[Creation and report of the Tunisian Fanconi Anemia Registry (TFAR)]

INTRODUCTION

Fanconi anemia (FA) is a genetically and phenotypically heterogeneous inherited disease. Many groups have established FA registries. In Tunisia, in collaboration with the Tunisian Fanconi Anemia Study Group (TFASG), we set up the Tunisian Fanconi Anemia Registry (TFAR).

PATIENTS AND METHODS

We contacted all hematology and pediatrics departments to include their FA patients diagnosed between January 1983 and December 2008. The registry is available on the TFASG web site (www.fanconi-tunisie.net).

RESULTS

Sorting the files brought out 142 patients belonging to 118 families. The mean age at diagnosis was 11 years. There was consanguinity in 86%, malformative syndrome in 91%, and pancytopenia at diagnosis in 69%. Of 28 patients, 95% belonged to the FANCA group. Androgen treatment was given in 109 cases and genoidentical bone marrow transplantation (BMT) in 27 patients. The diagnosis of a myelodysplastic syndrome was retained in 4%, acute leukemia in 6%, and a solid tumor in 2%. The median overall survival time in all patients is 17 years 5 months; it is significantly better in patients having received allografts (p=0.01).

CONCLUSION

FA seems frequent in Tunisia, which is in part explained by the high consanguinity and endogamy in this country. Hematologic impairment is still the most frequent revealing circumstance of the disease. It is often severe or moderate and requires androgen treatment or bone marrow transplantation. BMT should be proposed to all patients with an HLA-compatible donor.

A6 peptide activates CD44 adhesive activity, induces FAK and MEK phosphorylation, and inhibits the migration and metastasis of CD44-expressing cells

The A6 peptide (acetyl-KPSSPPEE-amino) has antitumor activity in the absence of significant adverse events in murine tumor models and clinical trials. A6 shares sequence homology with CD44, an adhesion receptor involved in metastasis that is also a marker of cancer stem cells and drug-resistant phenotypes. We investigated the mechanism of action of A6 by examining its effects on CD44 activity, cell migration, and metastasis. A6 inhibited the migration of a subset of ovarian and breast cancer cell lines, exhibiting IC(50) values of 5 to 110 nmol/L. The ability of A6 to inhibit migration in vitro correlated with CD44 expression. Immunopreciptation studies showed that CD44 binds A6 and that biotin-tagged A6 can be cross-linked to CD44. The binding of A6 altered the structure of CD44 such that it was no longer recognized by a monoclonal antibody to a specific epitope. Importantly, A6 potentiated the CD44-dependent adhesion of cancer cells to hyaluronic acid and activated CD44-mediated signaling, as evidenced by focal adhesion kinase and MAP/ERK kinase phosphorylation. In vivo, A6 (100 mg/kg delivered s.c. twice daily) reduced the number of lung foci generated by the i.v. injection of B16-F10 melanoma cells by 50% (P = 0.029 in an unpaired t test). We conclude that A6 potently blocks the migration of CD44-positive cells in vitro through an interaction with CD44 that alters its structure and activates CD44 to enhance ligand binding and downstream signaling. The concurrent ability of A6 to agonize the CD44 receptor suggests that CD44 activation may represent a novel strategy for inhibiting metastatic disease.

[Aicardi syndrome associated with severe congenital ptosis]

Aicardi syndrome is a rare neurodevelopmental disorder characterized by corpus callosum agenesis, chorioretinal lacunae and early-onset infantile spasms. We report a particular case of Aicardi syndrome characterized by the association of the classical triad of severe bilateral ptosis, pontocerebellar hypoplasia, and perisylvian polymicrogyria in a girl born to non-consanguineous parents, but whose mother suffered from idiopathic generalized epilepsy.

Abstract 1297: DDAIP improves the pharmacokinetic profile of PrevOnco® in different species: Comparison of DDAIP, CMC and PEG-300/400 formulations in mice, beagle dogs and cynomolgus monkeys

Our study in the accompanying abstract demonstrates that a low dose of PrevOnco® in combination with doxorubicin was efficacious in a liver cancer model. In this study we investigated the pharmacokinetic profile of PrevOnco® when formulated with 20% DDAIP or 20% PEG-300 in mice, dogs and cynomolgus monkeys. The goal was to evaluate the potential of formulation in DDAIP to increase PrevOnco® exposure in vivo.

