HOGA1 Gene Mutations of Primary Hyperoxaluria Type 3 in Tunisian Patients.

BACKGROUND: Primary hyperoxaluria type 3 (PH3) is due to mutations in the recently identified 4-hydroxy-2-oxoglutarate aldolase (HOGA1) gene. PH3 might be the least severe form with a milder phenotype with good preservation of kidney function in most patients. The aim of this study was to report three PH3 cases carrying mutations in HOGA1. MATERIALS AND METHODS: Genetic analysis of HOGA1 was performed in patients with a high clinical suspicion of PH after sequencing of AGXT and GRHPR genes, which was negative. Also, a complete AGXT/GRHPR MLPA was performed in these patients in order to detect large deletions/insertions. RESULTS AND DISCUSSION: Two different HOGA1 gene mutations were identified: the p.Pro190Leu in a homozygous state and the p.Gly287Val in two patients in homozygous and heterozygous carriers. The median age at onset of clinical symptoms was 3.93 years. Most of the patients had a positive family history for recurrent urolithiasis. The p.Pro190Leu mutation was reported with impaired renal function at follow-up; however, the p.Gly287Val was presented with normal renal function. All patients were presented with urolithiasis, but only one had a nephrocalcinosis. CONCLUSION: This study expanded the number of PH3 patients from 63 to 66 cases. The p.Pro190Leu and the p.Gly287Val mutations found in this study can provide a first-line investigation in Tunisian PH1 patients.

Nephrocalcinosis in Tunisian children.

Background Nephrocalcinosis is rare in children. Its etiologies are multiple. The aim of this study was to analyze the etiology of nephrocalcinosis in Tunisian children. Methods This retrospective study was conducted in the department of pediatrics in Charles Nicolle Hospital during a period of 10 years (2001-2010). Results There were 40 children. The mean age was 3.5 years. The most common signs and symptoms at presentation were growth retardation (42.5%) and hematuria (53.8%). At presentation, renal failure was detected in 70% of patients. The diagnosis of nephrocalcinosis was performed by ultrasonography. The etiology of nephrocalcinosis included primary hyperoxaluria type 1 (65%) and distal renal tubular acidosis (20%). A progression to renal insufficiency was observed in 18 cases. Conclusion Primary oxaluria is the principal cause of nephrocalcinosis; early diagnosis and treatment are mandatory as they help limiting renal function deterioration.

Focal segmental glomerulosclerosis in children.

Background Focal segmental glomerulosclerosis (FSGS) represents 20% of nephrotic syndrome in children. The clinical course and prognosis is heterogeneous in children. The aim of this study was to analyze treatment and outcome of children with FSGS. Methods This retrospective study was conducted in the Department of Pediatrics in Charles Nicolle Hospital during a 15-year period (1996-2010). Results There were 30 children, 16 boys and 14 girls. The mean age was 7 ± 4 years. Nephrotic syndrome was observed in 26 patients, hematuria was noticed in 2 patients and renal insufficiency was detected in 2 patients at presentation. FSGS, not otherwise specified, was the predominant variant. All patients with nephrotic syndrome were treated with steroids. Only three patients responded to it. Twenty one patients were treated with cisclosporin A and this resulted in a 57% complete remission and a 24% partial response. Cyclophosphamide was administered to 6 patients and engendered a 50% complete remission. Six patients were treated with mycophenolate mophetil and showed no response in all cases. Renal insufficiency has been developed in 12 children. Conclusion Results from this study showed that the majority of children with FSGS achieve a high sustained remission rate with ciclosporine A.

Peritoneal dialysis: Experience of the department of pediatrics of the hospital Charles Nicolle of Tunis.

