus erythematosus has been reported only rarely, probably due to a very low frequency. One hundred fifty-four children who were seen in 100 French pediatric centers between January 2002 and April 2005 were included. Fifteen (12 girls and three boys) out of the 81 (18.5 %) children with renal involvement presented histological features of membranous nephropathy. Their ages ranged from six to 15 years old (mean=11.3) at the age of SLE diagnosis and 8/15 children were of African origin. Isolated membranous nephropathy was observed in nine patients, of whom five patients displayed a complete recovery following immunosuppressive treatment. Associated proliferative lesions were observed on the first kidney specimen in two patients and in a further renal biopsy in four other patients, leading to a less favorable course of lupus nephropathy.

Subsequent progression to membranous glomerulonephritis following exacerbation of urticarial rash in systemic lupus erythematosus: report of 2 cases

Two Japanese female adolescents with systemic lupus erythematosus (SLE), known cases of urinary tract involvements: one with biopsy-proven class II lupus nephritis and the other one with lupus cystitis without overt glomerulonephritis (silent lupus), who after more than 4 years' observation presented with subsequent progression to membranous glomerulonephritis (MGN) following exacerbation of urticarial rash. Although it is well known that lupus nephritis shows histological transformation with time, the late progression to MGN from another World Health Organization histologic pattern has been reported to be less common in pediatric-onset SLE. Although pathogenesis of their MGN remains speculative, these clinical observation might suggest that a possible association between exacerbation of urticarial rash and subsequent progression to MGN in the selected patients with SLE.

IgG subclass deposits in glomeruli of lupus and nonlupus membranous nephropathies

Membranous nephropathy (MN) accounts for approximately 10% of all renal lesions of systemic lupus erythematosus (SLE). These membranous lesions often have a clinical presentation similar to that of idiopathic MN and may present before SLE is apparent clinically. However, unlike proliferative lesions of lupus nephritis (LN), membranous LN often does not show a "full-house" pattern of glomerular immunoglobulin and complement (C) deposits by immunofluorescence (IF); only nine of 14 such lesions that we examined stained for all of the following: IgG, IgA, IgM, C3, and C1q. Iskandar et al reported in 1992 that most cases of diffuse proliferative LN showed IgG3 as the major IgG subclass present in glomerular deposits; by contrast, IgG4 predominated in six of seven cases of MN of unspecified etiology. If IgG subclass deposition is similar in membranous and proliferative lesions of LN, then IF staining for IgG3 and IgG4 may be helpful in distinguishing lupus from nonlupus lesions in patients with MN who are lacking a firm diagnosis of SLE. We therefore stained cryostat sections of renal biopsies from 14 patients with SLE and MN (without a proliferative component; World Health Organization [WHO] classes Va and Vb) and 28 non-SLE patients with MN for IgG subclasses by direct IF; the observer was blind to the diagnosis for each case until all were read. The intensity of glomerular staining was graded on a 0 to 4+ scale with increments of 0.5+.(ABSTRACT TRUNCATED AT 250 WORDS)

Distal renal tubular acidosis as the initial manifestation of systemic lupus erythematosus in an adolescent

Distal renal tubular acidosis (dRTA) as the initial manifestation of systemic lupus erythematosus (SLE) has not been described previously. We report a 14-year-old female adolescent, first presenting with findings consistent with dRTA, whose renal biopsy demonstrated immune mesangial deposits consistent with lupus nephritis. Seven months later, she developed classic extrarenal manifestations of SLE. We recommend that adolescents with dRTA be evaluated and followed closely for the possibility of SLE.

Micro-angiopathic haemolysis, thrombocytopenia and nephrotic syndrome associated with membranous nephropathy in a Vietnamese boy

The unique association of idiopathic diffuse membranous nephropathy and micro-angiopathic haemolytic anaemia and thrombocytopenia is described. A 7 year old Vietnamese boy with a 1-month history of anaemia resistant to oral iron supplements presented with acute onset of nephrotic syndrome. Investigations revealed a micro-angiopathic haemolytic anaemia and thrombocytopenia. There was no associated oliguria or uraemia. Diffuse membranous nephropathy was diagnosed by renal biopsy. Apart from a fourfold rise in enterovirus titres, no underlying cause for the haematological or glomerular abnormalities was found. There was an apparent, partial haematological response to fresh frozen plasma infusions, but not to Vitamin E.

Acute renal failure as the initial manifestation of systemic lupus erythematosus in children

In two patients with systemic lupus erythematosus, acute renal failure was the initial manifestation. The diagnosis was eventually established on the basis of serologic tests and characteristic renal histopathologic findings. We emphasize the need to consider systemic lupus erythematosus as a cause of acute renal failure of glomerular origin, because appropriate therapy may alter the outcome of the disease.

Pathologic differentiation between lupus and nonlupus membranous glomerulopathy

The following clinical and pathologic features were evaluated in 170 patients with electron microscopically documented membranous glomerulopathy: age, sex, race, American Rheumatism Association lupus criteria, serum ANA, serum complement, glomerular hypercellularity, stage of subepithelial dense deposits, endothelial tubuloreticular inclusions, tubular basement membrane deposits, tissue ANA, glomerular deposition of IgG, IgM, IgA, C3, C4, and Clq. At the time of biopsy 148 patients had no clinical evidence for lupus, and 22 had a clinical diagnosis of lupus. Six additional patients eventually developed overt lupus after an average of 12 months. Incidences of serologic and pathologic features in lupus as compared with nonlupus membranous glomerulopathy were determined. These data were used to calculate sensitivity, specificity, positive and negative predictive values, and overall efficiency of each parameter in differentiating between lupus and nonlupus membranous glomerulopathy. In general, serologic, morphologic and immunohistopathologic features are more accurate at ruling out lupus than making the diagnosis of lupus. However, a number of features are significantly more frequent in lupus membranous glomerulopathy. Therefore, identification of these features, especially more than one, warrants a high suspicion of lupus rather than nonlupus membranous glomerulopathy even in patients without clinically overt systemic lupus erythematosus. The positive/negative predictive values of some of the pathologic features studied are as follows: mesangial dense deposits 63/99, subendothelial dense deposits 77/93, tubuloreticular inclusions 61/96, intense C1q deposition 47/95, tubular basement membrane deposits 100/87, and glomerular hypercelularity 26/86.

Hypocomplementemic idiopathic membranous glomerulopathy

Two asymptomatic teenage females with proteinuria, hematuria, and persistent hypocomplementemia are presented. Renal biopsy studies revealed membranous glomerulopathy. During follow-up periods of 4.0 and 4.5 years, the clinical courses and sequential monitoring of immunologic studies failed to demonstrate lupus erythematosus or other systemic disorders. Serum complement levels were consistent with activation of the alternate complement pathway in the first patient and the classic pathway in the second. In both cases further depression in serum complement levels occurred during intervals of greater urinary protein excretion. These findings suggest that the complement system may play a more important role in the pathogenesis of idiopathic membranous glomerulopathy than realized previously.