Methods: PK plasma analyses of PrevOnco® administered orally at 100 mg/Kg in 1% carboxy methyl cellulose (CMC) or in 10% PEG-400 were evaluated in nude mice. 20% PEG-300 and 20% DDAIP formulations were evaluated in mice (100 mg/Kg), dogs (5 mg/Kg) and monkeys (5 mg/Kg).

Results: Compared to 20% PEG-300, administration of PrevOnco® in 20% DDAIP induced 7-fold, 8-fold and 2-fold improvements in AUC in mice, dogs and cynomolgus monkeys, respectively. In mice, Cmax reached 4,700 ng/mL in DDAIP compared to 1,000 ng/mL in PEG-300 formulation. PrevOnco® levels were detectable up to 4 hours in DDAIP compared to 2 hrs in PEG-300. In dogs, PrevOnco® in 20% PEG-300 formulation had a Cmax of 125 ng/mL at Tmax = 1 hr. This concentration was maintained up to 2 hrs with levels undetectable at 4 hrs. PrevOnco® in 20% DDAIP formulation had a Cmax of 1,600 ng/mL at Tmax=1 hr and T1/2=3hrs. AUC values were 3,941 and 477 for DDAIP and PEG, respectively. In monkeys, PrevOnco® plasma levels following 5 mg/Kg oral administration reached a Cmax of 120 ng/mL in 20% DDAIP and 90 ng/mL in 20% PEG-400. Tmax was 1 hour and 0.5 hour while AUCs were 390 versus 154 (both DDAIP vs. PEG-400).

Conclusion: Formulating with DDAIP increased plasma levels of PrevOnco® following oral administration in mice, dogs and monkeys. Thus, DDAIP facilitated higher Cmax and AUC values as well as a longer T1/2. DDAIP formulation will allow a lower dose of PrevOnco® to be used while maintaining efficacy and reducing cytotoxicity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1297. doi:10.1158/1538-7445.AM2011-1297

Abstract 2535: PrevOnco® exhibits anti-tumor activity in in vitro and in vivo human tumor models: Combination therapy (PrevOnco® / Doxorubicin) demonstrates a better efficacy profile with enhanced survival rate in a liver cancer model

Background: The investigational anti-neoplastic agent PrevOnco® (know as Prevacid® /Lansoprazole®) is entering Phase II clinical trials in the US for hepatocellular carcinoma.

Objectives: This study examined the efficacy of PrevOnco® in both in vitro and in vivo human tumor models. The optimal oral formulation, pharmacokinetic parameters and its combination therapy with doxorubicin were evaluated.

Methods: Cytotoxicity was assessed in vitro by MTT analysis. In vivo efficacy was assessed in nude mice in 2 survival models of the pediatric kidney-derived G401 and SR leukemia, and one ectotopic HepG2 model.

Results: In MTT assays, PrevOnco® demonstrated a concentration-dependent cytotoxic effect against a number of cancer cell lines (MC116, HOP-62, MOLT4, HCT-15, JMI, RPMI6666, RS 1184, STA 486, SF539, U251, SF295, UACC-62). Synergistic activity was observed with doxorubicin but not with cisplatin. PrevOnco® was significantly more effective than Omeprezole or SCH-28080. Pharmacokinetic analysis in nude mice showed 10% PEG400 to be a better vehicle than carboxy-methyl cellulose. A mean maximum concentration (Cmax) of 20,242 ng/mL was detected at 0.5 hours (Tmax) with the mean dose adjusted area under the curve (AUC) determined to be 846.5 nM*hr/mg. The half life (T1/2) of the compound was 0.9 hours. PrevOnco® at 100 mg/kg given orally significantly prolonged the survival rate in the G401 kidney xenograft by 60% at day 70 whereas all mice in vehicle treaded group died. At study end (day 83) 26% of the mice remained alive in the treated group. SR leukemia xenograft treated with PrevOnco® survived through the end of the study with >80% of the mice remaining alive. PrevOnco® induced a dose-dependent reduction in tumor growth in hepG2 model. A synergestic antitumoral effect was obtained with the combination treatment of PrevOnco® at 30 mg/kg and doxorubicin at10 mg/kg. PrevOnco® levels in hepG2 tumors following 100 mg/Kg BID treatment for 3 consecutive days indicated accumulation of the drug into tumor tissue.