Introduction Peritoneal dialysis (PD) is still the most common modality used in treatment for children with End Stage Renal Disease (ESRD). The objective of this study was to identify the epidemiological, clinical, and microbiological factors affecting the outcome of PD. Methods In this study, we retrospectively reviewed the records of 85 patients who were treated with DP for the last ten years (from January 2004 to December 2013) in the Department of Pediatrics in Charles Nicolle hospital, Tunis. Results The mean duration of PD was 18.1±12 months (3.5-75 months). The average age of PD onset was 9.3±5.7 years (29 days-23 years). The sex ratio was 1.5. In a significant number of cases with ESRD, the primary cause is Congenital Anomalies of the Kidneys and Urinary Tract (CAKUT). Seventy-four of our patients (87%) had been treated with Automated PD. The average time between catheter placement and PD commencement was 3.9±4.6 days. Catheter change was 1.62 (1-5). Sixty-one patients (71.8%) had experienced at least one episode of peritonitis. The most frequently isolated organisms was the Gram-positive bacteria (61%). Survival rates without peritonitis at 12th, 24th and 36th months were 40%, 32% and 18%, respectively. Transition to permanent hemodialysis was required in 66% of patients. Conclusion Considering the important incidence of peritonitis in our patients, it is imperative to establish a targeted primary prevention.

Contribution of ultrasound scans in the first episode of urinary tract infection in children.

Background - Vesicoureteral reflux (VUR) is a common pediatric urologic disorder. After the first urinary tract infection (UTI), imaging studies are recommended, starting with a renal ultrasound (US) and voiding cystourethrography (VCUG). We propose to determine whether abnormalities found on US can help indicate the necessity of VCUG in children after the first urinary tract infection. Methods - A retrospective study included all children admitted with their first episode of urinary tract infection from January 2007 to December 2012. Results - A total of 311 children were included. The median age was 2.5 years, 72.3% were female. VUR Prevalence was 14%.  Forty-four patients were found to have VUR on VCUG, giving a prevalence of 14%. Of these 44 patients, 11 had grade I reflux, 6 had grade II reflux, 3 had grade III reflux, 15had grade IV reflux, and 9 had grade V reflux. Ultrasound findings were positive for VUR in 43 patients, 19 of them had RVU. Twenty five patients had a normal ultrasound but showed VUR on VCUG (11 had grade I reflux, six grade II reflux, three grade III reflux and five grade IV reflux).  The sensitivity and specificity of ultrasound in suggesting VUR were 43% and 91%, respectively. The positive predictive value of ultrasound in suggesting VUR was 44%; the negative predictive value was 91%. Conclusion - Renal ultrasound findings are specific for VUR in children with a first UTI, but no sensitive. Clinicians should consider renal ultrasound results to take decision on whether or not to proceed with a VCUG in the investigation of a first episode UTI in young children.

Nephrotic syndrome in children: risk factors for steroid dependence.

Background - Most patients with idiopathic nephrotic syndrome are steroid-responsive, about 50% relapse and often become steroid-dependent and exposed to long-term steroid complications. The aim of this study was to determine predictive risk factors for steroid dependence using clinical and biological variables present at onset of the disease. It may be useful to adapt the therapeutic strategy. Methods - Retrospective hospital-based cohort study in the department of pediatric nephrology of Charles Nicolle, Tunis, between 2002 and 2012 included 52 children with idiopathic steroid-responsive nephrotic. Results - Risk factors for steroid dependency identified from univariate analysis were season of the first episode (winter or autumn) (p=0.008), hyperalpha2globulinemia>16g/l (p=0.028), hyperbeta2globulinemia >3g/l (p=0.003), hypercholesterolemia>10mmol/l (p=0.001), proteinuria>110mg/kg/day (p=0.05), time to achieve remission>9 days (p=0,0001). Logistic regression revealed that time to first remission and hypercholesterolemia>10mmol/l at first presentation were independent risk factors for steroid dependency. Conclusion - Time to first remission, hypercholesterolemia more than 10mmol/l at first presentation and a respiratory tract infection at first relapse are independent risk factors for steroid dependency.

Mycophenolate mofetil in treatment of childhood steroid-dependent nephrotic syndrome.

OBJECTIVES: To establish the efficacy of mycophenolate mofetil (MMF) in steroid dependent nephrotic syndrome and to determine the predictive factors for a good response. METHODS: retrospective hospital-based cohort study in the department of pediatric of Charles Nicolle hospital, between 2005 and 2012 included 30 children with steroid-dependent nephritic syndrome who were treated with MMF. RESULTS: A total of 30 patients (20 boys and 10 girls) were included. The mean age at the time of diagnosis was 5.45 years and treatment with MMF was performed at a mean age of 10.84 years. Side effects of steroid were found in 17 patients. Four patients had renal impairment (ciclotoxicity). The evolution of the disease was 5.45 years. The average rate of relapse was 1.75 relapses / year. The minimum dose of corticosteroids was 0.74 mg / kg / day. During MMF therapy, the average rate of relapse was 0.45 relapses / year (p<0.0001). The average residual steroid dose was 0.2 mg/kg/ day. Responding patients were younger at the onset of MMF (8.57 versus 12.83, p=0.009), had a short development period (3.75 vs 7.03 years, p=0.05), had not received cyclosporine (p=0.02). CONCLUSION: MMF allows steroid sparing and reduces the number of relapse. It is more effective than the patients are young, with short disease outcome and had not previously been treated with cyclosporine.

