Efficacy of school urinary screening for membranoproliferative glomerulonephritis type 1

Benefits of incorporating urinary protein/creatinine ratio measurement in a school urine screening system: The experience of restructuring the school urinary screening system in Osaka Prefecture, Japan

AIM

School urine screening has been established in several countries of Asia, including Japan, Korea and Taiwan. In Osaka prefectural schools, the urine screening system had some problematic issues including an unclear referral procedure for students with abnormal urinary findings. Therefore, the school urine screening system was reviewed and restructured in 2004. The aim of this study was to assess the improvement in school urine screening through evaluation of the restructured Osaka prefectural school urinary screening system.

METHODS

The Osaka prefectural school urinary screening system was reviewed, mainly considering two points. One was the incorporation of standard urinary protein/creatinine ratio measurement instead of the traditional urine dipstick and urine sediment tests; the second point was that all students requiring further examination were referred to regional nephrologists.

RESULTS

After restructuring, the number of students who were referred to a medical institute for detailed examinations decreased to 10%, although the number of students newly diagnosed with kidney disease and the types of diagnosis did not change. The positive predictive value of screening increased to about 8 times the value before the system restructuring. The reductions enabled students who required further examination to be referred to regional nephrologists and has contributed to a decreased cost for these examinations.

CONCLUSION

Incorporating urinary protein/creatinine ratio measurement into the school urinary screening system, and updating the guiding principles, including referral to nephrology specialists, has enabled the school urinary screening system in Osaka Prefecture to become more efficient and have better cost performance.

Differences in clinical findings, pathology, and outcomes between C3 glomerulonephritis and membranoproliferative glomerulonephritis

BACKGROUND

To clarify the clinical manifestations of pediatric complement component C3 glomerulonephritis (C3GN), we retrospectively evaluated differences in the clinicopathological findings and prognosis between C3GN and immune-complex-mediated membranoproliferative glomerulonephritis (IC-MPGN).

METHODS

Thirty-seven patients diagnosed with "idiopathic MPGN" were enrolled in this retrospective study. The patients were divided into two groups, with Group 1 consisting of 19 patients diagnosed with IC-MPGN and Group 2 consisting of 18 patients diagnosed with C3GN. The clinical findings and the prognosis were investigated for both groups.

RESULTS

Thirteen patients in Group 2 were identified by mandatory annual school screening for urinary abnormalities. The incidence of macro-hematuria and the frequency of low serum C4 values were lower in Group 2 patients than in Group 1 patients. At the time of the second renal biopsy, urinary protein excretion, incidence of hematuria, frequency of low serum C3 values, and scores for mesangial proliferation, glomerular sclerosis, and interstitial fibrosis were higher in Group 2 patients than in Group 1 patients. At the most recent follow-up examination, the number of patients categorized as non-responding or with end-stage renal disease was higher in Group 2 patients than in Group 1 patients.

CONCLUSIONS

Our results suggest that the treatment response and prognosis of patients with C3GN are worse than those of patients with IC-mediated MPGN. Therefore, in the clinical context regarding treatment options and prognosis, it may be useful to classify idiopathic MPGN as C3GN or IC-MPGN. In addition, long-term follow-up of C3GN is necessary.

Renal histological features of school-age children with asymptomatic haematuria and/or proteinuria: a multicenter study

AIM

The risk of asymptomatic haematuria and/or proteinuria development into chronic progressive glomerulonephritis (CPG) is unclear. The indications for renal biopsy and follow-up on these asymptomatic children remain controversial.

METHODS

A multicenter, retrospective study was performed to investigate the renal histological features of school-age children with asymptomatic urine abnormalities.

RESULTS

A total of 112 asymptomatic children's renal biopsy data were studied. Most of the children (71%) received a renal biopsy because of isolated microscopic haematuria (IH), and these children were predominantly (60%) proven to have only mild lesions in the glomeruli. Approximately 30% of the children were biopsied because of asymptomatic proteinuria with or without microscopic haematuria (HP or isolated asymptomatic proteinuria (IP)), and these children were mostly (44-83%) indicated to have CPG, such as IgA nephropathy, focal segmental glomerulosclerosis, and Alport syndrome. The junior high school students had a greater percentage of HP than the primary school children. IgA nephropathy was the most common diagnosis in children who received renal biopsy because of HP.