Conclusion: PrevOnco® exhibited anti-neoplastic activity in both in vitro and in vivo, enhancing survival and inhibiting tumor growth. Synergistic activity was obtained with doxorubicin in xenograft model of liver cancer, suggesting a potential new combination therapy for the treatment of liver cancer with less toxicological liability.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2535. doi:10.1158/1538-7445.AM2011-2535

[Hypoplasia of the internal carotid artery: a rare cause of cerebral ischemic stroke in children]

Hypoplasia of the carotid arteries is a rare congenital anomaly which, when symptomatic, presents as cerebral ischemia or hemorrhage. We report a case of hypoplasia of the carotid arteries revealed by cerebral ischemic stroke in an infant with hereditary spherocytosis. The diagnosis was confirmed by MR angiography. We describe this rare cause of stroke in children and the characteristics of its association with hereditary spherocytosis.

[Cholelithiasis associated with portal cavernoma in children: 2 case reports]

The association of cholelithiasis and portal cavernoma is rarely described in adult or pediatric patients. We report 2 cases of gallstone associated with portal cavernoma in 2 girls. The first one suffered from Evans syndrome associated with congenital immune deficiency. The portal cavernoma was discovered with gallstone after splenectomy indicated because of high steroid dependence. In the second case, the cavernoma complicated neonatal umbilical catheterism. The gallstone was asymptomatic and discovered on annual ultrasonography. Septicemia, profound thrombocytopenia, and acute anaemia led to rapid death in the first case. However, the progression was favourable under celioscopic treatment in the second one. Our original observations suggest systematically searching for gallstone in children with portal cavernoma.

[Evolution of group A Rotavirus strains circulating in Tunisia over a 3-year period (2005-2007)]

BACKGROUND

Rotaviruses are the most frequent agents associated with diarrhoea in children worldwide. Analysis of mobility of the 11 segments of genomic RNA by polyacrylamide gel electrophoresis (PAGE) yields a pattern which is characteristic for a particular rotavirus isolate. The group A rotaviruses can be further characterized by analysis of VP7 and VP4 genes specificities, responsible for rotavirus classification into G and P genotypes, respectively. The aim of the present study was to determine the evolution of group A Rotavirus strains circulating in Tunisia over a 3-year period (2005-2007).

MATERIAL AND METHODS

A total of 1503 stool samples collected from children less than five years old, consulting or hospitalised in Tunisia for diarrhoea between 2005 and 2007, were screened for the presence of group A Rotaviruses. Rotavirus-positive specimens were further analyzed by PAGE and G/P-genotyped by multiplex semi-nested RT-PCR.

RESULTS

Rotaviruses were detected in 323 stool samples over 1503 (21 %). Long electropherotypes predominated in Tunisia during the whole period of study (N=158 vs N=82 short electropherotypes). VP7 genotyping showed the cocirculation of five different genotypes: G1, G2, G3, G4 and G9. VP4 typing detected four different P-genotypes: P[8], P[4], P[6] and P[11]. Rotavirus strains with G3P[8] specificity were predominating in Tunisia in 2005 and 2006, replaced by G2P[4] strains in 2007.

Pancreatic autoantibodies in Tunisian children with newly diagnosed type 1 diabetes

We analyzed 86 children with newly diagnosed type 1 diabetes for antibodies to islet cells (ICA), glutamic acid decarboxylase (GADA), second-islet antigen (IA-2A), and insulin (IAA) in order to evaluate the prevalence of immune-mediated type 1 diabetes, as well as to recognize which autoantibody combination is more frequently associated with the disease. A positive result for one or more diabetes-related antibodies evaluated was found in 78 children (90.7%). With regard to single autoantibody testing, ICA were found to be positive in 49 patients (57%), GADA in 56 (65.1%), IA-2A in 37 (43%), and IAA in 43 (50%) patients. Combining the determination of at least two autoantibodies, GADA and/or IAA were better detectable than other antibody combination, being positive in 70 patients (81.4%). GADA and IA-2A represent also a useful screening combination; being positive in 65 patients (75.6%). Our data indicate that the vast majority of cases of type 1 diabetes in children may be considered as immune-mediated and that multiple autoantibody analysis improves identification of the disease.

