Détermination de la fréquence de l'allèle A2M (2) des immunoglobulines A dans la population tunisienne par la technique de RFLP

The human IgA2 subclass has two allotypes A2m(1) and A2m (2). Using the RFLP technique, we determined the A2m(2) frequency in a sample of 29 tunisian individuals. In accordance with Lefranc and all. [6], the presence of a polymorphic EcoRI site of the A2m(2) allele was confirmed in our RFLP study whereas no BamHI nor HindIII polymorphisms were shown.Among the 29 cases studies, 11 were heterozygous A2m2-1, 17 homozygous A2m1-1 and 1 homozygous A2m2-2. The A2m2 allele frequency in the Tunisian population (0,22) is intermediate between the Europeen frequency and the African one.     

Intérêt de l’échographie dans le diagnostic de la cirrhose en milieu tropical

The main aim of our study was to determine the contribution of ultrasound in the diagnosis of cirrhosis. It was about prospective study cases/witnesses during 32 months. The patients were selected according to histological criteria of cirrhosis and chronic liver diseases, and also profited by an abdominal ultrasound. The main abnormalities significantly met during the cirrhosis were as follows: 1) atrophic liver: sensitivity 33.7%, specificity 80.3%, positive predictive value 69%; 2) irregular hepatic contours: sensitivity 79%, specificity 84.8%, positive predictive value 87.1%; 3) heterogeneous aspect of liver: sensitivity 73.2%, specificity 81.1%, positive predictive value 97.8%; 4) a portal vein above than 15 mm of diameter: sensitivity 36.1%, specificity 98.4%, positive predictive value 97.8%; 5) a maximum speed of blood flow portal below 15 cm/s: sensitivity 54.6%, specificity 77.2%, positive predictive value 75.8%; 6) a mean velocity below 12 cm/s: sensitivity 66.2%, specificity 81.8%, positive predictive value 82.6%; 7) a splenic vein above 10 mm of diameter: sensitivity 30.2%, specificity 100%, positive predictive value 100%; 8) the presence of shunts: a) left spleno-renal vein (shunt 1): sensitivity 34.8%, specificity 100%, positive predictive value 100%; b) umbilical vein (shunt 2): sensitivity 34.8%, specificity 100%, positive predictive value 100%. Abdominal ultrasound can be integrated in a strategy of none invasive diagnosis of cirrhosis because of the value of the signs met.     

Apport de la détection des anticorps antiphosphatidylsérine/prothrombine (aPS/PT) dans le diagnostic et la prise en charge du syndrome des antiphospholipides (SAPL)

Antiphospholipid syndrome (APS) is an autoimmune disease and one of the most common causes of acquired thrombophilia. It is characterised by the occurrence of thrombotic or obstetric events associated with the presence of persistent antiphospholipid antibodies. The diagnosis can be challenging, particularly because some biological tests can be disturbed by anticoagulant treatment or inflammation.In the recent years, new antiphospholipid antibodies, including anti-phosphatidylserine/prothrombin antibodies (anti-PS/PT), have emerged but their clinical significance and causality remain uncertain.Biologically, several studies have found a strong correlation between the presence of lupus anticoagulant (LA) and anti-PS/PT antibodies. Clinically, the presence of anti-PS/PT antibodies is associated with an increased risk of thrombosis and obstetric complications. There is also an association with thrombocytopenia, suggesting that the presence of anti-PS/PT antibodies may be associated with more severe clinical APS. Among seronegative APS patients, 6–17% of patients are positive for anti-PS/PT antibodies. This might influence the therapeutic management of patients.This article aims to provide an update on contribution of anti-PS/PT antibodies detection for the diagnosis and management of APS.