Survival of endodontically treated teeth in public dental service in Northern Finland: a practise-based register study

OBJECTIVE

The aim of this study was to explore the factors associated with the survival of root canal treated teeth in a practise-based study setting in a 5-year period.

MATERIAL AND METHODS

This retrospective study used data from the electronic patient registration system of the public dental services of the City of Oulu, Finland. The inclusion criteria for this study were patients aged ≥ 20 years who had root canal treatment (RCT) that was initiated in 2014. One RCT per patient was included in the study. A total of 713 patients met the inclusion criteria. The outcome variable for this study was the extraction of the RCT tooth during the 5-year period. Explanatory variables included age, diagnosis, tooth type (incisive, canine, premolar, molar), RCT technique (manual, motorized), time from RCT initiation to final restoration and type of final restoration (composite, glass ionomer, fixed dental prosthesis). To evaluate the association between the outcome variable and explanatory variables, Cox regression analyses were performed.

RESULTS

The overall survival rate was 91%. The middle-aged (40-59-years-old) and the oldest (60 and older) patients had a two-fold risk of extraction compared to younger (20-40-years-old) patients. Similarly, a short length of time from RCT initiation to final restoration (0-14 days) resulted in a nearly three times higher risk of extraction compared to a longer period (≥ 90 days).

CONCLUSIONS

The 5-year survival rate of RCTs seems high. Extractions were more common among patients over 40 years of age and if the RCT was completed shortly after its initiation.

Histologic and Clinical Factors Associated with Kidney Outcomes in IgA Vasculitis Nephritis

BACKGROUND

Nephritis is a common manifestation of IgA vasculitis and is morphologically indistinguishable from IgA nephropathy. While MEST-C scores are predictive of kidney outcomes in IgA nephropathy, their value in IgA vasculitis nephritis has not been investigated in large multiethnic cohorts.

METHODS

Biopsies from 262 children and 99 adults with IgA vasculitis nephritis ( N =361) from 23 centers in North America, Europe, and Asia were independently scored by three pathologists. MEST-C scores were assessed for correlation with eGFR/proteinuria at biopsy. Because most patients ( N =309, 86%) received immunosuppression, risk factors for outcomes were evaluated in this group using latent class mixed models to identify classes of eGFR trajectories over a median follow-up of 2.7 years (interquartile range, 1.2-5.1). Clinical and histologic parameters associated with each class were determined using logistic regression.

RESULTS

M, E, T, and C scores were correlated with either eGFR or proteinuria at biopsy. Two classes were identified by latent class mixed model, one with initial improvement in eGFR followed by a late decline (class 1, N =91) and another with stable eGFR (class 2, N =218). Class 1 was associated with a higher risk of an established kidney outcome (time to ≥30% decline in eGFR or kidney failure; hazard ratio, 5.84; 95% confidence interval, 2.37 to 14.4). Among MEST-C scores, only E1 was associated with class 1 by multivariable analysis. Other factors associated with class 1 were age 18 years and younger, male sex, lower eGFR at biopsy, and extrarenal noncutaneous disease. Fibrous crescents without active changes were associated with class 2.

CONCLUSIONS

Kidney outcome in patients with biopsied IgA vasculitis nephritis treated with immunosuppression was determined by clinical risk factors and endocapillary hypercellularity (E1) and fibrous crescents, which are features that are not part of the International Study of Diseases of Children classification.

Outcome of immunosuppression in children with IgA vasculitis-related nephritis

BACKGROUND AND HYPOTHESIS

IgA vasculitis with nephritis (IgAVN) is the most common vasculitis in children. Treatment recommendations are, due to a lack of evidence, based on expert opinion resulting in variation. The aim of this study was to describe clinical presentation, treatment and outcome of an extremely large cohort of children with biopsy proven IgAVN to identify prognostic risk factors and signals of treatment efficacy.

METHODS

Retrospective data were collected on 1148 children with biopsy proven IgAVN between 2005 and 2019 from 41 international paediatric nephrology centres across 25 countries and analyzed using multivariate analysis. The primary outcome was estimated glomerular filtration rate (eGFR) and persistent proteinuria at last follow up.

RESULTS

The median follow up was 3.7 years (IQR 2-6.2). At last follow up, 29% of patients had an eGFR < 90 ml/min/1.73m2, 36% had proteinuria and 3% had chronic kidney disease stage 4-5. Older age, lower eGFR at onset, hypertension and histological features of tubular atrophy and segmental sclerosis were predictors of poor outcome. There was no evidence to support any specific second line immunosuppressive regimen to be superior to others, even when further analysing subgroups of children with reduced kidney function, nephrotic syndrome or hypoalbuminemia at onset. Delayed start of immunosuppressive treatment was associated with a lower eGFR at last follow up.

CONCLUSION

In this large retrospective cohort, key features associated with disease outcome are highlighted. Importantly there was no evidence to support that any specific immunosuppressive treatments were superior to others. Further discovery science and well-conducted clinical trials are needed to define accurate treatment and improve outcomes of IgAVN.

Cytosolic phosphoenolpyruvate carboxykinase deficiency: Expanding the clinical phenotype and novel laboratory findings

Cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) deficiency due to the homozygous PCK1 variant has recently been associated with childhood-onset hypoglycemia with a recognizable pattern of abnormal urine organic acids. In this study, 21 children and 3 adult patients with genetically confirmed PEPCK-C deficiency were diagnosed during the years 2016 to 2019 and the available biochemical and clinical data were collected. All patients were ethnic Finns. Most patients (22 out of 24) had a previously published homozygous PCK1 variant c.925G>A. Two patients had a novel compound heterozygous PCK1 variant c.925G>A and c.716C>T. The laboratory results showed abnormal urine organic acid profile with increased tricarboxylic acid cycle intermediates and inadequate ketone body production during hypoglycemia. The hypoglycemic episodes manifested predominantly in the morning. Infections, fasting or poor food intake, heavy exercise, alcohol consumption, and breastfeeding were identified as triggering factors. Five patients presented with neonatal hypoglycemia. Hypoglycemic seizures occurred in half of the patients (12 out of 24). The first hypoglycemic episode often occurred at the age of 1-2 years, but it sometimes presented at a later age, and could re-occur during school age or adulthood. This study adds to the laboratory data on PEPCK-C deficiency, confirming the recognizable urine organic acid pattern and identifying deficient ketogenesis as a novel laboratory finding. The phenotype is expanded suggesting that the risk of hypoglycemia may continue into adulthood if predisposing factors are present.

Renal Phenotype in Mitochondrial Diseases: A Multicenter Study

AIMS

This study aimed to investigate associations between renal and extrarenal manifestations of mitochondrial diseases and their natural history as well as predictors of renal disease severity and overall disease outcome. The secondary aim was to generate a protocol of presymptomatic assessment and monitoring of renal function in patients with a defined mitochondrial disease.

METHODS

A multicenter, retrospective cohort study was performed by the Mitochondrial Clinical and Research Network (MCRN). Patients of any age with renal manifestations associated with a genetically verified mitochondrial disease were included from 8 expert European centers specializing in mitochondrial diseases: Gothenburg, Oulu, Copenhagen, Bergen, Helsinki, Stockholm, Rotterdam, and Barcelona.

