Management of urolithiasis in living kidney donors.

BACKGROUND: Kidney donors with asymptomatic stones were  previously excluded from the kidney donation list because of a potential increased morbidity risk for both the recipient and the donor. Currently, recent studies tend to consider these risks as overestimated. AIM: The aim of this study was to analyze our experience in the management of urolithiasis in potential donors. METHODS: We conducted a retrospective analysis during the period (2008-2015). We included donors with urilithiasis or a family history of urolithiasis whom had urinary biochemical analysis of urolithiasis. We identified the exact location, size, and anatomy of the kidney bearing the stone were identified. RESULTS: Among 252 potentially proposed living kidney donors (LKD) in two renal transplantation centers, we noted urinary lithiasis in 8 patients (3.17%). The mean age was 40,12±20 years old with a sex-ratio M/F at 0,3. We noted urinary lithiasis on radiographs in one case, on echographs in one case and on computerized tomography kidney angiography in 5 cases. All are not obese and without any medical history. In one case, there was no lithiasis detected but chemical urinary analysis was performed because of family renal stone history. We performed a 24-hours urine test, and examined PH, calcium and oxalate. The urine analysis, showed acidic pH and hypercalciuria in all cases associated to weddelite in 3 cases, hyperoxaluria in all cases. In one case, we noted vitamin D deficiency related hyperparathyroidism. Renal transplantation has been achieved in two cases. After a mean follow up of 11,25 months [range :27-84], no urological complications were noted. CONCLUSION: Urinary lithiasis may occur in proposed living kidney donors and may not contraindicate this donation.

Nephrolithiasis in living kidney donor: experience of nephrologists.

BACKGROUND: Living kidney donation for transplantation has become common practice. The decisions to accept a donor with nephrolithiasis are becoming frequent. AIM: The aim of our study was to report our experience in the living donor kidney with asymptomatic lithiasis. METHODS: Over a period of 4 years from 2009 to 2013 we collected 18 cases. From the clinical, metabolic and radiological data, we have determined the etiology of urolithiasis in our patients and established, after a literature review, a decision tree of kidney donation. RESULTS: Our study included 10 women and 8 men with a mean age of 43 years. The nephrolithiasis was discovered incidentally during radiological assessment through the urinary tract without preparation in 1 case, the abdominal ultrasound in 6 cases and the abdominal CT scan in 11 cases. The donation of kidney in our study was performed in 1 case and disqualified in the others cases especially for metabolic abnormalities. In the single couple donor-recipient, after a follow up of 5 years; we have not identified adverse side effects either in the donor or in the recipient patient. CONCLUSION: In living donors with nephrolithiasis the final decision of renal transplantation must be based on the confrontation between the clinical, biological and radiological data. Metabolic disorders constituted the mainly contraindication of kidney donation in our patients.

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.

Unusual clinical outcome of primary Hyperoxaluria type 1 in Tunisian patients carrying 33_34InsC mutation.

BACKGROUND: Primary hyperoxaluria type 1 (PH1), is a rare and heterogeneous disease and one of major causes of renal insufficiency in Tunisia, caused by mutations in the AGXT gene. 33-34InsC mutation, was mainly described in children with a severe clinical feature leading to early death, but it was uncommonly reported in adult patients. METHODS: Common mutations in AGXT were tested using PCR/RFLP technique in 111 patients (68 adult, 43 children) with suspected PH1. RESULTS: We described 16 cases (eight adult and eight children) with a 33-34InsC mutation with a median age of 24 years [6 months - 73 years]. All children were in end stage renal disease (ESRD) at the median age of 3 years due to lithiasis and/or nephrocalcinosis. Unfortunately, 75% of them died with a median age of 2.5 years. For the majority of adults only spontaneous elimination of urolithiasis were noted, 37.5% preserved until now a normal renal function and 62.5% of them reached ESRD at the median age of 55.8 ± 12.31 years old. CONCLUSION: In this study 33-34InsC mutation gives a controversial clinical effect in children and adults. The implication of other genetic and/or environmental factors can play a crucial role in determining the ultimate phenotype.

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.

