Thin basement membrane nephropathy and IgA glomerulonephritis: Can they be distinguished without renal biopsy?

BACKGROUND: Thin basement membrane nephropathy (TBMN) and IgA glomerulonephritis (IgA gn) are the most common primary glomerular conditions diagnosed on renal biopsy, performed for microscopic haematuria or microscopic haematuria with proteinuria. While up to 50% of patients with IgA gn will develop chronic renal failure, most patients with TBMN enjoy an excellent prognosis. Because TBMN is estimated to occur in up to 1% of the general population, differentiation between the two conditions without resort to renal biopsy is desirable. METHODS: This retrospective analysis of 248 patients diagnosed on renal biopsy as having either TBMN or IgA gn, sought to identify clinical or biochemical factors which would have enabled confident differentiation between the two conditions to be made without resort to renal biopsy. RESULTS: No single clinical or pathological variable adequately discriminated between the two conditions. Impaired renal function and heavy proteinuria were highly specific for IgA gn but lacked sensitivity in differentiating from TBMN. Isolated microscopic haematuria (IMH) was a more common finding in patients diagnosed with TBMN but, as a discriminator between TBMN and IgA gn, lacked sufficient specificity. However, if assumptions were made based on the differing incidence of a positive family history between IgA gn and TBMN, then specificity of >99% could be achieved. CONCLUSION: TBMN and IgA gn cannot be distinguished on the basis of clinical or pathological variables alone. However, in patients with IMH and a positive family history of either IMH or biopsy-proven TBMN, there is usually no need for renal biopsy.     

Repeat renal biopsy in children with IgA nephropathy

Serial renal biopsy findings in 61 children with IgA nephropathy were correlated with their clinical course. At the time of the second biopsy, 23 patients showed clinical remission defined as complete disappearance of proteinuria and hematuria with normal renal function while 38 had persistent urinary abnormalities with normal renal function at the second biopsy. There were no differences between the two groups with regard to initial clinical findings and pathologic findings of the initial renal biopsy. The second biopsy of patients with clinical remission showed improvement of the glomerular changes on light microscopy, disappearance or diminution of IgA deposits in the mesangium and decrease of electron-dense deposits, whereas the second biopsy of patients with persistent urinary abnormalities showed progression of glomerular changes on light microscopy, persistence of mesangial IgA deposits and persistence of electron-dense deposits. Our study results show the importance of repeat renal biopsy in children with IgA nephropathy with persistent urinary abnormalities, as a progression of glomerular changes is common in these patients. These observations suggest that the deposition of IgA in the mesangium may be responsible for the glomerular damage in children with IgA nephropathy.     

Clinical value of renal biopsy in patients with asymptomatic microscopic hematuria with and without low-grade proteinuria

BACKGROUND: The decision whether to perform renal biopsy on patients with persistent asymptomatic microscopic hematuria (AMH) with and without low-grade proteinuria (LGP) remains controversial as, although often diagnostic, the information gained seldom alters clinical management. Our study investigates the clinical value of renal biopsy in patients with isolated AMH versus those with AMH and LGP. METHODS: Between 1996 and 2002, we identified 89 patients with AMH and 46 with AMH and LGP. The patients were asymptomatic, free from systemic illness, had a sterile urine, normal serum creatinine, normal renal and bladder ultrasound, less than 2.5 g proteinuria/day, underwent successful renal biopsy and were followed-up for a mean period of 46 +/- 12 months. RESULTS: In patients with isolated AMH, thin basement membrane nephropathy (TBMN) was diagnosed in 43%, IgA nephropathy in 20%, minor abnormalities in 19% and normal biopsies in 18%. In patients with AMH and LGP, IgA nephropathy was diagnosed in 46%, other major nephropathies in 26%, minor abnormalities in 17%, TBMN in 7% and normal biopsies in 4%. At follow-up, 32% of AMH patients and 38% of AMH with LGP patients had a GFR of less than 90 ml/min and 36% and 56%, respectively were hypertensive. CONCLUSIONS: The results support the current consensus that routine renal biopsy is not indicated for isolated AMH but suggest that biopsy is indicated for AMH and LGP identifying major and potentially progressive nephropathies in 70% of patients, who should be managed by specialist nephrologists.     

