Molecular basis of complement factor I deficiency in Tunisian atypical haemolytic and uraemic syndrome patients.

AIM: The aim of the present study was to characterize the molecular basis of complement factor I deficiency in Tunisian atypical haemolytic and uremic syndrome patients with low factor I levels. METHODS: Six adults and seven children were enrolled in this study. Complement factor I levels were assessed by a homemade sandwich ELISA and ranged between 12.5% and 60%. Genomic DNA was amplified by way of a polymerase chain reaction using intronic primers flanking the 13 coding exons. Sequencing of amplified products was carried out by the dye terminator sequencing method. Molecular study was performed on parental samples for three dead paediatric patients. The control group consisted of 100 healthy Tunisian donors. RESULTS: We identified a total of 13 substitutions and one insertion: seven in introns, four in exons and three in UTR. The new mutations were c.-132G > C, c.71 + 181 T > A in 5'UTR and intron 1, respectively. Three intronic polymorphisms were predicted to have impact on splicing events: c.482 + 6C > T, c.884-42_884-41insTTAAA (rs34422850) and c.1429 + 33 A > G (rs9998151). They were three missense mutations leading to a p.Ile 357Met, p.Ile416Leu and p.GLu548Gln. p.Ile 357Met was found in two patients and one relative. Half of the patients had associated mutation and/or polymorphisms. CONCLUSION: This is the first genetic study in Tunisian and Maghrebin atypical haemolytic and uraemic syndrome patients. The high occurrence of Ile357Met mutation may reflect a founding effect. Functional impact of the two new mutations c.-132G > C and c.71 + 181A > T have to be studied. Association of simultaneous genetic abnormalities may explain the variability of atypical haemolytic and uraemic syndrome, penetrance and disease phenotype.

Co segregation of the m.1555A>G mutation in the MT-RNR1 gene and mutations in MT-ATP6 gene in a family with dilated mitochondrial cardiomyopathy and hearing loss: A whole mitochondrial genome screening.

Mitochondrial disease refers to a heterogeneous group of disorders resulting in defective cellular energy production due to dysfunction of the mitochondrial respiratory chain, which is responsible for the generation of most cellular energy. Because cardiac muscles are one of the high energy demanding tissues, mitochondrial cardiomyopathies is one of the most frequent mitochondria disorders. Mitochondrial cardiomyopathy has been associated with several point mutations of mtDNA in both genes encoded mitochondrial proteins and mitochondrial tRNA and rRNA. We reported here the first description of mutations in MT-ATP6 gene in two patients with clinical features of dilated mitochondrial cardiomyopathy. The mutational analysis of the whole mitochondrial DNA revealed the presence of m.1555A>G mutation in MT-RNR1 gene associated to the m.8527A>G (p.M>V) and the m.8392C>T (p.136P>S) variations in the mitochondrial MT-ATP6 gene in patient1 and his family members with variable phenotype including hearing impairment. The second patient with isolated mitochondrial cardiomyopathy presented the m.8605C>T (p.27P>S) mutation in the MT-ATP6 gene. The three mutations p.M1V, p.P27S and p.P136S detected in MT-ATP6 affected well conserved residues of the mitochondrial protein ATPase 6. In addition, the substitution of proline residue at position 27 and 136 effect hydrophobicity and structure flexibility conformation of the protein.

Novel and recurrent AID mutations underlie prevalent autosomal recessive form of HIGM in consanguineous patients.

Immunoglobulin class switch recombination deficiencies (Ig-CSR-D) are characterized by normal or elevated serum IgM level and absence of IgG, IgA, and IgE. Most reported cases are due to X-linked CD40L deficiency. Activation-induced cytidine deaminase deficiency is the most frequent autosomal recessive form, whereas CD40 deficiency is more rare. Herein, we present the first North African study on hyper IgM (HIGM) syndrome including 16 Tunisian patients. Phenotypic and genetic studies allowed us to determine their molecular basis. Three CD40LG mutations have been identified including two novels (c.348_351dup and c.782_*2del) and one already reported mutation (g.6182G>A). No mutation has been found in another patient despite the lack of CD40L expression. Interestingly, three AICDA mutations have been identified in 11 patients. Two mutations were novel (c.91T>C and c.389A>C found in one and five patients respectively), and one previously reported splicing mutation (c.156+1T>G) was found in five patients. Only one CD40-deficient patient, bearing a novel mutation (c.109T>G), has been identified. Thus, unlike previous reports, AID deficiency is the most frequent underlying molecular basis (68%) of Ig-CSR-D in Tunisian patients. This finding and the presence of specific recurrent mutations are probably due to the critical role played by inbreeding in North African populations.

