Minimal change nephrotic syndrome in association with strongyloidiasis

Although parasitic infections have been known to be associated with immune complex-mediated glomerular lesions, strongyloidiasis-related glomerulopathy has not been well documented. We report a patient with delayed-recognized disseminated strongyloidiasis who developed nephrotic syndrome 3 months after the beginning of the manifestations related to strongyloidiasis. A kidney biopsy showed minimal change disease. We treated strongyloidiasis and hesitated to give steroid therapy for the treatment of minimal change nephrotic syndrome (MCNS) because of the risk of aggravation of Strongyloides stercoralis infection. Surprisingly, resolution of heavy proteinuria occurred after anthelmintic therapy with ivermectin. This case suggests a possible causal relationship between S. stercoralis infection and MCNS. In addition, a review of another 4 cases previously reported in the literature demonstrates the importance of detecting underlying S. stercoralis infection in patients with nephrotic syndrome since steroid therapy can cause hyperinfection or disseminated strongyloidiasis, and which may lead to fatal outcome.

Thin basement membrane nephropathy cannot be diagnosed reliably in deparaffinized, formalin-fixed tissue

In diagnostic renal pathology, electron microscopy is ideally performed on glutaraldehyde-fixed, plastic resin-embedded tissue (EM-G). When no glomeruli are present in the portion of the biopsy fixed in glutaraldehyde, formalin-fixed, paraffin-embedded tissue can be reprocessed for electron microscopy (EM-F). The usefulness of this salvage technique for the diagnosis of thin basement membrane nephropathy (TBMN) has not been studied systematically. Here we compare the glomerular basement membrane (GBM) thickness by EM-G vs EM-F in 21 renal biopsies, including TBMN (eight patients), normals (two patients), minimal change disease (MCD) (six patients) and diabetic nephropathy (DN) (five patients). There was significant reduction of the GBM thickness by EM-F compared with EM-G across all diagnostic categories in all 21 cases. The mean percentage reduction in GBM thickness was 23% for the TBMN cases, 40% for the normal/MCD cases and 34% for the DN cases. Four patients with MCD had a mean GBM thickness by EM-F that fell below the defining threshold for diagnosis of TBMN. For the TBMN cases, the 99th percentile for GBM thickness by EM-F was 194 nm, suggesting that the diagnosis of TBMN by EM-F can be excluded with confidence if the GBM thickness is above 200 nm. No clear criteria could be established to diagnose TBMN by EM-F. Renal pathologists should be aware that reprocessing of paraffin tissue for EM causes artifactual GBM thinning that precludes accurate diagnosis of TBMN.

Minimal change disease: a review

Minimal change disease (MCD) is a histopathological lesion in the kidney that is most commonly associated with nephrotic syndrome. The majority of the cases are idiopathic. Pathogenesis is not well understood, although T-cell-related mechanisms are implicated. Massive proteinuria leads to hypoalbuminemia, salt retention, disorder of hemostasis, hyperlipidemia and increased susceptibility to infections. Renal biopsy remains the gold standard for diagnosis. MCD is highly responsive to corticosteroids. Other immunosuppressive agents such as cyclophosphamide, cyclosporin, azathioprine and mycophenolate mofetil have been used to treat cases which are resistant to steroids.

Glomerular involution in children with frequently relapsing minimal change nephrotic syndrome: An unrecognized form of glomerulosclerosis?

Global glomerulosclerosis can be divided in the vascular (obsolescent) type and the glomerulopathic (solidified) type. In biopsies from children with recurrent nephrotic syndrome owing to minimal change nephropathy (MCN), we noticed small, globally sclerosed glomeruli that appeared to be distinct from global glomerulosclerosis. These small sclerosed glomeruli are best described as involuted glomeruli. We have characterized these involuted glomeruli in detail. We studied biopsies of 18 children (11 male, 7 female) with frequently relapsing MCN and evaluated possible explanatory variables. The involuted glomeruli can be differentiated from the other types of global glomerulosclerosis. Most notable is the presence of vital podocytes and parietal epithelial cells, which have retained their staining characteristics, in between the matrix, and the absence of periglomerular and tubulo-interstitial fibrosis. We observed involuted glomeruli in 12 out of 18 biopsies; the median percentage of involuted glomeruli was 6% (range 0-33%). The percentage of involuted glomeruli correlated with age at renal biopsy and the interval between onset of disease and time of renal biopsy, but not with gender, age at onset of disease, or prednisone dose. Multivariate analysis revealed that the interval between onset of disease and time of renal biopsy was the only independent predictor. In conclusion, glomerular involution is a special form of global glomerulosclerosis. The absence of periglomerular and tubulo-interstitial fibrosis suggests a different pathogenesis. Glomerular involution is a slow process. The clinical data suggest that involution is related to the duration of the disease process.

