Significance of mesangial IgA deposition in minimal change nephrotic syndrome: a study of 60 cases

Primary IgA nephropathy with nephrotic-range proteinuria in Chinese children

To investigate the clinicopathological features and outcomes of primary IgA nephropathy with nephrotic-range proteinuria in Chinese children. Patients with biopsy-proven IgA nephropathy and nephrotic-range proteinuria between January 2011 and December 2017 were included, and their proteinuria and renal function were followed up. A total of 90 patients were enrolled, and 21.1% (19/90) of them had decreased renal function at diagnosis. Complete remission, partial remission, and no response of proteinuria occurred in 88.6% (70/79), 10.1% (8/79), and 1.3% (1/79), respectively, of the 79 patients who were followed up for 6 to 104 months. 73.7% (14/19) of the patients with decreased renal function at diagnosis recovered to normal level while 26.3% (5/19) of them did not recover or progressed to end-stage renal disease. Two patients with normal renal function at diagnosis progressed to renal insufficiency during follow-up period. By multivariate analysis, the risk for renal function deterioration was significantly higher in the partial remission and no response groups than in the complete remission group. Remission of proteinuria was important for improving renal prognosis in children with IgA nephropathy and nephrotic-range proteinuria. The outcomes for pediatric patients appeared to be better than that reported in adults.

Characterization of IgA Deposition in the Kidney of Patients with IgA Nephropathy and Minimal Change

Approximately 5% of patients with IgA nephropathy (IgAN) exhibit mild mesangial lesions with acute onset nephrotic syndrome and diffuse foot process effacement representative of minimal change disease (MCD). It is not clear whether these unusual cases of IgAN with MCD (IgAN-MCD) are variant types of IgAN or coincidental deposition of IgA in patients with MCD. In a retrospective multicenter cohort study of 18 hospitals in Korea, we analyzed 46 patients with IgAN-MCD. Patients with endocapillary proliferation, segmental sclerosis, and crescent were excluded, and the clinical features and prognosis of IgAN-MCD were compared with those of pure MCD. In addition, we performed galactose-deficient IgA1 (KM55) staining to characterize IgAN-MCD. Among the 21,697 patients with glomerulonephritis enrolled in the database, 46 patients (0.21%) were diagnosed with IgAN-MCD, and 1610 patients (7.4%) with pure MCD. The 46 patients with IgAN-MCD accounted for 0.6% of primary IgAN patients (n = 7584). There was no difference in prognosis between patients with IgAN-MCD and those with only MCD. IgA and KM55 showed double positivity in all patients with IgAN-MCD (n = 4) or primary IgAN (n = 5) under double immunofluorescent staining. However, in four patients with lupus nephritis, mesangial IgA was deposited, but galactose-deficient-IgA1 (Gd-IgA1) was not. These findings suggest that IgAN-MCD is a dual glomerulopathy in which MCD was superimposed on possibly indolent IgAN. We confirmed by KM55 staining that IgAN-MCD is true IgAN, enabling better characterizations of the disease. Furthermore, IgAN-MCD shows a good prognosis when treated according to the usual MCD treatment modality.

Mycophenolate mofetil therapy for steroid-resistant IgA nephropathy with the nephrotic syndrome in children

BACKGROUND

Immunoglobulin A nephropathy (IgAN) presents as nephrotic syndrome (NS) relatively rarely, and the current treatment experience of IgAN patients with NS is mostly with adults. The objective of our study was to investigate the efficacy of corticosteroids and mycophenolate mofetil (MMF) in treating childhood immunoglobulin A nephropathy (IgAN) with nephrotic syndrome.

METHODS

A total of 58 children (39 boys and 19 girls) diagnosed with nephrotic syndrome and primary IgAN were enrolled in the study. All the patients were administered prednisone 2 mg/kg per day for 8 weeks. Steroid-resistant patients were treated with the combined use of MMF (dose of 20 ~ 30 mg/kg per day) and prednisone for 6-12 months. The prednisone dose was reduced stepwise during the combined treatment.

RESULTS

Of the 58 children, 14 were steroid-sensitive (M, S, and T variants of the Oxford classification were 0 in most children), and 44 cases who presented serious pathological damage to the kidney were steroid-resistant. The estimated glomerular filtration rate (eGFR) of the steroid-resistant children (86.69 ± 26.85 ml/min/1.73 m(2)) was significantly lower (P < 0.05) than that of the steroid-sensitive children (106.89 ± 26.94 ml/min/1.73 m(2)). After 4 months of combined MMF treatment in 33 steroid-resistant children, complete remission of proteinuria was found in 21 cases, partial remission of proteinuria in 6 cases, and no response was found in 6 cases. Except for the T variant, other variants of the Oxford classification, including M, E, and S morphological variables, was not significantly different among patients complete remission, those with partial remission, and those with no response. The eGFR of children with complete remission of proteinuria (100.04 ± 18.47 ml/min/1.73 m(2)), that of those with partial remission (92.24 ± 27.63 ml/min/1.73 m(2)), and that of those with no response (72.17 ± 27.55 ml/min/1.73 m(2)) were significantly different (P < 0.05).

