Molecular heterogeneity of factor XI deficiency in Tunisia.

Factor XI (FXI) deficiency is a rare inherited bleeding disorder that is highly prevalent in Ashkenazi Jewish ancestry but sporadically observed in most ethnic groups. It is heterogeneous both in clinical presentation and in genetic causality. Although a large spectrum of mutations associated with this disorder has been reported in several populations, genetic data of FXI deficiency in Tunisia are poorly described. The purpose of this study was to determine the molecular basis of FXI deficiency among Tunisian patients. Fourteen index cases from nine unrelated families with FXI deficiency, referred to Hemophilia Treatment Center of Aziza Othmana Hospital, were included in this study. The patients' F11 genes were amplified by PCR and subjected to direct DNA sequencing analysis. Sequencing analysis of F11 genes identified three distinct mutations; the Jewish type II nonsense mutation E117X, one previously reported missense mutation E602Q and one novel missense mutation V271M, which led to the disruption of the third apple domain structure of FXI. Furthermore, seven polymorphisms previously described, were also detected: C321F, c. 294A>G, -138 A>C, p.D125D, p.T249T, p.G379G, p.D551D. This report represents the first genetic study analyzing the molecular characteristics of factor XI deficiency within Tunisian population. Identification of the Jewish type II mutation in two families, as well as one missense previously reported mutation and one novel mutation confirmed the genetic heterogeneity of this disorder. Screening a large number of Tunisian factor XI deficient would reveal the spectrum mutations causing factor XI deficiency in Tunisia.

[Contribution and limits of CD157 in the detection of the paroxysmal nocturnal hemoglobinuria clone: a case report]. / Apport et limites du CD157 pour la recherche d'un clone d'hémoglobinurie paroxystique nocturne Illustration par un cas.

Flow cytometry is the gold standard for the detection of paroxysmal nocturnal hemoglobinuria (PNH) clones. Several antibody panels have been used with varying sensitivities and specificities. The CD157 is one of the glycosylphosphatidylinositol-anchored molecules tested and widely used. The CD157 deficiency is rare. We report a case of an isolated CD157 deficiency discovered during the search for the PNH clone in a patient with a plastic anemia. The interpretation of the results in this case poses a problem of false positive. We discuss how to deal with these difficulties encountered by the biologist, detailing the various possible causes. This observation also underlines the importance of following international guidelines before making the diagnosis of the PNH clone which has significant implications.

The Glanzmann's Thrombasthenia in Tunisia: A Cohort Study.

BACKGROUND: The Glanzmann's thrombasthenia (GT) is a rare autosomal-recessive bleeding disorder with uncommon neonatal revelation. It is due to abnormalities of quantitative and/or qualitative αIIbß3 integrin. This cell adhesion receptor is essential for platelet aggregation and allows the formation of a hemostatic plug if the vessel is damaged by injury. The clinical picture of GT is variable, with mucocutaneous bleeding due to non-functional platelets. Management requires a good expertise in bleeding disorders. We describe the clinical and the epidemiological data of GT in Aziza Othmana Hospital Hemophilia Center. METHODS: This was a retrospective study of all patients with GT monitored and treated in our hemophilia center during the period of 2011 - 2015. RESULTS: Twenty-seven patients among the 35 patients included in our hemophilia center registry were studied. The most common sign encountered is the gingival bleeding. In our women cohort, one completed her pregnancy. The consanguinity is present with a frequency of 62%. Treatments used depending on the case are tranexamic acid, platelet transfusion, packed red blood cells and rFVIIa, respectively. CONCLUSION: GT is relatively frequent in Tunisia and especially in the North of the country which can be explained by the high consanguinity in our population.

Factors associated with severe sepsis: prospective study of 94 neutropenic febrile episodes.

Severe sepsis defined as infection-induced organ dysfunction or hypoperfusion abnormalities predispose to septic shock and increased mortality in neutropenic setting. We aimed at determining predictors of severe sepsis in neutropenic patients. Between 1 October and 31 December 2007, 41 patients (21 with acute myeloid leukemia, 19 with acute lymphoid leukemia and one with autologous stem cell transplantation for a mantle cell lymphoma) with chemotherapy-induced neutropenia (<0.5 x 10(9)/l) lasting for more than 7 days were included in this study. The median age was 28 years (range: 3-58 years). All patients were on oral antibacterial (colistin and gentamicin) and anti-fungal (amphotericin B) prophylaxis. The first neutropenic febrile episode was treated with piperacillin/tazobactam and colistin IV; if the patient remains febrile at 48 h from the start of this first line of treatment, amphotericin B i.v. is added. Imipenem was introduced in the case of non-response and finally glycopeptides were introduced according to the IDSA criteria. Severe sepsis and septic shock are defined according to the criteria of the consensus conference of the ACCP/SCCM excluding the leukocyte count since all the patients were neutropenic. Ninety-four febrile episodes were observed: 27 microbiologically documented (28.7%), six clinically documented (6.3%) and 61 fever of unknown origin (65%). Microbiologically documented infections were: 13 Gram-negative organisms, 11 Gram-positive organisms and three combined (Gram+ and -). Clinically documented infections were pneumonia (two), neutropenic enterocolitis (one), sinuses infection (one) and cutaneous infection (two). Severe sepsis accounted for 22 febrile episodes. Factors associated with the occurrence of severe sepsis were: hypophosphatemia (<0.8 mmol/l; p=0.05, OR=3.9, 95% CI: 1.3-45.7), hypoproteinemia (<62 g/l; p=0.006, OR=4.1, 95% CI: 1.4-11.4) and non-adapted antibiotherapy at the onset of severe sepsis (p=0.019, OR=2.7, 95% CI: 1.02-7.39). However, heart rate/systolic blood pressure ratio <1.1 (p<0.001, OR=0.1, 95% CI: 0.03-0.31) and Creactive protein <80 mg (p=0.001, OR=0.14, 95% CI: 0.04-0.54) were not predictive.