Knowledge and Attitudes Toward Organ Donation Among Tunisian Adults: Results of a National Survey.

OBJECTIVES: Attitudes and knowledge toward organ donation can influence a person's willingness to donate. The aim of this study was to assess attitudes and knowledge regarding organ donation among Tunisian adults. MATERIALS AND METHODS: We conducted a crosssectional survey at the national level from January 23 to February 15, 2017, among 1026 Tunisian adults. We used a standardized questionnaire to collect data by phone call. We performed statistical analyses with Stata software (version 11). RESULTS: The study included 495 male and 531 female participants. Forty-one percent of participants were 18 to 30 years old. In total, 81.7% had heard about organ donation. Fewer than half of respondents (47.8%) were aware that organ donation is regulated. In total, 80.7% accepted to donate their organs after death, and 32.2% had mentioned their opinion to relatives or friends. Only 1% had added their donor status on their national identity cards. CONCLUSIONS: Tunisian adults seem to have positive attitudes regarding organ donation. However, the proportion of respondents who included their donor status on their national identity cards was low. It is important to enhance information and education on organ donation in an effort to mitigate the shortage of organs.

The role of IL-23/IL-17 axis in human kidney allograft rejection.

Th17 cell subset has been implicated in autoimmune diseases, tumor immunity and, transplant rejection. In order to investigate the role of IL-17/IL-23 pathway in allograft outcome, intragraft expression of IL-17 mRNA and single nucleotide polymorphisms (SNPs) of IL-17A, IL-17F, IL-17RC, and IL23R genes were evaluated with a quantification of IL-17A, IL-17F, and IL-23 plasma levels. This study revealed that recipients with acute rejection (AR) had a significant increase in IL-17A mRNA expression levels after transplantation compared to controls (P = 0.037). Moreover, IL-17A plasma levels were significantly higher in AR group; pretransplantation (Day-1 [D-1]): P = 0.00022 and posttransplantation (Day 7 [D7]): P < 10-14 . IL-17F and IL-23 plasma levels were significantly higher in AR at D7 only (47.86 vs. 22.99 pg/ml; and 33.82 vs. 18.811 pg/ml; P = 0.015 and P < 10-17 , respectively). Using receiver-operating characteristic curves, D7 IL-17A and IL-23 plasma levels exhibited excellent sensitivities and specificities for predicting AR. Genetic study revealed no association between IL-17A, IL-17F, IL-17RC, and IL23R studied SNPs and AR. Nevertheless, a significant improvement of graft survival was found in kidney transplant recipients carrying IL-17F-rs763780*A/A, IL-17RC*G/G, and *G/A genotypes. Besides, IL-17A mRNA levels were significantly higher in patients carrying the IL-23R*G/G genotype comparatively to those with *G/A genotype. Based on these findings, significant increase of IL-17A mRNA and protein levels in AR recipients that are genetically controlled highlights the role of this cytokine that can be a useful clinical biomarker to predict early acute renal allograft rejection.

Thirty Years of Experience at the First Tunisian Kidney Transplant Center.

OBJECTIVES: The aim of this study was to report the results of 30 years of experience at the first kidney transplant center in Tunisia. MATERIALS AND METHODS: All kidney transplants performed at the center between June 1986 and June 2016 were included. The study period was divided into 3 decades. Recipient and donor data and follow-up information were obtained from a local database and patient medical records. Comparative analyses were performed using the t test for continuous variables and the Χ² test for qualitative variables. Patient and graft survival rates were calculated according to the actuarial method, and comparison of survival curves was performed according to the logrank test. RESULTS: The mean age of recipients was 32.7 ± 11.5 years (range, 6-65 y) with a gender ratio of 2.2. Duration of prekidney transplant dialysis varied from 2 months to 20 years (median, 27.5 mo); 1.7% of patients underwent transplant preemptively. Kidneys were recovered from deceased donors in 21.2% of cases and from living donors in 78.8%. The proportion of deceased donors dropped from 27.4% during the period 2006-2010 to 12.9% during the period 2011-2015 (P < .04). Patient survival rates at 1, 5, 10, 15, and 20 years were 96%, 89.3%, 79.5%, 71.1%, and 65.4%. Graft survival rates were 95%, 86.5%, 76.2%, 66.3%, and 57.2%. The annual graft loss was 2.9%, with a mortality rate of 2.4% and without significant differences between patients receiving deceased-donor and living-donor organs. CONCLUSIONS: Kidney transplant activity remains suboptimal in our country. The reduction in deceased-donor organs could be related to the political transformations facing our country with their resulting social and economic consequences. Efforts should be made to increase governmental resources and to improve both public awareness of organ donation and the motivation of transplant teams.