RESULTS

Of the 36 patients included, two-thirds had mitochondrial DNA-associated disease. Renal manifestations were the first sign of mitochondrial disease in 19%, and renal involvement was first identified by laboratory tests in 57% of patients. Acute kidney injury occurred in 19% of patients and was the first sign of renal disease in the majority of these. The most common renal manifestation was chronic kidney disease (75% with stage 2 or greater), followed by tubulopathy (44.4%), the latter seen mostly among patients with single large-scale mitochondrial DNA deletions. Acute kidney injury and tubulopathy correlated with worse survival outcome. The most common findings on renal imaging were increased echogenicity and renal dysplasia/hypoplasia. Renal histology revealed focal segmental glomerulosclerosis, nephrocalcinosis, and nephronophthisis.

CONCLUSION

Acute kidney injury is a distinct renal phenotype in patients with mitochondrial disease. Our results highlight the importance to recognize renal disease as a sign of an underlying mitochondrial disease. Acute kidney injury and tubulopathy are 2 distinct indicators of poor survival in patients with mitochondrial diseases.

HLA-DQ and HLA-DRB1 alleles associated with Henoch-Schönlein purpura nephritis in Finnish pediatric population: a genome-wide association study

BACKGROUND

The pathophysiology of Henoch-Schönlein purpura (HSP) is still unclear, but several findings suggest that genetic factors may influence disease susceptibility. We aimed to perform a genome-wide association study (GWAS) in pediatric HSP patients with an emphasis on severe HSP nephritis.

METHODS

The study included 46 HSP patients, 42 of whom had undergone kidney biopsy. Forty-nine pediatric patients with an inflammatory bowel disease (IBD) served as an autoimmune disease control group while Finnish bone marrow and blood donors represented the general reference population (n = 18,757). GWAS was performed for HSP and IBD samples in a case-control manner against the reference population. The analysis also included imputation of human leukocyte antigen (HLA) alleles.

RESULTS

GWAS analysis in HSP revealed several polymorphisms from the HLA region that surpassed the genome-wide significance level. Three HLA class II alleles were also significantly more frequent in HSP than in the reference population: DQA1*01:01, DQB1*05:01, and DRB1*01:01. Haplotype DQA1*01:01/DQB1*05:01/DRB1*01:01 occurred in 43.5% of HSP patients, whereas its frequency was 8.2% in IBD patients and 15.0% in the reference population. HSP patients with this haplotype showed similar baseline clinical findings and outcome as HSP patients negative for the haplotype. In IBD patients, no polymorphism or HLA allele appeared significant at the genome-wide level.

CONCLUSIONS

Our results suggest that haplotype DQA1*01:01/DQB1*05:01/DRB1*01:01 is associated with susceptibility to HSP, but not with the severity of the kidney involvement. These HLA associations did not occur in IBD patients, suggesting that they are specific to HSP and not related to susceptibility to autoimmune diseases in general.

Developing and validating models for predicting nursing home admission using only RAI-HC instrument data

OBJECTIVE

In recent years research has identified important predictors for nursing home admission (NHA). However, as far as we know, the previous risk models use complex variable sets from many sources and the output is a single risk value. The objective of this study was to develop an NHA risk model with a variable set from single data source and richer output information.

METHODS

In this study, we developed a model selecting variables only from the RAI-HC (Resident Assessment Instrument - Home Care) system. Furthermore, we used principal component analysis and K-means clustering to target proper interventions for high-risk clients.

RESULTS

The performance of the model was close to the complex previous model (recall [Formula: see text] vs. [Formula: see text] and specificity [Formula: see text] vs. [Formula: see text]). For the risk clients, three intervention clusters (deficiency in physical functionality, deficiency in cognitive functionality and depression and mood disorders) were found.

CONCLUSION

The NHA risk model and intervention clusters are important because they enable the identification of proper interventions for the right clients. The fact that the model with RAI-HC data alone was accurate enough simplifies the integration of the NHA risk model into practice because it uses data from one system and the algorithm can be integrated easily into the source system.

Methylprednisolone or cyclosporine a in the treatment of Henoch-Schönlein nephritis: a nationwide study

BACKGROUND

Optimal treatment of Henoch-Schönlein purpura nephritis (HSN) remains unclear. We evaluated outcome of pediatric HSN patients treated initially with either methylprednisolone (MP) or cyclosporine A (CyA) in Finland between 1996 and 2011.

METHODS

Outcome of 62 HSN patients was evaluated by screening urine and blood samples (n = 51) or by collecting clinical parameters from medical charts until last follow-up visit (n = 11). Sixty (97%) patients had nephrotic-range proteinuria and/or ISKDC grade ≥ III before initial treatment. Patients were initially treated with either MP pulses (n = 42) followed by oral prednisone or with CyA (n = 20). Fifty-nine (95%) patients received angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers.

RESULTS

Mean follow-up time was 10.8 years (range 3.2-21.2 years). One patient developed end-stage renal disease and another had decreased renal function (eGFR < 60 mL/min/1.73m²), both initially treated with MP (3%). Six patients (5 MP, 1 CyA) had eGFR between 60 and 89 mL/min/1.73m² (10%). Eighteen patients (13 MP, 5 CyA) had proteinuria and/or hematuria (29%) and four of them had proteinuria > 0.5 g/day at end of follow-up. Sixteen (38%) MP-treated and two (10%) CyA-treated patients needed additional immunosuppressive treatment (RR 3.81, 95% CI 1.16-14.3, p = 0.035). Late initiation of treatment was associated with an increased risk for persistent proteinuria.

CONCLUSIONS

Long-term outcome was relatively good in both treatment groups. However, since urinary abnormalities may persist or develop, long-term follow-up of HSN patients is mandatory. Early initiation of treatment had a favorable effect on proteinuria.

IL-10 polymorphisms +434T/C, +504G/T, and -2849C/T may predispose to tubulointersititial nephritis and uveitis in pediatric population

BACKGROUND

Tubulointerstitial nephritis (TIN) and uveitis syndrome (TINU) are likely to be autoimmune diseases. Based on previous studies, adults with isolated idiopathic uveitis have polymorphisms in interleukin 10 (IL-10) and tumor necrosis factor α (TNF-α) genes. We aimed to evaluate the presence of IL-10 and TNF-α polymorphisms in a nationwide cohort of pediatric TIN/TINU patients.

METHODS

Single nucleotide polymorphisms in IL-10 (+434T/C, +504G/T, -1082G/A, -2849C/T) and in TNFα (-308G/A, -238G/A, -857C/T) genes were genotyped in 30 well-defined pediatric patients with idiopathic TIN/TINU syndrome. Control group frequencies for these SNPs were obtained from 393 independent Finnish subjects.

RESULTS

The homozygous minor allele in IL-10 +434T (rs2222202) and IL-10+504G (rs3024490) was found in all patients with TIN or TINU syndrome while the frequency of these minor alleles in the control population was 44% and 23%, respectively (p <0.001). In IL-10 SNP -2849 (rs6703630) a significant difference was found with genotype TT in all patients (p = 0.004) and in subgroups with TINU syndrome (p = 0.017) and TINU syndrome with chronic uveitis (p = 0.01) compared to reference population. There were no statistical differences in any of the studied TNF-α genotypes between TIN/TINU patients and control population.