CONCLUSION

Corticosteroid therapy showed satisfactory efficacy in IgAN children with nephrotic syndrome and slight pathological damage. The effect of MMF was good for steroid-resistant IgAN children, but poor for those with tubular atrophy/interstitial fibrosis and renal function impairment.

Minimal change disease and IgA deposition: separate entities or common pathophysiology?

Introduction. Minimal Change Disease (MCD) is the most common cause of nephrotic syndrome in children, while IgA nephropathy is the most common cause of glomerulonephritis worldwide. MCD is responsive to glucocorticoids, while the role of steroids in IgA nephropathy remains unclear. We describe a case of two distinct clinical and pathological findings, raising the question of whether MCD and IgA nephropathy are separate entities or if there is a common pathophysiology. Case Report. A 19-year old man with no medical history presented to the Emergency Department with a 20-day history of anasarca and frothy urine, BUN 68 mg/dL, Cr 2.3 mg/dL, urinalysis 3+ RBCs, 3+ protein, and urine protein : creatinine ratio 6.4. Renal biopsy revealed hypertrophic podocytes on light microscopy, podocyte foot process effacement on electron microscopy, and immunofluorescent mesangial staining for IgA. The patient was started on prednisone and exhibited dramatic improvement. Discussion. MCD typically has an overwhelming improvement with glucocorticoids, while the resolution of IgA nephropathy is rare. Our patient presented with MCD with the uncharacteristic finding of hematuria. Given the improvement with glucocorticoids, we raise the question of whether there is a shared pathophysiologic component of these two distinct clinical diseases that represents a clinical variant.

Clinical features and outcomes of IgA nephropathy with nephrotic syndrome

BACKGROUND AND OBJECTIVES

Nephrotic syndrome (NS) is a rare manifestation of IgA nephropathy (IgAN). Clinical characteristics and long-term outcomes of this condition have not yet been explored.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A multicenter observational study was conducted between January 2000 and September 2010 in 1076 patients with biopsy-proven IgAN from four medical centers in Korea. The primary outcome was a doubling of the baseline serum creatinine concentration.

RESULTS

Of the 1076 patients, 100 (10.2%) presented with NS; complete remission (CR), partial remission (PR), and no response (NR) occurred in 48 (48%), 32 (32%), and 20 (20%) patients, respectively. During the median follow-up of 45.2 months, 24 patients (24%) in the NS group reached the primary endpoint compared with 63 (7.1%) in the non-NS group (P<0.001). The risk of reaching the primary endpoint was significantly higher in the PR (P=0.04) and NR groups (P<0.001) than in the CR group. Among patients with NS, 24 (24%) underwent spontaneous remission (SR). SR occurred more frequently in female patients and in patients with serum creatinine levels ≤1.2 mg/dl and a >50% decrease in proteinuria within 3 months after NS onset. None of the patients with SR reached the primary endpoint and they had fewer relapses during follow-up.

CONCLUSIONS

This study demonstrated that the prognosis of NS in IgAN was not favorable unless PR or CR was achieved. In addition, SR was more common than expected, particularly in patients with preserved kidney function and spontaneous decrease in proteinuria shortly after NS onset.

Reversible minimal change nephrotic syndrome and glomerular IgA deposition associated with nonparenteral heroin abuse: a case report

OBJECTIVE

To report for the first time a case of reversible minimal change nephrotic syndrome with immunoglobulin A (IgA) deposition associated with heroin.

CLINICAL PRESENTATION AND INTERVENTION

A 29-year-old male heroin abuser who developed nephrotic syndrome was admitted to our clinic. Renal biopsy revealed minimal change disease with IgA deposition. Because spontaneous complete remission was observed after cessation of heroin, a diagnosis of minimal change nephrotic syndrome with IgA deposition associated with heroin abuse was considered.

CONCLUSION

This case showed minimal change nephrotic syndrome with IgA deposition that had a benign clinical course.

Malignant pleural mesothelioma with associated minimal change disease and acute renal failure

Paraneoplastic manifestations in malignant pleural mesothelioma are rare. We report a case of malignant pleural mesothelioma associated with minimal change disease (MCD). A 58-year-old man with occupational exposure to asbestos presented with severe peripheral edema, heavy proteinuria, and acute renal failure shortly after the diagnosis of mesothelioma had been confirmed. The renal biopsy demonstrated MCD. The underlying pathogenesis of this association remains unknown.