Prediction of T Cell Epitopes from Leishmania major Potentially Excreted/Secreted Proteins Inducing Granzyme B Production.

Leishmania-specific cytotoxic T cell response is part of the acquired immune response developed against the parasite and contributes to resistance to reinfection. Herein, we have used an immune-informatic approach for the identification, among Leishmania major potentially excreted/secreted proteins previously described, those generating peptides that could be targeted by the cytotoxic immune response. Seventy-eight nonameric peptides that are predicted to be loaded by HLA-A*0201 molecule were generated and their binding capacity to HLA-A2 was evaluated. These peptides were grouped into 20 pools and their immunogenicity was evaluated by in vitro stimulation of peripheral blood mononuclear cells from HLA-A2+-immune individuals with a history of zoonotic cutaneous leishmaniasis. Six peptides were identified according to their ability to elicit production of granzyme B. Furthermore, among these peptides 3 showed highest affinity to HLA-A*0201, one derived from an elongation factor 1-alpha and two from an unknown protein. These proteins could constitute potential vaccine candidates against leishmaniasis.

Risk factors and consequences of delayed graft function.

The impact of delayed graft function (DGF) on the outcome of renal transplantation remains controversial. We analyzed the risk factors for DGF and its impact on graft and patient survival. A total of 354 renal transplants performed between June 1986 and April 2000 were analyzed. Variables analyzed included donor and recipient age, method and duration of renal replacement therapy, HLA mismatch, cold and warm ischemia times, biopsy-confirmed acute rejection, length of stay in the hospital, serum creatinine at the end of first hospitalization as well as graft and patient survival at one, three, five and ten years. The study patients were divided into two groups: patients with DGF (G1) and those without DGF (G2). DGF occurred in 50 patients (14.1%), and it was seen more frequently in patients transplanted from deceased donors (60% vs. 40%, P <0.0001). The cause of DGF was acute tubular necrosis, seen in 98% of the cases. Univariate analysis showed a statistically significant difference between the two groups G1 and G2 in the following parameters: average duration on dialysis (52.3 vs. 36.4 months, P = 0.006), HLA mismatch (44.9% vs. 32.11% P = 0.015), donor age (35.9 vs. 40.2 years, P = 0.026), cold ischemia time (23 vs. 18.2 h, P = 0.0016), warm ischemia time (41.9 vs. 38.6 mn, P = 0.046), length of stay in the hospital during first hospitalization (54.7 vs. 33.2 days, P <0.0001), serum creatinine at the end of first hospitalization (140 vs. 112 µmol/L, P <0.0001) and at three months following transplantation (159 vs. 119 µmol/L, P = 0.0002). Multivariate analysis revealed the following independent risk factors for DGF: deceased donor (RR = 13.2, P <0.0001) and cold ischemia time (RR = 1.17, P = 0.008). The graft survival at one, three, five and ten years was 100%, 93%, 88.3% and 78.3% in G1 versus 100%, 95.9% 92.8% and 82.3% in G2; there was no statistically significant difference. The patient survival at one, three, five and ten years was 100%, 91.3%, 83.6% and 74.4% in G1 versus 100%, 95.9%, 94% and 82.6% in G2 with a statistically significant difference (P = 0.04). Prolonged cold ischemia time and transplantation of kidneys from deceased donors were the main risk factors for DGF in our study. Also, DGF significantly affected patient survival but had no influence on graft survival.

CD86 +1057G>A polymorphism and susceptibility to acute kidney allograft rejection.

INTRODUCTION: CD86 is a costimulatory molecule that participates in the regulation of T-cell lymphocytes activation. Thus, we examined a genetic marker on the CD86 gene in kidney transplant outcome. MATERIALS AND METHODS: In our retrospective study, 168 kidney allograft recipients were genotyped by direct sequencing. Patients were classified into 2 groups of 29 human leukocyte antigen (HLA)-identical haplotype allograft recipients and 139 recipients showing one or more mismatches in the HLA haplotype. Forty-five patients (26.8%) developed at least 1 acute rejection (AR) episode, 7 in the first and 38 in the second group. RESULTS: Acute rejection was associated with the presence anti-HLA antibodies before transplantation (P = .03). The AA genotype and A allele at position +1057 in the CD86 gene were more frequent in patients without AR (9.75% and 28.5%, respectively) compared with those showing an AR (2.22% and 23.3%, respectively). This difference was statistically significant in the anti-HLA-positive recipients, as AA frequency was 31.3% in non-AR patients and zero in AR ones (P = .04) and A allele frequency was 46.9% and 20.8%, respectively (P = .04). Patients bearing AA genotype reached a higher graft survival time (9.84 years) than those carrying GA (8.21 years, P = .32) or GG (7.61 years, P = .72) genotypes. CONCLUSIONS: These results suggest that AA genotype and A allele of CD86 +1057G>A polymorphism may confer a protection against acute kidney allograft rejection in Tunisian patients.