CONCLUSIONS

A significant difference in the frequency of IL-10+434T and +504G alleles was found between TIN/TINU patients and control population. Genotype -2849TT was more frequently present in patients with TINU syndrome than in the reference subjects. Genetic variation in the inflammatory mediators may predispose to autoimmune nephritis and uveitis.

Novel homozygous PCK1 mutation causing cytosolic phosphoenolpyruvate carboxykinase deficiency presenting as childhood hypoglycemia, an abnormal pattern of urine metabolites and liver dysfunction

Clinical and laboratory data were collected from three Finnish patients including a sibling pair and another unrelated child with unexplained childhood hypoglycemia. Transient elevation of alanine transaminase, lactate and tricarboxylic acid cycle intermediates, especially fumarate, were noticed in urine organic acid analysis. Exome sequencing was performed for the patients and their parents. A novel homozygous PCK1 c.925G>A (p.G309R) mutation was detected in all affected individuals. COS-1 cells transfected with mutant PCK1 transcripts were used to study the pathogenic nature of the detected variant. The COS-1 transfected cells showed the mutant gene to be incapable of producing a normally functioning cytosolic phosphoenolpyruvate carboxykinase (PEPCK) enzyme. This report further delineates the clinical phenotype of isolated cytosolic PEPCK deficiency and offers a metabolic pattern helping to recognize these patients. Cytosolic PEPCK deficiency should be considered in the differential diagnosis of children presenting with hypoglycemia, hepatic dysfunction and elevated tricarboxylic acid intermediates in urinary organic acid analysis.

Novel OCRL mutations in patients with Dent-2 disease

Dent disease is an X-linked tubulopathy frequently caused by mutations in the CLCN5 gene encoding the voltage-gated chloride channel and chloride/proton antiporter, ClC-5. About 15% of patients with a Dent' phenotype have mutations in the OCRL gene, which also causes Lowe oculocerebrorenal syndrome. To distinguish these patients from the more severe Lowe phenotype, they are diagnosed as having Dent-2 disease. We studied 14 CLCN5-negative patients from 12 families with a phenotype resembling Dent disease for defects in OCRL. In six of these kindreds three novel (c.149+1G>A, c.1126A>T, c.1547T>C) and three repeatedly observed mutations (c.166_167delTT, c.901C>T, c.1426C>T) were discovered. With the exception of a lower prevalence of nephrocalcinosis, the renal phenotype is identical with patients harboring a CLCN5 mutation. Affected children may have some of the extra-renal symptoms of Lowe syndrome, such as peripheral cataracts, mental impairment, stunted growth or elevation of creatine kinase/lactate dehydrogenase, blurring the distinction between those two clinical entities.

Prednisone in the treatment of tubulointerstitial nephritis in children

BACKGROUND

Patients with tubulointerstitial nephritis (TIN) may develop permanent renal impairment. However, there are no prospective studies available on the treatment of TIN.

METHODS

The effect of prednisone in the treatment of TIN was evaluated in a total of 17 patients who received prednisone or who were followed up without medication. The patient group was subdivided based on the initial plasma creatinine (PCr), below or above 150 μmol/l.

RESULTS

All prednisone-treated patients had normal plasma creatinine (PCr) after 1 month of treatment (median 59.1 [45-85] μmol/l) whereas only 50 % of patients in the non-treatment group had normal creatinine (median 81.0 [42-123] μmol/l) at the same time point (p = 0.025). During 6 months' follow-up, PCr decreased in all patient groups; however, it decreased significantly only in prednisone-treated patients with baseline PCr >150 μmol/l (p < 0.001). At the end of follow-up, no difference in PCr, glomerular filtration rate (GFR), or low molecular weight (LMW) proteinuria could be found between the study groups. A considerable number of patients in both groups had subnormal GFR and/or persistent LMW proteinuria at the 6-month follow-up visit. Eighty-two percent of the patients had uveitis.

CONCLUSIONS

Prednisone speeds up the recovery from renal symptoms of TIN, especially in patients with severe nephritis. The renal function did not differ significantly between prednisone and control patients after 6 months' follow-up.

HLA associations with tubulointerstitial nephritis with or without uveitis in Finnish pediatric population: a nation-wide study

The human leukocyte antigen (HLA) genotype has been shown to associate with tubulointerstitial nephritis (TIN) and tubulointerstitial nephritis with uveitis syndrome (TINU). The association of HLA genes with TIN was examined in this nation-wide study. HLA genotyping was performed in 31 pediatric patients with biopsy-proven TIN. All patients were examined by an ophthalmologist to diagnose possible uveitis. Class II HLA genotypes of TIN patients were compared with the Finnish reference population. We found a significant association between the HLA alleles DQA1*04:01 [risk ratio (RR) 5.0, 95% confidence interval (CI) 2.0-11.2], DQB1*04:02 (RR 2.7, 95% CI 1.4-5.3), and DRB1*08 (RR 3.8, 95% CI 1.5-8.4) and TIN. Uveitis was found in 20/31 (64.5%) patients. HLA genotyping of the TINU patients showed additional risk HLA alleles: DQA1*01:04 (RR 6.1, 95% CI 1.5-17.8), and DRB1*14 (RR 8.2, 95% CI 2.2-22.1). The alleles DQA1*01:04 (RR 8.8, 95% CI 2.2-26.5), DQA1*04:01 (RR 3.2, 95% CI 1.2-7.3), and DRB1*14 (RR 12.0, 95% CI 3.2-33.0) were more frequent in patients with TIN and chronic uveitis than in reference population. The HLA class II haplotype DQA1*04:01/DQB1:04:02/DRB1*08 was the most common combination in our study population (58.1%). None of the patients had haplotype DQA1*04:01/DQB1*06:02/DRB1*15, which is common in Finland. HLA genotype did not predict the renal outcome. We found a strong association between certain HLA genotypes both in TIN and TINU patients. The TIN/TINU-associated HLA alleles appear to vary depending on study population.

Tubulointerstitial nephritis and uveitis syndrome in children: a prospective multicenter study

PURPOSE

To evaluate the occurrence and characteristics of uveitis related to tubulointerstitial nephritis (TIN) in children.

DESIGN

Prospective, observational, multicenter, partly placebo-controlled treatment trial.

PARTICIPANTS

Nineteen children with a biopsy-proven TIN.

METHODS

Patients were treated with prednisone or followed without treatment. In addition to the nephrologic evaluations, the prospective follow-up included structured ophthalmological examinations at the onset of TIN and at 3 and 6 months after the diagnosis.

MAIN OUTCOME MEASURES

Occurrence, clinical features, and outcome of uveitis.

RESULTS

Some 84% (16/19) of the patients had uveitis, 83% (5/6) in the nontreatment group and 82% (9/11) in the prednisone-treated group. The remaining 2 patients, originally in the nontreatment group, were switched to the prednisone group after 2 weeks. Both of them developed uveitis. Altogether, 3 patients developed uveitis during prednisone treatment and 2 patients showed worsening of uveitis despite the systemic corticosteroid. Some 50% (8/16) of the patients with uveitis presented with no ocular symptoms; 88% (14/16) of the patients had a chronic course of uveitis. Two patients were diagnosed with uveitis before nephritis; nephritis and uveitis were diagnosed within 1 week from each other in 7 patients, and uveitis developed 1 to 6 months after the diagnosis of TIN in 7 patients.