Morphometric analysis of podocyte foot process effacement in IgA nephropathy and its association with proteinuria

The effacement of podocyte foot processes is a well-known phenomenon occurring in many glomerulonephritides with proteinuria. The fundamental sign of IgA nephropathy is hematuria, but proteinuria also frequently occurs. The authors measured the extent of foot process effacement in 100 IgA nephropathy cases with proteinuria and correlated it with the amount of proteinuria. The extent of foot process effacement was greater in the nephrotic proteinuria group than in the subnephrotic proteinuria or control groups. The degree of foot process effacement was positively correlated with proteinuria. This study demonstrates that proteinuria in IgA nephropathy is closely related to foot process effacement.

Expression of fibrosis-associated molecules in IgA nephropathy treated with cyclosporine

Cyclosporine (CsA) treatment in immunoglobulin A nephropathy (IgAN) is controversial and has not been widely studied. The aim of this study was to investigate the effects of CsA on renal histology and the expression of interstitial fibrosis-associated molecules in childhood IgAN. The subjects were 18 children (age 4.2-13.9 years; male:female 13:5) who had been treated with CsA for 8 or 12 months and who had renal biopsies before and after treatment. Renal biopsies were assessed by routine histology and immunohistochemistry against osteopontin (OPN), transforming growth factor-beta (TGF-beta), CD68, and CD34. The degree of proteinuria and mesangial IgA deposits decreased or disappeared after treatment in all cases, and the percentage of patients with diffuse mesangial proliferation decreased from 44.4 to 22.2%. However, interstitial fibrosis developed or was aggravated in nine patients (50%) after treatment and was associated with an increased degree of interstitial inflammation in five patients. Tubular OPN expression (45.3 +/- 23.4 vs. 37.6 +/- 19.3%) and the degree of CD68-positive macrophage infiltration (136.1 +/- 88.2 vs. 132 +/- 86.0/mm(2)) were not increased after CsA treatment, but TGF-beta expression was significantly increased (6.4 +/- 4.2 vs. 13.3 +/- 9.9%; p = 0.025). Microvascular density was increased and peritubular capillaries were of small caliber in inflamed areas. We conclude that increased levels of TGF-beta and the development of interstitial fibrosis limit the long-term use of CsA in IgAN patients. Osteopontin and macrophages may be indirectly involved in renal fibrosis by prolonging interstitial inflammation rather than by directly increasing TGF-beta expression.

Clinicopathologic characteristics of IgA nephropathy with steroid-responsive nephrotic syndrome

Nephrotic syndrome is an unusual manifestation of IgA Nephropathy (IgAN). Some cases respond to steroid treatment. Here we describe a case-series of IgAN patients with steroid-responsive nephrotic syndrome. Twelve patients with IgAN with steroid-responsive nephrotic syndrome were evaluated and followed up. All patients presented with generalized edema. Renal insufficiency was found in two patients. The renal biopsy of eight patients revealed wide foot process effacement in addition to the typical features of IgAN. They showed complete remission after steroid therapy. Seven relapses were reported in five patients; six of the relapsed cases responded to steroid therapy. Compared with steroid-non-responsive patients, the patients with steroid-responsive nephrotic syndrome had shorter symptom duration, more weight gain, more proteinuria, and lower histologic grade than did those that had steroid-non-responsive nephrotic syndrome at presentation. None of the responders progressed to end stage renal disease, whereas five (38%) non-responders required dialysis or renal transplantation. Patients with IgAN who have steroid-responsive nephrotic syndrome likely have both minimal change disease and IgAN. The clinical features of sudden onset of generalized edema, initial heavy proteinuria and initial severe hypoalbuminemia might help identify the subset of patients, especially in low grade IgAN.

Hypothesis: dysregulation of immunologic balance resulting from hygiene and socioeconomic factors may influence the epidemiology and cause of glomerulonephritis worldwide

Glomerular diseases show diverse epidemiological characteristics throughout the world, which has been suggested to be caused by differences in genetics of the underlying populations or environmental exposure to the putative antigens or agents that either trigger or induce the disease. Recently, an alteration in immune balance of the T helper 1 (T(H)1) and T helper 2 (T(H)2) subsets has been implicated as a mechanism to explain the relative increase in allergic diseases in industrialized nations. According to the Hygiene Hypothesis, overcrowding and poor hygiene early in life may protect from atopic diseases because exposure to microbes predisposes in favor of a T(H)1-dominant response. Conversely, dominance of the T(H)2 subset would be responsible for the increasing incidence of allergies. We present the hypothesis that this imbalance may help explain the predilection for membranoproliferative glomerulonephritis (GN) and mesangial proliferative GN to be associated with developing and/or poor nations, whereas immunoglobulin A nephropathy and minimal change disease are observed more commonly in industrialized nations. The implication of the Hygiene Hypothesis is that clinical expression of immune-mediated renal disease would depend on the prevailing T(H)1/T(H)2 balance, rather than the etiologic agent, and it may help explain the epidemiological pattern of glomerular diseases worldwide.