Clinicopathological features and the prognosis of IgA nephropathy in Japanese children on long-term observation

Childhood-onset IgA nephropathy: is long-term recovery possible?

BACKGROUND

IgA nephropathy (IgAN) is the most common glomerulonephritis worldwide. While studies have primarily focused on identifying risk factors for disease progression, very few data exist on the likelihood of achieving complete recovery from the disease.

METHODS

We conducted a single-center retrospective study on all consecutive patients with biopsy-proven IgAN diagnosed between 1986 and 2018 in our pediatric center. Biopsies were classified according to the MEST-C Oxford classification score. "Complete clinical remission" was defined as the absence of proteinuria, hematuria, and hypertension in patients with normal kidney function who had been off therapy for more than 2 years.

RESULTS

Overall, 153 patients with age at onset of 10.6 ± 4 years were enrolled in the study. Of these, 41 achieved "complete clinical remission." The estimated probability of complete clinical remission at 10 years was 43% (95%CI 33-54). However, seven patients relapsed within 10 years. Multivariable analysis showed that higher age at onset (HR 0.89, 95%CI 0.80-0.98, p = 0.017) and segmental glomerulosclerosis lesions (HR 0.28, 95%CI 0.10-0.79, p = 0.017) decreased significantly the chances of achieving complete clinical remission. Immunosuppressive therapy was not significantly associated with clinical outcomes.

CONCLUSIONS

Approximately one-third of patients with pediatric-onset IgAN achieve prolonged remission, in particular, very young children at disease onset without sclerotic glomerular lesions. Longer term follow-up is needed to assess if these patients have achieved permanent remission.

Cost-Effectiveness of School Urinary Screening for Early Detection of IgA Nephropathy in Japan

Importance

The evidence for and against screening for chronic kidney disease in youths who are asymptomatic is inconsistent worldwide. Japan has been conducting urinary screening in students for 50 years, allowing for a full economic evaluation that includes the clinical benefits of early detection and intervention for chronic kidney disease.

Objectives

To evaluate the clinical effectiveness and cost-effectiveness of school urinary screening in Japan, with a focus on the benefits of the early detection and intervention for IgA nephropathy, and to explore key points in the model that are associated with the cost-effectiveness of the school urinary screening program.

Design, Setting, and Participants

This economic evaluation with a cost-effectiveness analysis used a computer-simulated Markov model from the health care payer's perspective among a hypothetical cohort of 1 000 000 youths aged 6 years in first grade in Japanese elementary schools, followed up through junior and high school. The time horizon was lifetime. Costs and clinical outcomes were discounted at a rate of 2% per year. Costs were calculated in Japanese yen and 2020 US dollars (¥107 = US $1).

Interventions

School urinary screening for IgA nephropathy was compared with no screening.

Main Outcomes and Measures

Outcomes were costs and quality-adjusted life-years (QALYs). Cost-effectiveness was determined by evaluating whether the incremental cost-effectiveness ratio (ICER) per QALY gained remained less than ¥7 500 000 (US $70 093).

Results

In the base case analysis, the ICER was ¥4 186 642 (US $39 127)/QALY, which was less than the threshold. There were 60.3 patients/1 000 000 patients in the no-screening strategy and 31.7 patients/1 000 000 patients in the screening strategy with an end-stage kidney disease. Cost-effectiveness improved as the number of screenings decreased (screening frequency <3 times: incremental cost, -¥75 [US $0.7]; incremental QALY, 0.00025; ICER, dominant), but the number of patients with end-stage kidney disease due to IgA nephropathy increased (40.9 patients/1 000 000 patients). Assuming the disutility due to false positives had a significant impact on the analysis; assuming a disutility of 0.01 or more, the population with no IgA nephropathy had an ICER greater than the threshold (¥8 304 093 [US $77 608]/QALY).

Conclusions and Relevance

This study found that Japanese school urinary screening was cost-effective, suggesting that it may be worthy of resource allocation. Key factors associated with cost-effectiveness were screening cost, the probability of incident detection outside of screening, and IgA nephropathy incidence, which may provide clues to decision-makers in other countries when evaluating the program in their own context.