CONCLUSIONS

There was no statistically significant difference in the occurrence of uveitis in patients with TIN in the prednisone and nontreatment groups. In this study, the occurrence of uveitis associated with TIN was considerably higher than previously reported. Uveitis related to TIN may develop late and is often asymptomatic. The ophthalmological follow-up of all patients with TIN is warranted for at least 12 months starting with 3-month intervals.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any material discussed in this article.

Transmembrane collagen XVII is a novel component of the glomerular filtration barrier

The kidney filtration barrier consists of the capillary endothelium, the glomerular basement membrane and the slit diaphragm localized between foot processes of neighbouring podocytes. We report that collagen XVII, a transmembrane molecule known to be required for epithelial adhesion, is expressed in podocytes of normal human and mouse kidneys and in endothelial cells of the glomerular filtration barrier. Immunoelectron microscopy has revealed that collagen XVII is localized in foot processes of podocytes and in the glomerular basement membrane. Its role in kidney has been analysed in knockout mice, which survive to birth but have high neonatal mortality and skin blistering and structural abnormalities in their glomeruli. Morphometric analysis has shown increases in glomerular volume fraction and surface densities of knockout kidneys, indicating an increased glomerular amount in the cortex. Collagen XVII deficiency causes effacement of podocyte foot processes; however, major slit diaphragm disruptions have not been detected. The glomerular basement membrane is split in areas in which glomerular and endothelial basement membranes meet. Differences in the expression of collagen IV, integrins α3 or β1, laminin α5 and nephrin have not been observed in mutant mice compared with controls. We propose that collagen XVII has a function in the attachment of podocyte foot processes to the glomerular basement membrane. It probably contributes to podocyte maturation and might have a role in glomerular filtration.

Cyclosporine A vs. methylprednisolone for Henoch-Schönlein nephritis: a randomized trial

Knowledge about how to treat severe Henoch-Schönlein nephritis (HSN) is scarce. The aim of our study is to compare cyclosporine A (CyA) and methylprednisolone pulses (MP) in the treatment of severe HSN. Out of 24 pediatric HSN patients with nephrotic-range proteinuria or crescentic HSN in kidney biopsy, seven were randomized to receive CyA for 12 months at an initial dose of 5 mg/kg and eight to receive 3 MP pulses of 30 mg/kg followed by prednisone for 4 months. The other nine patients received identical treatment without randomization. Kidney biopsies were performed at inclusion and after 2 years. The primary outcomes were the duration of proteinuria and hematuria, estimated glomerular filtration rate, and renal biopsy histology. All the 11 CyA-treated patients achieved resolution of nephrotic-range proteinuria within 3 months, while the MP-group response was slower, and in 6/13 was not achieved with the initial treatment. Additional immunosuppressive treatment was needed in none of the CyA-treated patients but in six patients treated with MP (difference in proportion 46%, p = 0.008). The 2-year control biopsies were similarly improved in both groups. After mean 6.1 years (2.2-10.4 years), 16 patients (eight CyA, eight MP) had no renal symptoms and six (three CyA, three MP) had persistent nephropathy but normal renal function. One MP-treated patient had reduced renal function and another had developed ESRD and received a renal transplant. CyA gave a 100% resolution of nephrotic-range proteinuria and a 100% renal survival rate without additional therapy after a mean follow-up of 6 years. Treatment of HSN with CyA is efficacious, safe and not inferior to MP.

Growth hormone therapy is safe and effective in patients with lysinuric protein intolerance

BACKGROUND

Lysinuric protein intolerance (LPI) is an autosomal recessive cationic amino acid transport defect characterized by episodes of postprandial hyperammonemias and spontaneous protein aversion. Subnormal growth is common in spite of appropriate nutritional therapy. Growth hormone (GH) therapy promotes appetite, protein synthesis and accretion, but its possible growth-promoting effects and safety in patients with LPI are poorly known.

METHODS

Four LPI children aged 7-16 years were treated with GH for a period of 3-4.5 years. Dietary intakes and plasma amino acid levels were analyzed frequently in addition to routine monitoring of GH therapy.

RESULTS

Insulin-like growth factor-1 concentration was low and bone age was delayed in all LPI patients, but GH provocative test was pathological in only one of the patients. During the 3-4.5 years of GH therapy (dose 0.035-0.050 mg/kg/day), bone age did not catch up but height standard deviation score (SDS) improved by 0.7-1.8 SDS. There were no episodes of hyperammonemias.

CONCLUSIONS

Our data support safety and growth-promoting potential of long-term GH therapy in patients with LPI.

Clinical outcome and occurrence of uveitis in children with idiopathic tubulointerstitial nephritis

Acute idiopathic tubulointerstitial nephritis (TIN) is considered a condition with a good long-term prognosis. However, there is evidence that some patients develop permanent renal impairment. The aim of this study was to evaluate the clinical characteristics of TIN at the time of diagnosis in children and determine whether the findings upon presentation predict renal outcome. The clinical data and biopsy findings from 26 children with idiopathic TIN admitted to four Finnish university hospitals were analyzed retrospectively. Twenty-five patients (96%) manifested renal insufficiency. After the mean follow-up time of 2.75 years (SD 2.5; 0.9-13.5), 4 patients (15%) had permanent renal insufficiency and 8 patients (31%) had persistent low-molecular weight proteinuria. Uveitis was found in 12 patients (46%). Four of these patients (33%) developed chronic uveitis. Our analysis showed that none of the laboratory or biopsy findings upon presentation prognosticated renal outcome. No correlation between renal disease and uveitis could be found either. The occurrence of uveitis among TIN patients was higher than previously reported. Uveitis may develop late and without recurrence of renal dysfunction. Therefore, follow-up by a pediatrician and by an ophthalmologist is warranted in children with acute TIN for at least 12 months from diagnosis.

Renal manifestations of Henoch-Schonlein purpura in a 6-month prospective study of 223 children

OBJECTIVE

To assess the risk factors for developing Henoch-Schönlein purpura nephritis (HSN) and to determine the time period when renal involvement is unlikely after the initial disease onset.

DESIGN

A prospective study of 223 paediatric patients to examine renal manifestations of Henoch-Schönlein purpura (HSP). The patient's condition was monitored with five outpatient visits to the research centre and urine dipstick testing at home.

RESULTS

HSN occurred in 102/223 (46%) patients, consisting of isolated haematuria in 14%, isolated proteinuria in 9%, both haematuria and proteinuria in 56%, nephrotic-range proteinuria in 20% and nephrotic-nephritic syndrome in 1%. The patients who developed HSN were significantly older than those who did not (8.2±3.8 vs 6.2±3.0 years, p<0.001, CI for the difference 1.1 to 2.9). Nephritis occurred a mean of 14 days after HSP diagnosis, and within 1 month in the majority of cases. The risk of developing HSN after 2 months was 2%. Prednisone prophylaxis did not affect the timing of the appearance of nephritis. The risk factors for developing nephritis were age over 8 years at onset (OR 2.7, p=0.002, CI 1.4 to 5.1), abdominal pain (OR 2.1, p=0.017, CI 1.1 to 3.7) and recurrence of HSP disease (OR 3.1, p=0.002, CI 1.5 to 6.3). Patients with two or three risk factors developed nephritis in 63% and 87% of cases, respectively. Laboratory tests or blood pressure measurement at onset did not predict the occurrence of nephritis.