Nodular gastritis: an endoscopic indicator of Helicobacter pylori infection in children.

BACKGROUND: Helicobacter pylori (Hp) infection is a common and universally distributed bacterial infection. It is predominantly acquired in childhood. AIM: To assess the relationship between endoscopic nodular gastritis and Hp infection. METHODS: A retrospective study was conducted in children who underwent upper gastrointestinal endoscopy for chronic abdominal pain. All children who had five gastric biopsies for histologic analysis, urease test and Hp culture were included in the study. The Sensitivity and sensibility of nodular gastritis were determined and different parameters were studied according the presence or not of nodular gastritis(age, gender, Hp status, gastritis score and lymphoid follicles). RESULTS: 49 children, mean age 6.9 ± 3 years (range 1-12 years) were eligible for the analysis. Hp Infection was diagnosed in 35 out of the 49 children (71.5 %). Nodular gastritis was recorded in 16 out of 49 children and in 14 infected children and 2 out of 14 non infected children (p=0.07), 40% sensitivity, 85.7% specificity, 87.5% positive predictive value, and 36,4% negative predictive value. The parameters associated significantly to the presence of nodular gastritis were older age: (p=0.04), Hp infection: (p=0.01), chronic gastritis: (p=0.05), active gastritis: (p=0.02), follicular gastritis: (p=0.005), higher gastritis score: (p=0.005). Completely normal gastric mucosal histology was never found in infected children with antral nodularity. Among all infected children, the gastritis score was significantly higher when there was a nodular gastritis and follicular gastritis was significantly associated to nodular gastritis. CONCLUSION: The endoscopic pattern of antral nodularity identifies children with Hp infection, and active chronic follicular gastritis.

Infantile Parotid Hemangioma With Diagnostic Dilemma: A Case Report.

INTRODUCTION: Salivary gland tumors are uncommon in children; hemangiomas are one of them. We report a case of infantile hemangioma of the parotid gland which posed a diagnostic dilemma. PATIENTS AND METHODS: Four-month-old infant presented with swelling at the parotid gland region, which was progressively increasing. There was a diagnostic dilemma with initial misdiagnosis as acute parotitis. Imaging studies with ultrasonography and CT with contrast were requested. RESULTS: Imaging studies revealed hyperintense lobulated mass suggestive of parotid hemangioma. Vascular consultation recommended conservative management with follow-up after 3 months. On follow-up, there was an increase in mass size, and propranolol was started. Swelling showed a good response on the next follow-up visit and is still on medical management. CONCLUSION: Parotid hemangiomas frequently pose a diagnostic dilemma, but the typical noninflammatory nature of the swelling and radiological evaluation confirms the diagnosis.

[Evaluation of materno-foetal infectious risk after isolated premature rupture of membranes in at term new-born]. / Évaluation du risque d'infection materno-foetale après rupture prématurée des membranes isolée chez le nouveau-né à terme.

BACKGROUND: Premature rupture of membranes (PROM) is defined as rupture of membranes occurring before the onset of labor. It complicates 5 to 10 % of pregnancies. It continues to be a major cause of morbidity and mortality in the newborn. AIM: To evaluate infectious risk associated with PROM in at term and asymptomatic new-born and to study this risk according to the duration of rupture. METHODS: Retrospective study in neonatal unit of Charles Nicolle hospital of Tunis including all cases with isolated PROM in at term new-born during the year 2007. RESULTS: 299 cases were identified over 3749 live births that is an incidence of 8 %, divided to: 21 cases (7 %) between 6 and 12 hours, 86 cases (28.8 %) between 12 and 18 hours, 61 cases (20.4 %) between 18 and 24 hours and 131 cases (43.8 %) more than 24 hours. Diagnosis of colonization was reported in 54 % of cases when PROM occurred between 12 and 18 hours versus respectively 27.3%, 0 % and 18 % in respectively subset of 6 to 12 hours, 18 to 24 hours and more than 24 hours (p=0,03). 62 % of foeto-maternel infections were reported in subset of PROM more than 24 hours and 13.8 % in the subset between 18 and 24 hours. CONCLUSION: Our study emphasizes the important risk of foetomaternel infection associated with isolated PROM. This risk is major when the rupture exceed 12 hours but the limit of 18 hours can unrecognized some cases of probable foeto-maternel infection.