Neonatal lupus erythematosus with congenital heart block in twins.

Background - Neonatal lupus erythematosus is an uncommon acquired autoimmune disease caused by transplacental passage of maternal antibodies SSA/Ro, SSB/La or U1 ribonucleoproteins. The most common clinical manifestations are skin rash, cardiac lesions, thrombocytopenia, anemia and hepatosplenomegaly. Complete congenital heart block is usually irreversible needing a pacemaker implantation in two-thirds of cases. Cases report - We report neonatal lupus erythematosus with complete congenital heart block in twins. Newborns were delivered by caesarean section at week 38 of gestation with a heart rate regular at 70 beats per minute. Both twins and mother were positive for antinuclear, anti-SSA, and anti-SSB antibodies. Twins received single-chamber pacemaker implants at day 12 of life. The evolution was immediately favorable with a heart rate around 110 beats per minute. The follow-up was 2 years. The twins are currently asymptomatic. Conclusion - Complete congenital heart block is the most serious manifestation of the neonatal lupus erythematosus associated with significant morbidity and mortality.

Report of the Tunisian Registry of Primary Immunodeficiencies: 25-Years of Experience (1988-2012).

PURPOSE: Primary immunodeficiencies (PIDs) are a large group of diseases characterized by susceptibility to not only recurrent infections but also autoimmune diseases and malignancies. The aim of this study was to describe and analyze the distribution, clinical features and eventual outcome of PID among Tunisian patients. METHODS: We reviewed the record of 710 patients diagnosed with Primary Immunodeficiency Diseases (PIDs) from the registry of the Tunisian Referral Centre for PIDs over a 25-year period. RESULTS: The male-to-female ratio was 1.4. The median age at the onset of symptoms was 6 months and at the time of diagnosis 2 years. The estimated prevalence was 4.3 per 100,000 populations. The consanguinity rate was found in 58.2 % of families. According to the International Union of Immunological Societies classification, spectrums of PIDs were as follows: combined T-cell and B-cell immunodeficiency disorders account for the most common category (28.6 %), followed by congenital defects of phagocyte (25.4 %), other well-defined immunodeficiency syndromes (22.7 %), predominant antibody deficiency diseases (17.7 %), diseases of immune dysregulation (4.8 %), defect of innate immunity (0.4 %) and complement deficiencies (0.4 %). Recurrent infections, particularly lower airway infections (62.3 %), presented the most common manifestation of PID patients. The overall mortality rate was 34.5 %, mainly observed with combined immunodeficiencies. CONCLUSION: The distribution of PIDs was different from that reported in Western countries, with a particularly high proportion of Combined Immunodeficiencies and phagocyte defects in number and/or function. More is needed to improve PID diagnosis and treatment in our country.

Congenital heart disease in 37,294 births in Tunisia: birth prevalence and mortality rate.

AIM: To investigate the previously unknown birth incidence, treatment, and mortality of children with congenital heart disease in Tunisia. METHODS: We undertook a retrospective review of medical records of all patients who were born in 2010 and 2011, and were diagnosed in Sfax (Tunisia) with congenital heart defect. RESULTS: Among 37,294 births, 255 children were detected to have congenital heart disease, yielding a birth incidence of 6.8 per 1000. The most frequently occurring conditions were ventricular septal defects (31%), ostium secundum atrial septal defects (12.9%), and pulmonary valve abnormalities (12%). Coarctation of the aorta, tetralogy of Fallot, univentricular physiology, pulmonary atresia with ventricular septal defect, and transposition of the great arteries were found in 4.3%, 6.2%, 3.4%, 2.7%, and 2.7%, respectively. During the follow-up of 1 year, 23% of the children died. About three-quarters of those deaths happened before surgery. CONCLUSION: The present study is in line with the general estimates in the world. It has revealed a high case of mortality among the patients awaiting corrective surgery. These children need more facilities.

Plasma Exchange for Lyme Neuroborreliosis delayed diagnosis: A case report.