Acute poststreptococcal glomerulonephritis superimposed on IgA nephropathy

Superimposition of poststreptococcal glomerulonephritis (PSGN) on the course of IgA nephropathy (IgAN) is uncommon. A case of PSGN during IgA nephropathy is presented. A 30-year-old man who had alternating gross and microscopic hematuria for 7 months underwent a renal biopsy. The first renal biopsy revealed IgAN with mesangial deposits of IgA and C3. Two months later, the patient suffered generalized edema, proteinuria, hematuria, an increased ASO titer and a decreased C3 level. A second renal biopsy revealed diffuse endocapillary proliferative glomerulonephritis with epimembranous hump-like electron-dense deposits of C3, but the original mesangial IgA deposits had disappeared. A diagnosis of acute PSGN was indicated. Two months after the onset of acute nephritic syndrome, the patient remained asymptomatic, except for microscopic hematuria and proteinuria. Some cases with persistent proteinuria or hematuria after PSGN are probably related to preexisting IgAN.     

Signs and symptoms of thin basement membrane nephropathy: a prospective regional study on primary glomerular disease-The Limburg Renal Registry

BACKGROUND: To chart the epidemiology of primary glomerular disease by means of a prospective regional study in the southern part of The Netherlands. METHODS: Experienced renal technicians collected renal biopsies, blood, and 24-hour urine samples at the bed site in each of the participating hospitals. The material was processed and analyzed at the University Hospital Maastricht. Analysis included light microscopy, immunohistochemistry, and electron microscopy of the biopsies as well as serologic and chemical analysis. RESULTS: Primary IgA nephropathy (IgAN), membranous glomerulopathy, antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis and thin basement membrane nephropathy (TBMN) are the most common primary glomerular diseases in this order of sequence. Our data show the clinical and histologic phenotype of TBMN to be diverse: the vast majority of TBMN has chronic microscopic hematuria, frequently associated with hypertension in late middle age; about 15% of TBMN has in addition substantial proteinuria which is associated in the majority of cases with the lesions of focal segmental glomerulosclerosis (FSGS). In 5% of TBMN a nephrotic syndrome is observed, occasionally associated with FSGS tip lesions. CONCLUSION: These results support the notion that TBMN is a disease of genetic heterogeneity; it is not a benign renal condition in a substantial number of patients, particularly those in late middle age.     

Histological differences in new-onset IgA nephropathy between children and adults.

BACKGROUND: It is suggested that IgA nephropathy (IgAN) manifests differently in children vs adults on the basis of biopsy findings. However, this has been difficult to establish owing to the uncertainty of the timing of disease onset in adult IgAN. We addressed this question by comparing both histology and leucocyte accumulation in biopsies of recently diagnosed childhood and adult IgAN. METHODS: Biopsies taken within 2 years from the onset of renal abnormalities in 33 childhood (10 +/- 3 years of age) and 38 adult (35 +/- 6 years) cases of IgAN were examined for histological changes (cellularity in mesangial, endocapillary and extracapillary areas, matrix expansion, adhesions/crescents and interstitial damage), glomerular deposition of immunoglobulin and complement, and the presence of macrophages, activated macrophages and T cells by immunohistochemistry. RESULTS: Glomerular hypercellularity owing to increased cells in mesangial area was prominent in paediatric IgAN and significantly greater than in adult IgAN. In contrast, glomerular matrix expansion, crescent formation and interstitial damage were more severe in adults compared to paediatric IgAN. Indeed, glomerular hypercellularity correlated with proteinuria in paediatric but not in adult IgAN, whereas glomerular matrix correlated with proteinuria and renal function in adult but not in paediatric IgAN. The degree of C3c deposition was significantly greater in paediatric IgAN, while deposition of fibrinogen was greater in adult IgAN. Glomerular and interstitial CD68+ macrophages and a subset of sialoadhesin (Sn)+ activated macrophages were identified in both paediatric and adult IgAN, being significantly greater in number in adult IgAN. Glomerular leucocyte infiltration correlated with proteinuria while interstitial leucocyte infiltration correlated with interstitial damage in both groups. However, only the subset of Sn+ macrophages gave a significant correlation with renal function, glomerular hypercellularity and glomerular matrix. CONCLUSIONS: This study has demonstrated significant differences in the early glomerular lesions of IgAN in children vs adults. Furthermore, Sn+ activated macrophages are implicated in the pathogenesis of IgAN in both patient groups. The prognostic significance of these findings warrants further study.     