Changes in glucose metabolism and reversion of genes expression in the liver of insulin-resistant rats exposed to malathion. The protective effects of N-acetylcysteine.

Organophosphorus pesticides are known to disturb glucose homeostasis and increase incidence of metabolic disorders and diabetes via insulin resistance. The current study investigates the influence of malathion on insulin signaling pathways and the protective effects of N-acetylcysteine (NAC). Malathion (200 mg/kg) and NAC (2 g/l) were administered orally to rats, during 28 consecutive days. Malathion increases plasma glucose, plasma insulin and glycated hemoglobin levels. Further, we observed an increase of insulin resistance biomarkers and a decrease of insulin sensitivity indices. The GP, GSK3ß and PEPCK mRNA expressions were amplified by malathion while, the expression of glucokinase gene is down-regulated. On the basis of biochemical and molecular findings, it is concluded that malathion impairs glucose homeostasis through insulin resistance and insulin signaling pathways disruptions in a way to result in a reduced function of insulin into hepatocytes. Otherwise, when malathion-treated rats were compared to NAC supplemented rats, fasting glucose and insulin levels, as well as insulin resistance indices were reduced. Furthermore, NAC restored liver GP and PEPCK expression. N-acetylcysteine showed therapeutic effects against malathion-induced insulin signaling pathways disruption in liver. These data support the concept that antioxidant therapies attenuate insulin resistance and ameliorate insulin sensitivity.

Effects of Rosmarinus officinalis L. as essential oils or in form of leaves supplementation on goat's production and metabolic statute.

The effects of rosemary supply in form of essential oils (REO) or leaves (RL) on performances of goats were investigated. Thirty goats were allocated into three equal groups, which were fed oat-hay ad libitum and 400 g of concentrate during the two last weeks of pregnancy and 600 g during the first 8 weeks of lactation. Three-control diet (C) was a mixture of barley, soybean meal and mineral vitamin supplement. The experimental concentrates contained the same mixture of the control diet plus 0.6 g/kg of REO or its equivalent supply RL (60 g/kg). Rosemary supply did not affect dry matter (DM), organic matter (OM), crude protein (CP) and neutral detergent fiber (NDF) digestibility. While urinary nitrogen loss was higher for experimental groups than the C (P = 0.03). Daily milk production was significantly higher (P = 0.007) for rosemary groups (694 and 582 ml for RL and REO, respectively) than C group (442 ml). Rosemary decreased numerically (P > 0.05) the fat content (23, 25 and 26.5 g/l for REO, RL and C groups, respectively) but significantly increased the fat (P = 0.003) and protein content (P = 0.008). The growth rate of kids was significantly higher (P = 0.008) for RL (111 g) than that for REO and C (97 and 83 g, respectively). However, rosemary has not shown significant effect on the plasma metabolite concentrations. Given the facility to obtain the rosemary leaves, this form of rosemary use is recommended as natural alternative to improve the performances of goats.

Lipid metabolism disturbances contribute to insulin resistance and decrease insulin sensitivity by malathion exposure in Wistar rat.

Several studies showed that organophosphorus pesticides disturb glucose homeostasis and can increase incidence of metabolic disorders and diabetes via insulin resistance. The current study investigates the influence of malathion on glucose metabolism regulation, in vivo, during subchronic exposure. Malathion was administered orally (200 mg/kg), once a day for 28 consecutive days. Plasma glucose, insulin and Glycated hemoglobin levels were significantly increased while hepatic glycogen content was decreased in intoxicated animals compared with the control group. Furthermore, there was a significant disturbance of lipid content in subchronic treated and post-treated rats deprived of malathion for one month. In addition, we used the homeostasis model assessment (HOMA) to assess insulin resistance (HOMA-IR) and pancreatic ß-cell function (HOMA-ß). Our results show that malathion increases insulin resistance biomarkers and decreases insulin sensitivity indices. Statistical analysis demonstrates that there was a positive and strong significant correlation between insulin level and insulin resistance indices, HOMA-IR, HOMA-ß. Similarly, a negative and significant correlation was also found between insulin level and insulin sensitivity indices. For the first time, we demonstrate that malathion induces insulin resistance in vivo using homeostasis model assessment and these changes were detectable one month after the end of exposure. To explain insulin resistance induced by malathion we focus on lipid metabolism disturbances and their interaction with many proteins involved in insulin signaling pathways.