Vascular complications after pediatric kidney transplantation.

BACKGROUND: Vascular complications, especially those including the renal vein, remain a major cause of lost graft. AIMS: To evaluate retrospectively the incidence and management of vascular complications after pediatric renal transplantation and to assess possible risk factors and their effects on patient and graft. METHODS: A total of 82 consecutive renal transplants were performed in 79 patients at a single institution. The diagnosis of vascular complications was suspected in the presence of suggestive symptoms and confirmed by Doppler ultrasound and if necessary by a computed tomographic angiography. Urgent exploration was performed in all suspected cases. RESULTS: There were seven vascular complications (8,5%), including renal vein thrombosis in four patients, renal artery stenosis in one, and sural thrombophlebitis in two. The thrombosis of the graft vein which is the main complication occurred at mean 24 hours after renal transplantation. All these patients needed transplant nephrectomy after thrombosis event. In the remaining cases, the outcome was favorable even for the patient with transplant renal artery stenosis. CONCLUSIONS: Vascular complications are common and serious events affecting patient and graft survivals. A perfect surgical technique and rigorous radiological monitoring may result in decreased incidence and severity of these complications.

Sjogren-Larsson Syndrome: A case series of five members from an extended family with a novel mutation.

BACKGROUNDD: Sjogren-Larsson syndrome (SLS) is a rare autosomal recessive disorder, characterized by a triad of spastic tetraplegia or diplegia, congenital ichthyosis, and intellectual disability. METHODS: We report a seven-years-old female born to consanguineous parents who presented with erythematous dry scaly skin all over the body sparing the face, without collodion membrane which started since birth. There were associated with global developmental delay and seizure disorder. SLS was suspected and hence sequence analysis of the ALDH3A2 gene by next-generation sequencing was performed for the patient. RESULTS: A novel nucleotide exchange in homozygous state at position c.1320 in exon 9 of the ALDH3A2 gene (c.1320T>A), leading to a stop of the protein sequence (p.Tyr440) was detected in the patient. Genetic testing of the patient's extended family revealed another four affected family members with the same mutation. CONCLUSIONS: SLS should be suspected in any patient with a triad of ichthyosis, intellectual disability and spastic di/tetraplegia. Molecular genetic testing of the ALDH3A2 gene should be performed to confirm the diagnosis. Extended family screening is highly recommended.

Infantile cystinosis: From dialysis to renal transplantation.

Cystinosis is an autosomal recessive, lysosomal storage disease characterised by the accumulation of the amino acid cystine in different organs and tissues. It is a multisystemic disease that can present with renal and extra-renal manifestations. In this report, we present the first case of transplanted nephropathic cystinosis in a Tunisian child. A 4-year-old Tunisian boy born to nonconsanguineous parents, was treated in our medical services in 1990 for cystinosis. Since the age of five months, he developed symptoms of severe weight loss, vomiting, dehydration, and polyuria. He manifested the Toni Debré Fanconi syndrome. Slit lamp examination of the anterior segment of both eyes revealed fine, shiny crystal-like deposits diffusely distributed in the corneal epithelium and the stroma. Our patient had renal failure. At the age of seven, he reached terminal chronic renal failure and was treated with peritoneal dialysis. Hemodialysis was started at the age of nine years. At the age of 13 years, he received a renal transplantation and was started on cysteamine 1999, five months after the renal transplantation. Currently, the patient is 28-year-old. The graft has survived 15 years after the transplantation. Renal functions were stable with a serum creatinine of 123 µmol/L at last follow-up.

Primary hyperoxaluria in infants.