CONCLUSION

The authors recommend weekly home urine dipstick analyses for the first 2 months for patients with HSP. Patients with nephritis should be followed up for more than 6 months as well as the patients with HSP recurrence.

Clinical course of extrarenal symptoms in Henoch-Schonlein purpura: a 6-month prospective study

OBJECTIVE

To describe the extrarenal symptoms and clinical course of Henoch-Schönlein purpura (HSP).

DESIGN

A prospective national multicentre trial with 6-month follow-up. Patients A total of 223 newly diagnosed paediatric HSP patients.

RESULTS

Purpura was the initial symptom in 73% of the patients and was preceded by joint or gastrointestinal manifestations in the rest by a mean of 4 days. Joint symptoms, abdominal pain, melena, nephritis and recurrences occurred in 90%, 57%, 8%, 46% and 25% of the patients, respectively. Orchitis affected 17/122 (14%) of the boys. Seven patients developed protein-losing enteropathy characterised by abdominal pain, oedema and serum albumin under 30 g/l, and an additional 49 patients had subnormal albumin levels without any proteinuria. Positive fecal occult blood (26/117, 22%) and α1-antitrypsin (7/77, 9%) suggested mucosal injury even in the patients without gastrointestinal symptoms. HSP was often preceded by various bacterial, especially streptococcal (36%) and viral infections. Previous streptococcal infection did not induce changes in the level of complement component C3. Recurrences were more frequent in patients >8 years of age (OR 3.7, CI 2.0 to 7.0, p<0.001) and in patients with nephritis (OR 4.6, CI 2.3 to 8.9, p<0.001). Patients with severe HSP nephritis had more extrarenal symptoms up to 6 months. There was no difference in the clinical course between the prednisone-treated and non-treated patients during the 6-month follow-up.

CONCLUSIONS

Serum albumin is often low in HSP patients without proteinuria, due to protein loss via the intestine. Although corticosteroids alleviate the symptoms, they seem not to alter the clinical course of HSP during 6 months of follow-up.

Individuals with mutations in XPNPEP3, which encodes a mitochondrial protein, develop a nephronophthisis-like nephropathy

The autosomal recessive kidney disease nephronophthisis (NPHP) constitutes the most frequent genetic cause of terminal renal failure in the first 3 decades of life. Ten causative genes (NPHP1-NPHP9 and NPHP11), whose products localize to the primary cilia-centrosome complex, support the unifying concept that cystic kidney diseases are "ciliopathies". Using genome-wide homozygosity mapping, we report here what we believe to be a new locus (NPHP-like 1 [NPHPL1]) for an NPHP-like nephropathy. In 2 families with an NPHP-like phenotype, we detected homozygous frameshift and splice-site mutations, respectively, in the X-prolyl aminopeptidase 3 (XPNPEP3) gene. In contrast to all known NPHP proteins, XPNPEP3 localizes to mitochondria of renal cells. However, in vivo analyses also revealed a likely cilia-related function; suppression of zebrafish xpnpep3 phenocopied the developmental phenotypes of ciliopathy morphants, and this effect was rescued by human XPNPEP3 that was devoid of a mitochondrial localization signal. Consistent with a role for XPNPEP3 in ciliary function, several ciliary cystogenic proteins were found to be XPNPEP3 substrates, for which resistance to N-terminal proline cleavage resulted in attenuated protein function in vivo in zebrafish. Our data highlight an emerging link between mitochondria and ciliary dysfunction, and suggest that further understanding the enzymatic activity and substrates of XPNPEP3 will illuminate novel cystogenic pathways.

Does the secular increase in body mass in children contribute to the increasing incidence of type 1 diabetes?

BACKGROUND

The incidence of type 1 diabetes in children has increased in most developed countries after World War II, and simultaneously, normal children have experienced accelerated weight gain and growth.

OBJECTIVE

We set out to explore whether any relationship can be seen between the incidence of childhood type 1 diabetes and changes in linear growth and body mass in Finnish children over a 12-yr period.

METHODS

Incidence rates for type 1 diabetes in Finnish children under the age of 15 yr were obtained from the National Central Drug Registry. The rates were averaged for 3-yr intervals over the 15-yr period 1979-1993 and related to data on mean height, weight, and body mass index (BMI) in 15-yr-old children generated for the years 1980, 1983, 1986, 1989, and 1992 by the 'Cardiovascular Risk in Young Finns' study.

RESULTS

There was a positive correlation between the incidence of childhood type 1 diabetes and mean heights (r = 0.84; p = 0.039), mean weights (r = 0.85; p = 0.036), and mean BMIs (r = 0.87; p = 0.028) in 15-yr-old children over the 12-yr study period.

CONCLUSIONS

This observation suggests that accelerated linear growth and increasing body mass may contribute to the rising incidence of childhood type 1 diabetes seen in most developed countries since World War II. This effect might be mediated through increased beta-cell stress induced by hyperinsulinemia and decreased insulin sensitivity, associated with rapid linear growth and obesity.

Prevalence, segregation, and phenotype of the mitochondrial DNA 3243A>G mutation in children

OBJECTIVE

We studied the prevalence, segregation, and phenotype of the mitochondrial DNA 3243A>G mutation in children in a defined population in Northern Ostrobothnia, Finland.

METHODS

Children with diagnoses commonly associated with mitochondrial diseases were ascertained. Blood DNA from 522 selected children was analyzed for 3243A>G. Children with the mutation were clinically examined. Information on health history before the age of 18 years was collected from previously identified adult patients with 3243A>G. Mutation segregation analysis in buccal epithelial cells was performed in mothers with 3243A>G and their children whose samples were analyzed anonymously.

RESULTS

Eighteen children were found to harbor 3243A>G in a population of 97,609. A minimum estimate for the prevalence of 3243A>G was 18.4 in 100,000 (95% confidence interval, 10.9-29.1/100,000). Information on health in childhood was obtained from 37 adult patients with 3243A>G. The first clinical manifestations appearing in childhood were sensorineural hearing impairment, short stature or delayed maturation, migraine, learning difficulties, and exercise intolerance. Mutation analysis from 13 mothers with 3243A>G and their 41 children gave a segregation rate of 0.80. The mothers with heteroplasmy greater than 50% tended to have offspring with lower or equal heteroplasmy, whereas the opposite was true for mothers with heteroplasmy less than or equal to 50% (p = 0.0016).

INTERPRETATION

The prevalence of 3243A>G is relatively high in the pediatric population, but the morbidity in children is relatively low. The random genetic drift model may be inappropriate for the transmission of the 3243A>G mutation.

Novel OCRL1 mutations in patients with the phenotype of Dent disease

BACKGROUND

Dent disease is an X-linked tubulopathy frequently caused by mutations affecting the voltage-gated chloride channel and chloride/proton antiporter ClC-5. A recent study showed that defects in OCRL1, encoding a phosphatidylinositol 4,5-bisphosphate 5-phosphatase (Ocrl) and usually found mutated in patients with Lowe syndrome, also can provoke a Dent-like phenotype (Dent 2 disease).