IgA nephropathy

IgA nephropathy (IgAN), the most prevalent primary glomerulonephritis worldwide, carries a considerable lifetime risk of kidney failure. Clinical manifestations of IgAN vary from asymptomatic with microscopic or intermittent macroscopic haematuria and stable kidney function to rapidly progressive glomerulonephritis. IgAN has been proposed to develop through a 'four-hit' process, commencing with overproduction and increased systemic presence of poorly O-glycosylated galactose-deficient IgA1 (Gd-IgA1), followed by recognition of Gd-IgA1 by antiglycan autoantibodies, aggregation of Gd-IgA1 and formation of polymeric IgA1 immune complexes and, lastly, deposition of these immune complexes in the glomerular mesangium, leading to kidney inflammation and scarring. IgAN can only be diagnosed by kidney biopsy. Extensive, optimized supportive care is the mainstay of therapy for patients with IgAN. For those at high risk of disease progression, the 2021 KDIGO Clinical Practice Guideline suggests considering a 6-month course of systemic corticosteroid therapy; however, the efficacy of systemic steroid treatment is under debate and serious adverse effects are common. Advances in understanding the pathophysiology of IgAN have led to clinical trials of novel targeted therapies with acceptable safety profiles, including SGLT2 inhibitors, endothelin receptor blockers, targeted-release budesonide, B cell proliferation and differentiation inhibitors, as well as blockade of complement components.

Differences in response to treatment in children with severe IgA nephropathy according to patient age

AIM

To clarify whether the response to treatment of IgA nephropathy (IgAN) differs depending on patient age, we examined the response to treatment according to age of onset in children with IgAN.

METHODS

We collected data for 44 children with severe IgAN. The children were retrospectively divided into three groups based on their age at disease onset. Group 1 consisted of 24 children under 11 years old, group 2 consisted of 9 children aged 12 to 13 years, and group 3 consisted of 11 children aged over 14 years old. The clinical features and prognosis were analyzed for each group.

RESULTS

The urinary protein excretion and serum IgA values in group 3 were higher than those in groups 1 and 2 at the most recent follow up, and histological findings showed that the MESTCG scores in group 3 were higher than those in group 1. Furthermore, the incidence of patients with persistent nephropathy or renal insufficiency in group 3 was higher than those in groups 1 and 2.

CONCLUSIONS

Patients aged 14 years and older with IgAN may respond poorly to treatment compared with those younger than 14 years old. Therefore, care must be taken regarding response to treatment and relapse when treating older children.

Treatment strategy with multidrug therapy and tonsillectomy pulse therapy for childhood-onset severe IgA nephropathy

BACKGROUND

IgA nephropathy is a typical chronic glomerulonephritis that tends to occur in childhood.

METHOD

We reviewed the report on pathogenesis, treatment strategy with multidrug therapy and tonsillectomy pulse therapy for childhood-onset severe IgA nephropathy to clarify the pathophysiology and treatment of IgA nephropathy in childhood.

RESULTS

In recent years, it has been found that the pathogenesis at onset is associated with aberrant glycosylation at the IgA1 hinge. Given this genetic background, the aberrantly glycosylated IgA1immune complex produced by antigen-stimulated T cells and B cells is deposited in the glomeruli. Inflammation is induced via activation of the complement, macrophages and mesangial cells, and glomerular damage progresses thereafter. Treatment is selected according to the severity of IgA nephropathy. In order to prevent the development of renal damage, it is important to control the associated immune responses. For severe IgA nephropathy, in particular, multidrug therapy with prednisolone, immunosuppressants, and angiotensin enzyme synthesis inhibitors and tonsillectomy methylprednisolone pulse therapy are now performed- and, as a result, the number of renal deaths has decreased and the long-term prognosis has improved.

CONCLUSION

The prognosis of IgA nephropathy is improving. In the future, it will be important to develop a treatment method that takes into consideration the fact that children are in their growth and development stage and, therefore, seeks to minimizes side effects.