Clinical predictors of non-diabetic renal disease in patients with non-insulin dependent diabetes mellitus

Background: Several studies had suggested that non-diabetic renal disease (NDRD) was common among non-insulin dependent diabetes mellitus (NIDDM) patients with renal involvement. Methods: We prospectively studied the prevalence of NDRD among a Chinese NIDDM population. Renal biopsy specimens were evaluated with light-, immunohistological and electron-microscopy. The cohort consisted of 51 patients who had NIDDM and proteinuria >1 g/24 h. Results: Patients with both isolated diabetic nephropathy (DN, n=34) and NDRD (n=17) had comparable duration of DM, creatinine clearance, serum creatinine, albumin and glycosylated haemoglobin levels, as well as incidences of retinopathy, neuropathy and hypertension. Significantly more patients with NDRD had microscopic haematuria (P=0.043) or non-nephrotic proteinuria (P=0.004). IgA nephropathy accounted for 59% of the NDRD identified. Conclusions: In this study, microscopic haematuria and non-nephrotic proteinuria predicted the presence of NDRD among NIDDM patients presenting with renal disease.     

IgA nephropathy is not a rare disease in the United Kingdom

A retrospective analysis of all renal biopsies performed in the Grampian Region of Scotland during 1977-1980 revealed that IgA nephropathy was the most frequently encountered glomerular lesion. The commonest indications for renal biopsy were the presence of asymptomatic urinary abnormalities (90/184; 48.9%) especially asymptomatic haematuria (42/184; 22.8%). A histological diagnosis was made in 36 of the 42 patients presenting with asymptomatic haematuria (85.7%); 16 of the 26 cases of IgA nephropathy presented in this way. Overall, IgA nephropathy was detected in 14.1% of all biopsies and accounted for 21.8% of primary glomerular diseases. This study indicates that IgA nephropathy is apparently more common in Grampian than elsewhere in the United Kingdom. However, it is suggested that this does not represent a true variation in the prevalence of the condition; IgA nephropathy is probably a common cause of haematuria in the United Kingdom.     

Polymorphism of the ACE gene in Henoch-Schönlein purpura nephritis

Individuals with IgA nephropathy (IgAN) who are homozygous for the deletion (D) polymorphism of the gene for angiotensin converting enzyme (ACE) are reported to be at increased risk of progressive renal damage. Since IgAN and Henoch-Schönlein purpura with associated nephritis (HSPN) share a common aetiology, we have investigated this influence in 31 children with HSPN. The distribution of genotypes was as follows: II: 4, ID: 17 and DD: 10 patients. Median length of follow-up was 4.5 years (range 0.5–15.75 years). Severe onset with nephrotic oedema and crescent formation on renal biopsy was seen in 10 of 17 patients with ID genotype and 5 of 10 patients with DD genotype. In the ID group, 2 patients have undergone renal transplantation and 4 have persistent proteinuria 4, 7, 9 and 10 years after presentation. One patient in the DD group has been transplanted and 1 patient has proteinuria and a reduced glomerular filtration rate 5 years after initial presentation. All other patients have either made a complete recovery or have microscopic haematuria alone. These results do not support an association between disease severity and DD genotype in children with HSPN; however larger studies are required to confirm this.     

