Implementing multiplexed genotyping of non-small-cell lung cancers into routine clinical practice.

BACKGROUND: Personalizing non-small-cell lung cancer (NSCLC) therapy toward oncogene addicted pathway inhibition is effective. Hence, the ability to determine a more comprehensive genotype for each case is becoming essential to optimal cancer care. METHODS: We developed a multiplexed PCR-based assay (SNaPshot) to simultaneously identify >50 mutations in several key NSCLC genes. SNaPshot and FISH for ALK translocations were integrated into routine practice as Clinical Laboratory Improvement Amendments-certified tests. Here, we present analyses of the first 589 patients referred for genotyping. RESULTS: Pathologic prescreening identified 552 (95%) tumors with sufficient tissue for SNaPshot; 51% had ≥1 mutation identified, most commonly in KRAS (24%), EGFR (13%), PIK3CA (4%) and translocations involving ALK (5%). Unanticipated mutations were observed at lower frequencies in IDH and ß-catenin. We observed several associations between genotypes and clinical characteristics, including increased PIK3CA mutations in squamous cell cancers. Genotyping distinguished multiple primary cancers from metastatic disease and steered 78 (22%) of the 353 patients with advanced disease toward a genotype-directed targeted therapy. CONCLUSIONS: Broad genotyping can be efficiently incorporated into an NSCLC clinic and has great utility in influencing treatment decisions and directing patients toward relevant clinical trials. As more targeted therapies are developed, such multiplexed molecular testing will become a standard part of practice.

Cost-effective detection of non-antidouble-stranded DNA antinuclear antibody specificities in daily clinical practice.

OBJECTIVES: To compare the utility of indirect immunofluorescence for the detection of antinuclear antibodies (ANA-IIF) and a fully automated test (ELiA Symphony) that detects antibodies against a mixture of nuclear and cytoplasmic antigens (ENA), to select sera that should be tested for non-antidouble-stranded DNA (dsDNA) antinuclear antibodies in a relatively expensive automated line immunoassay (INNO-LIA ANA update, Lineblot). METHODS: All 328 sera sent to the laboratory for ANA or anti-ENA tests, over a 4 month period were evaluated in all three assays. Results were related to signs and symptoms of systemic autoimmune disease (AID) that patients had before or at the time of blood sampling. RESULTS: Overall, 72 (22%) sera were Lineblot positive. Of 198 patients without clinical manifestations of AID, 7% were Lineblot positive. Limiting Lineblot to sera positive in either ANA-IIF or Symphony tests failed to detect 26 (ANA-IIF) and 22 (Symphony) Lineblot-reactive sera, with 15 sera being negative in both assays. From a clinical point of view, failure to detect these reactivities was not important in most cases. CONCLUSIONS: Restriction of performance of Lineblot to patients with at least one criterion for AID is an ideal and cost-effective strategy. In ignorance of clinical signs and symptoms, screening of sera by ANA-IIF or Symphony strongly reduces the costs of anti-ENA detection, with minimal loss in diagnostic capacity. Based on small differences, including the fact that anti-dsDNA antibodies give a positive ANA-IIF, we prefer screening with ANA-IIF over Symphony.

A comparison between the Farr radioimmunoassay and a new automated fluorescence immunoassay for the detection of antibodies against double stranded DNA in serum.

OBJECTIVE: To compare test characteristics of the Farr radioimmunoassay and an automated fluorescence immunoassay (ELIA dsDNA test) for the diagnosis of systemic lupus erythematosus (SLE). METHODS: A cross sectional study comprising 440 samples from 440 patients, sent to the laboratory over a three month period for anti-dsDNA testing. Chart review was performed, blinded for test results, to count for each patient the number of American College of Rheumatology criteria for the classification of SLE that were fulfilled. At least four criteria were met by 248 (56%) patients (SLE), one to three criteria by 77 (18%) (lupus-like disease, LLD), and no criterion by 115 (26%) (non-SLE/non-LLD). Results from serum samples from the non-SLE/non-LLD and SLE groups were used to calculate receiver operating characteristic curves. RESULTS: For the Farr assay, specificities of 95% and 99% corresponded to sensitivities of 72% and 56% respectively. For the ELIA dsDNA test these levels of specificity corresponded to sensitivities of 44% and 17% respectively. CONCLUSIONS: The Farr radioimmunoassay is superior to the ELIA dsDNA test for identifying patients with SLE.

Large-scale production of natural cytokines during activation and expansion of human T lymphocytes in hollow fiber bioreactor cultures.