Remission of Proteinuria May Protect against Progression to Chronic Kidney Disease in Pediatric-Onset IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) is one of the most common primary glomerulopathies diagnosed in children and adolescents. This study aimed to evaluate the clinical features in and outcomes of pediatric IgAN over the last 30 years. Patients who were diagnosed before age of 18 at 20 centers in Korea were evaluated retrospectively. Of the 1154 patients (768 males, 386 females) with a median follow-up of 5 years, 5.6% (n = 65) progressed to stage 3–5 chronic kidney disease (CKD). The 10- and 20-year CKD-free survival rates were 91.2% and 75.6%, respectively. Outcomes did not differ when comparing those in Korea who were diagnosed prior to versus after the year 2000. On multivariate analysis, combined asymptomatic hematuria and proteinuria as presenting symptoms and decreased renal function at the time of biopsy were associated with progression to CKD, while remission of proteinuria was negatively associated with this outcome. Patients who presented with gross hematuria or nephrotic syndrome tended toward positive outcomes, especially if they ultimately achieved remission. While remission of proteinuria might imply that the disease is inherently less aggressive, it also can be achieved by management. Therefore, more aggressive management might be required for pediatric-onset IgAN.

Serum IgA/C3 and glomerular C3 staining predict severity of IgA nephropathy

BACKGROUND

The aim of this study was to determine whether serum immunoglobulin A/complement factor 3 (IgA/C3) ratio and glomerular C3 staining predict outcome in IgA nephropathy.

METHODS

We collected data for 44 IgA nephropathy children treated with multi-drug combination therapy. The children were retrospectively divided into four groups based on serum IgA/C3 ratio and glomerular C3 staining: group A, IgA/C3 ratio >2.68 (median) and glomerular C3 staining ≥2.0, n = 9; group B, IgA/C3 ratio >2.68 and glomerular C3 staining <2.0, n = 7; group C, IgA/C3 ratio <2.68 and glomerular C3 staining ≥2.0, n = 7; and group D, IgA/C3 ratio <2.68 and glomerular C3 staining <2.0, n = 21. Clinical features; pathology at the first and second renal biopsy and at the latest follow up; and prognosis were analyzed for the four groups.

RESULTS

At the most recent follow up, urinary protein excretion, incidence of hematuria, and serum creatinine in group A were all higher than in group D. At the second biopsy, crescent absence/presence ratio; mesangial hypercellularity, segmental glomerulosclerosis or adhesion, endocapillary hypercellularity, and tubular atrophy/interstitial fibrosis as well as crescents and global glomerulosclerosis (MESTCG) score; and clonicity index in group A were higher than in group D. All patients in group D had normal urine, and the prevalence of persistent nephropathy in group A was higher than in group D.

CONCLUSIONS

Serum IgA/C3 ratio and glomerular C3 staining can predict outcome in IgA nephropathy.

Inflammation in IgA nephropathy

Immunoglobulin A nephropathy (IgAN) is the most frequently occurring primary glomerulonephritis in Caucasian and Asian populations. Nonetheless, therapeutic recommendations are based on weak evidence, large controlled trials are scarce and, in particular, the additional value of immunosuppression beyond comprehensive supportive measures is not well-established. The use of immunosuppressants is supported by experimental insights into IgAN pathogenesis that suggest an autoimmune component in disease development. The so-called "multi-hit" theory comprises multiple steps, starting with defective glycosylation of IgA subclass IgA1 that results in overproduction of galactose-deficient IgA1 (Gd-IgA1), occurrence of anti-Gd-IgA1 autoantibodies, and mesangial deposition of nephritogenic immune complexes. This eventually results in an increased mesangial cell proliferation, inflammatory responses, and complement activation. Recent genome-wide association studies have identified several susceptibility genes, many of which support the "multi-hit" concept. In light of these discoveries, it is astonishing that the vast majority of adult IgAN patients obviously do not need and/or benefit from immunosuppressive therapies in the first place. In fact, a number of supportive measures are highly effective in reducing the risk for disease progression in many patients. These measures need to be optimized before immunosuppression should be considered at all. In this review we focus on the underlying pathogenetic cornerstones and the central question of whether systemic inflammation in adult IgAN patients should be treated. Treatment options in children with IgAN are also discussed.

Long-term follow up of pediatric immunoglobulin A nephropathy treated with tonsillectomy plus methylprednisolone pulse therapy

BACKGROUND

The aim of this study was to clarify the long-term efficacy of tonsillectomy plus methylprednisolone pulse therapy (tonsillectomy pulse therapy [TMP]) for pediatric immunoglobulin A nephropathy (IgAN). The clinical and laboratory findings as well as the prognosis for IgAN treated with TMP at long-term follow up were evaluated.

