Predictive Factors of Renal Graft Failure in Tunisian Children and young adults: A Retrospective Study.

INTRODUCTION: Pediatric end-stage renal disease is a rare but severe condition that causes numerous complications and impairs the quality of life of children. Kidney transplantation is the therapy of choice in pediatric end-stage renal disease. AIM: Our study aimed to identify the predictive factors of renal graft failure after kidney transplantation in Tunisian children and young adults. METHODS: We conducted a retrospective bicentric study of children and young adults (age≤20 years) who had undergone renal transplantation between 1989 and 2019 in Tunisia. We analyzed long-term survival rates and complications after pediatric kidney transplantation and searched for predictive parameters for graft dysfunction. We used a univariate and a multivariate analysis to identify predictive factors of graft survival. RESULTS: A total of 112 patients underwent 115 kidney transplantations. Graft failure occurred in 30% of the cases. The overall 1-, 3-, 5- and 10-year graft survival rates were 92%, 89.1%, 85.9% and 74.5% respectively. The following parameters strongly influenced graft survival: immunosuppressive regimen including an association other than Mycophenolate mofetil- tacrolimus and corticosteroids (p=0.002), year of transplant (p<0.0001 for 1987-2000), deceased donor (p = 0.039), underlying etiology of end-stage renal disease (p=0.045), occurrence of acute or chronic rejection (p<0.001), a urine protein greater than 0.3 g/l per day (p=0.002), post-transplant urologic complications (p=0.002), five-year creatinine level>1.28 mg/dl (p<0.001). The overall 1-, 3-, 5- and 10-year patients survival rates were 97%, 95%, 90.2% and 84.4% respectively. CONCLUSIONS: Our study identified several predictive factors of graft failure in Tunisian children and young adults undergoing renal transplantation.

Delayed Graft Function in Pediatric Kidney Transplant: Risk Factors and Outcomes.

OBJECTIVES: We aimed to identify risk factors and outcomes of delayed graft function in pediatric kidney transplant. MATERIALS AND METHODS: This retrospective study included all kidney transplant recipients ≤19 years old followed up in our department for a period of 34 years, from January 1989 to December 2022. RESULTS: We included 113 kidney transplant recipients. Delayed graft function occurred in 17 cases (15%). Posttransplant red blood cell transfusion was strongly associated with delayed graft function (adjusted odds ratio = 23.91; 95% CI, 2.889-197.915). Use of allografts with multiple arteries and cold ischemia time >20 hours were risk factors for delayed graft function (adjusted odds ratio = 52.51 and 49.4; 95% CI, 2.576-1070.407 and 1.833-1334.204, respectively). Sex-matched transplants and living donors were protective factors for delayed graft function (adjusted odds ratio = 0.043 and 0.027; 95% CI, 0.005-0.344 and 0.003-0.247, respectively). Total HLA mismatches <3 played a protective role for delayed graft function (adjusted odds ratio = 0.114; 95% CI, 0.020-0.662), whereas transplant within compatible but different blood types increased the risk of delayed graft function (adjusted odds ratio = 20.54; 95% CI, 1.960- 215.263). No significant correlation was shown between delayed graft function and allograft survival (P = .190). Our study suggested delayed graft function as a key factor in allograft rejection-free survival (adjusted odds ratio = 3.832; 95% CI, 1.186-12.377). Delayed graft function was a negative factor for early graft function; patients with delayed graft function had a lower estimated glomerular filtration rate at discharge (P = .024) and at 3 (P = .034), 6 (P = .019), and 12 months (P = .011) posttransplant. CONCLUSIONS: Delayed graft function is a major determinant of early graft function and allograft rejection-free survival. Further research is required to establish proper preventive measures.

An exceptional cause of polyuria-polydipsia syndrome in a 10-year-old boy.

Polyuria-polydipsia syndrome is a frequent symptom in pediatrics, primarily attributed to diabetes mellitus. In the context of diabetes insipidus, this syndrome can stem from central or nephrogenic factors. Sjögren's syndrome, an uncommon autoimmune disease in children, can affect multiple organs. Kidney involvement as described in adults is usually related to glomerular or tubular impairment, often linked to distal tubular acidosis. As a kidney involvement during childhood, Sjögren's syndrome has rarely been reported. Hereby, we present the case of Sjögren's syndrome revealed by polyuria-polydipsia syndrome in a 10-year-old boy.

Predictive factors of urinary tract infections caused by extended-spectrum ß-lactamase-producing Escherichia coli in children: a prospective Tunisian study.