METHODS

We investigated 20 CLCN5-negative males from 17 families with a phenotype resembling Dent disease for defects in OCRL1.

RESULTS

In our complete series of 35 families with a phenotype of Dent disease, a mutation in the OCRL1 gene was detected in 6 kindreds. All were novel frameshift (Q70RfsX88 and T121NfsX122, detected twice) or missense mutations (I257T and R476W). None of our patients had cognitive or behavioral impairment or cataracts, 2 classic hallmarks of Lowe syndrome. All patients had mild increases in lactate dehydrogenase and/or creatine kinase levels, which rarely is observed in CLCN5-positive patients, but frequently found in patients with Lowe syndrome. To explain the phenotypic heterogeneity caused by OCRL1 mutations, we performed extensive data-bank mining and extended reverse-transcriptase polymerase chain reaction analysis, which provided no evidence for yet unknown (tissue-specific) alternative OCRL1 transcripts.

CONCLUSION

Mutations in the OCRL1 gene are found in approximately 23% of kindreds with a Dent phenotype. Defective protein sorting/targeting of Ocrl might be the reason for mildly elevated creatine kinase and lactate dehydrogenase serum concentrations in these patients and a clue to suspect Dent disease unrelated to CLCN5 mutations. It remains to be elucidated why the various OCRL1 mutations found in patients with Dent 2 disease do not cause cataracts.

Long-term outcome 19 years after childhood IgA nephritis: a retrospective cohort study

We evaluated the natural long-term outcome after childhood IgA nephritis. Altogether 55 patients with biopsy-proven IgA nephritis were identified, 37 (67%) responded to the health questionnaire and 31 (56%) participated in the medical examination after a mean follow-up of 18.7 years (SD 6.2; range 8.5-29.8). The results of medical examination, onset data and the re-analysis of original biopsies of 31 participants were used when analyzing the predictive factors for persistent nephropathy, i.e. constant proteinuria/hematuria or end-stage renal disease (ESRD). All patients' medical history data were obtained from regional hospitals and renal survival data from the national kidney register. Six (11%) of the 55 identified patients had developed ESRD. Sixteen (52%) of the 31 participants were not attending for regular follow-up visits after the acute phase. Twenty-two (71%) had renal symptoms and 12 (39%) were receiving drugs for hypertension/proteinuria at their latest follow-up visit. The chronicity index and total biopsy score in the first renal biopsy were higher in patients with persistent nephropathy or ESRD than in those without (p=0.022 and p=0.014, respectively). Nine (69%) of the 13 subjects who had been over 16 years of age at diagnosis had persistent nephropathy or ESRD, compared with 4 (22%) of the 18 subjects who had been under 16 years of age (relative risk 3.1, 95% CI 1.2-8.0). Pregnancy complications were common: 12 (55%) of the 22 pregnancies had been complicated by proteinuria and/or hypertension, and the prematurity rate was 30%. Long-term follow-up during adulthood is needed even after mild childhood IgA nephritis, especially in women during and after pregnancy.

Fructose- 1,6-Bisphosphate Supports Cerebral Energy Metabolism in Pigs after Ischemic Brain Injury Caused by Experimental Particle Embolization

BACKGROUND

Fructose-1,6-bisphosphate (FDP) is a high-energy intermediate that enhances glycolysis, preserves cellular adenosine triphosphate stores, and prevents the increase of intracellular calcium in ischemic tissue. Since it has been shown to provide metabolic support to the brain during ischemia, we planned this study to evaluate whether FDP is neuroprotective in the setting of combining hypothermic circulatory arrest (HCA) and irreversible embolic brain ischemic injury.

METHODS

Twenty pigs were randomly assigned to receive 2 intravenous infusions of either FDP (500 mg/kg) or saline. The first infusion was given just before a 25-minute period of HCA and the second infusion immediately after HCA. Immediately before HCA, the descending aorta was clamped and 200 mg of albumin-coated polystyrene microspheres (250-750 mm in diameter) were injected into the isolated aortic arch in both study groups.

RESULTS

There were no significant differences between the study groups in terms of neurological outcome. Brain lactate/pyruvate ratio was significantly lower (P = .015) and brain pyruvate levels (P = .013) were significantly higher in the FDP group compared with controls. Brain lactate levels were significantly higher 8 hours after HCA (P = .049).

CONCLUSION

The administration of FDP before and immediately after HCA combined with embolic brain ischemic injury was associated with significantly lower brain lactate/pyruvate ratio and significantly higher levels of brain pyruvate, as well as lower lactate levels 8 hours after HCA. FDP seems to protect the brain by supporting energy metabolism. The neurological outcome was not improved, most likely resulting from the irreversible nature of the microsphere occlusion.

Early prednisone therapy in Henoch-Schönlein purpura: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To evaluate the efficacy of early prednisone therapy in preventing renal and treating extrarenal and renal symptoms in Henoch-Schönlein purpura (HSP) in a placebo-controlled trial.

STUDY DESIGN

A total of 171 patients (84 treated with prednisone and 87 receiving placebo) were included and followed up for 6 months. The endpoints were renal involvement at 1, 3, and 6 months and healing of extrarenal symptoms. The analyses were performed on an intent-to-treat basis.

RESULTS

Prednisone (1 mg/kg/day for 2 weeks, with weaning over the subsequent 2 weeks) was effective in reducing the intensity of abdominal pain (pain score, 2.5 vs 4.8; P = .029) and joint pain (4.6 vs 7.3; P = .030). Prednisone did not prevent the development of renal symptoms but was effective in treating them; renal symptoms resolved in 61% of the prednisone patients after treatment, compared with 34% of the placebo patients (difference = 27%; 95% confidence interval = 3% to 47%; P = .024).

CONCLUSIONS

The general use of prednisone in HSP is not supported, but patients with disturbing symptoms may benefit from early treatment, because prednisone reduces extrarenal symptoms and is effective in altering (but not preventing) the course of renal involvement.

Muscular dystonia and athetosis in six patients with congenital nephrotic syndrome of the Finnish type (NPHS1)

Congenital nephrotic syndrome of the Finnish type (NPHS1, CNF) is an autosomal recessively inherited disease occurring due to mutations in the nephrin gene (NPHS1). Two main Finnish mutations exist: Fin-major and minor, which both cause a lack of nephrin and absence of the slit diaphragm between the podocytes. This leads to severe proteinuria, nephrotic syndrome and infections, and without dialysis or renal transplantation, death in infancy. Between 1984 and 2003, six (8.6%) of the 70 NPHS1 patients diagnosed at our institution had, in addition to their renal disease, similar neurological symptoms. All six showed a severe dyskinetic cerebral palsy-like syndrome with dystonic features, athetosis and a hearing defect. The neurological symptoms became apparent during their 1st year of life and were diagnosed before 11 months of age. MRI showed increased signal intensity in T2-weighted images in the globus pallidus area. No mitochondrial gene mutations explaining the neurological symptoms were found, nor did external neurological complications explain them when compared with 29 NPHS1 control patients. Four children died at an early age: two during dialysis and two shortly after renal transplantation. Two are still alive with a functioning graft. Both have severe motor defects, but are mentally active and social.