METHODS

We collected data on 33 IgAN children treated with TMP. The children were retrospectively divided into two groups. Group 1 consisted of 18 children treated with TMP as the initial therapy, and group 2 consisted of 15 children treated with TMP as rescue therapy for IgAN relapse. The clinical features, and laboratory and pathological findings, including those at first and second renal biopsy as well as at the latest follow up, were analyzed for both groups.

RESULTS

Mean urinary protein excretion, incidence of hematuria, and serum creatinine in groups 1 and 2 were all decreased significantly after TMP compared with beforehand. The percentage of glomeruli showing crescents after TMP in groups 1 and 2 was significantly lower than before TMP. At the most recent follow up, 94% of patients in group 1 and 87% in group 2 had normal urine, 6% in group 1 and 13% in group 2 had minor urinary abnormalities, and no patients in either group had active renal disease or renal insufficiency.

CONCLUSIONS

TMP is effective in ameliorating urinary abnormalities and improving the long-term outcome of pediatric IgAN both as an initial and as a rescue treatment.

Successful therapy with tonsillectomy plus pulse therapy for the relapse of pediatric IgA nephropathy treated with multi-drugs combination therapy

Immunoglobulin A nephropathy (IgAN) is the most common form of chronic glomerulonephritis worldwide.　In Japan, the treatment for use as an initial therapy was established in Guidelines for the Treatment of Childhood IgA nephropathy; however, no rescue therapy for recurrent or steroid-resistant pediatric IgAN was established.　We report here a 15-year-old boy with severe IgAN, who was treated with combination therapy involving prednisolone, mizoribine, warfarin, and dilazep dihydrochloride for 2 years.　The response to the combination therapy was good and both proteinuria and hematuria disappeared.　The pathological findings at the second renal biopsy were improved and PSL was discontinued.　However, due to nonadherence to the treatment regimen and tonsillitis, macrohematuria and an increase of proteinuria were again observed and the pathological findings at the third renal biopsy showed clear deterioration.　The patient was, therefore, diagnosed with recurrent IgAN.　Tonsillectomy plus methylprednisolone pulse therapy (TMP) was performed as a rescue therapy for the recurrence of severe IgAN.　Both the proteinuria or hematuria subsequently disappeared, and no proteinuria or hematuria has been observed and kidney function has remained normal during a 5-year follow-up.　The patient experienced no severe side effects associated with the drug regimens.　In conclusion, our case suggests that TMP may be an effective and useful rescue therapy for recurrent IgAN after multi-drug combination therapy.

IgA Nephropathy in Children: A Multicenter Study in Poland

IgA nephropathy (IgAN) is the most common form of glomerulonephritis in pediatric population. The clinical presentation of the disease in children ranges from microscopic hematuria to end-stage kidney disease. The aim of the study was to retrospectively assess clinical and kidney biopsy features in children with IgAN. We assessed a cohort of 140 children, 88 boys, 52 girls with the diagnosis of IgAN in the period of 2000-2015, entered into the national Polish pediatric IgAN registry. The assessment included the following: proteinuria, hematuria, glomerular filtration rate (GFR), arterial blood pressure, and the renal pathological changes according to the Oxford classification and crescents formation, as modifiable and unmodifiable risk factors. The incidence of IgAN in Poland was set at 9.3 new cases per year. The mean age at onset of IgAN was 11.9 ± 4.3 years, and the most common presentation of the disease was the nephritic syndrome, recognized in 52 % of patients. Kidney biopsy was performed, on average, 1.3 ± 2.0 years after onset of disease. Based on the ROC analysis, a cut-off age at onset of disease for GFR <90 mL/min/1.73 m² (risk factor of progression) was calculated as 13.9 years. Unmodifiable lesions: segmental sclerosis, tubular atrophy/interstitial fibrosis (S1, T1-2) in the Oxford classification and crescents in kidney biopsy were significantly more common in Gr 1 (>13.9 years) compared with Gr 2 (<13.9 years), despite a significantly shorter time to kidney biopsy in the former. We conclude that IgAN in children may be an insidious disease. A regular urine analysis, especially after respiratory tract infections, seems the best way for an early detection of the disease.