AIM: To identify the predictive factors for the occurrence of community-acquired urinary tract infections caused by Extended-Spectrum ß-Lactamase-Producing Escherichia coli in children. METHODS: This was a single-center prospective observational study of children and young adults with community-acquired urinary tract infections caused by Extended-Spectrum ß-Lactamase-Producing Escherichia coli. The study was conducted in the pediatric nephrology department in Charles Nicolle Hospital, Tunis, Tunisia from January 1st, 2019, to December 31, 2020. Patients ≤20 years with community-acquired urinary tract infection caused by Escherichia coli were included prospectively in our study. RESULTS: We collected 290 urinary tract infections in 218 patients, including 92 urinary tract infections due to Extended-Spectrum ß-Lactamase-Producing Escherichia coli. The mean age of children was 50.10±54.28 months, with a female predominance in 65.2% of cases. Risk factors for the acquisition of multidrug-resistant bacteria were antibiotic therapy in the previous three months, antibiotic prophylaxis, hospitalization in the year preceding the urinary tract infections, and outpatient care in the previous six months (p < 0.05). Resistance to Ceftazidime, Cefotaxime, Cefixime, Gentamicin and Ofloxacin was significantly associated with the presence of an Extended-Spectrum ß-Lactamase strain. Antibiotic resistance was significantly more observed in the age group above 6 years. Co-habitation with health care worker was a risk factor for resistance to Amoxicillin-Clavulanic Acid. CONCLUSION: Understanding the epidemiological profile and risk factors for ESBL-producing UTIs, including Extended-Spectrum ß-Lactamase-producing Escherichia coli in the pediatric population, could improve the therapeutic approach and lead to more rational prescription of antibiotics.

Unusual cause of cerebral calcifications in an 8-year-old girl.

Key Clinical Message: Genetic counseling and genetic screening for hyperoxaluria should be recommended for children with urinary lithiasis for early management to avoid progression to oxalosis especially if there is a family history of lithiasis.Primary hyperoxaluria type 1 (PH1) is caused by a deficiency of the liver peroxisomal enzyme alanine-glyoxylate aminotransferase (AGT) resulting in overproduction of calcium oxalates. In its later stage, a systemic deposit of calcium oxalates is observed. We present the case of an 8-year-old girl with exceptional neurological involvement secondary to this disease.

Mechanical complications of peritoneal dialysis in Tunisian children.

INTRODUCTION: Peritoneal dialysis (PD) is the method of choice for extra-renal replacement therapy (ERT) for children with end-stage renal disease (ESRD), because of its various advantages. However, it presents different infectious and non-infectious complications, causes of important morbidity and mortality. AIM: To determine the mechanical complications of PD in our center and to identify risk factors of their occurrence. METHODS: We retrospectively collected the records of 99 patients who were treated with PD within the past eleven years in the department of pediatrics of the University Hospital Charles Nicolle of Tunis. Analysis examining possible risque factors were performed using parametric and non-parametric tests. RESULTS: A total of 63 patients had mechanical complications with an incidence of peritoneal dialysis catheter revision of 1 procedure every 38 months. The causes were dominated by catheter migration (27.5%) and obstruction by fibrin or blood clotting (19.8%). A history of peritonitis (p=0.046) and the presence of comorbidity (p=0.008) were the two independent risk factors for catheter revision. Inguinal hernia was noted in six patients. No patient presented with a hydrothorax. Seven patients presented an episode of hemoperitoneum. CONCLUSION: Our results lead us to focus our efforts on preventing peritonitis and controlling morbidity. Prospective studies will enable us to confirm our results.

Primary hyperoxaluria type 1: Clinical, genetic, and evolutionary characteristics in Tunisian children.

INTRODUCTION: There are three types of primary hyperoxaluria, with type 1 considered the most severe. AIM: To analyze the clinical, genetic, and evolutionary characteristics of type 1 primary hyperoxaluria with pediatric onset. METHODS: This was a retrospective, descriptive study that included Tunisian children under the age of 18 at the time of diagnosis over a period of 25 years (January 1, 1996, to December 31, 2022). RESULTS: Thirty-five patients were included, with a mean age of 4.1 years. The most common presenting circumstances of the disease were nephrolithiasis and end-stage renal failure. The average serum creatinine level was 225.42 µmol/l. Five mutations were identified, with the p.Ile244Thr mutation being the most prevalent. Nephrocalcinosis, surgical intervention, and a creatinine level ≥57 µmol/l were predictive of progression to end-stage renal failure. The infantile form was predictive of mortality. CONCLUSIONS: Screening for the disease would improve the prognosis of this condition.

Primary focal segmental glomerulosclerosis in children: epidemiology, clinical presentation and prognosis.

INTRODUCTION: Focal segmental glomerulosclerosis is a histopathological entity. AIM: To analyze the epidemiological, clinical and histological profile of primary focal segmental glomerulosclerosis in children, as well as their prognostic factors. METHODS: This was a retrospective cross-sectional study over a period of 20 years (2001-2020), conducted in the Department of Pediatrics at Charles Nicolle Hospital in Tunis, which included children followed for primary focal segmental glomerulosclerosis. RESULTS: There were 35 children, 19 boys and 16 girls. The median age was 4.5 years. Nephrotic syndrome was seen in 88% of patients. Macroscopic hematuria was found in 4 cases, hypertension in 8 cases and renal failure in 7 cases at presentation. The most common variant was the not otherwise specified variant (77.1%). Steroid-sensitive nephrotic syndrome was observed in 71% of cases, and steroid-resistance in 29% of cases. Treatment with cyclosporine was indicated in 23 patients with complete remission rate of 56.5%. 42,8% children had progressed to chronic kidney disease, including an end-stage renal disease in 11.5% of cases. Only the presence of a family history of kidney disease was found as a predictive factor of progression to chronic kidney disease and end-stage renal disease. Renal survival rates were estimated at 100% at 3 years, 85% at 5 years and 73% at 10 years. CONCLUSION: Identification of patients at high risk for chronic kidney disease progression, such as those with a family history of kidney disease or those who have failed to respond to corticosteroids, would allow therapeutic adjustments.