[Neonatal screening of congenital toxoplasmosis. Prospective study]. / Depistage neonatal de la toxoplasmose congenitale: etude prospective.

BACKGROUND: While toxoplasmosis infection in women is often benign, transmission of maternal infection to the fetus can lead to severe sequelae. Because the majority of patients with acute toxoplasmosis are asymptomayic, a systematic serologic screening program will needed with monthly serologic screening of all seronegative pregnant women until delivery. The aim of this study was to identify cases of congenital toxoplasmosis among all live births of women found to be seronegative in pregnancy once at least. METHODS: During a prospective study period of 16 months (from 07/02/2003 to 30/06/2004) we conduct a neonatal screening of all live births of women found to be seronegative in pregnancy once at least. Peripheral samples were obtained from every couple mother/infant. Serological methods performed for diagnosis of toxoplasma specific IgM and IgG antibodies were Hemaglutination and Enzyme-linked immunosorbent assay (ELISA). RESULTS: Four cases of congenital toxoplasmosis were diagnosed after birth. All cases were asymptomatic and a specific treatment was started soon after diagnosis. The clinical and serologic evolution was normal in three cases. A serologic rebound at two years was reported in one case with a chorioretinitis in the examination of the ocular fundus. CONCLUSION: Neonatal as well maternal screening during pregnancy and at birth should be systematic to prevent, diagnose and treat early the affected neonates usually asymptomatic.

Acute rejection episodes after kidney transplantation.

Acute rejection episodes (AREs) are a major determinant of renal allograft survival. The incorporation of new immunosuppressive agents explains, at least partially, the improvement seen in the results of transplantation in recent years. The objectives of this study are to analyze the incidence and severity of AREs, their risk factors and their influence on graft and patient survival. We retrospectively studied 280 kidney transplants performed in adults at the Charles Nicolle Hospital, Tunis, between 1986 and 2004. The diagnosis of ARE was based on clinical data and response to treatment. Allograft biopsies were performed in ten cases. The treatment of AREs consisted of pulse methylprednisolone and anti-thymocyte globulin. There were 186 males (66.4%) and 94 females (33.6%), and their mean age was 31 +/- 8.9 years. Overall, the 280 study patients experienced a total of 113 AREs. Of them, 85 had only one ARE, 28 had two to three and none had more than three AREs. A total of 68 AREs were completely re-versible, 42 were partially reversible while three could not be reversed with treatment. The mean inci-dence of AREs was 40.4%. The incidence was > 45% between 1986 and 1997, decreased to 20.5% between 1998 and 2000 and to 9% between 2001 and 2004. Graft survival rates in patients with and without AREs were respectively 91% and 93% at three years, 82% and 90% at five years and 73% and 83% at 10 years. We found a decrease in the incidence of AREs in recent years in our study patients, and this was related to the introduction of sensitized cross-match and the newer immunosuppressive agents, particularly MMF. Additionally, AREs had a deleterious impact on late graft survival in our study population.

Human platelet antigens polymorphisms and susceptibility of thrombosis in hemodialysis patients.

To investigate the association between the polymorphisms of human platelet antigen (HPA)-1,2,3,4,5 and susceptibility to develop thrombosis accident in arteriovenous fistula (AVF), genomic DNA of 112 hemodialysis (HD) patients and 100 healthy blood donors were genotyped by PCR-SSP. The patients were classified into 2 groups: G1 included 54 HD patients presented at least one thrombotic episode on the level of the AVF, and G2 included 58 HD patients without any episode of thrombosis. The allelic frequencies of HPA-1, 2, 3, and 5 among patients and controls did not reveal significant differences. However, the HPA-4b allele was significantly more frequent in G1 than in controls or in G2 patients (23.1% vs. 11.5% and 0.9%, respectively), p<0.01 and p<0.001. The genotype distribution of HPA-4 polymorphism reveals that the HPA-4a4b genotype was more frequent in G1 patients (23/54: 42.6%) than in all HD patients (25/112: 22.3%) or in G2 patients (1/58: 1.72%) (p<0.001, odds ratio: 45.6). Among 24 HD patients with HPA-4a4b genotype, 23 (96%) developed at least 1 or more thrombotic episode on the level of their AVF. However, 30 patients (34.5%) among 87 HD patients with HPA-4a4a genotype presented thrombotic episode (p<0.001). These results reveal a significant association between HPA-4a4b and thrombosis, and it is likely that HPA polymorphisms could be useful markers for potential risk of thrombosis in hemodialysis.