[Susceptibility markers in Tunisian first-degree relatives of patients with type 1 diabetes]

To identify the profile of anti-pancreas autoantibodies and elucidate the HLA DRB1, DQB1 polymorphism in Tunisian first-degree relatives of patients with type 1 diabetes, we recruited 96 relatives from 21 families with at least one diabetic child. Islet cell antibodies (ICA) were detected by immunofluorescence on monkey pancreas; glutamate decarboxylase (GADA), IA2 (IA2-A) and insulin (IAA) antibodies were measured by RIA. HLA class II DRB1 and DQB1 alleles were typed by PCR-SSP. ICA, GADA, IA2-A and IAA were found in respectively 11.5, 4.2, 5.2 and 8.3% of relatives. Twenty-two out of 96 had at least one antibody and 20 out of these 22 had a susceptibility allele (DRB1*03, DRB1*04, DQB1*02 or DQB1*0302) with or without protective allele (DRB1*11, DRB1*13, DRB1*15 or DQB1*06). All of the 5 relatives having 2 autoantibodies or more carried the DRB1*04-DQB1*0302 susceptible haplotype. In conclusion, this observational study confirms in a Tunisian population known epidemiological data and demonstrates the usefulness of follow-up to determine the predictive value of studied markers.

La maladie de Cowden : une nouvelle observation pédiatrique

We report on a paediatric observation of Cowden's disease in a 6-year-old child. Familial steroid-resistant nephrotic syndrome was associated to papulous and papillomatous lesions of gingiva and oral mucosa, multiple hamartoma of the back and of upper limbs, facial dysmorphism and follicular thyroid cancer. Thyroid cancer evolved favorably after surgical treatment, radioactive iodine and L-thyroxin supplementation. Nephrotic syndrome evolved to chronic renal insufficiency after 11 years. The early diagnosis of Cowden's disease, or multiple hamartoma syndrome, allows a careful monitoring of the patients who are facing the risk of cancer transformation, which is the principal complication of the condition.

8-Substituted Analogues of 3-(3-Cyclopentyloxy-4-methoxy-benzyl)-8-isopropyl- adenine: Highly Potent and Selective PDE4 Inhibitors

3-(3-Cyclopentyloxy-4-methoxy-benzyl)-8-isopropyl-adenine V11294 (1) has been identified as a lead structure, which selectively inhibits human lung PDE4 (436 nM) and is also active in a number of in vitro and in vivo models of inflammation. Here we describe the synthesis and pharmacology of a series of highly potent 8-[(benzyloxy)methyl]-substituted analogues, with potencies in the range 10-300 nM. In addition, several compounds showed interesting PDE4 subtype specificities, for example, the 3-thienyl derivative 5v, which showed 6-10 nM potency at PDE4B, D3, and D5 and a 20- to 200-fold selectivity over A and D2, respectively.

[Determination of anti-transglutaminase antibodies in the diagnosis of coeliac disease in children: results of a five year prospective study]

AIM

To evaluate the interest of IgA antibodies to tissue transglutaminase in the diagnosis of children coeliac disease compared with anti-endomysium and anti-gliadin antibodies.

SUBJECTS AND METHODS

Seventy children with coeliac disease (mean age: 5 years and 8 months) and 99 disease controls (mean age: 4 years and 5 months). IgA anti-transglutaminase were tested by ELISA using a human recombinant tissue transglutaminase. IgA anti-endomysium were detected by indirect immunofluorescence on monkey oesophagus.

RESULTS

The middle rate of IgA anti-transglutaminase was 101.06 units in patients and only 0.47 unit in controls. IgA anti-transglutaminase and IgA anti-endomysium were in agreement in 98.8% of cases; only two cases were discordant (+/- and -/+). Globally, the two markers had the same sensitivity (90%), specificity (98%), negative (93.2%) and positive (96.9%) predictive values. For anti-gliadin antibodies, the IgG were more sensitive (88.6%) and the IgA more specific (93.9%).

CONCLUSION

IgA anti-tissue transglutaminase can be used instead of IgA anti-endomysium as a serological marker of screening and diagnosis of coeliac disease in children after 3 years.

[Gaucher's disease in Tunisia (multicenter study)]

Gaucher's disease is one of the rare lysosomial disease that could receive substitutive enzymatic treatment which may improve considerably the prognosis of certain forms. The purpose of this work is to study the epidemiology of the disease in Tunisia, to highlight the diagnostic and therapeutic difficulties and also to precise our subsequent needs for substitutive medication.

PATIENTS AND METHODS

We have conducted a retrospective survey of the hospital wards that were susceptible to take care of patients having Gaucher's disease. These wards are the paediatric, neonatology, internal medicine, haematology, neurology and cardiology wards.