Clinicopathological role of kidney injury molecule-1 in immunoglobulin A nephropathy

BACKGROUND

Urinary kidney injury molecule-1 (KIM-1) is an early and sensitive biomarker of acute kidney injury, but it is unclear if it is a biomarker of chronic glomerulonephritis. We evaluated whether urinary KIM-1 levels in patients with immunoglobulin A (IgA) nephropathy can be a marker to reflect clinicopathological severity and predict the prognosis.

METHODS

We measured urinary KIM-1 levels in 40 patients (15 males; mean age 36.6±12.9 years) with IgA nephropathy and 10 healthy people (5 males; mean age 37.3±9.6 years) as controls. The correlation of urinary KIM-1 levels with patients' clinical parameters, histological grades, and follow-up data were analyzed using the modified H. S. Lee grading system and tubulointerstitial change scores.

RESULTS

Urinary KIM-1 levels were higher in patients with IgA nephropathy than healthy controls (P=0.001). Univariate and multivariate regression analyses showed that urinary KIM-1 levels had a direct correlation with H. S. Lee grade and tubulointerstitial inflammation (P=0.004 and P=0.011, respectively).

CONCLUSION

In patients with IgA nephropathy, urinary KIM-1 has a significant correlation with histopathologic severity.

Pathology of IgA nephropathy

IgA nephropathy is defined by the presence of IgA-dominant or co-dominant immune deposits within glomeruli. Biopsy specimens meeting these diagnostic criteria have a range of histological changes that are reflected in the variable clinical course of IgA nephropathy. The impact of histology on outcomes in IgA nephropathy has been clarified in a number of large retrospective clinicopathological studies. These studies have consistently demonstrated that the stage of disease at presentation, as indicated by the extent of interstitial fibrosis and tubular atrophy in the biopsy, is the strongest histological predictor of renal survival. The effect of active proliferative lesions on the disease course is less clear cut, owing in part to considerable treatment bias in most published retrospective studies. There is evidence that endocapillary hypercellularity and cellular crescents are responsive to immunosuppressive therapy, but this observation requires confirmation in prospective randomized controlled trials. Future challenges include improving the reproducibility of histological scoring, particularly for the presence and extent of endocapillary lesions, and to improve prognostic modelling by combining histological data with clinical variables and biomarker data.

Assessment of the effect of mesangial hypercellularity in childhood nephropathies to the clinical and laboratory findings

AIM

To assess the relationship between mesangial hypercellularity in various childhood nephropathies and clinical and laboratory parameters.

METHODS AND PATIENTS

The reports of the renal biopsies were evaluated retrospectively. The patients with diagnosis of IgA nephropathy (isolated and Henoch-Schönlein nephritis), IgM nephropathy, or isolated mesangial proliferative glomerulonephritis were included. Each nephropathy group was divided into two subgroups according to the severity of mesangial hypercellularity as mild and severe. The biochemical data and histopathological findings of the patients were recorded.

RESULTS

When the groups were compared, it was found that the patients with IgA nephropathy had hematuria (p = 0.043) and the patients with IgM nephropathy had nephrotic syndrome more frequently than the other patients (p = 0.01). No difference was detected between the groups regarding the severity of mesangial hypercellularity. On the other hand, when the groups were evaluated within themselves, no significant association was detected between the severity of mesangial hypercellularity and clinical and laboratory parameters. It was determined that the renal biopsy was performed earlier in patients with Henoch-Schönlein nephritis compared to the other cases (p = 0.004). Compared to the isolated IgA nephropathy group, it was found that the number of cases with severe mesangial hypercellularity was higher and the level of proteinuria was more prominent in patients with Henoch-Schönlein nephritis. Additionally, when the patients with Henoch-Schönlein nephritis were evaluated, the degree of proteinuria was found to be higher in patients with severe mesangial hypercellularity compared to those of showing mild mesangial hypercellularity (p = 0.002).