CONCLUSIONS

Our findings indicate that IP and especially HP may have a high risk of development into CPG. IH, however, has a relatively low risk of severe histological lesions. Thus, IH per se might not be suggested as an indication for early renal biopsy. Long-term follow-up is necessary for these asymptomatic children.

An 11-year-old girl with antineutrophil cytoplasmic antibody-associated glomerulonephritis identified by a school urinary screening program

Antineutrophil cytoplasmic autoantibody-associated glomerulonephritis (GN) in childhood is rare and has a poor prognosis. We report an 11-year-old girl with renal-limited antineutrophil cytoplasmic autoantibody-associated vasculitis. Proteinuria and hematuria were first detected by a school urinary screening (SUS) program. Histopathological examination revealed pauci-immune necrotizing GN. She did not display purpura or peripheral neuropathy. She was diagnosed with antineutrophil cytoplasmic autoantibody-associated GN based on proteinuria, high serum titers of antineutrophil cytoplasmic autoantibodies (ANCAs), and pauci-immune necrotizing GN. The patient was treated with combination therapy, consisting of methylprednisolone and urokinase pulse, prednisolone, mizoribine (MZB), warfarin, and dilazep hydrochloride. At 2 months after treatment, urinary protein excretion was decreased and the hematuria had disappeared, while the serum titer of ANCAs was also decreased. The dose of prednisolone was tapered, and proteinuria and hematuria later disappeared at 9 months after treatment. In conclusion, we reported an 11-year-old girl with renal-limited antineutrophil cytoplasmic autoantibody-associated vasculitis early identified by a SUS program and treated with multi-drug combination therapy including MZB. On the basis of our results, we believe that a SUS programs may be effective for the early identification and treatment of children with renal-limited antineutrophil cytoplasmic autoantibody-associated vasculitis.

Two children with obesity-related glomerulopathy identified in a school urinary screening program

The incidence of obesity-related glomerulopathy (ORG) has increased over the last decade, but there have been few reports on ORG in Japanese children. Reported herein are two children with ORG identified on school urinary screening (SUS). Patient 1 was a 12-year-old boy in whom proteinuria was first detected on SUS. His body mass index (BMI) was 33.8 kg/m(2) and he had hypertension and hyperuricemia. Patient 2, a 10-year-old boy, also had proteinuria identified on SUS. His BMI was 34.8 kg/m(2) , and he had fatty liver, hyperuricemia, and hypercholesterolemia. Both were diagnosed with ORG based on obesity, proteinuria, and renal pathological findings. After treatment, including candesartan, food restriction and physical exercise, urinary protein excretion was decreased in both cases. We believe that such school urinary screening programs may be effective for the early identification and treatment of children with ORG.

Prognostic factors in children with membranoproliferative glomerulonephritis type I

The clinical outcome of patients with membranoproliferative glomerulonephritis (MPGN) varies, with some patients progressing to end-stage renal disease. The aim of this retrospective study was to analyze the initial clinical signs and laboratory test results associated with an MPGN prognosis. The study cohort consisted of 47 patients with idiopathic MPGN Type I treated at the National Institute of Pediatrics, Mexico City, between 1971 and 2001. The median follow-up was 3 years. The three different outcomes of interest were death, renal failure, and nephrotic syndrome. The patients' ages ranged between 4 and 16 years. All patients had different degrees of proteinuria, hyperlipidemia, and microscopic/macroscopic hematuria, and 85.1% of them showed hypocomplementemia. Clinical outcomes varied, however, the most common was nephrotic syndrome, either alone or combined with other syndromes, which accounted for 74.5% of all cases. Fifteen patients died. Treatment with methylprednisolone improved the patient's condition, while the use of chloroquine or cyclophosphamide worsened it. Twenty-two patients had some degree of renal failure; glomerular filtration rate (GFR) levels and albumin values were negatively associated to renal failure, while treatment with methylprednisolone decreased the probability of renal failure. Nephrotic syndrome persisted in 18 patients; hemolytic complement and hemoglobin values were negatively associated with nephrotic syndrome, while macroscopic hematuria was positively associated with it. Signs that suggested a poor prognosis during diagnosis were low GFR, low albumin, low hemolytic complement, and macroscopic hematuria. Treatment with methylprednisolone seemed to improve prognosis, however, this needs to be confirmed with randomized studies.