[The role of type II collagen fragments and X-ray progression of knee osteoarthritis]. / Rôle des marqueurs de dégradation du collagène de type II au cours de la progression de l'arthrose du genou.

AIMS: To investigate the association between type II collagen fragments and the presence of knee osteoarthritis (OA) in the Tunisian population and to determine whether this biomarker can predict X-ray progression of this disease. METHODS: Type II collagen C-telopeptide (uCTX-II) and helical peptide (sHelix-II) were assessed in 125 female patients with knee osteoarthritis aged 54 ± 8 years over 2 years and 57 female age-matched controls. The markers were measured at baseline, 1 and 2 yrs' follow-up corresponding to x-ray time points. RESULTS: Only urinary CTX-II values were significantly 48% higher in knee OA patients compared with controls (p=0.001). The longitudinal changes over 2 yrs in Helix-II were also significantly associated with Joint Space Narrowing: JSN (p=0.03). Over the 2-yr study period average CTX-II levels were not significantly higher in progressor compared with non-progressor (339.96 vs 256.00; NS). CONCLUSION: The data presented here suggest that CTX-II may be useful to identify patients with knee OA. These results demonstrate significantly association between progression of this disease and alterations levels of Helix-II.

Prevalence of hemoglobin variants in a diabetic population at high risk of hemoglobinopathies and optimization of HbA1c monitoring by incorporating HPLC in the laboratory workup.

BACKGROUND: In Tunisia, diabetes mellitus and hemoglobinopathies are major public health problems. Glycated hemoglobin (HbA1c) is recommended for long-term monitoring of diabetes mellitus, but the presence of hemoglobin variants may interfere with HbA1c measurement. The aim was to determine the prevalence of hemoglobin variants in Tunisian diabetics and optimize the monitoring of diabetics using HbA1c. METHODS: The study enrolled 9,792 Tunisian diabetic patients. HbA1c was measured by cation-exchange high-pressure liquid chromatography (HPLC). All the chromatograms were analyzed for the presence of Hb variants. RESULTS: We identified 228 cases (2.33%) of Hb variants with D-10 HPLC (Bio-Rad): 191 with HbA/S trait, 27 with HbA/C trait, and 10 hemoglobin variants with the mention 'Variant-Window' on the chromatograms and subsequently identified as HbA/S on Variant I HPLC (Bio-Rad). Thus, the prevalence of HbS was 2.05%. We did not find any homozygous variant. All HbA1c results were reported to the treating physician. CONCLUSIONS: To evaluate glycated hemoglobin in populations with a high prevalence of hemoglobinopathies, we should use the HPLC method, which is easy, economical, and reliable. Based on an algorithm, hemoglobin variants visualized on HPLC should be reported to the physician to improve the management of patients.

Association of inflammatory response and oxidative injury in the pathogenesis of liver steatosis and insulin resistance following subchronic exposure to malathion in rats.

Insulin resistance and risk of type 2 diabetes are the most important complications following exposure to organophosphorous (OPs) pesticides. Regarding the importance of liver on metabolic pathways regulation, in particular blood glucose homeostasis, we focused on liver inflammation and oxidative damages in a subchronic model of toxicity by malathion. Adult male Wistar rats of body weight 200-250g were used for the study. Malathion (200mg/kg b.w./day) was administered to rats by oral intubation for 28 days. Glycemic and insulin resistance indices, markers of liver injury, markers of inflammation and oxidative stress were assessed. Malathion-treated rats showed increased glycemia, insulinemia and glycated hemoglobin level, HOMA-IR and HOMA-ß indices, plasma activities of hepatocellular enzymes, lipid peroxidation index, CD3(+)/CD4(+) and CD3(+)/CD4(+) and pro-inflammatory cytokines when decreased antioxidant status in liver was noted. Most of our study indicates that malathion promotes insulin resistance, inflammation and Hepatosteatosis in subchronic model of exposure. On the basis of biochemical and molecular findings, it is concluded that insulin resistance induced by malathion occurs through oxidative stress and related pro-inflammatory markers in a way to result in a reduced function of insulin in liver cells.