CONCLUSION

It was observed that there is no direct relation between the severity of mesangial hypercellularity and clinical and laboratory findings in various childhood nephropathies. However, when Henoch-Schönlein nephritis is compared with IgA nephropathy, it was found that the severity of mesangial hypercellularity was higher in cases with Henoch-Schönlein nephritis and the level of proteinuria was more prominent in those cases. However, no difference was detected in glomerular filtration rates and biochemical data with regard to the level of mesangial hypercellularity.

Comparison of clinicopathological features between children and adults with IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is prevalent among both children and adults. Illumination of the differences between them is important for clinical doctors.

METHODS

We retrospectively compared clinicopathological features in 110 children and 908 adults with IgAN.

RESULTS

The male to female ratio was 1.62:1 in children and 0.85:1 in adults. Most patients lacked triggers, but IgAN was preceded by upper respiratory infection (URI) in 45.5% of children and 20.2% of adults. Gross hematuria was the most common initial symptom in children (53.6%), especially in those associated with URI (82.0%), while other symptoms and abnormal laboratory parameters were more common in adults. Estimated glomerular filtration rate (eGFR) was higher in children than in adults. Co-deposition of IgA and C3 were found in 50.9% of children, while IgA deposit was often accompanied by two or more immune complexes in adults. The frequency of subclass I was significantly higher in children than in adults. Mild histological lesions were more common in pediatric IgAN patients associated with URI than other patients.

CONCLUSIONS

Pediatric patients showed relatively mild clinical manifestations and histological lesions compared with adult patients. URI was the most important trigger for IgAN, particularly in children. IgAN associated with URI was relatively mild.

Urinary protein markers predict the severity of renal histological lesions in children with mesangial proliferative glomerulonephritis

BACKGROUND

Several renal histopathological features, including mesangial hypercellularity, glomerulosclerosis, tubular atrophy and interstitial fibrosis, are considered to be independent predictors of end-stage renal failure in patients with glomerular diseases. Mesangial proliferative glomerulonephritis (MesPGN) is characterized by proliferations of mesangial cells with increase in mesangial matrix and/or deposits in mesangial region. The purpose of this study is to determine the association between urinary protein markers measured at the same time as renal biopsy and the severity of renal histological lesions in children with MesPGN, and to evaluate whether these markers could serve as predictors of severe renal histological lesions in this population.

METHODS

Ninety-eight children with MesPGN (40 with IgA nephropathy, 37 with IgM nephropathy, and 21 with MesPGN without IgA/IgM deposition) were enrolled. Urinary level of IgG, albumin, transferrin, α1-microglobulin, β2-microglobulin and N-acetyl-β-glucosaminidase from a morning sample before biopsy was measured.The scores of mesangial hypercellularity, glomerulosclerosis, and tubule-interstitial damage were used to semi-quantitatively evaluate renal histological lesions.

RESULTS

The urine proteins, as independent factors associated with severe mesangial cellularity (> 5 mesangial cells/ mesangial area) were transferrin, albumin, α1-microglobulin, IgG and 24-hour total protein, with severe glomerulosclerosis (≥ 10 % glomeruli showing segmental adhesions or sclerosis) were transferrin and 24-hour total protein, and with severe tubule-interstitial damage (focal or diffuse tubular and interstitial lesions) were transferrin and N-acetyl-β-glucosaminidase. Urinary transferrin achieved the area under-the-receiver-operating-characteristic curve (AUC) of 0.86 and 0.82, respectively, for predicting severe mesangial cellularity and glomerulosclerosis. Urinary N-acetyl-β-glucosaminidase achieved the highest AUC of 0.82 for predicting severe tubule-interstitial damage. The combination of urinary protein markers, however, did not improve the predictability for renal histological lesions.

CONCLUSIONS

Urinary protein markers are useful to predict the severity of renal histological lesions in children with MesPGN, which suggests that urinary proteins might be useful to predict the development and progression of renal histological lesions, and assist in evaluating the outcome and prognosis in children with MesPGN as non-invasive and easily repeatable indicators on the follow-up examination.

The short-term therapeutic effects of TCM for IgA nephropathy in children

OBJECTIVE

To evaluate the short-term therapeutic effects of TCM for IgA nephropathy in children.

METHODS

Sixty-two children with primary IgA nephropathy diagnosed for the first time by renal biopsy in the authors' hospital were randomly divided into a group of 34 cases treated with both TCM and Western medicine and a group of 28 cases treated with Western medicine for six months. The improvements in urinary protein and red blood cell (RBC) were observed and the scores for TCM symptoms and signs were evaluated after 3 months and 6 months of treatment.