The infantile form of primary hyperoxaluria type-1 (PH-1) is characterized by a rapid progression to the end-stage renal disease (ESRD) due to both increased oxalate load and reduced glomerular filtration rate. In the literature, data on this form are limited. The purpose of this study is to analyze retrospectively the clinical, biological, and radiological features of children who were diagnosed with PH-1 during the 1(st) year of life. We reviewed the records of all children with PH-1 diagnosed and followed-up at our department between January 1995 and December 2013. Among them, only infants younger than 12 months of age were retrospectively enrolled in the study. Fourteen infants with the median age of two months were enrolled in the study. At diagnosis, 11 patients had ESRD. All patients had nephrocalcinosis and two of them had calculi. The diagnosis was established in nine patients on the basis of the positive family history of PH-1, bilateral nephrocalcinosis, and quantitative crystalluria. In four patients, the diagnosis was made with molecular analysis of DNA. Kidney biopsy contributed to the diagnosis in one patient. During follow-up, two patients were pyridoxine sensitive and preserved renal function. Seven among 11 patients who had ESRD died, four patients are currently undergoing peritoneal dialysis. Children with infantile PH and ESRD are at high risk of early death. Peritoneal dialysis is not a treatment of choice. Combined liver-kidney transplantation is mandatory.

A novel mutation in the AGXT gene causing primary hyperoxaluria type I: genotype-phenotype correlation.

Primary hyperoxaluria type I (PH1) is an autosomal recessive metabolic disorder caused by inherited mutations in the AGXT gene encoding liver peroxisomal alanine : glyoxylate aminotransferase (AGT) which is deficient or mistargeted to mitochondria. PH1 shows considerable phenotypic and genotypic heterogeneity. The incidence and severity of PH1 varies in different geographic regions. DNA samples of the affected members from two unrelated Tunisian families were tested by amplifying and sequencing each of the AGXT exons and intron-exon junctions. We identified a novel frameshift mutation in the AGXT gene, the c.406_410dupACTGC resulting in a truncated protein (p.Gln137Hisfs*19). It is found in homozygous state in two nonconsanguineous unrelated families from Tunisia. These molecular findings provide genotype/phenotype correlations in the intrafamilial phenotypic and permit accurate carrier detection, and prenatal diagnosis. The novel p.Gln137Hisfs*19 mutation detected in our study extend the spectrum of known AGXT gene mutations in Tunisia.

[Etiologies of end-stage renal disease of children in Tunisia]. / Épidémiologie de l'insuffisance rénale terminale de l'enfant en Tunisie.

BACKGROUND: The end-stage renal disease (ESRD) in children has special features in terms of etiologies, therapeutic modalities and access to renal transplantation. In Tunisia, there are no data on the epidemiology of ESRD in children. The aim of our study was to describe epidemiology of ESRD among Tunisian children. METHODS: This retrospective study was conducted in pediatric departments in Charles-Nicolle Hospital, Tunis and Hedi Chaker hospital, Sfax, during a period of 15 years (1st January 1998-31st December 2013). We included children who develop ESRD before the age of 15 years. RESULTS: In total, 166 patients were included. The median duration of follow-up was 48 months. We collected respectively 24 children (14.5%) aged less than 2 years, 24 children (14.5%) aged between 2 and 6 years and 118 children (71%) older than 6 years. The sex ratio was equal to 1.4. The mean incidence was 4.25 cases per million children. The main causes were represented by congenital anomalies of the kidneys and urinary tract (35.5%), hereditary renal disease (31.3%) and glomerular kidney disease (9.6%). All patients were treated in kidney transplant dialysis programs; the main mode of dialysis was represented by peritoneal dialysis, which represented the initial dialysis mode in 81% of cases. The transition to hemodialysis was noted in 43.4% cases. Thirty-eight patients (22.8%) were transplanted. The mortality rate was 27.1%. The leading cause of death was cardiovascular diseases (37.7%) and infections (22.2%). CONCLUSION: The creation of a national registry of kidney disease in Tunisia is necessary for a better knowledge of needs for dialysis and renal transplantation in children.

Tuberculosis following kidney transplantation: report of paediatric case.