Antioxidant and anti-inflammatory effects of N-acetylcysteine against malathion-induced liver damages and immunotoxicity in rats.

AIMS: Occupational exposure to organophosphate pesticides is becoming a common and increasingly alarming world-wide phenomenon. The present study is designed to investigate the preventive effect of N-acetylcysteine on malathion-induced hepatic injury and inflammation in rats. MAIN METHODS: Adult male Wistar rats of body weight 200-230 g were used for the study. Malathion (200mg/kg b.w./day) was administered to rats by oral intubation and N-acetylcysteine (2g/l) in drinking water for 28 days. Rats were sacrificed on the 28th day, 2h after the last administration. Markers of liver injury (aspartate transaminase, alanine transaminase, alkaline phosphatase and lactate desyhdogenase), inflammation (leukocyte counts, myeloperoxidase, immunophenotyping of CD4(+) and CD8(+), interleukin-1ß, interleukin-6 and interferon-γ expression) and oxidative stress (lipid peroxidation, reduced glutathione and antioxidant status) were assessed. KEY FINDINGS: Malathion induced an increase in activities of hepatocellular enzymes in plasma, lipid peroxidation index, CD3(+)/CD4(+) and CD3(+)/CD4(+) percent and pro-inflammatory cytokines, when decreased antioxidant status in liver was noted. When malathion-treated rats were compared to NAC supplemented rats, leukocytosis, T cell count and IL-1ß, IL-6, INF-γ expression were reduced. Furthermore, NAC restored liver enzyme activities and oxidative stress markers. SIGNIFICANCE: Malathion induces hepatotoxicity, oxidative stress and liver inflammation. N-acetylcysteine showed therapeutic effects against malathion toxicity.

Effects of N-acetyl-l-cysteine, in vivo, against pathological changes induced by malathion.

Malathion toxicity has been related to the inhibition of acetylcholinesterase, induction of oxidative stress, liver damage and impairment of kidney function as well as hematotoxicity. N-acetyl-l-cysteine (NAC) has been shown to possess curative effects in experimental and clinical investigations. The present study was designed to evaluate the protective effect of NAC against toxic consequences of malathion exposure in Wistar rats. Malathion was given daily to rats via oral gavage and NAC in drinking water during seven days. When malathion-treated rats were compared with control, a leukocytosis and reduced hemoglobin (HGB) content were detected. Furthermore, malathion produced a significant increase in liver enzymes such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase and creatinine kinase. In addition, a decrease in acid phosphatase activity, protein and globulin levels were observed in malathion-treated rats compared with control. Moreover, analyses of the mineral status showed a disturbance in calcium, magnesium, phosphore and iron contents of the malathion-treated rats. Interestingly, NAC showed therapeutic effects against malathion toxicity. Indeed, HGB content and all liver enzymes were restored to normal values. Finally, the use of NAC as therapeutic agent for only seven days during malathion exposure showed interesting results on tissues damages.

[Prevalence of non-conventional cardiovascular risk factors in Tunisian diabetics]. / Prévalence des facteurs de risque cardiovasculaire non conventionnels chez les sujets diabétiques tunisiens.

