Differential effect of drug interference in immunogenicity assays.

The presence of anti-drug antibodies (ADA) in adalimumab-treated patients is associated with reduced serum adalimumab levels and a lower clinical response. Currently, there is no standard for measurement of anti-drug antibodies and many factors influence the results. Consequently, the incidence of ADA as reported in different studies varies considerably.

Changes of ferritin and CRP levels in melanoma patients treated with adjuvant interferon-α (EORTC 18952) and prognostic value on treatment outcome.

Adjuvant therapy with interferon-α (IFN) only benefits a small subgroup of melanoma patients and a predictive marker selecting responders does not exist. IFN induces increased ferritin and decreased C-reactive protein (CRP) levels; however, an association with treatment effect was not studied. Serum was collected from patients participating in the European Organization for Research and Treatment of Cancer 18 952 trial comparing adjuvant treatment with IFN to observation.

C-reactive protein elicits white blood cell activation in humans.

Objective: Consistent epidemiologic evidence suggests that acute infections increase the risk for acute cardiovascular events. We tested in humans whether activation of peripheral leukocytes in reaction to the administration of recombinant human C-reactive protein (rhCRP) may provide a mechanism for infectious diseases to promote atherosclerotic disease.

Methods And Results: By using quantitative real-time polymerase chain reaction analysis, whole-blood expression profiles were analyzed for 95 inflammatory markers before and after infusion of 1.

Development and validation of an enzyme-linked immunosorbent assay for the quantification of trastuzumab in human serum and plasma.

Trastuzumab, a humanized monoclonal antibody, is used for the treatment of breast cancer patients who overexpress the HER2 receptor. To optimize therapy, pharmacokinetic studies are necessary. The aim of this study was to develop an enzyme-linked immunosorbent assay (ELISA) for trastuzumab to support these pharmacokinetic studies.

Cytokine induction by pyrogens: comparison of whole blood, mononuclear cells, and TLR-transfectants.

Given the shortcomings in the measurement of pyrogenic contamination of pharmaceuticals and/or test substances by means of the rabbit pyrogen test and the Limulus amoebocyte lysate (LAL) test, several in vitro pyrogen tests have been developed based on the measurement of cytokine production by monocytes. In this study we measured cytokine production (IL-6, IL-8, IL-1beta, and TNF) in diluted whole blood (WB), mononuclear cells (MNC), and HEK cells stably transfected with CD14 and Toll-like Receptor-2 (TLR2) or TLR4, after stimulation with both standard pyrogens and contaminated substances. Our study demonstrated that in MNC, IL-6 production was more sensitive to pyrogen stimulation than IL-1beta and TNF production.

Potentiation of Toll-like receptor-induced cytokine production by (1-->3)-beta-D-glucans: implications for the monocyte activation test.

The monocyte activation test (MAT) has been introduced as an alternative for the detection of pyrogens in pharmaceuticals with the rabbit pyrogen test or the Limulus amebocyte lysate (LAL) test. The basis of the MAT is that pyrogens, via Toll-like receptors (TLRs) expressed on monocytes, stimulate cytokine production. Here, we report that, at concentrations that did not induce whole blood cytokine production when tested separately, (1-->3)-beta-D-glucans powerfully co-stimulated cytokine production (IL-6/IL-8) induced by ligands for TLR1/2, TLR2/6, TLR4, and TLR5.

4-Hydroxy-oxyphenbutazone is a potent inhibitor of cytokine production.

4-Hydroxy-oxyphenbutazone (4OH-OPB), is currently in phase II trials for its immunosuppressive effect in patients with rheumatoid arthritis. 4OH-OPB and other compounds related to phenylbutazone were tested for their effect on in vitro cytokine production by monocytes and lymphocytes present in peripheral mononuclear cells (PBMC) or whole blood (WB) cultures, and compared against phenylbutazone and oxyphenbutazone, two known anti-inflammatory drugs. In PBMC cultures, 4OH-OPB was by far the most potent inhibitor, and both monokines and Th1 and Th2 lymphokines were efficiently inhibited at low concentrations.

Mycophenolic acid and methotrexate inhibit lymphocyte cytokine production via different mechanisms.

Mycophenolic acid (MPA) and methotrexate (MTX) are immunosuppressive drugs used for the treatment of various immunological disorders. MPA is an inhibitor of inosine monophosphate dehydrogenase and MTX is a folate antagonist that inhibits tetrahydrofolate reductase. Production of T cell cytokines in whole blood cultures, as well as in PBMC cultures, is inhibited by a low concentration of both drugs.