School urinalysis screening in Korea

Since 1998, by law, all school children in Korea must have an annual urinalysis. The first early morning urine specimen is examined by a simple dipstick method for the detection of proteinuria, haematuria and glucose. If a urine test is positive, a second test is performed by paediatric nephrologists. We analysed urinalysis data of school urinalysis screening. We also analysed the results of clinical data and the renal biopsy findings of patients referred to our medical centre due to abnormal urinalysis result. To date, about five million students have been screened since annual school urinalysis started in January 1998. Among them, isolated proteinuria was about 0.2%, occult blood was about 0.8%, and glucosuria was about 0.07% from January 1998 to December 2004. Among referred patients, renal biopsy was taken in 63.1% of isolated haematuria, 10.5% of isolated proteinuria and 69.9% of haematuria combined with proteinuria. Histopathological findings are IgA nephropathy in 43.8%, mesangial proliferative glomerulonephritis in 38.4%, Henoch-Schönlein nephritis in 2.7%, membranoproliferative glomerulonephritis in 1.6% and lupus nephritis in 0.5%. Alport disease showed 0.6% as a hereditary disease. In conclusion, the school urinalysis screening could detect chronic renal disease in its early stage. Early detection using school urinalysis screening and confirmatory diagnosis by renal biopsy seems to be helpful for assessment of prognosis and intervention of chronic renal disease progression.

Efficacy of urine screening at school: experience in Shanghai, China

To explore the prevalence of hematuria or proteinuria in school children in Shanghai and to evaluate the screening methods, we conducted urine screening in more than 40,000 school children between 2003 and 2005. Children were tested with dipsticks read manually (method A) or dipsticks read by machines (method B) combined with a sulfosalicylic acid test or microscopy. Some children were tested once, and others who had abnormal results in the first screening were tested again 2 weeks later. The prevalence of urine abnormalities in the first screening was more than 5.00% and of the second screening about 1.00%. Either method B or testing two urine samples for each child had higher specificity. As to the direct cost, that of screening twice with method A was lower than just screening once with method B. So using method A to screen twice for each child was not only convenient and economical, but also could reduce the false positive rate effectively. More than 10 months of follow-up diagnosed two cases of IgA nephropathy. Asymptomatic chronic renal diseases in school children could be detected through school urine screening. For Shanghai, China, screening twice using method A might be the best choice.

Long-term follow-up of atypical membranoproliferative glomerulonephritis: are steroids indicated?

Atypical membranoproliferative glomerulonephritis (MPGN) has been reported to have a good prognosis when treated with corticosteroids. However, this recommendation is based on uncontrolled trials and is associated with many complications. The purpose of our study is to determine whether steroid therapy is indicated for atypical MPGN. The cases of seven patients with atypical MPGN are reported in this study. Urinary abnormalities of five of them were detected by urine screening at school, of two because of macrohematuria. Hypocomplementemia was noted in six patients. All but one patient were treated without corticosteroids, and five with angiotensin-converting enzyme inhibitors (ACEI) and/or the Chinese herbal medicine Sairei-to (TJ-114). One patient recovered spontaneously from proteinuria and was therefore not treated, and one who developed severe proteinuria during observation was treated with corticosteroids. After an average follow-up period of 10.0 years, five patients showed normal urinary findings, one had hematuria and one proteinuria. At the most recent follow-up, the renal function of all patients remained within the normal range, and serum C3 had returned to normal levels in five out of six. These findings suggest that the indication of steroid therapy for atypical MPGN should be re-examined, since most of the patients with atypical MPGN seem to have an excellent prognosis without treatment with corticosteroids.