Frequency of renal diseases and clinical indication for renal biopsy in children (Report of the Italian National Registry of Renal Biopsies in Children)

Background. Children's renal biopsy data were gathered for 3 consecutive years (1992-1994) by the Group of Renal Immunopathology of the Italian Society of Pediatric Nephrology, which opened a paediatric section of the Italian Registry of Renal Biopsies. Materials. The Registry recorded the histological diagnosis and the clinical data at renal biopsy of 432 children ⩽15 years old (mean age 8.96±3.7 years). Results. The most common glomerulonephritis (GN) at renal biopsy was idiopathic IgAGN (18.8%) and the most frequent secondary GN was Henoch-Schonlein purpura (HSP) nephritis (11.6%). Minimal-change disease (MCD) accounted for 11.6%, focal and segmental sclerosis (FSG) 8.5%, mesangial proliferative GN (MPGN) 9.5%, membranoproliferative GN 5.5%, and thin-membrane disease 5%. Lupus nephritis was diagnosed in 5% and Alport's GN in 3.9% of the cases. The annual incidence of primary GN in Italian children was 11.1 cases per million children population (p.m.c.p.), IgAN accounting for 3.1 cases, MCD 2.3, and HSP nephritis 1.9 cases p.m.c.p. respectively. Italian children underwent renal biopsy because of isolated microscopic haematuria in 19.3% of the cases, non-nephrotic proteinuria with or without microscopic haematuria in 31.2%, and nephrotic-range proteinuria in 34.2%, less frequently (15.3%) because of acute or chronic renal failure. Children with persistent isolated microscopic haematuria had most frequently IgAN (34.9%) or thin-membrane disease (25.3%), while those with non-nephrotic proteinuria had IgAN (30.4%) and HSP nephritis (23%). In cases with nephrotic proteinuria renal biopsy showed MCD in 34.5% of the cases, FSG in 16.9%, and MPGN in 12.2%. When renal biopsy was performed in chronic renal failure chronic interstitial renal disease was detected in 62.5% of the cases. Conclusions. This National Registry provides data on the indications for performing renal biopsy in Italian children and on the frequency and annual incidence of histological lesions detected. IgAN, primary or related to HSP, was the most common nephritis in Italian children undergoing renal biopsy.     

Thin basement membrane nephropathy associated with other glomerular diseases

Many reports confirm that thin basement membrane nephropathy (TBMN) commonly occurs together with other glomerular diseases such as minimal change glomerulonephritis, diabetes, membranous nephropathy, immunoglobulin (Ig)A glomerulonephritis, and focal segmental glomerulosclerosis. We postulate 3 explanations for these observations. The association of minimal change glomerulonephritis with TBMN probably is artifactual whereas the association with diabetes and membranous glomerulonephritis probably is coincidental. However, the link between TBMN and IgA disease and focal segmental glomerulosclerosis may be pathogenetic. Clinical evidence indicates that the presence of an associated glomerulopathy significantly worsens the prognosis of TBMN. Thus, patients with TBMN and another glomerular lesion usually have more marked proteinuria, and are more likely to have hypertension and renal insufficiency. The frequency of another glomerulopathy in patients with TBMN means that all patients in whom TBMN is suspected but who have heavy proteinuria or renal insufficiency should undergo a renal biopsy examination. However, there is no evidence that TBMN alters the prognosis of another glomerulopathy, and, in particular, patients with TBMN and IgA disease do not have different clinical features or a worse prognosis than those with IgA disease alone.     

The product of duration and amount of proteinuria (proteinuria index) is a possible marker for glomerular and tubulointerstitial damage in IgA nephropathy