Mistreatment of university students most common during medical studies

BACKGROUND

This study concerns the occurrence of various forms of mistreatment by staff and fellow students experienced by students in the Faculty of Medicine and the other four faculties of the University of Oulu, Finland.

METHODS

A questionnaire with 51 questions on various forms of physical and psychological mistreatment was distributed to 665 students (451 females) after lectures or examinations and filled in and returned. The results were analysed by gender and faculty. The differences between the males and females were assessed statistically using a test for the equality of two proportions. An exact two-sided P value was calculated using a mid-P approach to Fisher's exact test (the null hypothesis being that there is no difference between the two proportions).

RESULTS

About half of the students answering the questionnaire had experienced some form of mistreatment by staff during their university studies, most commonly humiliation and contempt (40%), negative or disparaging remarks (34%), yelling and shouting (23%), sexual harassment and other forms of gender-based mistreatment (17%) and tasks assigned as punishment (13%). The students in the Faculty of Medicine reported every form of mistreatment more commonly than those in the Faculties of Humanities, Education, Science and Technology. Experiences of mistreatment varied, but clear messages regarding its patterns were to be found in each faculty. Female students reported more instances of mistreatment than males and were more disturbed by them. Professors, lecturers and other staff in particular mistreated female students more than they mistreated males. About half of the respondents reported some form of mistreatment by their fellow students.

CONCLUSION

Students in the Faculty of Medicine reported the greatest amount of mistreatment. If a faculty mistreats its students, its success in the main tasks of universities, research, teaching and learning, will be threatened. The results challenge university teachers, especially in faculties of medicine, to evaluate their ability to create a safe environment conducive to learning.

Functional evaluation of Dent's disease-causing mutations: implications for ClC-5 channel trafficking and internalization

ClC-5 is a member of the ClC family of voltage-gated chloride channels. Loss-of-function mutations of its corresponding gene (CLCN5) cause Dent's disease, an X-linked kidney disorder, characterized by low-molecular weight proteinuria, hypercalciuria, nephrocalcinosis/nephrolithiasis, and progressive renal failure. Here, we examined the effect of different mutations on function and cellular trafficking of the recombinant protein. Mutant CLCN5 cDNAs were generated by site directed mutagenesis for two premature stop codon variants (R347X and M517IfsX528), and several missense mutations (C221R, L324R, G462 V, and R516 W). We also tested L521R (instead of L521RfsX526 observed) and mutants G506E and R648X (previously reported by others). After heterologous expression in Xenopus oocytes, ClC-5 channel activity and surface expression were determined by two-electrode voltage-clamp analysis and ClC-5 surface ELISA, respectively. Except for the R516 W and R648X variants, none of the mutated proteins induced functional chloride currents or reached the plasma membrane. This is readily understandable for the truncation mutations. Yet, the tested missense mutations are distributed over different transmembrane regions, implying that correct channel structure and orientation in the membrane is not only a prerequisite for proper ClC-5 function but also for Golgi exit. Interestingly, the R648X mutant although functionally compromised, displayed a significant increase in surface expression. This finding might be explained by the deletion of a ClC-5 carboxy-terminal PY-like internalization signal, which in turn impairs channel removal from the membrane. Our observations further imply that recruitment of ClC-5 to alternative routes (plasma membrane or early endosomes) in the trans-Golgi network is mediated via different signal sequences.

Efficacy and safety of pravastatin in children and adolescents with heterozygous familial hypercholesterolemia: a prospective clinical follow-up study

Heterozygous familial hypercholesterolemia (HeFH) is associated with elevated cholesterol levels and early-onset atherosclerosis. We assessed the efficacy and safety for up to 2 yr of pravastatin treatment in 19 girls and 11 boys (age range, 4.1-18.5 yr) with HeFH. Pravastatin was started at 10 mg/d, with a forced titration by 10 mg at 2, 4, 6, and 12 months until the target cholesterol level [< or =194 mg/dl (< or =5 mmol/liter)] was reached. By 2, 4, 6, 12, and 24 months of treatment, the total cholesterol levels had, respectively, decreased by 19, 20, 23, 27, and 26%, and the low-density lipoprotein cholesterol levels had decreased by 25, 27, 29, 33, and 32% compared with the dietary baseline values. Seventeen percent of patients had lipid deposits (carotid plaque, xanthomas, or corneal arcus) at baseline, and 27% had deposits at 1 yr. The side effects were mild, and no clinically significant elevations in alanine aminotransferase, creatine kinase, or creatinine were seen. Growth and pubertal maturation remained normal in all subjects. In conclusion, pravastatin treatment was safe and well tolerated. The efficacy in children with slight or moderate hypercholesterolemia was satisfactory, but in children with severe hypercholesterolemia, it was insufficient.

Dietary factors affecting susceptibility to urinary tract infection

Urinary tract infection (UTI) is usually an ascending infection caused by bacteria derived from stools. Since the bacterial composition of stools is dependent on the diet, it is likely that the risk of UTI will change with changes in the diet. Most data describing diet as a risk factor for UTI come from epidemiological and interventional trials. It has been shown in a case-control setting that frequent consumption of fresh berry or fruit juices and fermented milk products containing probiotic bacteria decreases the risk for UTI recurrence in women. Several interventional trials have found Vaccinium berry products to provide protection from UTI recurrence. Probiotics have not been able to prevent UTI in interventional trials. However, the lack of an effect may be related to too low a dose or to the use of non-optimal products in these trials. Limited data are available on the effects of nutrition on UTI in children. However, there is no reason to expect that children would be different from adults in this respect. In this review, we discuss the dietary factors affecting the susceptibility to UTI.

Four additional CLCN5 exons encode a widely expressed novel long CLC-5 isoform but fail to explain Dent's phenotype in patients without mutations in the short variant

BACKGROUND

Dent's disease is caused by mutations in the CLCN5 gene coding for the chloride channel CLC-5. However, sequencing of CLCN5 exonic regions in some patients presenting with low-molecular-weight proteinuria and hypercalciuria - the hallmarks of Dent's disease - failed to identify causative mutations.

AIM

Given the observation that some species harbour a CLCN5 mRNA encoding an extended CLC-5 aminoterminus compared with the so far known human form, we worked on the presumption that an orthologous (longer) CLCN5 transcript is also present in humans and that our patients may have mutations herein.

METHODS

Extensive databank mining, reverse transcription polymerase chain reaction (RT-PCR) and automated sequencing were used in the search for novel CLCN5 transcripts. The human CLCN5 gene was investigated in 7 patients out of five families by direct automated sequencing of PCR-amplified DNA products.

RESULTS

Two new human CLCN5 transcripts expressed in kidney and various other tissues could be identified. These arise from a novel site of transcription initiation, alternative splicing and the use of four additional CLCN5 exons. If being translated, both these mRNAs would lead to an enlarged CLC-5 protein consisting of 816 amino acids by adding 70 aminoterminal residues to the so far known 746-amino-acid-long isoform. Sequence analysis of the henceforward 17 CLCN5 exons revealed no mutation in the patients with a phenotype resembling Dent's disease.

CONCLUSIONS

Despite the identification of further targets to explain Dent's disease, the molecular defect in our patients remains to be elucidated. Hence, their phenotype may be explained by mutations that affect so far unknown regulating elements of the CLCN5 gene or another gene(s), probably encoding CLC-5 accessory protein(s).