Lyme neuroborreliosis (LNB) is a rare infectious disease, caused by Borrelia burgdorferi spirochetes and responsible for a variety of neurological manifestations. The most common manifestations of LNB in children are cranial nerve involvement, especially facial nerve palsy often accompanied by lymphocytic meningitis. In this article, we present a case of a 4-year-old boy presented to our emergency department with abdominal pain evolving for a week and symmetrical ascending progression of weakness responsible for severe respiratory failure. Diagnosis of Guillain-Barré syndrome (GBS) was initially suspected. Although our patient had received 2 courses (each of 5 days) of Intravenous immunoglobulin (IVG) treatment, no clinical improvement was observed. The diagnosis of LNB was confirmed by detection of both IgG and IgM specific antibodies in serum. The patient's muscle weakness got better after a 2- week course of Ceftriaxone but respiratory muscle failure didn't improve with two extubation failures. Consequently, we decided to conduct plasmapheresis procedures. We managed to extubate the child and discharge him after a good recovery of his symptoms. Pediatricians must consider LNB disease in the differential diagnosis of GBS, especially when the patient didn't recover after IVG treatment. This case shows that plasmapheresis could be effective for pediatric neuroborreliosis cases with severe neurological disorders.

How MRI can contribute to the diagnosis of acute demyelinating encephalomyelitis in children.

OBJECTIVE: To illustrate through 10 pediatric cases, the clinical features, course, and importance of neuroimaging (especially MRI) in guiding the diagnosis of acute disseminated encephalomyelitis (ADEM) and controlling patients after treatment. METHODS: A retrospective review of 10 pediatric cases of ADEM, with special regard to the MRI features, presenting to the Pediatric Departments, Hedi Chaker Hospital, Sfax, Tunisia between January 2002 and December 2008. RESULTS: Children with ADEM presented with variable and multiple neurological signs most often occurring after an infectious episode, especially after upper respiratory tract infection. The MRI permitted confirmation of the diagnosis by showing demyelinating lesions either in the brainstem, the cerebellum, the cerebral white and grey matter, or in the spine of all patients. CONCLUSION: Acute disseminated encephalomyelitis is characterized by multifocal demyelinating lesions resulting in varied neurological signs. The MRI is the technique of choice to show these lesions.

Antinuclear antibodies in children: clinical signification and diagnosis utility.

BACKGROUND: Antinuclear antibodies (ANA) test is used to screen adults as well as children for connective tissue diseases (CTD) and autoimmune hepatitis. However, interpretation of ANA positivity can be delicate. AIM: to determine clinical significance and diagnosis utility of ANA positivity in children. METHODS: Patients from a general pediatric department with ANA positive results were included (follow-up period of 2 years). ANA screening was performed by indirect immunofluorescence (IIF) on HEp-2 cells substrate (BioSystems®). In case of ANA positivity (cut-off: 1:80), the specificity was determined by IIF on Crithidia luciliea substrate (BioSystems®) and immunodot (Euroimmun®). RESULTS: Among 102 ANA tests, 55 (53,9%) were positive. We recorded the data of 38 patients (age average: 9,5 years - sex ratio: 0.72). The most frequent signs were join pain (55,3%). ANA titer varied between 1:80 (39,5% of cases) and 1:1280 (2,6% of cases). Typing was negative in 89,5% of cases. The majority (42,1%) of children with positive ANA test had musculoskeletal diseases. The others (57,9%) had systemic lupus erythematosus(n=2),  overlap syndrome(n=1), rheumatoid purpura(n=2), idiopathic thrombocytopenic purpura(n=1), coeliac disease(n=1) or non-autoimmune diseases/no confirmed diagnosis(n=15). CONCLUSIONS: ANA prevalence in children was relatively high. When the pretest probability is low, the positive predictive value for CTD or autoimmune hepatitis is low. However, depending on the clinical context, ANA detection can represent a supplement diagnostic tool for these diseases and/or can lead to a clinico-biological monitoring.

Contribution of laparoscopy in the abdominal tuberculosis diagnosis: retrospective study of about 11 cases.

OBJECTIVE: Abdominal tuberculosis is one of the most frequent extra-pulmonary localizations. Its diagnosis is difficult and may lead to a delayed prescription of specific treatment. This study is aimed at stressing the role of laparoscopy associated with a biopsy in the diagnostic confirmation of abdominal tuberculosis particularly in doubtful cases. METHODS: The diagnostic features of 11 cases hospitalized for abdominal tuberculosis in the Paediatric Surgery Department of Fattouma Bourguiba Hospital in Monastir for a 6-year period (2001-2006), were evaluated retrospectively. The diagnosis of abdominal tuberculosis was substantiated histopathologically by laparoscopy in all cases. The epidemiological and clinical characteristics along with the laboratory, radiological and histological data were studied. RESULTS: Eleven cases of abdominal tuberculosis with a mean age of 5.6 years were diagnosed. It was peritoneal tuberculosis in all cases and associated with intestinal localization in one case. A conversion to laparotomy was practiced in three patients: appendicular plastron in one case, pseudo-tumor aspect of an intestinal loop in another case and because of their pathological aspect appendicectomy and caecum biopsy in the third. The diagnosis was confirmed histologically by biopsies in nine cases and on excision pieces in the other two cases. All patients had an uneventful course with an antituberculosis treatment. CONCLUSION: Abdominal tuberculosis is still frequent in Tunisia. Because of its non-specific clinical presentation and the limited means of investigation, a laparoscopy with biopsy should be practiced as first line diagnostic tool in case of doubtful abdominal tuberculosis. The earlier the diagnosis is established and an adapted antituberculosis treatment is started, the better the prognosis is.