BACKGROUND/AIMS: IgA nephropathy (IgAN) is one of the major causes for chronic renal failure (CRF). Presence of massive proteinuria, hypertension, increased serum creatinine level and sclerotic histopathological changes of the glomerulus are known to be determinants for the progression of CRF. However, the relationships between duration of proteinuria/hematuria and histopathological changes, which may be correlated with the renal prognosis, have not been clarified. METHODS: A cross-sectional, univariate analysis of clinical parameters on the four glomerular and three tubulointerstitial histopathological grades in 57 untreated biopsy-proven IgAN patients (M/F = 32/25) was performed. RESULTS: The age at the time of renal biopsy (35.2 +/- 13.0 years; mean +/- SD), average duration of proteinuria (5.3 +/- 5.8 years), mean urinary protein excretion (0.99 +/- 1.22 g/day), serum creatinine (Cr 0.97 +/- 0.28 mg/dl), Cr clearance (Ccr 75.5 +/- 29.4 ml/min), and blood urea nitrogen (BUN 15.4 +/- 3.9 mg/dl) were well correlated with both histopathological grades. The product of duration (years) and urinary protein excretion (g/day) at the time of renal biopsy was more significantly correlated with glomerular and tubulointerstitial histopathological grades and serum Cr. CONCLUSION: The natural course of IgAN is steadily progressive depending on the duration and amount of proteinuria. The product of these two factors (proteinuria index) may be a useful predictor for glomerular and interstitial histopathological changes and the fate of renal function in IgAN.     

Clinicopathological correlations in nephrotic children with IgA nephropathy

Background. The prognostic significance of nephrotic syndrome (NS) in children with IgA nephropathy (IgAN) is unclear. Methods. NS was found in eight children with IgAN (mean onset age, 9.3 years). The clinicopathological findings of these eight children were investigated. Results. Five patients presented with macroscopic hematuria, while the remaining three were discovered in a school urinary screening program or by chance urinalysis. Six patients developed NS at the onset, and two developed NS later in the course of IgAN. All patients were treated with corticosteroids. At the end of follow-up, heavy proteinuria persisted in four children, one of whom had renal dysfunction at the onset of NS and developed end-stage renal failure, and two of whom developed NS after the onset of IgAN. Proteinuria decreased to less than 1 g/day 3 months after NS in four patients, two of whom showed disappearance of proteinuria afterward. Renal biopsy specimens revealed mesangial proliferation and crescent formation in all patients. The degree of persisting proteinuria was correlated with the presence of glomerular sclerosis, fibrous crescents, tubulo-interstitial changes on light microscopy, and depositions of C3 on immunofluorescence microscopy. Conclusions. Children who developed NS after the onset of IgAN developed renal dysfunction; the prognosis of those who showed chronic histopathological changes on renal biopsy specimens was poor, even in these young children. Received: April 17, 2000 / Accepted: July 4, 2000     

Persistent dipstick haematuria following renal transplantation

Despite widespread testing for dipstick haematuria following renal transplantation, there are no published series describing the prevalence and possible causes of this complication in an adult population. A cross-sectional study of 640 renal transplant recipients under review at our follow-up clinic was performed. Persistent haematuria was defined as a minimum of 1+ of blood on urinalysis stick testing detected at not fewer than 75% of clinic visits since its onset, or since the start of routine testing, present over a period of at least 4 weeks. The prevalence of persistent dipstick haematuria was 13.3%. Median serum creatinine was higher in patients with persistent haematuria but age, gender and length of time since transplantation were not significantly different. Potential explanations for persistent haematuria in 21 of 85 affected patients were chronic infection, ureteric stent without chronic infection, regular or intermittent self-catheterization, persistent menstrual bleeding, anticoagulant therapy, graft calculus, and allograft renal cell carcinoma. Recurrent or de novo glomerular disease was confirmed by graft biopsy in 10 of 85 patients. Among the 41 recipients whose original cause of renal failure was IgA nephropathy (IgAN), the prevalence of persistent haematuria was 31.7% compared with 12% in the remaining patients (relative risk 2.6, 95% CI: 1.6-4.3). Persistent haematuria in IgAN patients was not associated with gender, age or time since transplantation. After 29 months of follow-up, 20% of patients with haematuria had progressed to graft failure or death compared with 11.6% of the unaffected group (p = 0.029). However, despite the association with earlier graft failure, haematuria did not predict this endpoint independently of renal function.     