Spontaneous hemothorax in a 10-year-old boy with COVID-19.

Spontaneous hemothorax occurs in the absence of trauma or iatrogenic causes. Etiologies of spontaneous hemothorax in children include connective tissue disease, neoplasia and coagulopathy, which is associated with thromboembolic events. We present the case of a 10-year-old chronic hemodialysis patient with spontaneous hemothorax with a concurrent COVID-19 infection.

Monogenic urinary lithiasis in Tunisian children: 25 years' experience of a referral center.

OBJECTIVE: To describe the clinical, biochemical and evolutive profile of monogenic urinary lithiasis in Tunisian children followed up in a reference service, during a 25 years period. METHODS: This was a single-center retrospective observational study of children with urolithiasis, conducted in the pediatric nephrology department in Charles Nicolle Hospital, Tunis, Tunisia over 25 years (January 1st, 1996 to December 31, 2020). Children≤18 of age with urolithiasis with or without nephrocalcinosis related to a monogenic disease were included in our study. RESULTS: A total of 66 children were included in our study. Patients were 5.92±3.48 years of age at the time of urolithiasis diagnosis, and 5.33±3.66 years of age at the time of the underlying pathology diagnosis. The inherited urolithiasis disorders found in our series were: primary hyperoxaluria in 44 cases, cystinuria in 9 cases, Lesch Nyhan syndrome in 5 cases. Renal tubular acidosis was found in 3 cases, and hereditary xanthinuria in 2 cases. Bartter syndrome, adenine phosphoribosyltransferase deficiency and Hereditary hypophosphatemic rickets with hypercalciuria were found in 1 case each. After an average follow-up of 6.45±3.79 years, six patients were in end-stage renal disease. Three patients had died, all of them being followed for primary hyperoxaluria type 1. CONCLUSIONS: Monogenic urinary lithiasis, although rare, are most likely under-diagnosed in countries with high consanguinity such as Tunisia. The screening of these diseases seems to be of primary importance because of their significant morbidity.

Thromboembolic complications in children with primary nephrotic syndrome: A Tunisian series.

INTRODUCTION: Nephrotic syndrome is a common pathology in children. Despite its good prognosis, it can become complicated and threaten the patient's vital and functional prognosis. Thromboembolic complications are rare but serious. AIM: To study the main thromboembolic events and their outcome during primary nephrotic syndrome in children. METHODS: It was a retrospective study of the records of children followed for primary nephrotic syndrome who presented one or more thromboembolic events. RESULTS: Twenty thromboembolic events in 19 children were identified (15 boys and 4 girls). The average age was 5.13±3.4 years at the time of NS diagnosis. The location of the thrombosis was venous in 14 cases. Cerebral venous thrombosis was noted in seven cases, pulmonary thromboembolism in five cases. We noted deep venous thrombosis of lower limbs in three cases, occlusive mesenteric ischemia in two cases, vein portal thrombosis in one case, renal vein thrombosis in one case, and thrombosis of a peripheral artery in one case. CONCLUSION: Venous and arterial thrombotic complications can occur in children with nephrotic syndrome. Clinical features may be subtle; therefore, neuroimaging and angiographic techniques are essential for diagnosis.

Lupus Nephritis in Tunisian Children: Predictive Factors of Poor Outcomes.

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder of unknown etiology. Lupus nephritis (LN) is one of the most severe clinical manifestations observed in patients with SLE; it is more frequent and more severe in children than in adults. The aim of our study was to assess the predictive factors of poor outcomes in Tunisian children with LN. This was a multicenter retrospective observational study on 40 pediatric patients with biopsy-proven LN from five nephrology departments in Tunisia. The patients were 12.33 ± 3.3 years of age at the time of their kidney biopsy. Eleven patients developed end-stage renal disease (ESRD) (27.5%), and seven patients died. Overall, 18 (45%) patients reached our composite endpoint (ESRD or death). An age at diagnosis of more than 14 years, elevated serum creatinine at the time of the kidney biopsy, the existence of wire loops, thromboembolic complications as well as infectious complications are the most important clinical features associated with an increased risk of ESRD. Predictive factors of death were a baseline creatinine level of more than 2.26 mg/dL, a high proteinuria at baseline, fibrous crescents determined by renal biopsy, thromboembolic complications, infectious compli-cations, and ESRD. In summary, our results suggest that early and appropriate management is the best guarantee of a good renal outcome in children with LN.