Emerging minimal-change nephrotic syndrome in a patient with chronic mesangial proliferative lupus nephritis

A 41-year-old Japanese woman with a 25-year history of systemic lupus erythematosus was admitted because of abrupt onset of nephrotic syndrome and acute renal failure. Renal biopsy specimen showed only mild mesangial proliferative glomerulonephritis associated with mesangial deposition of immunoglobulins/complements. No significant immune deposits were found in the glomerular capillary walls, but mild foot process effacement was observed on electron microscopy. Further, two-month corticosteroid therapy improved her massive proteinuria and renal dysfunction, indicating that this patient showed minimal-change nephropathy superimposed on mesangial proliferative lupus nephritis.

Minimal-change nephrotic syndrome in a hematopoietic stem-cell transplant recipient

BACKGROUND

A 61-year-old woman received standard immunizations, including Haemophilus influenzae type B, diphtheria, tetanus toxoid, and unconjugated 23-valent pneumococcal vaccine (Pneumovax), Merck & Co., Inc., Whitehouse Station, NJ), 1 year after undergoing nonmyeloablative hematopoietic stem-cell transplantation for acute myelogenous leukemia. After 5 days, she developed fatigue with progressive weight gain and edema, and 14 days after immunization she presented with anasarca and was found to have acute renal failure and nephrotic proteinuria.

INVESTIGATIONS

Physical examination, serum chemistry, examination of urine sediment, renal ultrasound using Doppler scanning, 24 h urine collection, and renal biopsy.

DIAGNOSIS

Minimal-change nephrotic syndrome with acute tubular injury.

MANAGEMENT

Aggressive diuresis and oral corticosteroid therapy.

Spontaneous remission of therapy-resistant minimal change nephritis in an adult woman 12 years after onset of the disease

A 23-year old woman was admitted to our hospital because of severe edema due to steroid resistant minimal change nephritis (MCN). The diagnosis was proven by renal biopsy nine years ago. At that time, steroid therapy led to a complete remission. Seven years later, patient was 22 years old, a relapse with severe nephrotic syndrome occurred. The diagnosis MCN was confirmed by a second renal biopsy. A combined therapy with prednisolone and cyclosporine A (CSA) led only to a partial reduction of protein excretion, the edema did not disappear. After 3 months, patient declined further therapy with CSA. On admission to our hospital, one year later in December 2000, the woman showed a severe nephrotic syndrome with edema and fluid lung, despite high doses of furosemide. Urinary protein excretion was 12.5 g/day, serum creatinine was increased to 1.4 mg/dl, the serum protein was reduced to 47 g/l. A repeated renal biopsy confirmed again the diagnosis MCN. Once again, a steroid bolus monotherapy over 4 weeks and an immunosuppressive therapy with CSA over 6 weeks had no effect on proteinuria. Further therapy regimes with mofetil mycophenolat, azathioprine, chlorambucil and cyclophosphamide over a period of 6-12 weeks of each regime was not well tolerated, proteinuria remained high with > 10 g/day. Moreover the patient suffered from severe edema despite furosemide infusions. Therefore, an additional mechanical ultrafiltration was performed 2-4 times monthly. Three months after the last immunosuppressive therapy the edema disappeared spontaneously, the diuretic therapy could be stopped. Serum creatinine was 0.8 mg/dl, protein in urine was still high with 9.8 g/day but serum protein for the first time was normal with 65 g/l. Three months later, the protein excretion was reduced to 0.48 g/l, and all other laboratory data were normal. Meanwhile, the woman has now enjoyed a complete second spontaneous remission for a period of three years.