[Vascular trombosis of renal graft: 9 cases]. / Thromboses vasculaires du greffon apres transplantation renale: a propos de 9 cas.

BACKGROUND: Allograft renal thrombosis can occur in 1 to 6% of cases. Many predisposing factors has been identified especially alteration of coagulation. AIM: We analyzed in this study frequency and predisposing factors of renal graft thrombosis. METHODS: We report a retrospective study including 319 renal transplant recipients. RESULTS: Nine patients (2.8%) presented veinous graft thrombosis in 5 cases and arterial thombosis in 4 cases. There were 6 men and 3 women aged of 30.6 years meanly (10-56) which developed the thrombosis 6 days (1-48) after the transplantation. All patients were detransplanted after 16.2 days and 1 patient died. CONCLUSION: Thrombosis constitute an important cause of graft loss. A perfect surgical technic and prophylactic treatment in high risk patients are necessary to reduce this complication.

The involvement of HLA -DRB1*, DQA1*, DQB1* and complement C4A loci in diagnosing systemic lupus erythematosus among Tunisians.

BACKGROUND: Genetic susceptibility to systemic lupus erythematosus (SLE) varies among populations. Few data exist on associations of HLA class II and class III alleles of the major histocompatibility complex (MHC) and susceptibility to SLE in Tunisians. PATIENTS AND METHODS: We compared HLA-DRB1*, DQA1, DQB1* and C4 allotypes in 62 Tunisian SLE patients and 100 matched controls. We also assessed the association of specific alleles with distinct autoantibody profiles in SLE patients. RESULTS: HLA-DRB1*0301, -DRB1*1501 and C4AQO alleles were increased in the SLE patients, while the frequencies of HLA-DRB1*04 and DQB1*03 were decreased. HLA-DQA1*0102 and DQA1*0501 were significantly increased in the SLE patients. HLA-DQB1*0201 and DQB1*0602 were more frequent in the SLE patients. C4A*QO and C4B*QO were increased in frequency in the SLE patients compared to the controls, but only C4A null was significantly increased. Eleven of 17 SLE patients with the C4 null allele were HLA-DRB1*0301 positive. Three of 16 SLE patients with HLA-DRB1*1501 were associated with HLA-DQB1*0501 rather than DQB1*0602, as has been reported in European SLE patients. CONCLUSIONS: The MHC class II alleles (DRB1, DQA1, DQB1) and C4 null associations noted in other ethnic groups are also found in Tunisians, suggesting shared susceptibility factors across ethnic lines in predisposition to SLE. In contrast to other ethnic groups, MHC class II alleles are not associated with the presence of specific autoantibodies in Tunisian SLE patients.

[The role of major histocompatibility complex genes in the pathogenesis of chronic inflammatory bowel diseases]. / Place des genes du complexe d'histocompatibilite dans la pathogenie des maladies inflammatoires chroniques de l'intestin.

Genetic factors, among which the HLA class II coding genes, are implicated in IBD pathogenesis. When considering the ethnic heterogeneity of the studied population and the IBD clinical heterogeneity, UC appears more dependent to HLA genes than CD. UC and HLA genes: HLA DR 4 gene would protect from UC. HLA DR2 gene, particularly the DRB 1 * 1502 allele, is predisposing for more severe forms necessitating a corticotherapy, while DRB 1 * 0301 allele is associated with less needs for surgery. CD and HLA genes: HLA DR 7 gene and the DRB 3 * 0301 allele predispose to CD, while HLA DR 2 and DR 3 genes may be protective factors. Thus, for MC patient, the DRB 1 * 0301/DQB*0201 haplotype might be associated with less occurrence of fistulas or severe forms requiring immunosuppressive therapy.

[Immunological study in sickle cell disease patients: importance of the complement system]. / Etude immunologique du drepanocytaire homozygote: importance du systeme complementaire.

Ten Tunisian patients, with homozygote sickle cell disease and asplenia were studied to investigate and to determine possible immunological function defects. Obtained results directed us to an abnormality of the alternate complement pathway activation which is expressed by a decreased hémolytic activity, while the classic pathway is normal. Quantification of C3, C4, C5, C6, C7 and factor B by immunochemical assay were normal, whereas factor B functional activity was depressed to a mean level of about half of normal in eight patients, IgG was increased in one subject and IgA in two others. Numeration of Band T cells revealed slight decrease in proportion of CD3 and CD4 at one patient associated with an increase in B cells, but normal or increased absolute numbers of all cells population.