RESULTS

There was no significant difference in the total effective rate between the two groups (chi2 = 4.743, P > 0.05 after treatment for 3 months; and chi2 = 1.953, P > 0.05 after treatment for 6 months). However, the cure plus marked effect rate in the group treated with both TCM and Western medicine was higher than that in the group treated with Western medicine (71.9% vs 45.5%, P < 0.05 after treatment for 3 months). At the end of treatment, significant difference were found in the effective rate (9.3% vs 10.5%, chi2 = 9.653, P < 0.01) and in the total score (0.81+1.18 vs 3.42 + 2.52, t = 4.19, P < 0.001) between the two groups.

CONCLUSION

Treatment with both TCM and Western medicine can effectively improve the TCM symptoms and signs in child patients with IgA nephropathy, and alleviate hematuria and albuminuria.

Idiopathic immunoglobulin A nephropathy in children and adolescents

Immunoglobulin A nephropathy is now recognized as the glomerular disease most often associated with progressive renal failure in patients around the world. In many cases it is not known when the disease starts to inflict glomerular injury, but recent studies that have shown genetically determined abnormalities in glycosylation of the IgA molecule suggest that this may begin in early life. This review focuses on recent advances in our understanding of IgA nephropathy, with special emphasis on clinical aspects of the disease when it presents in children and adolescents. In addition, the sections dealing with therapeutic options for patients with IgA nephropathy concentrate on studies that have been carried out on children. Whenever possible, data from randomized controlled clinical trials have formed the basis for recommendations. Unfortunately, this is not always possible, because of the lack of such trials in patients with IgA nephropathy.

The Oxford classification of IgA nephropathy: pathology definitions, correlations, and reproducibility

Pathological classifications in current use for the assessment of glomerular disease have been typically opinion-based and built on the expert assumptions of renal pathologists about lesions historically thought to be relevant to prognosis. Here we develop a unique approach for the pathological classification of a glomerular disease, IgA nephropathy, in which renal pathologists first undertook extensive iterative work to define pathologic variables with acceptable inter-observer reproducibility. Where groups of such features closely correlated, variables were further selected on the basis of least susceptibility to sampling error and ease of scoring in routine practice. This process identified six pathologic variables that could then be used to interrogate prognostic significance independent of the clinical data in IgA nephropathy (described in the accompanying article). These variables were (1) mesangial cellularity score; percentage of glomeruli showing (2) segmental sclerosis, (3) endocapillary hypercellularity, or (4) cellular/fibrocellular crescents; (5) percentage of interstitial fibrosis/tubular atrophy; and finally (6) arteriosclerosis score. Results for interobserver reproducibility of individual pathological features are likely applicable to other glomerulonephritides, but it is not known if the correlations between variables depend on the specific type of glomerular pathobiology. Variables identified in this study withstood rigorous pathology review and statistical testing and we recommend that they become a necessary part of pathology reports for IgA nephropathy. Our methodology, translating a strong evidence-based dataset into a working format, is a model for developing classifications of other types of renal disease.

Accumulation of macrophages expressing myeloid-related protein 8 associated with the progression of sclerotic changes in children with IgA nephropathy

Myeloid-related protein (MRP) 8 is a calcium-binding protein of the S100 family. The renal accumulation of macrophages expressing MRP8 is associated with the inflammatory activity of glomerulonephritis. We evaluated the renal accumulation of macrophages expressing MRP8 in children with IgA nephropathy (IgAN). We collected data on 25 IgAN children who had been treated with prednisolone and divided these patients into two groups: Favorable group, consisting of 11 patients with normal urine and 6 with minor urinary abnormalities at 4.3 +/- 1.3 years after initial treatment; and Unfavorable group, consisting of 8 patients with persistent nephropathy. The pathological renal findings were compared between both groups. The second biopsy was performed at two years after first biopsy at 5.5 +/- 4.9 months from onset. In Favorable group, the glomerular accumulation of macrophages expressing MRP8, and mesangial cells expressing alpha-smooth muscle actin (alpha-SMA) were lower in the second biopsy specimens than those of the first biopsy specimens. In Unfavorable group, the glomerular accumulation of macrophages expressing MRP8 detected in the second biopsy specimens was similar to that of the first biopsy, while the number of mesangial cells expressing alpha-SMA and the index of renal sclerosis were higher in the second biopsy than in the first biopsy. The indexes of renal sclerosis were higher in children with more macrophages expressing MRP8 than in children with less macrophages expressing MRP8. Our results suggest that renal macrophages expressing MRP8 may be involved in the progression of sclerotic changes in children with IgAN.