Clinicopathologic correlation of C1q nephropathy in children

BACKGROUND

Clinicopathologic correlation of C1q nephropathy is clarified poorly. The aim of our study is to clarify clinicopathologic correlation in childhood C1q nephropathy.

METHODS

Thirty children aged 3 to 15 years who met criteria proposed by Jennette and Hipp were enrolled in this study.

RESULTS

According to their presentation at onset, children were divided into 2 groups: the asymptomatic urinary abnormalities (asymptomatic) group (n = 18) and the nephrotic syndrome (NS) group (n = 12). Light microscopy showed minimal change disease (MCD) in 22 children (73%), mesangial proliferative glomerulonephritis in 6 children (20%), and focal segmental glomerulosclerosis (FSGS) in 2 children (7%). Four children in the asymptomatic group and all children in the NS group were administered prednisolone and/or cyclosporine. Normal urinalysis results were found in 8 children in the asymptomatic group and 3 children in the NS group during the follow-up period of 3 to 15 years. Eight children in the NS group were frequent relapsers at the latest follow-up. Two children with FSGS (1 child, asymptomatic group; 1 child, NS group) received dialysis 10 and 15 years after the diagnosis. There were no differences in histological findings and clinical outcomes between the 2 groups. Four children with MCD in the NS group underwent a second biopsy. C1q deposits disappeared in 2 children, and 1 of these 2 children showed FSGS.

CONCLUSION

Childhood C1q nephropathy is found in a wide clinical spectrum. Some children showed disappearance of C1q deposits through the follow-up period. A large number of children with C1q nephropathy showed MCD. However, FSGS may develop in some children on repeated biopsy. Therefore, long-term follow-up is needed in children with C1q nephropathy.

The diagnosis of minimal change disease in diabetic nephropathy

Proteinuria is common in diabetic patients and usually reflects the presence of diabetic glomerulosclerosis. This paper reviews the differential diagnosis of proteinuria in diabetic patients and discusses the role of renal biopsy examination in identification and management of minimal change disease in this cohort. Identification of nondiabetic glomerular disease requires careful correlation of clinical history and renal biopsy findings and may have important implications for prognosis and therapy.

Ezrin--a useful factor in the prognosis of nephrotic syndrome in children: an immunohistochemical approach

BACKGROUND

Minimal change disease (MCD) and diffuse mesangial proliferation (DMP) are the most common pathomorphological forms of nephrotic syndrome glomerulopathies in children. The clinical course of DMP can be characterised by either DMP-sensitivity (DMP-S) or DMP-resistance (DMP-R) to steroids, resulting in an unfavourable course of the glomerulopathy. Although the clinical processes of DMP-S and DMP-R are initially identical, resistance to steroids may be foreseen by the immunohistochemical expression of cytoskeleton-associated proteins in podocytes.

AIMS

To estimate the immunohistochemical expression of ezrin in children with MCD, DMP and focal segmental glomerulosclerosis (FSGS) and to evaluate its usefulness in predicting resistance to steroids.

MATERIALS AND METHODS

Renal biopsy specimens of patients with MCD (n = 15), DMP (n = 16) and FSGS (n = 6) were taken. The control tissue consisted of normal-appearing cortex taken from kidneys resected for localised neoplasms (n = 6). The indirect immunohistochemical protocol for the use of a monoclonal antibody directed against ezrin was used.

RESULTS

The immunohistochemical expression of ezrin in cases progressively reduced from MCD to DMP-S to DMP-R to FSGS. Except for DMP-R and FSGS (p>0.05), the difference in ezrin expression in podocytes was significant.

CONCLUSION

Ezrin can be a potent marker of podocyte injury (podocytopathy) and may help in the histological qualification of MCD, DMP and FSGS. The increased permeability of the filtration barrier in steroid-resistant and proteinuric glomerulopathies may be a consequence of subcellular changes in podocyte-associated proteins following decreased expression of ezrin.