We studied the large-scale production of a variety of natural cytokines during the activation and expansion of human T lymphocytes in a hollow fiber bioreactor culture system. Peripheral blood mononuclear cells (PBMC) were activated using phytohemagglutinin plus recombinant interleukin-2 (IL-2). Phytohemagglutinin was either present in the hollow fiber bioreactor during the entire 15-16-day culture period or only during the 20-h preactivation of the PBMC in culture bags. The expanding T lymphocytes were mainly CD3+,8+ and exerted maximal natural, activated, bispecific monoclonal antibody-redirected and lectin-dependent cytolytic activities between days 9 and 13 of culture. IL-1 and IL-4 were only produced in low amounts. IL-8 and lymphotoxin were primarily produced during the first week of culture. Harvest of the hollow fiber bioreactor culture supernatant at the time of peak cytokine concentration would have yielded per 10(8) PBMC input between 3.7 and 4.9 micrograms of IL-8 (at days 2 or 3), and between 0.02 and 0.5 microgram of lymphotoxin (at days 6 or 7). Tumor necrosis factor-alpha and IL-6 were produced during the entire culture period of 15 or 16 days: per 10(8) PBMC input, between 0.1 and 0.4 microgram of tumor necrosis factor-alpha (at days 2 or 3) and between 0.03 and 0.5 microgram of IL-6 (at days 15 or 16). Production of interferon-gamma and granulocyte-macrophage colony-stimulating factor started from initiation of cultures onwards to reach peak levels at the end of the 15- or 16-day culture period, yielding at that time between 2.1 and 17.7 micrograms/ml of interferon-gamma and between 0.4 and 4.2 micrograms of granulocyte-macrophage colony-stimulating factor per 10(8) PBMC input. The production of tumor necrosis factor-alpha, IL-6, interferon-gamma, and granulocyte-macrophage colony-stimulating factor was proportional to the extent of lymphocyte multiplication. These results demonstrate the usefulness of hollow fiber bioreactor cultures to produce natural cytokines during the activation and expansion of predominantly CD3+,8+ T lymphocytes.

Release of cytokines and soluble cell surface molecules by PBMC after activation with the bispecific antibody CD3 x CD19.

Bispecific antibodies (BsAb) consist of two different heavy and light chains and may bind to two different antigens present on different cell types. With their dual specificity BsAb may recognize effector cells (e.g. T cells) on one hand and tumour cells (e.g. malignant B cells) on the other hand. The authors analysed whether T cell activation and subsequent killing of malignant B cells mediated by the bispecific antibody CD3 x CD19 was reflected by the release of cytokines. In addition, the authors investigated whether the in vitro cytokine release was similar to that observed in vivo in the patients treated with BsAb. The in vitro release of cytokines into the supernatant of cell cultures of peripheral blood mononuclear cells (PBMC) and malignant B cells was measured after incubation with either the bispecific antibody CD3 x CD19 or the monospecific anti-CD3 (aCD3) antibody in the presence or absence of interleukin (IL)-2. Release of tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), IL-6, IL-8, IL-10, soluble (s) CD4, sCD8 and sCD25 by PBMC was equal under both conditions and could be used as an indicator for T cell activation. However, the cytokine pattern and level did not correlate with the cytotoxic capacity, which was 4 logs higher with BsAb + IL-2 compared to aCD3 + IL-2. The in vitro pattern of cytokine release was similar to that observed in vivo in the serum of patients treated with BsAb and IL-2, indicating the possibility of predicting cytokine release in future patients with other therapeutic regimens.

Targeting of cytotoxic T cells against leukemic B cells by bispecific antibody (aCD3 x aCD19) does not distract the T cell from its primary target.

Bispecific Abs (BsAb) represent a novel format of immunotherapy, recognizing immune effector cells (e.g., T cells), on the one hand, and target cells (e.g., tumor cells), on the other hand. To be successful, cross-linking of the two cell types is necessary for effector cell activation and subsequent killing of the malignant target cells. We asked the question, whether CTL that were incubated with the BsAb aCD3 x aCD19 and malignant B cells and activated to kill the malignant B cells were still able to eliminate their natural target cells (e.g., virus-infected autologous body cells). To test this, HLA-A*0201-restricted, influenza-specific CTL were incubated with BsAb- and HLA-A*0201-positive B lymphoid tumor cells in combination with HLA-A*0201-positive, virus-infected non-B lymphoid cells as natural target cells. The results showed that even in the presence of BsAb and high amounts of tumor B cells, CTL were still capable of eliminating the virus-infected non-B lymphoid target cells; actually, CTL recognized and eliminated the homologous original target cells preferentially.

Efficacy and toxicity of plasma-cell-reactive monoclonal antibodies B-B2 and B-B4 and their immunotoxins.

