[Contribution of RT-PCR for diagnosis of chronic myeloid leukemia]

The molecular analysis of chromosomal abnormalities associated with hematological malignancies allowed the identification of genes involved in theses rearrangements as well as of some recurrent mechanisms. Polymerase chain reaction [PCR] tools are now available to detect these rearrangements, allowing a better follow-up of these diseases. Chronic myeloid leukemia is a myeloproliferative disorder characterized by a reciprocal translocation t[9;22][q34;q11] which results in a bcr-abl fusion gene. Retro-transcription polymerase chain reaction [RT-PCR] is used to detect bcr-abl to establish diagnosis and to monitor patients. We report here the results of 30 patients samples tested in the hematology laboratory at Pasteur Institute, diagnosed as chronic myeloid leukemia and monitored with RT-PCR. Our results highlight the interest of molecular tools to diagnose and monitor patients mainly when cytogenetic techniques are irrelevant such as cases with complex chromosomal rearrangements or when patients achieve Philadelphia negativity after treatment

Human monoclonal IgMs with anti-Mycoplasma pneumoniae antibody activity

We have previously reported that IgM antibodies to Pep13 P1, the major immunogenic peptide of Mycoplasma pneumoniae [MP] P1 cytoadhesin involved in microorganism cytoadherence, is a part of the natural antibody repertoire expressed early in life. Hence, Pep13P1 belongs to the panel of self and non-self antigens recognized by the primitive B cell repertoire. Considering that antibody activity of human monoclonal IgM associated with lymphoproliferative diseases is representative of the immune repertoire, we analyze, in this study, the antibody reactivity to P1 of twenty human monoclonal IgMs. Interestingly, we show that 25% of them are of anti-Pep13P1 specificity: one is a MIgM with reactivity against intermediate filaments, two are MIgMs with anti-MAG specificity and two IgMs with previously unknown antibody activity. Our results indicate that anti-P1 IgM antibodies are parts of the autoreactive than the heteroreactive B cell repertoire and Pep13P1 may have structural similarities with an unknown self antigen as the corresponding physiologic ligand

[Risk factors of leishmanin-skin test positivity in transmission of Leishmania infantum in the center of Tunisia]

This work aims to estimate prevalence and evaluate risk factors of leishmanin-skin test positivity. A cross-sectional leishmanin skin test study was carried out on a sample of 3190 healthy volunteers living in the gouvernorates of Kairouan and Kasserine. Age standardized prevalence of leishmanin-skin test positivity was 45.9% [CI95% = [43.9-47.9]] confirming the hyper endemicity of this region. The rate of leishmanin-skin test positivity ranged from 75.9% [CI95% = [71.9-79.5]] in Zaghdoud [Kairouan] to 6.5% [CI95% = [3.7-11.01] in Abdeladhim [Kasserine]. There is no significant difference between men and women suggesting a similar exposure to infection. In the districts of Zaghdoud, Sidi Amor, El Hajeb and chbika, age specific rates showed a rapid increasing positive prevalence with age reaching a proportion exceeding 80% after the age of 15 years. However, the age specific prevalence from other delegations showed a progressive increasing trend with age, with a low rate for younger children and a plateau of 75% after 45 years. Multivariate analysis of leishmanin-skin test positivity risk factors showed that only district and age are determinants of this infection