S. Aloui

Cytomegalovirus ischemic colitis and transverse myelitis in a renal transplant recipient.

We report a rare case of cytomegalovirus (CMV)-associated ischemic colitis and transverse myelitis (TM) occurring precociously after renal transplantation. A 57-year-old male was transplanted with a cadaveric kidney on 5 June 2009. The patient was CMV seropositive and the donor was seronegative. Transplantation was followed shortly by TM, which resulted in paraplegia. The results of magnetic resonance imaging of the spinal cord showed abnormalities. Twenty days after transplantation, he developed abdominal pain with melena and was diagnosed as having CMV-associated ischemic colitis confirmed by colonoscopy and biopsy. Serological data and identification of the viral genome by polymerase chain reaction were confirmatory for CMV. Treatment consisted of intravenous ganciclovir, followed by polyvalent immunoglobulin. The outcome was favorable. Symptomatic CMV infection is relatively common among the renal transplant population. Early colonoscopy is beneficial for making a quick diagnosis and therefore helps to institute a prompt management of CMV colitis. Myelitis is less common in transplant recipients and diagnosis, therefore, was more difficult.

Acute post-infectious glomerulonephritis in adults: A single center report

Acute post-infectious glomerulonephritis (APIGN) is uncommonly seen in adults; its incidence is progressively declining, particularly in developed countries. The aim of this study was to evaluate the epidemiological, clinical and biologic features of APIGN in a Tunisian center. A retrospective descriptive analytic study was carried out on 50 patients aged more than 15 years who were admitted to the Monastir Hospital between 1991 and 2007, with a diagnosis of APIGN. There were more males than females (66% vs. 34%), and the mean age of the patients was 36.8 ± 10 years. Only 10% had an immunocompromised background, including diabetes. The most common site of infection was upper respiratory tract, followed by skin and pneumonia. The most common causative agent was Streptococcus (66%), followed by Staphylococcus (12%). 73.8% of the patients had low C3 complement levels. The mean peak serum creatinine was 190 μmol, and 4% of patients required acute dialysis. The patients were followed-up for a mean period of 18 months (range, 0.16-97 months). During follow-up, of the 46 patients reviewed in the consultation, the majority showed complete remission, 12 patients had persisting abnormalities such as hypertension in 17%, chronic renal failure in 8% and proteinuria in 6.5%, and one patient had concomitant hypertension and chronic renal failure. Our study suggests that APIGN is still endemic in some parts of the world such as Tunisia, and our data showed a favorable prognosis in adults.

Predictors of early post-operative hypocalcemia after parathyroidectomy for secondary hyperparathyroidism

We sought to identify predictors of development of early post-operative hypocalcemia after parathyroidectomy for secondary hyperparathyroidism. The patients were divided into two groups according to their serum calcium (Ca) levels within 24 hours of undergoing para-thyroidectomy: the hypocalcemia group (22 patients) with post-operative serum Ca levels of 2 mmol/L or less, and the normocalcemia group (48 patients), with post-operative serum Ca levels higher than 2 mmol/L. By using multivariate stepwise logistic regression analysis, high pre-operative serum Ca level had the strongest predictive value of development of early hypocalcemia with an adjusted odds ratio (aOR) of 3.01, followed by hypo-albuminemia (aOR = 2.72), younger age (aOR = 2.56), and high pre-operative alkaline phosphatase (ALP) levels (aOR = 2.28). We conclude that among patients with secondary hyperparathyroidism, age, levels of pre-operative serum Ca, ALP and albumin correlate positively with the development of early post-operative hypocalcemia. Patients with one of these factors should be monitored more closely in the early post-parathyroidectomy period.

Brown tumors in dialyzed patients with secondary hyperparathyroidism: report of 16 cases.

Brown tumors (BTs) are relatively uncommon but they are serious complications of renal osteodystrophy. The objective of this study was to analyze the clinical, biological, and radiological characteristics of 16 patients with BTs provoked by secondary hyperparathyroidism (sHPT) and its response to the decrease in parathyroid hormone levels after parathyroidectomy (PTX). The management of that uncommon condition was also reviewed. We conducted a retrospective study including 16 end‐stage renal disease patients who underwent subtotal PTX between 1997 and 2007 for severe sHPT with BTs. Our study included 10 men and 6 women, whose average age was 34 years. All patients were on dialysis. Ten of them were on dialysis for more than 5 years. The median duration on dialysis was 84 months. Patients included suffered from swellings associated with functional limitations. BTs had multiple locations in 7 patients. Jaw was the most frequent location (62%). Radiography and tomodensitometry demonstrated a mixed radio lucent and radio‐opaque lesions with an expansion of the cortical bone. Bone scan demonstrated an increased uptake of lesions. Chirurgical treatment was indicated in all cases because of severe refractory sHPT with functional limitations and/or disfiguring deformities. In all cases, BTs stopped its progression and even decreased in size. However, it was insufficient in four cases, which required a surgical resection. PTX remains an efficacious approach in resistant cases of sHPT with persistent BTs.

Atypical hemolytic uremic syndrome in the Tunisian population

BackgroundHemolytic uremic syndrome consists of a triad of acquired hemolytic anemia, thrombocytopenia and renal failure.AimOur objectives were to determine epidemiology, clinical and laboratory characteristics of patients with atypical hemolytic uremic syndrome (aHUS) to determine the relationship between the complement protein deficit and aHUS in the Tunisian population.MethodsWe studied retrospectively four cases of atypical HUS in adults admitted in the Nephrology Department of Fattouma Bourguiba Universitary Hospital in Monastir between 2000 and 2008.ResultsThree patients had renal failure that required dialysis. One of them received kidney transplantation with no further recurrence of aHUS. Three patients had normal C3, C4, CFH, and FB levels, and in all patients anti-FH autoantibodies were absent. The kidney biopsy of one patient showed in addition to lupus glomerulonephritis histological findings consistent with TMA. A decrease in C3, C4 and CFH levels in this patient was found both before and after the cure.ConclusionNephrologists should be aware of autoimmune conditions and genetic abnormalities of the complement regulatory genes as possible pathogenic mechanisms in atypical HUS patients.