BACKGROUND: The cardiovascular risk appears very early in the history of diabetes mellitus and is related not only to hyperglycemia but mainly to the other risk factors associated to diabetes mellitus. OBJECTIVE: To evaluate the prevalence of non-conventional cardiovascular risk factors in a Tunisian diabetic population. PATIENTS AND METHODS: The prospective study enrolled 120 type 2 diabetic patients recently diagnosed and 60 healthy people, sex and age matched. All have benefited from blood sampling in order to analyze biological parameters routinely undertaken in diabetes. Non-conventional cardiovascular risk factors were also determined such as: microalbuminuria of 24 hours, high sensitivity C-reactive protein (hs CRP), homocysteinemia, vitamin B12, folate and insulinemia. The participants have also benefited from abdominal echography to search nonalcoholic hepatic steatosis. RESULTS: Diabetics were aged 51.4 ± 8.9 years in comparison with healthy people (50.1 ± 6.39 years). A positive microalbuminuria was observed in 27.5% of diabetics versus 6.9% in healthy people (OR=5.1; P=0.001). The two third of diabetics had metabolic syndrome versus 25% of healthy people (OR=6.0; P<0.001) and insulinoresistance evaluated by HOMA-IR, was 3.4 ± 0.2 in diabetics versus 2 ± 0.1 in healthy people; P<0.001. HsCRP level was significantly higher in diabetics in comparison with healthy people (3.7 ± 0.2mg/L versus 1.9 ± 0.3mg/L; P<0.001) and hyperhomocysteinemia was more frequently found in diabetics. Also, we noted that 69.6% of patients had hepatic steatosis versus only 24.6% of healthy people (OR=7.1; P<0.001). CONCLUSION: The non-conventional cardiovascular risk factors were more frequently found in early diagnosed type 2 diabetic patients than in healthy people. These non-conventional factors could be helpful in stratification of the cardiovascular risk level and also in the screening of ischemic heart diseases.

Advantage of HbA1c assay by HPLC D-10 versus cobas integra 400 in a population carrier for HbS and HbC.

BACKGROUND: Several studies demonstrate significant bias in analytical methods used to measure glycohemoglobin. The clinical importance of that fact is evident when HbA1c overestimation leads to aggressive glucose management, resulting in more frequent hypoglycaemic episodes. Our study was aimed to compare two automated instruments (Integra 400 and D-10) in the evaluation of HbA1c in the Tunisian population. METHODS: Samples of 205 Tunisian diabetic patients were collected. The HbA1c assay was done simultaneously with a first generation immunoturbidimetric assay on an INTEGRA 400 (ROCHE) and using ionic exchange high pressure liquid chromatography (HPLC) on a D-10 system (BIO-RAD). RESULTS: Correlation is determined by linear regression analysis: D-10 = 0.921*(Integra 400) +1.125; coefficient of correlation (r) = 0.946. This r increases to 0.973 when samples of carriers for HbS and HbC (n = 9) are filtered out. For the carrier patients, significant differences in the percentage of HbA1c were observed relating to the methodology used. CONCLUSIONS: Laboratories must be aware of hemoglobin variant interferences on their methods of assessment of glycated hemoglobin. Using ion-exchange HPLC to control glycated hemoglobin seems to be essential to prevent mis-management in diabetic patients and to permit the diagnosis of the presence of HbS in patients.

Primary hyperoxaluria type 1 in Tunisian children.

To determine the clinical, biological, and radiological futures of primary hyper-oxaluria type 1 in Tunisian children, we retrospectively studied 44 children with primary hyper-oxaluria type 1 who were treated in our center from 1995 to 2009. The diagnosis was established by quantitative urinary oxalate excretion. In patients with renal impairment, the diagnosis was made by infrared spectroscopy of stones or kidney biopsies. The male-to-female ratio was 1:2. The median age at diagnosis was 5.75 years. About 43% of the patients were diagnosed before the age of five years with initial symptoms dominated by uremia. Four patients were asymptomatic and diagnosed by sibling screenings of known patients. Nephrocalcinosis was present in all the patients; it was cortical in 34%, medullary in 32%, and global in 34%. At diagnosis, 12 (27%) children were in end-stage renal disease. Pyridoxine response, which is defined by a reduction in urine oxalate excretion of 60% or more, was obtained in 27% of the cases. In the majority of patients, the clinical expression of primary hyperoxaluria type 1 was characterized by nephrocalcinosis, urolithiasis, and renal failure; pyridoxine sensitivity was associated with better outcome.

Association of serum levels of aggrecan ARGS, NITEGE fragments and radiologic knee osteoarthritis in Tunisian patients.