Nephrotic Syndrome and Renal Failure After Allogeneic Stem Cell Transplantation: Novel Molecular Diagnostic Tools for a Challenging Differential Diagnosis

BACKGROUND

Sudden onset of nephrotic syndrome after allogeneic stem cell transplantation is rare and has been associated mostly with membranous glomerulonephritis related to chronic graft-versus-host disease (cGVHD). We report a case of nephrotic syndrome and rapidly progressive renal failure occurring in a young woman 3 years after allogeneic stem cell transplantation from her HLA-identical brother. In the renal biopsy, a diffuse mononuclear cell infiltrate was observed. Furthermore, histological analysis, immunofluorescence, and electron microscopy of the kidney specimen defined the diagnosis as minimal change disease, a T-cell-mediated glomerulopathy associated with lymphoproliferative disorders, but that has never been described as an isolated manifestation of cGVHD.

METHODS

The differential diagnosis was performed by using immunohistochemistry and laser capture microdissection combined with Taq-Man quantitative polymerase chain reaction.

RESULTS

Infiltrating mononuclear cells in renal tissue consisted of T cells expressing DNA levels of a Y chromosome-specific gene quantitatively similar to those observed in a male subject, showing that these cells derived from the transplant donor and definitely excluding leukemia relapse. However, the large number of infiltrating T cells allowed the possibility that in this patient, minimal change disease could be related to an atypical form of GVHD.

CONCLUSION

This is the first study to use molecular techniques to show the differential diagnosis of nephrotic syndrome after allogeneic stem cell transplantation. This novel method approach might represent a key tool to characterize kidney infiltrate after allogeneic stem cell transplantation.

Influence of the relapse and remission periods on hearing status in children with minimal change nephrotic syndrome

OBJECTIVE

Minimal change nephrotic syndrome (MCNS) is characterized by the onset of NS (Nephrotic Syndrome) without systemic disease, hypocomplementemia, or other serious signs of renal disease. Hearing status is not very well known in MCNS. Our objective was to address this question and to find out remission and relapse periods of the syndrome would affect the hearing of the patients.

METHODS AND PATIENTS

Otologic status of 26 children with clinical MCNS was investigated in relapse and remission periods using audiometry and tympanometry. The pure tones that were obtained at the frequencies 250, 500, 1000, 2000, 4000 and 6000 Hz were noted. Pure tone averages (PTAs) were calculated at 500, 1000, 2000 and 4000 Hz frequencies.

RESULTS

In both remission and relapse periods, PTA of the patients did not change and was 13 dB. The frequency specific pure tone results were not significantly different between the right and left ears of the patients as well as between the remission and relapse periods (p > 0.05). In the relapsing and remission periods, type A tympanogram was encountered in 86.4% and 92.3% of the ears, respectively. Type B tympanogram was encountered in 11.5% and 3.8% of the ears in the relapsing and remission periods, respectively. Type C tympanogram was encountered in 3.8% of the ears both in the relapsing and remission periods. Differences between the tympanometry results were not significant (p > 0.05).

CONCLUSION

MCNS in childhood is not associated with an alteration in the hearing status, both in remission and relapse periods of the disease.

Does electron microscopy change the view of the diagnosis of IgA nephropathy?

Our study is aimed to reveal the frequency and clinical significance of the coincidence of two widely spread entities, e.g. minimal change disease (MCD) and IgA nephropathy (IgAN), claimed to be found in an overwhelming number in some Asian regions. We retrospectively analyzed clinical and histological data from 627 renal biopsies, performed in our department from January 2002 to January 2005 and completed electron microscopy in 112 specimens diagnosed as IgAN. The coincidence of IgAN and MCD was found in 8 patients (7.1%). The coincidence of IgAN and minimal change nephrotic syndrome (MCNS) clinically--especially presence of nephrotic syndrome and the response to drug therapy (with corticosteroids)--behaves as "pure" MCN. Our data from Czech Republic seem to suggest that the combination of IgAN with MCNS can be found relatively frequently not only in Asian patients (as stressed by some authors of Asian origin) but also in European inhabitants. The pathogenesis of the coincidence of IgAN and MCD needs to be elucidated by further studies.