Hematuria and proteinuria in a mass school urine screening test

A total of 1,044 school children identified with hematuria and/or proteinuria during a mass school urine screening test were referred to pediatric nephrologists at 13 hospitals in Korea. These children had isolated hematuria (IH) (60.1%), isolated proteinuria (IP) (26.4%: transient, 19.6%; orthostatic, 4.9%; persistent, 1.9%) or combined hematuria and proteinuria (CHP) (13.5%). The patients history, physical examination, laboratory tests, kidney ultrasound and Doppler ultrasonography were obtained. Renal biopsies were performed on 113 children who showed severe proteinuria, hypertension, abnormal renal function, family history of chronic renal disease, systemic diseases or persistent hematuria and/or proteinuria for more than 12 months. IgA nephropathy (IgAN), thin basement membrane nephropathy (TBMN), membranoproliferative glomerulonephritis (MPGN), focal segmental glomerulosclerosis (FSGS), other GN, Alport syndrome and lupus nephritis were detected. IgAN and TBMN were the most common causes in the CHP group and IH group, respectively. Abnormal findings on the renal ultrasound with or without Doppler ultrasonography were noted in 147 cases (suspected nutcracker phenomenon, 65; increased parenchymal echogenicity, 40; hydronephrosis, 15). This study showed that the use of a mass school urine screening program can detect chronic renal disease in its early stage and recommends that more attention should be paid to identifying those children with CHP and massive proteinuria. A school urine screening program can detect chronic renal disease in its early stage. When mass screening is used, the initial aggressive diagnostic procedures such as renal biopsy are not needed. In addition, a regular follow-up for those children with IH and IP is certainly warranted.     

Immunoglobulin a nephropathy: Pathological markers of renal survival in paediatric patients

IgA nephropathy (IgAN) is one of the leading causes of glomerulonephritis characterized by the findings of IgA and IgG immune deposits in the mesangium of kidney biopsies from patients with persistent microscopic haematuria. IgAN is frequently detected among adolescents and young adults. IgAN presents a highly variable course that includes a spectrum from a very mild disease to end‐stage renal disease (ESRD). There are several clinical and histological factors that strongly determined the final outcome of patients with IgAN. Pathological variables associated with unfavorable outcomes are mesangial hypercellularity, segmental glomerulosclerosis, endocapillary hypercellularity and interstitial fibrosis/tubular atrophy, according to the Oxford classification. Moreover, some studies also suggest a role for complement activation in the pathogenesis of IgAN. In this regard, staining for C4d may be an independent risk factor for the development of ESRD in IgAN. Despite the growing number of studies assessing IgAN risk factors, this kind of investigation in paediatric patients is still very limited. The aim of this article is to revise pathological markers related to deterioration of renal function in paediatric patients with IgAN, particularly those that can independently affect renal survival.     

伴足细胞尿的IgA肾病的临床病理特征

目的 探讨伴足细胞尿的IgA肾病（IgAN）患者的临床病理特点。方法 入选IgAN患者36例,其中男性20例,女性16例,平均年龄（34．1±12．2）岁。10例健康志愿者为健康对照。足细胞排泄的定量检测采用尿沉渣涂片免疫组化染色直接计数。进行尿液足细胞排泄与肾脏病理的相关分析。结果 （1）IgAN患者尿细胞podocalyxin阳性率为61%,健康对照组为0（P＜0．05）。（2）与非大量蛋白尿（＜3．0 g/24 h）IgAN患者比较,大量蛋白尿（≥3．0 g/24 h）IgAN患者的尿液足细胞检测阳性率、尿液足细胞排泄数、足细胞与尿肌酐的比值以及足细胞占尿液小管上皮细胞的百分数均显著增高（P＜0．05）。IgAN患者足细胞排泄水平与蛋白尿水平呈正相关（r=0．446,P=0．007）。（3）与无足细胞尿的患者比较,伴足细胞尿的IgAN患者的蛋白尿水平显著增高,血浆白蛋白水平显著降低,肾小管上皮细胞与尿肌酐的比值亦显著增高（P＜0．05）。但伴与不伴足细胞尿的2组IgAN患者在年龄、性别、血压、Scr、血红蛋白水平以及血浆脂质代谢等方面差异均无统计学意义（P＞0．05）。（4）尿足细胞的排泄与细胞新月体或细胞纤维性新月体、小球血管襻腔狭窄和足突广泛融合病变有关,而与系膜、内皮细胞病变及局灶基底膜增厚无关。伴足细胞尿的患者肾小球和肾小管间质纤维化更明显（P＜0．05）。伴有新月体的患者其尿液足细胞排泄水平、尿液上皮细胞和管型的排泄均增加（P＜0．05）。结论 足细胞尿不仅是IgAN患者肾小球损伤的结果,也是IgAN患者活动性损伤的指标。足细胞尿排泄的水平与蛋门尿水平呈正相关,与肾脏病理类型也有一定的关系。     