IgA nephropathy and Henoch-Schönlein purpura nephritis

PURPOSE OF REVIEW

IgA nephropathy and Henoch-Schönlein purpura nephritis are common glomerular disorders in pediatrics that can potentially progress to end-stage renal disease in some patients. This review summarizes our current understanding of the pathogenesis of these closely related conditions and discusses the rationale for development of diagnostic tests and prognostic markers. The review also presents the best data for long-term outcome, clinical markers of prognosis, and the results of randomized controlled trials.

RECENT FINDINGS

Our understanding of the defective galactosylation of O-linked glycans in the hinge region of human IgA1 and its role in the pathogenesis of IgA nephropathy and Henoch-Schönlein purpura nephritis has evolved over the past decade. This review discusses studies that suggest that demonstration of galactose-deficient IgA1 in the serum may become an important diagnostic tool for these conditions. Proteomic techniques for development of biomarkers for diagnosis and prognosis show promise. Although data from randomized controlled trials have failed to support the use of immunosuppressive agents in pediatric IgA nephropathy and Henoch-Schönlein purpura nephritis, recent data indicate that angiotensin converting enzyme inhibitor therapy is indicated for reduction of proteinuria.

SUMMARY

Childhood IgA nephropathy and Henoch-Schönlein purpura nephritis have the potential for serious morbidity, either during childhood or later in adulthood. In the future clinical tests will be used for noninvasive diagnosis and as markers for judging response to treatment, particularly in those individuals at highest risk for eventual progression to end-stage renal disease.

IgA nephropathy: what's new?

Although IgA nephropathy has only been recognized as a definitive entity for fewer than 40 years, its place in the world as a prominent cause for progressive kidney disease is well established. The extent to which we understand the role of genetically derived abnormal forms of the IgA molecule in the disease is evolving, and this will, hopefully, translate into more specific modes of treatment for patients in the future. In the meantime, we have few specific therapeutic options, most of which have not been well studied in large numbers of patients. The extent to which we can define which patients are likely to progress--and hence should be considered candidates for treatment--will be discussed in this Commentary. In addition, the notion that some patients may have reached "the point of no return" will also be addressed. Unfortunately, most of the comments will be based on results obtained in studies conducted in adults--a situation that is very familiar to pediatric nephrologists.

Natural History and Prognostic Factors of IgA Nephropathy Presented with Isolated Microscopic Hematuria in Chinese Patients

BACKGROUND/AIMS

IgA nephropathy (IgAN) with isolated microscopic hematuria (IMH) is prevalent in Asian countries including China. However, the natural history of IgAN with IMH has not yet been clarified. The aim of this study was to review the natural course and prognostic factors of IgAN with IMH in Chinese patients.

METHODS

We retrospectively studied 135 patients (43 males and 92 females) followed up for a mean period of 92 +/- 28 months. In order to identify factors associated with renal progression, clinical and pathological data at onset were reviewed.

RESULTS

During the follow-up period, hematuria of 16 patients (12%) disappeared while persistent microscopic hematuria was seen in 119 patients (88%), and proteinuria was present in 39 patients (29%). The prevalence of hypertension was 32% (43 patients), and 20% (27 patients) developed renal insufficiency. The prevalence of proteinuria and hypertension in the microalbuminuria group was significantly higher than those in the normoalbuminuria group. Poor renal outcome is usually associated with hematuria, microalbuminuria, and tubulointerstitial lesions.

CONCLUSION

IgAN with IMH may not imply favorable outcome, so early diagnosis and careful follow-up are clinically significant. Hematuria, microalbuminuria, and tubulointerstitial lesions are useful markers to identify those patients at high risk for renal progression.