Immunotherapy based on the delivery of toxic agents to the tumor site using monoclonal antibodies (mAb) may be a promising modality in the treatment of hematological malignancies. In the selection of mAb, both for ex vivo but even more for in vivo therapy, not only their reactivity to the neoplastic cells should be considered, but also reactivity to other body constituents. Here we describe the screening of two human plasma-cell-reactive mAb B-B2 and B-B4, which may be used for immunotherapy of multiple myeloma. Cross-reactivity of B-B2 and B-B4 was determined by immunohistochemistry on a series of tissues. This revealed for both B-B2 and B-B4 a strong staining of epithelial cells in various organs, e.g. lung, liver, skin, kidney and gut, while only a weak and diffuse staining was seen with endothelial cells. In bone marrow reactivity was only found with plasma cells and not with hemopoietic precursors (CD34+ cells). Immunotoxins from B-B2 and B-B4 were constructed by coupling them to the plant-derived ribosome-inactivating protein saporin. Both B-B2 and B-B4 immunotoxins appeared to be efficient in specific inhibition of protein synthesis in plasma cell lines (IC50 respectively 1 nM and 0.1 nm). The immunotoxins were also tested on epithelial cell line A431, on liver cell line HepG2 and on human umbilical vein endothelial cells. The epithelial cell line A431 was reactive with both B-B2 and B-B4, but was only inhibited by B-B4 immunotoxin. Cell line HepG2 was reactive with both mAb, but was not inhibited by either immunotoxin. The endothelial cells showed no reactivity with B-B2 and B-B4 and were not inhibited by either immunotoxin. Bone marrow treated with B-B2 and B-B4 immunotoxin did not show a decrease in colonies of hemopoietic precursor cells. Incubation of multiple-myeloma-derived bone marrow with these immunotoxin resulted in a clear decrease of the number of plasma cells. From these data we conclude that B-B2 and B-B4 immunotoxin can be used for ex vivo bone marrow purging. Discrepancies were found between immunohistochemistry, binding assays and cytotoxicity assays with the mAb and the immunotoxin, which underlines the necessity for these various assays as a preclinical screening.

Expression of two interleukin 4 mRNA isoforms in B lymphoid cells.

Expression of an alternative spliced IL4 mRNA was found in in vitro activated T cells. In this study we show that the expression of IL4 mRNA, as well as the expression of this alternatively spliced form of IL4 mRNA, is not restricted to these cells. We analyzed different human lymphoid tissues and cell lines of different origin and found that the alternatively spliced IL4 transcripts are also expressed in human lymphoid tissues, in purified B cells, in the various B cell-derived cell lines, and even in nonlymphoid cell lines. Stimulation with the phorbol ester PMA enhanced expression of both transcripts in all cells studied. The two IL4 transcripts were cloned and sequenced from the B cell line Namalwa. In the alternatively spliced form, the same exon 2 is deleted as has been observed in in vitro activated T cells. In principle, such alternatively spliced mRNA may give rise to a truncated IL4 protein, as the deletion does not result in a frameshift. We tested supernatants of activated PBMC, cell lines, and cell extracts for the presence of IL4 protein. We found IL4 protein expression in activated PBMC, but not in any of the stimulated cell lines or in the purified B cells. Using a modified in situ hybridization method with Dig-labeled PCR products, however, these cells did express IL4 mRNA. This shows that transcription of both IL4 forms is not restricted to T cells and can be induced in other cell types as well. Using these non-T cells, no protein has been found in the supernatant, however. It is possible that transcription of the IL4 gene is not necessarily followed by translation and that translation into the IL4 protein requires an additional signal.

Associated autoimmunity in Addison's disease.

As the last extensive series of patients with Addison's disease and coincident autoimmune phenomena were published approximately two decades ago, we studied the cause of the disease, the prevalence of autoimmune disorders and the frequency of occurrence of autoantibodies in 91 patients (31 men and 60 women, mean age 45.3-years-old, range 12-77) with Addison's disease. The cause of Addison's disease in six patients was tuberculosis (6.6%), and autoimmune adrenalitis was considered to be the cause in 83 patients (91.2%). In two patients (2.2%) other causes were responsible for Addison's disease. In 47% of the patients with autoimmune Addison's disease at least one other autoimmune disorder was present. Primary hypothyroidism had the highest prevalence (20.5%), followed by vitiligo (9.6%), non-toxic goiter (8.4%), premature menopause (7.3% of the women), Graves' disease (6%), pernicious anaemia (4.8%), Sjögren's disease (2.4%), hypoparathyroidism (1.2%), type 1 diabetes mellitus (1.2%) and coeliac disease (1.2%). The frequency of autoantibodies in the patients with autoimmune Addison's disease was: adrenal antibodies (82.7%), antibodies against microsomal antigens (58%), thyroglobulin antibodies (23.4%), parietal cell antibodies (19.8%), pancreatic islet cell antibodies (6.2%) and ovary antibodies (3.7% of the women). In comparison with other extensive series of patients with Addison's disease, we found the highest prevalence of autoimmune adrenalitis as the cause of Addison's disease, the highest prevalence of hypothyroidism and vitiligo as concomitant autoimmune disorders and the lowest prevalence of type 1 diabetes mellitus.