Cyclosporin A for the treatment of severe Henoch-Schönlein glomerulonephritis

We evaluated the efficacy of cyclosporin A (CyA) for treating pediatric patients with severe Henoch-Schönlein glomerulonephritis (HSP-GN) and nephrotic-range proteinuria. Seven pediatric HSP-GN patients (5 boys, 2 girls) were treated with CyA, with a mean age of 10.6 years at diagnosis (range 7.2-15.2 years) and mean follow-up times of 6.0 years (range 4.4-8.9 years) from diagnosis and 5.2 years (range 3.4-7.7 years) from the beginning of the CyA treatment. All had developed nephrotic-range proteinuria within 1-3 months of the HSP diagnosis. A renal biopsy was performed on all the patients, and two showed rapidly progressive glomerulonephritis. They all received additional angiotensin converting enzyme inhibitor medication and one to three types of immunosuppressive treatment had been tried in five of the seven patients before CyA was initiated at a mean interval of 0.7 years after diagnosis (range 0.1-2.0 years). All the patients responded to the CyA treatment within a mean of 1.4 months (range 1 week to 4 months). Four patients achieved a stable remission and had been without CyA treatment for a mean of 3.7 years (range 2.9-5.3 years) by the end of the follow-up. Three patients seemed to become CyA dependent, since they developed proteinuria when the treatment was stopped. CyA treatment had been started significantly earlier ( P=0.045) in the former group (mean 0.2 years, range 0.1-0.3 years) than in the latter (mean 1.5 years, range 1.2-2.0 years). Renal function was preserved in all patients, the glomerular filtration rate, plasma cystatin C, serum albumin, and serum creatinine being within normal limits at the end of the follow-up. We conclude that CyA treatment for severe treatment-resistant HSP-GN is promising, since four of the seven patients enjoy stable remission and all have retained their renal function after a mean follow-up of 6.0 years. However, some patients seem to develop CyA-dependent nephritis.

Outcome of Henoch-Schoenlein nephritis with nephrotic-range proteinuria

PATIENTS AND METHODS

All children with Henoch-Schoenlein glomerulonephritis (HSP-GN) and nephrotic-range proteinuria (> 40 mg/h/m2), treated at 5 university hospitals and in 1 central hospital in Finland during in 1990-1997, were analyzed retrospectively. The mean age of these 19 patients (8 girls, 11 boys) at the time of diagnosis was 9.9 years (range 4.6-15.1 years). A renal biopsy had been performed in all cases, giving findings according to the classification used in the International Study of Kidney Diseases in Children (ISKDC) of grade II (4 patients), grade III (10), grade IV (4) and grade V (1). Six patients underwent a second biopsy.

RESULTS

The yearly incidence of nephrotic-range HSP-GN in Finland was 2 per 1 million children under 15 years of age. After a mean follow-up of 4.6 years (range 9 months-9.1 years), 3 patients (15.7%) had no signs of nephritis, 11 (57.9%) had proteinuria < 1 g/day or microscopic hematuria, 2 (10.5%) had proteinuria > 1 g/day, and 3 (15.7%) had developed ESRD or uremia. 47% of the patients needed medication for proteinuria at the time of the latest follow-up. The first kidney biopsy did not predict the outcome of HSP-GN, since all the patients with the poorest outcome had only ISKDC II-III findings in their first biopsy.

CONCLUSION

According to our series, the morbidity in cases of HSP-GN with nephrotic-range proteinuria is high and a close clinical follow-up is needed. The treatment of HSP-GN patients should be based on the clinical presentation rather than on the biopsy findings.

Fructose-1,6-bisphosphate for improved outcome after hypothermic circulatory arrest in pigs

OBJECTIVE

Fructose-1,6-bisphosphate is a high-energy intermediate in the anaerobic metabolism. It enhances glycolysis, preserves cellular adenosine triphosphate, and prevents the increase of intracellular calcium during ischemia. The potential neuroprotective effect of fructose-1,6-bisphosphate during hypothermic circulatory arrest was evaluated in a surviving porcine model.

METHODS

Twenty-four pigs were randomly assigned to receive two intravenous infusions of either fructose-1,6-bisphosphate (500 mg/kg) or saline solution. The first infusion was given immediately before a 75-minute period of hypothermic circulatory arrest and the second was given immediately after hypothermic circulatory arrest.

RESULTS

The 7-day survivals were 83.3% in the fructose-1,6-bisphosphate group and 41.7% in the control group (P =.09). The treated animals had significantly better postoperative behavioral scores. The administration of fructose-1,6-bisphosphate was associated with higher venous phosphate and sodium levels, lower venous ionized calcium levels, higher blood osmolarity, and a better fluid balance. Intracranial pressure and venous creatine kinase isoenzyme MB were significantly lower in the fructose-1,6-bisphosphate group during rewarming (P =.01 and P =.001, respectively). Among the treated animals, brain glucose, pyruvate and lactate levels tended to be higher, brain glycerol levels tended to be lower, and the histopathologic score of the brain was significantly lower (P =.04).

CONCLUSIONS

Intravenous administration of fructose-1,6-bisphosphate at 500 mg/kg before and after hypothermic circulatory arrest in a surviving porcine model was associated with better survival, behavioral outcome, and histopathologic score. The observed lower blood creatine kinase isoenzyme MB and brain glycerol levels and the higher brain glucose, pyruvate, and lactate levels in the fructose-1,6-bisphosphate group suggest that this drug has supportive effects on myocardial and brain metabolisms.

The adult kidney 24 years after childhood Henoch-Schönlein purpura: a retrospective cohort study

BACKGROUND

Henoch-Schönlein purpura arising in childhood could cause renal impairment or even an end-stage renal disease later in life. We aimed to assess long-term outcome of childhood Henoch-Schönlein purpura after 24 years.

METHODS

We studied a cohort of 26 boys and 26 girls who were treated for Henoch-Schönlein purpura at Helsinki University Hospital during 1964-83. Mean follow-up was 24.1 years (SD 6.0; 16.4-36.5). All participants were asked about their state of health in a questionnaire, and 47 (90%) were examined by a doctor. Patients' medical history data were obtained from health-care centres and regional hospitals.

FINDINGS

Seven (35%) of 20 adults who had severe Henoch-Schönlein purpura and glomerulonephritis at onset had renal impairment as adults, compared with two (7%) of 27 with mild or no renal symptoms at onset (relative risk 4.7, 95% CI 1.3-18.7). Relative risk for a poor outcome was 5.0 in women (1.1-32.5) and 2.0 in men (0.2-17.5). All patients with no renal symptoms at onset had a good outcome after 24 years of follow-up. Severity of first kidney biopsy finding did not correlate with risk of a poor outcome. 16 (70%) of 23 pregnancies had been complicated by hypertension, proteinuria, or both. Five (56%) of the nine women with complicated pregnancies had a poor renal outcome.

INTERPRETATION

Long-term follow-up of all patients who had Henoch-Schönlein purpura with severe renal symptoms at onset is needed during adulthood. All women who had even mild renal symptoms at onset of Henoch-Schönlein purpura should be carefully observed during and after pregnancy.