Myeloid-related protein 8 expression on macrophages is a useful prognostic marker for renal dysfunction in children with MPGN type 1

BACKGROUND

To clarify the role of subclasses of macrophages in chronic glomerulonephritis, we evaluated the relationship between myeloid-related protein 8 (MRP8) and MRP14 expression on macrophages and the progression of membranoproliferative glomerulonephritis (MPGN).

METHODS

We enrolled 35 patients with MPGN type 1 who had a normal creatinine clearance at the time of their first renal biopsy and divided them into 2 groups based on clinical status at the time of their most recent examination: 12 patients with normal urine test results and 12 patients with minor urinary abnormalities at the latest observation (group 1) and 7 patients with persistent nephropathy and 4 patients with renal insufficiency (group 2). The first and second renal biopsy findings and MRP8 and MRP14 expression on macrophages were investigated in both groups.

RESULTS

Mean scores for positive glomerular and interstitial MRP8 and CD68 staining at the time of the first and second biopsies were significantly higher in group 2 than group 1. At the time of the second biopsy, mean scores for interstitial CD68-positive (CD68 +) staining were higher in group 2 than group 1. Mean scores for glomerular and interstitial MRP8 + and CD68 + staining at the time of the first biopsy correlated with the chronicity index at the time of second biopsy in both groups.

CONCLUSION

Results suggest that MRP8 expression on macrophages in glomeruli and interstitial lesions at the first biopsy can be a useful prognostic marker for renal dysfunction in children with MPGN type 1.

Long-term follow-up of diffuse membranoproliferative glomerulonephritis type I

In Japan, the school urinary screening system facilitates early detection and treatment of membranoproliferative glomerulonephritis (MPGN) in childhood. The present study investigated the long-term prognosis in 19 children with diffuse MPGN type I who received steroid therapy. Before signs of glomerulonephritis were confirmed, all patients displayed abnormal urinalysis results, predominantly through school urinary screening. Treatment comprised a regimen of alternate-day prednisolone after steroid pulse or cyclophosphamide therapy, and follow-up was continued for 10-24 years. Excluding 1 patient on short-term therapy, 18 patients received long-term alternate-day prednisolone therapy for 4-12 years. Treatment was discontinued when amelioration was confirmed on renal biopsy. As of the last observation, urinary abnormalities and hypocomplementemia had disappeared in 15 patients, while mild proteinuria without hypocomplementemia remained in 4 patients. No patients required hemodialysis. Moreover, no severe adverse effects attributable to treatment were identified other than mild short stature. Early detection and therapy using pulse methylprednisolone followed by alternate-day prednisolone was thus confirmed as safe and useful for treating diffuse MPGN type I.

Predicting the prognosis of renal dysfunction by renal expression of α-smooth muscle actin in children with MPGN type 1

BACKGROUND

To clarify whether renal alpha-smooth muscle actin (alpha-SMA)-positive cell and macrophage accumulation can predict the prognosis of renal dysfunction, we evaluated them by means of multivariate analysis and compared them with other clinical predictors in patients with membranoproliferative glomerulonephritis (MPGN) type 1 with normal renal function.

METHODS

We enrolled 35 patients with MPGN type 1 who had normal creatinine clearance at the time of renal biopsy. These patients were divided into 2 groups based on clinical status at the last examination. Group 1 consisted of 12 patients with normal urine and 12 patients with minor urinary abnormalities at the latest observation, whereas group 2 consisted of 7 patients with persistent nephropathy and 4 patients with renal insufficiency. The first and second renal biopsy findings, including alpha-SMA and CD68-positive staining, were investigated for both groups.

RESULTS

Mean scores for glomerular and interstitial alpha-SMA staining in group 2 were significantly higher than those in group 1. At the second biopsy, mean scores for interstitial CD68-positive staining in group 2 were higher than those in group 1. Mean scores for glomerular and interstitial alpha-SMA at the first biopsy correlated with the chronicity index at the second biopsy in both groups.

CONCLUSION

Our results suggest that glomerular and interstitial alpha-SMA expression at the first biopsy can predict the prognosis of children with MPGN type 1.