Epidemiology and disease burden of tuberculosis in south of Tunisia over a 22-year period: Current trends and future projections.

BACKGROUND: Tuberculosis (TB) is a public health problem worldwide. Characterizing its trends over time is a useful tool for decision-makers to assess the efficiency of TB control programs. We aimed to give an update on the current chronological trends of TB in Southern Tunisia from 1995 to 2016 and to estimate future trajectories of TB epidemic by 2030. METHODS: We retrospectively collected data of all notified TB new cases by the Center of Tuberculosis Control between 1995 and 2016 in South of Tunisia. Joinpoint Regression Analysis was performed to analyze chronological trends and annual percentage changes (APC) were estimated. RESULTS: In the past 22 years, a total of 2771 cases of TB were notified in Southern Tunisia. The annual incidence rate of TB was 13.91/100,000 population/year. There was a rise in all forms of TB incidence (APC = 1.63) and in extrapulmonary tuberculosis (EPTB) (APC = 2.04). The incidence of TB increased in children and adult females between 1995 and 2016 (APC = 4.48 and 2.37, respectively). The annual number of TB declined in urban districts between 2004 and 2016 (APC = -2.85). Lymph node TB cases increased (APC = 4.58), while annual number of urogenital TB decreased between 1995 and 2016 (APC = -3.38). Projected incidence rates would increase to 18.13 and 11.8/100,000 population in 2030 for global TB and EPTB, respectively. CONCLUSIONS: Our study highlighted a rise in all forms of TB and among high-risk groups, notably children, females and lymph node TB patients in the last two decades and up to the next one.

[Adenocarcinoma of the rectum in a 14-year-old]. / Adénocarcinome du rectum chez 1 enfant de 14 ans.

Colorectal cancer is rare in children and adolescents. It is usually associated with predisposing genetic factors, aggressive histology, and poor prognosis. Two familial syndromes are best characterized, hereditary nonpolyposis colorectal cancer and familial adenomatous polyposis. They are autosomal dominant inherited disorders. We report the case of a 14-year-old girl having a Dukes D adenocarcinoma of the rectum with peritoneal extension and bone metastases.

[Positivity of antineutrophil cytoplasmic antibodies in children: prevalence and etiologies]. / Positivité des anticorps anti-cytoplasme des polynucléaires neutrophiles chez l'enfant : prévalence et étiologies.

In adults, anti-neutrophil cytoplasmic antibodies (ANCA) are considered as serological markers of several diseases, especially vasculitis and glomerulonephritis. Since ANCA are rarely positive in children, few data about the clinical relevance of these auto-antibodies in pediatric population have been reported. Therefore, our study aims to describe the spectrum of disorders associated with positive ANCA in Tunisian children. This study had been carried out over a period of 12 years and a half. All patients under the age of 15 for whom ANCA screening was performed in our laboratory were included. Clinical data were collected retrospectively. Indirect immunofluorescence (IFI) technique for ANCA detection was performed using PNN smears fixed with ethanol, formalin and, if necessary, methanol. Positive results were tested using immunodot to characterize the antigenic targets (myeloperoxydase (MPO) and proteinase 3 (PR3)). Our results showed that 410/5,990 (6.8%) laboratory requests for ANCA screening were for children. Forty (9.7%) requests were positive (24 children). Clinical data were available for 19 patients only. Sex-ratio (F/M) was 1.25. The mean age was 9 years and a half (3-15 years). The most frequent IIF patterns were x-ANCA (n=12) and p-ANCA (n=7). In our patients, the most frequent conditions associated to ANCA were treatment with benzylthiouracil for hypothyroidism (n=6), inflammatory bowel disease (n=4) and hemolytic anemia (n=4). In conclusion, the positivity of ANCA in children seems to be a rare event. Associated conditions include clinical disorders specific to the pediatric population. Treatment with benzylthiouracil is an etiology to be taken into consideration.