Tacrolimus therapeutic drug monitoring in Tunisian renal transplant recipients: Effect of post-transplantation period☆

BACKGROUND Most previous studies having focused on therapeutic drug monitoring of tacrolimus in renal transplant recipients have assessed the clinical response of patients. The aim of this study is to investigate the influence of post-transplant delay on tacrolimus dose, trough levels (C0) and dose/C0 ratio in a Tunisian renal transplant population. PATIENTS AND METHODS A retrospective study including 110 renal transplant patients has been performed. Tacrolimus trough concentrations were adjusted according to the target range proposed by the European consensus conference on tacrolimus optimization. Samples for determination of tacrolimus blood level were subdivided according to the post-transplantation period into three groups. RESULTS The initial dose required was 0.17 ± 0.05 mg/kg/day during the first 3 months after transplantation. A reduction of 36 and 65% of tacrolimus initial dose during the second (3-12 months) and third period after transplantation (>12 months), respectively, was required to maintain the concentration level within therapeutic range. These results were different from those found in other studies performed in different populations. We hypothesize that these differences in dosing requirement may be due to an interethnic polymorphism in the expression of enzymes involved in tacrolimus metabolism. CONCLUSION These results could provide a simple therapeutic strategy to optimize tacrolimus prescription after renal transplantation in Tunisian population.

Deafness and blindness in a renal transplant recipient with cryptococcal meningitis.

Infections are a major determinant of outcome in kidney transplantation. Opportunistic pathogens are common in kidney recipients and several organs can be affected. Central nervous system infection in transplant recipients is a medical emergency. There is limited information in the literature concerning post-transplantation cryptococcal infection. Deafness and blindness are not classic findings. We report a case of meningocerebral cryptococcosis complicated by deafness and blindness after kidney transplantation. Physicians need to consider the possibility of Cryptococcus neoformans when symptoms persist despite empiric antimicrobial therapy.

Insuffisance rénale aiguë et obstacle mycélien : à propos d’un cas

Fungus ball is rarely associated with acute renal failure (ARF). We report the case of a 65-year-old diabetic patient who has been admitted for a right kidney infection. Urinary exam showed a leucocyturia with a negative urine culture. Ultrasonography showed pelvicaliceal dilation. Nephroscopy revealed a fungal material in ureter. Culture of this material was positive for Candida tropicalis. After endoscopic and antifongic therapy, the serum creatinin decreased from 336 micromol/L to 150 micromol/L, indicating the good evolution of his renal function.

Mutational Analysis of Agxt in Tunisian Population with Primary Hyperoxaluria Type 1: Mutational Analysis in Tunisian PH1 patients

Primary hyperoxaluria type 1 (PH1) is an autosomal recessive metabolic disorder caused by inherited mutations in the AGXT gene encoding liver peroxisomal alanine:glyoxylate aminotransferase (AGT). PH1 is a clinically and genetically heterogeneous disorder. The aim of our study was to analyze and characterize the mutational spectrum of PH1 in Tunisian patients.

Development of Limited Sampling Strategies for the Estimation of Tacrolimus Area Under the Curve in Adult Kidney Transplant Recipients According to the Posttransplantation Time.

Background: Limited sampling strategies (LSS), using few sampling times after dosing, have been used to reliably predict tacrolimus area under the 12-hour concentration–time curve (AUC). Because the pharmacokinetics of tacrolimus is subject to significant changes over the exposure time to this drug, it can be hypothesized that the reliability of the LSS would also change. This study aimed to develop a reliable and practical LSS allowing the estimation of tacrolimus AUC in Tunisian kidney transplant recipients taking into account the posttransplantation time. Methods: Thirty Tunisian patients were enrolled into 3 groups (10 in each group) according to the posttransplantation period: period 1: between 1 day and 3 months, period 2: between 3 and 12 months and period 3 over 12 months, as defined by the European consensus conference on the therapeutic drug monitoring of tacrolimus. Samples were collected just before and 0.5, 1, 2, 4, 6, 8, and 12 hours after tacrolimus administration. The full pharmacokinetic profiles obtained from these timed concentration data were used to choose the best sampling times. Error indices (mean absolute prediction error and the root mean squared prediction error) were used to evaluate the predictive performance. Results: Among the 1-point estimations, the C4-predicted AUC showed the highest correlation with the measured one during period 1 and period 2 (r2 = 0.94 and 0.91, respectively) but not period 3 (r2 = 0.76). The C0-predicted and the measured AUC become less and less correlated from period 1 to period 3 (r2 = 0.81, 0.75, and 0.66), respectively. Only the model including the C0/C2 provided a high correlation between predicted and measured tacrolimus AUC regardless of the posttransplant period (r2 = 0.95, 0.96, 0.98 and root mean squared prediction error = 4.1, 5.8, 4.2 during periods 1, 2, and 3, respectively). Conclusions: Our data clearly indicate that the predictive performance of LSS is prone to change according to the posttransplantation time. A 2–time point LSS was found to be sufficient to predict tacrolimus AUC. The LSS using C0 and C2 is reliable, accurate, and practical to estimate the AUC of tacrolimus regardless of the posttransplantation time.