Recipients of solid organ transplantation are, because of immunosuppressive therapy, at high risk to develop opportunistic infections including tuberculosis (TB). The incidence, clinical manifestations, and optimal diagnostic tests of this disease in this population have not been adequately defined. In this paper, we report a case of 13 year-old boy who developed pulmonary tuberculosis following a second renal transplantation from a deceased donor. The described case points diagnostic difficulties of the tuberculosis disease which are due to insidious and non specific clinical presentation. Also, the treatment is delicate because interaction between immunosuppressive drugs and antituberculosis drugs.

Williams-Beuren syndrome associated with single kidney and nephrocalcinosis: a case report.

Williams-Beuren syndrome is a rare neurodevelopmental disorder, characterized by congenital heart defects, abnormal facial features, mental retardation with specific cognitive and behavioral profile, growth hormone deficiency, renal and skeletal anomalies, inguinal hernia, infantile hypercalcaemia. We report a case with Williams-Beuren syndrome associated with a single kidney and nephrocalcinosis complicated by hypercalcaemia. A male infant, aged 20 months presented growth retardation associated with a psychomotor impairment, dysmorphic features and nephrocalcinosis. He had also hypercalciuria and hypercalcemia. Echocardiography was normal. DMSA renal scintigraphy showed a single functioning kidney. The FISH generated one ELN signal in 20 metaphases read and found the presence of ELN deletion, with compatible Williams-Beuren syndrome.

[Outcome of rapidly progressive glomerulonephritis post-streptococcal disease in children]. / Profil évolutif de la glomérulonéphrite rapidement progressive post-infectieuse de l'enfant.

BACKGROUND: Rapidly progressive glomerulonephritis is a rare form of postinfectious glomerulonephritis. The aim of this study was to describe the outcome of our patients with severe post-streptococcal glomerulonephritis. METHODS: This retrospective study was conducted in the department of pediatrics in Charles-Nicolle Hospital during a period of 13 years (1997-2009). RESULTS: Twenty-seven children were identified. The mean age was 8.7 years. All patients presented renal failure at presentation. The mean serum creatinine at presentation was 376.9 µmol/L. Six patients presented nephrotic syndrome. Twenty-six children had renal biopsies. Renal biopsies showed crescents in 24 cases. Eighteen children received pulse dose of corticosteroids (66.6%) and 6 children (22%) received pulse dose of corticosteroids and cyclophosphamide. Eleven patients required dialysis. At last follow-up, 22 patients (81.5%) had normal kidney function, 2 had renal dysfunction and 3 reached end stage renal disease. The only significant determinant for renal survival was the supportive dialysis (P=0.015). CONCLUSION: Rapidly progressive glomerulonephritis is uncommon. There have been significant advancements in supportive, as well as specific therapy, but the outcome continues to be poor.

[Peritonitis in pediatric patients receiving peritoneal dialysis]. / Péritonite infectieuse sur cathéter de dialyse péritonéale chez l'enfant.

BACKGROUND: Peritonitis on catheter of dialysis represents the most frequent complication of the peritoneal dialysis (PD) in the pediatric population. It remains a significant cause of morbidity and mortality. In this study, we investigated the risk factors for peritonitis in children. METHODS: In this study, we retrospectively collected the records of 85 patients who were treated with PD within the past ten years in the service of pediatrics of the University Hospital Charles-Nicolle of Tunis. RESULTS: Peritonitis rate was 0.75 episode per patient-year. Notably, peritonitis caused by Gram-positive organisms were more common. Analysis of infection risk revealed three significant independent factors: the poor weight (P=0.0045), the non-automated PD (P=0.02) and the short delay from catheter insertion to starting PD (P=0.02). The early onset peritonitis was significantly associated with frequent peritonitis episodes (P=0.0008). The mean duration between the first and second episode of peritonitis was significantly shorter than between PD commencement and the first episode of peritonitis. We revealed a significant association between Gram-negative peritonitis and the presence of ureterostomy (0.018) and between Gram-positive peritonitis and the presence of exit-site and tunnel infections (0.02). Transition to permanent hemodialysis was needed in many children but no death occurred in patients with peritonitis. CONCLUSION: Considering the important incidence of peritonitis in our patients, it is imperative to establish a targeted primary prevention. Nutritional care must be provided to children to avoid poor weight. The automated dialysis has to be the modality of choice.