OBJECTIVES: Proteolytic degradation of aggrecan is a hallmark of the pathology of osteoarthritis. The aim of this study was to develop enzyme-linked immunosorbent assay (ELISA) to quantify the serum levels of specific aggrecan fragments generated by aggrecanases-mediated cleavage. We investigated the relationships between these two aggrecan degradations fragments and urinary CTX-II levels. METHODS: The competitive ELISAs employ a polyclonal antibody raised against the aggrecan fragments containing two neoepitopes NITEGE(373)and (374)ARGSVI. We measured serum levels of ARGSV and NITEGE in 125 women with knee osteoarthritis (mean±SD age of 53.6±7.6 years, mean±SD disease duration of 3.6±3.8 years), and 57 women age-matched controls. RESULTS: Aggrecan neoepitopes assays showed an intra- and inter-assay imprecision (CV) lower than 20% for both tests and good linearity. Median serum ARGSVI (by 18%; P=0.002), and NITEGE (36.4%; P<0.001) levels were significantly decreased in patients with knee osteoarthritis compared with controls. Minimal joint space width was negatively correlated with ARGSVI (r=-0.368, P=0.04) and NITEGE (r=-0.274, P=0.038) in knee osteoarthritis patients. Median urinary CTX-II levels were significantly increased by 39.5% (P=0.001) in knee OA patients compared with controls. CONCLUSION: Markers of degradation aggrecan were analyzed for the first time in an African osteoarthritis population. These markers can be used to monitor aggrecanase activity in human joint disease. Their combination with CTX-II can improve clinical investigation of patients with osteoarthritis patients.

Lidocaïne test for easier and less time consuming assessment of liver function in several hepatic injury models.

PURPOSE: In this study, we developed an ex vivo functional assay to assess liver metabolic capacity adapted from the lidocaïne test in rats. METHODS: Animals used were subjected to different models of liver injury: hypothermic ischemia (H/I, n = 8), ischemia-reperfusion (I/R, n = 8) and CCl4 induced liver cirrhosis (n = 11), and compared with sham operated rats (n = 5). Livers were then extracted and a fragment of whole tissue was incubated with lidocaïne for 15, 30, 60, 120, 240, 360, and 720 min at which both lidocaïne and its major metabolite monoethylglycinexylidide (MEGX) were measured by high performance liquid chromatography (HPLC). A histological study and biochemical assays (transaminase levels) were also performed to further evaluate and confirm our data. RESULTS: Pharmacokinetic profile of lidocaïne metabolism in sham-operated animals revealed that the maximum concentration of MEGX is achieved at 120 min. Both lidocaïne metabolism and MEGX formation levels were significantly altered in all three models of hepatic injury. The extent of hepatic damage was confirmed by increased levels of transaminase levels and alteration of hepatocyte's structure with areas of necrosis. CONCLUSION: Our method provides reliable and reproducible results using only a small portion of liver which allows for a fast and easy assessment of liver metabolic capacity. Moreover, our method presents an alternative to the in vivo technique and seems more feasible in a clinical setting.

Primary hyperoxaluria type 1 in Tunisian children.

BACKGROUND: Primary hyperoxaliuria type 1 is an autosomal recessive disorder characterized by increasing urinary excretion of calcium oxalate, recurrent urolithiasis, nephrocalcinosis, and accumulation of insoluble oxalate throughout the body. This inborn error of metabolism appears to be a common cause of end stage renal disease in Tunisia. AIMS: To review the clinical, biological and radiological futures of primary hyperoxaluria type 1 and to correlate these aspects with the development of end-stage renal disease. METHODS: we retrospectively reviewed 44 children with Primary hyperoxaliuria type I who were treated in our department during a period of 15 years between 1995 and 2009. The diagnosis was established by quantitative urinary oxalate excretion. In patient with renal impairment, the diagnosis was made by infrared spectroscopy of stone or by renal biopsy. RESULTS: Male to female ratio was 1.2. The median age at diagnosis was 5.75 years. About 43 % of those were diagnosed before the age of 5 years. Initial symptoms were dominated by uraemia. Four patients were asymptomatic and diagnosed by sibling screening of known patients. Nephrocalcinosis was present in all patients. It is cortical in 34%, medullary in 32% and global in 34%. At diagnosis, twelve children were in end-stage renal disease (27%). Pyridoxine response, which is defined by a reduction in urine oxalate excretion of 60% or more, was found in 27%. CONCLUSION: In the majority of patients, the clinical expression of Primary hyperoxaliuria type 1 is characterized by nephrocalcinosis, urolithiasis and renal failure. Pyridoxine sensitivity is associated with better outcome.