[Post-streptococcal glomerulonephritis in the south of Tunisia: A 12-year retrospective review]. / La glomérulonéphrite aiguë post-streptococcique de l'enfant dans le sud tunisien : étude rétrospective de 12 ans.

AIM: Post-streptococcal glomerulonephritis (PSGN) is a frequent cause of acute nephritis in children. This study aimed to describe the epidemiology, clinical characteristics and outcomes of PSGN and look for predictor's factors of severity. METHODS: A 12-year retrospective review of case notes and laboratory data was conducted at a department of pediatrics, pediatric emergency and intensive care, Hedi Chaker Hospital. RESULTS: One hundred seventy eight children were treated for PSGN with a mean age of 7.6 ans±3.43 ans. One hundred and forty-two patients (80%) had a history of a recent upper respiratory tract or skin infection. Streptococcal pharyngitis was the most common cause, identified in 113 patients (67.6%). Macroscopic hematuria and edema were noted in 135 (75.8%) and 114 cases (64%) respectively. Hypertension was present in 55 patients (31%). Oliguria was noted in 30 children (16.8%). Sixty-six subjects (37%) developed acute renal impairment (creatinine≥70 micromoles/L). No correlation was demonstrated between acute renal impairment and age, sex, triggering infection, anemia and white blood cell count. Creatinine greater than 56.35 micromoles/L was associated with a high risk of developing high blood pressure. The mean length of admission was 5.8 days±4.44. Only one subject has ongoing renal dysfunction. CONCLUSION: PSGN remains a common nephropathy in our region. The detection and effective treatment of any infection that may be involved can reduce the incidence of this disease.

[Hepatopulmonary syndrome and portal hypertension]. / Syndrome hepatopulmonaire et hypertension portale.

BACKGROUND: The hepatopulmonary syndrome is known by the association of chronic hepatopathy and refractory hypoxemia linked to pulmonary vasodilatation. The hepatopathy may be an hepatic cirrhosis, a congenital porto-case shunt, a porte cavernous angioma or a portal high blood pressure. AIM: Report new cases CASE REPORT: We report the observation of a girl followed from the age of 5 years for type I auto-immune hepatitis complicated of portal high blood pressure, in whom the hepatopulmonary syndrome appears 6 years later and the diagnosis was established in front of the presence of clinical signs (cyanosis and fingers clubbing) associated to a severe hypoxia at 43 mmHg without heart attack and in front of the results of scintigraphy use with albumine micro-agregat marked to technetium 99 m which objected an increase of perfusion at the lungs and an extra pulmonary fixation (cerebral, thyroïdien and renal). In front of the severity of hypoxia and the intensity of the extra pulmonary fixation which corresponds the importance of the shunts, the hepatic transplantation shouldn't be realized and the child followed only a salt-free diet associated to a martial addition and to treatment by propanolol. CONCLUSION: The hepatopulmonary syndrome is a diagnosis to evocate in front of all hypoxia happening during the evolution of a chronic hepatopathy with portal high blood pressure. Its prognosis is severe in the absence of a hepatic transplantation.

[Vasculitis with renal involvement and antineutrophil cytoplasmic antibodies (ANCA) in a child receiving benzylthiouracil]. / Vascularite avec atteinte rénale et anticorps anticytoplasme des polynucléaires neutrophiles (ANCA) après prise de benzylthio-uracile chez l'enfant.

Vasculitis associated to antineutrophil cytoplasmic antibodies (ANCA) is a rare complication of therapy with antithyroid medication. They were mainly described in patients treated with propylthiouracil (PTU), carbimazole, methimazole and rarely by benzylthiouracil (Basden). We report a case of 12-years-old girl treated by benzylthiouracil for Grave's disease who developed after 2 years vasculitis associated with cutaneous involvement (generalized ulcer necrotic purpura) and glomerulonephritis with proteinuria of 24 hours at 26 mg/kg/day, microscopic hematuria and renal failure with creatinemia level at 135 micromol/l. The ANCA type antiMPO (myeloperoxidase) was positive. The histology study of the renal needle biopsy was in favour with focal necrotizing glomerulonephritisand crescents with different evolutive stages. The discontinuation of benzylthiouracil and the treatment by the corticoids involved a disappearance of cutaneous lesions, a negative result of proteinuria, a normalization of the renal function (creatinemia=84 micromol/l) and a disappearance of hematuria and ANCA. These results permitted to announce hypothesis that benzylthiouracil was implicated in development of vasculitis associated to ANCA.