High functional P-glycoprotein activity is more often present in T-cell acute lymphoblastic leukaemic cells in adults than in children.

There is a distinct difference in prognosis between childhood versus adult acute lymphoblastic leukaemia (ALL). To define whether multidrug resistance (MDR) genes might contribute to this distinction, the expression and functional activity of P-glycoprotein (P-gp) and MDR associated proteins (MRP) were determined with RT-PCR (MDR-1, MRP1, MRP2, MRP3) and flow cytometry (P-gp and MRP). Patient samples were obtained from 36 children and 35 adults with de novo ALL. Of these patients, 38 showed a T-lineage and 33 showed a B-lineage immunophenotype. In the samples, large variability in P-gp activity (0.8-4.9) and MRP activity (1.1-13.9) was observed. Most T-ALL patients with high P-gp activity were adults (89%). The mRNA expression of MDR-1 correlated weakly with P-gp activity. In contrast, MRP activity did not correlate with the mRNA expression of MRP1, MRP2 and MRP3. In T-ALL, a worse overall survival and event-free survival was observed with increasing P-gp activity. P-gp activity had no prognostic impact in B-lineage ALL. In addition, high MRP activity did not influence treatment outcome in either T- or B-lineage ALL. Multivariate Cox regression analysis, showed P-gp activity to be the only unfavourable prognostic factor for overall survival in T-ALL. In conclusion, this study demonstrates the prognostic relevance of P-gp activity in T-ALL. Since the majority of the patients with high P-gp activity were adults, P-gp might contribute to the poor prognosis of adult T-ALL

Comparative analysis of the humoral immune response to Moraxella catarrhalis and Streptococcus pneumoniae surface antigens in children suffering from recurrent acute otitis media and chronic otitis media with effusion.

Item does not contain fulltextA prospective clinical cohort study was established to investigate the humoral immune response in middle ear fluids (MEF) and serum against bacterial surface proteins in children suffering from recurrent acute otitis media (rAOM) and chronic otitis media with effusion (COME), using Luminex xMAP technology. The association between the humoral immune response and the presence of Moraxella catarrhalis and Streptococcus pneumoniae in the nasopharynx and middle ear was also studied. The levels of antigen-specific IgG, IgA, and IgM showed extensive interindividual variation. No significant differences in anti-M. catarrhalis and anti-S. pneumoniae serum and MEF median fluorescence intensity (MFI) values (anti-M. catarrhalis and antipneumococcal IgG levels) were observed between the rAOM or COME groups for all antigens tested. No significant differences were observed for M. catarrhalis and S. pneumoniae colonization and serum IgG levels against the Moraxella and pneumococcal antigens. Similar to the antibody response in serum, no significant differences in IgG, IgA, and IgM levels in MEF were observed for all M. catarrhalis and S. pneumoniae antigens between OM M. catarrhalis- or S. pneumoniae-positive and OM M. catarrhalis- or S. pneumonia-negative children suffering from either rAOM or COME. Finally, results indicated a strong correlation between antigen-specific serum and MEF IgG levels. We observed no significant in vivo expressed anti-M. catarrhalis or anti-S. pneumoniae humoral immune responses using a range of putative vaccine candidate proteins. Other factors, such as Eustachian tube dysfunction, viral load, and genetic and environmental factors, may play a more important role in the pathogenesis of OM and in particular in the development of rAOM or COME.1 juni 201