RESULTS

In this study we have observed 27 cases of Gaucher's disease over a period of 18 years (1983-2001). The age at onset ranges from birth to 73 years of age, with an average age of 14.5 years. According to the age at onset and the clinical presentation, we classify our patients into: 20 cases of type 1 (74%), three cases of type 2 (12%), and three cases of type 3 (12%), and one case of unspecified type.Gaucher's disease type 1: The age at onset ranged from 10 months to 73 years with an average of 19 years. The main clinical signs that we have observed were splenomegaly, hepatomegaly, pallor, haemorrhagic appearance and also osteoporosis and bone pain observed in 40% of the cases. The diagnosis was based on histology showing the Gaucher's cells in various tissues while the diagnosis obtained by the dosage of glucocerebrosidase took place only in 50% of the cases. The treatment has always been symptomatic (analgesics, transfusion). A splenectomy was performed in 47% of the cases and none of the patients received a specific treatment. The follow-up period ranged from 1 month to 18 years with an average follow-up of 4 years. Among the 12 patients having a follow-up of at least 1 year, we have noticed an improvement after splenectomy in three cases, a stability in three cases and two worsening cases dealing mainly with bone problems. One patient aged 73 died from respiratory problem and three were lost to follow-up. Gaucher's disease type 2: We have observed three cases of Gaucher's disease type 2 diagnosed at 1 day, 45 days and 3 months of age. The visceral manifestations were serious and the neurological features included seizures, hypertony, ocular-nerve palsies and psychometric decline. The three patients died. Gaucher's disease type 3: Three patients were probably suffering from Gaucher's disease type 3 with visceral manifestations observed at the ages of 9 months, 1 year and 3 years, and also neurological signs observed at respective ages of 2.5 and 3 years. Two patients died and the remaining one was lost to follow-up.

CONCLUSION

Gaucher's disease is not exceptional in Tunisia. Type 1 is by far the most common one. We have noticed some insufficiency in the diagnosis as the glucocerebrosidase enzymatic dosage was performed only in 50% of the cases as well as therapeutic insufficiency with no prescription of the specific treatment.

4-(2-Pyridyl)piperazine-1-carboxamides: potent vanilloid receptor 1 antagonists

A series of 4-(2-pyridyl)piperazine-1-carboxamide analogues based on the lead compound 1 was synthesized and evaluated for VR1 antagonist activity in capsaicin-induced (CAP) and pH (5.5)-induced (pH) FLIPR assays in a rat VR1-expressing HEK293 cell line. Potent VR1 antagonists were identified through SAR studies. From these studies, 18 was found to be very potent in the in vitro assay [IC(50)=4.8 nM (pH) and 35 nM (CAP)] and orally available in rat (F%=15.1).

N-(4-tertiarybutylphenyl)-4-(3-chloropyridin-2-yl)tetrahydropyrazine -1(2H)-carbox-amide (BCTC), a novel, orally effective vanilloid receptor 1 antagonist with analgesic properties: I. in vitro characterization and pharmacokinetic properties

Vanilloids such as capsaicin have algesic properties and seem to mediate their effects via activation of the vanilloid receptor 1 (VR1), a ligand-gated ion channel highly expressed on primary nociceptors. Although blockade of capsaicin-induced VR1 activation has been demonstrated in vitro and in vivo with the antagonist capsazepine, efficacy in rat models of chronic pain has not been observed with this compound. Here, we describe the in vitro pharmacology of a highly potent VR1 antagonist, N-(4-tertiarybutylphenyl)-4-(3-chloropyridin-2-yl)tetrahydropyrazine-1(2H)-carbox-amide (BCTC). Similar to capsazepine, this compound inhibits capsaicin-induced activation of rat VR1 with an IC50 value of 35 nM. Interestingly however, BCTC also potently inhibits acid-induced activation of rat VR1 (IC50 value of 6.0 nM), whereas capsazepine is inactive. Similarly, in the rat skin-nerve preparation both BCTC and capsazepine block capsaicin-induced activation, whereas the response to acidification is inhibited by BCTC, but not by capsazepine. Specificity for VR1 was demonstrated against 63 other receptor, enzyme, transporter, and ion channel targets. BCTC was orally bioavailable in the rat, demonstrating a plasma half-life of approximately 1 h and significant penetration into the central nervous system. Thus, BCTC is a high potency, selective VR1 antagonist that, unlike capsazepine, has potent blocking effects on low pH-induced activation of rat VR1. These properties make it a more suitable candidate than capsazepine for testing the role played by VR1 in rat models of human disease.