Thin basement membrane nephropathy associated with minimal change disease in a 15-year-old boy

Thin basement membrane nephropathy (TBMN) is characterized clinically by persistent hematuria, minimal proteinuria, normal renal function, another family member with hematuria, and a benign course. Especially in childhood TBMN, proteinuria of any degree is reported to be uncommon. We report on a boy with benign familial hematuria found by urinary screening at 3 years of age who presented with nephrotic syndrome (NS) at 15 years of age. His renal histology showed TBMN associated with minimal change disease (MCD). Treatment with corticosteroid resulted in complete remission of NS in a short period of time, while isolated hematuria persisted during the follow-up period despite this therapy. We speculate, therefore, that the nephrotic range proteinuria is not due to TBMN but rather is the manifestation of associated MCD. Several cases of TBMN with NS have been reported in adults, but it has not yet been reported in children in the literature. To our knowledge, this is the first case of childhood TBMN associated with NS resulting from coincidental MCD.     

Immunoglobulin A nephropathy complicating ulcerative colitis

Ulcerative colitis is rarely associated with immunoglobulin A nephropathy (IgAN). The development of IgA nephropathy complicates further the clinical course of patients with ulcerative colitis. A 72-year old man with a 30-year history of ulcerative colitis requiring colectomy and modest renal insufficiency secondary to complications of nephrolithiasis and renal artery stenosis developed glomerular hematuria, proteinuria and progressive renal failure. Percutaneous kidney biopsy revealed IgAN with extensive glomerular and interstitial sclerotic changes. After resection of a chronically infected ileo-rectal pouch, renal function improved, while hematuria and proteinuria gradually disappeared without specific treatment of the IgAN. The manifestations of IgAN complicating ulcerative colitis can be improved with effective treatment of the bowel disease even when there are extensive sclerotic changes in the kidneys.     

Changes in the glomerular density and size in serial renal biopsies during the progression of IgA nephropathy

BACKGROUND: Although there have been many reports on clinicopathological studies of IgAN, information is limited regarding the long-term evolution of a renal histology by analysing samples obtained not only during normal renal function but also after the establishment of an impaired renal function in individual patients. METHODS: We analysed 18 pairs of serial biopsy specimens from 18 patients with IgA nephropathy (IgAN) in whom the first renal biopsies were performed while normal renal function was still present and the second biopsies were performed after impaired renal function was established. The glomerular density (GD, number of non-sclerotic glomeruli per renal cortical area) and mean glomerular area (MGA) were compared between the specimens. RESULTS: The GD at the first biopsy of each patient showed a striking variation (1.3-5.2/mm(2)). As a whole, the GD decreased (2.7 +/- 1.2 versus 1.4 +/- 0.7/mm(2)) and the MGA increased (19.7 +/- 4.2 x 10(3) versus 23.5 +/- 4.5 x 10(3) mm(2)) between the biopsies, respectively. The degrees of change in the GD and the MGA between the biopsies differed remarkably among the individuals. The patients with a high GD in the first biopsy progressed slowly, but showed a large decrease in the GD and a large increase in the MGA between the biopsies, respectively. The patients with a low GD, who already had enlarged glomeruli in the first biopsy, tended to progress rapidly. CONCLUSIONS: Our results suggest that both the nephron number and glomerular enlargement play a crucial role as compensatory mechanisms against renal functional deterioration in progressive IgAN. The GD during normal renal function may determine these compensatory changes and thereby make it possible to predict the renal prognosis in IgAN.