Interleukin-12 (IL-12) is a cytokine that promotes cell-mediated immunity to intracellular pathogens by inducing type 1 helper T cell (TH1) responses and interferon-gamma (IFN-gamma) production. IL-12 binds to high-affinity beta1/beta2 heterodimeric IL-12 receptor (IL-12R) complexes on T cell and natural killer cells. Three unrelated individuals with severe, idiopathic mycobacterial and Salmonella infections were found to lack IL-12Rbeta1 chain expression. Their cells were deficient in IL-12R signaling and IFN-gamma production, and their remaining T cell responses were independent of endogenous IL-12. IL-12Rbeta1 sequence analysis revealed genetic mutations that resulted in premature stop codons in the extracellular domain. The lack of IL-12Rbeta1 expression results in a human immunodeficiency and shows the essential role of IL-12 in resistance to infections due to intracellular bacteria.

We have reported a deficiency of a 91-kDa glycoprotein component of the phagocyte NADPH oxidase (gp91 phox ) in neutrophils, monocytes, and B lymphocytes of a patient with X chromosome-linked chronic granulomatous disease. Sequence analysis of his gp91 phox gene revealed a single-base mutation (C 3 T) at position ؊53. Electrophoresis mobility-shift assays showed that both PU.1 and hematopoietic-associated factor 1 (HAF-1) bound to the inverted PU.1 consensus sequence centered at position ؊53 of the gp91 phox promoter, and the mutation at position ؊53 strongly inhibited the binding of both factors. It was also indicated that a mutation at position ؊50 strongly inhibited PU.1 binding but hardly inhibited HAF-1 binding, and a mutation at position ؊56 had an opposite binding specificity for these factors. In transient expression assay using HEL cells, which express PU.1 and HAF-1, the mutations at positions ؊53 and ؊50 significantly reduced the gp91 phox promoter activity; however, the mutation at position ؊56 did not affect the promoter activity. In transient cotransfection study, PU

In extensive preclinical testing, a CD3 x CD19 bispecific antibody (BsAb) induced killing of malignant B cells by resting T cells even in an autologous situation. In a 14 day clonogenic assay using a CD19+ pre-B cell line (REH), BsAb required repeated administration together with IL-2 to achieve a 5 log kill by resting peripheral blood T cells. Intravenously administered BsAb in an intrapatient dose escalation study of 3 patients with B cell non-Hodgkin's lymphoma showed limited toxicity (WHO grade II fever and chills) due to tumor necrosis factor-alpha (TNF-alpha) release by T cells. Pharmacokinetics with 2.5 mg BsAb showed peak levels of 200-300 micrograms/ml and a t1/2 of 10.5 h. The next patient, with chronic lymphocytic leukemia (CLL), received 0.6 mg BsAb/m2 as an i.v. infusion preceded by 1 MU IL-2/m2 s.c. Improved T cell activation was noted, as indicated by an increase in IFN-gamma, IL-6, IL-8, and IL-10, in addition to high TNF-alpha increases. TNF-alpha increases were highest on the first day. Toxicity remained restricted to grade II fever and chills, observed every day after the infusion of BsAb. No clear clinical effects were seen in this chemotherapy-resistant CLL patient with a high tumor burden. If subsequent patients also show limited toxicity, treatment of patients with a lower tumor load seems to be warranted to evaluate the efficacy of CD3 x CD19 BsAb therapy.

Background External quality assessment (EQA) programs for general chemistry tests have evolved from between laboratory comparison programs to trueness verification surveys. In the Netherlands, the implementation of such programs has reduced inter-laboratory variation for electrolytes, substrates and enzymes. This allows for national and metrological traceable reference intervals, but these are still lacking. We have initiated a national endeavor named NUMBER (Nederlandse UniforMe Beslisgrenzen En Referentie-intervallen) to set up a sustainable system for the determination of standardized reference intervals in the Netherlands. Methods We used an evidence-based 'big-data' approach to deduce reference intervals using millions of test results from patients visiting general practitioners from clinical laboratory databases. We selected 21 medical tests which are either traceable to SI or have Joint Committee for Traceability in Laboratory Medicine (JCTLM)-listed reference materials and/or reference methods. Per laboratory, per test, outliers were excluded, data were transformed to a normal distribution (if necessary), and means and standard deviations (SDs) were calculated. Then, average means and SDs per test were calculated to generate pooled (mean±2 SD) reference intervals. Results were discussed in expert meetings. Results Sixteen carefully selected clinical laboratories across the country provided anonymous test results (n=7,574,327). During three expert meetings, participants found consensus about calculated reference intervals for 18 tests and necessary partitioning in subcategories, based on sex, age, matrix and/or method. For two tests further evaluation of the reference interval and the study population were considered necessary. For glucose, the working group advised to adopt the clinical decision limit. Conclusions Using a 'big-data' approach we were able to determine traceable reference intervals for 18 general chemistry tests. Nationwide implementation of these established reference intervals has the potential to improve unequivocal interpretation of test results, thereby reducing patient harm.