Evaluation of Fc gamma receptor mediated T-cell activation by two purified CD3 x CD19 bispecific monoclonal antibodies with hybrid Fc domains.

Two bispecific monoclonal antibodies (BsAb), differing in H chain isotype combination, were made for treatment of B-cell leukaemia/lymphoma; QAI-2, CD3-mouse-IgG1 x CD19-mouse-IgG2a and QAI-3, CD3-mouse-IgG1 x CD19-mouse-IgG2b. Both purified BsAb proved equally effective for their ability to target pre-activated T cells towards CD19 positive tumour cells. In T-cell proliferation assays, the capacity of Fc gamma RIa (CD64), Fc gamma RIIa-R131 and Fc gamma RIIa-H131 (CD32) transfected fibroblasts was tested to present the BsAb. The BsAb combining mouse (m) IgG1 and mIgG2a promoted T-cell activation in combination with the Fc gamma RIa transfectant; the mIgG1-mIgG2b BsAb was only marginally active. Both BsAb could not induce T-cell activation when presented by either of the Fc gamma RIIa transfectants. Similar results were obtained using PBMC cultures, containing Fc gamma RIa+/Fc gamma RIIa+ monocytes as accessory cells. The importance of Fc gamma R-dependent BsAb-mediated T-cell activation emerged from experiments with T cells and CD19 positive B-cell lines, showing that cross-linking via CD19+ target cells alone did not induce T-cell proliferation. Therefore, BsAb with functionally different Fc domains represent alternative strategies in BsAb therapy, the efficacy of which deserves to be compared in vivo.

In vitro and in vivo measurement of cell-mediated immunity in patients with HIV-1 infection.

We studied the usefulness of the in vitro lymphoproliferation assay and the in vivo skin test in HIV-1-infected patients by using Clostridium tetani and tuberculin as testing antigens. Moreover, the relationship between data obtained from both assays was studied. In 56 HIV-infected patients not receiving antiretroviral therapy CD4+ cell counting was performed. In addition, in vitro (lymphocyte proliferation assay) and in vivo (delayed type hypersensitivity skin test) measuring of the immune status was done using C. tetani and tuberculin as testing antigens. When using C. tetani a significant correlation between the results of both tests and the CD4+ cell count was found. In contrast to earlier reports from African countries, in vivo skin testing using tuberculin did not yield clinically significant information on the degree of immunodeficiency. We explain our findings by the fact that health care policy in The Netherlands encompasses vaccination with C. tetani, which enables the application of C. tetani as testing antigen for measuring immune function both in vitro and in vivo.

Monoclonal gammopathy as a model for B-cell differentiation: from "paraprotein" to artificial antibodies.

During the past fifty years new biochemical and cell biological techniques have been introduced in clinico-pathological practice. Studies on the bone-marrow related malignancy multiple myeloma (MM) proved particularly rewarding for the elucidation of basic concepts in immunology. In fact, by studying the characteristic monoclonal serum components, hallmarking this disease, the basic structure of immunoglobulins and their various types could be described. Two examples of the impact of using MM as a model system in studies on immunological differentiation will be presented: the involvement of precursor cells and the homing of malignant plasma cells in MM. Conversely, two examples of the growing impact of immunology on the clinical handling of MM will be given: new differential diagnostic procedures as well as novel developments in immunotherapy of MM.

VAD chemotherapy for refractory multiple myeloma.

Thirty-four patients with refractory multiple myeloma were treated with 4-d continuous infusions of vincristine and adriamycin in combination with 4-d pulsed high-dose dexamethasone (VAD). Of 31 evaluable patients, 16 entered a complete remission (50%) and three a partial remission (10%). No difference in response rate was observed between primary refractory and relapsed patients. The median response duration was 9 months and the median survival of the responding patients was 12 months versus 4 months for the non-responders. Ten patients have currently survived longer than 360 d, of which six are stable in complete remission without therapy. All responding patients showed a remarkable improvement of their performance status and 70% of these patients became pain-free. Bacterial infection was the major complication and was probably due to the intensive corticosteroid programme. Severe myelosuppression was rarely observed. Irrespective of the response to VAD, a high beta 2-microglobulin of 4 micrograms/ml or more was a bad prognostic parameter. As early relapses were seen especially in this group of patients, in the patients with a plasma-cell LI% of 3 or more, and in patients with previous anthracyclin treatment, early consolidation, with, for instance, high dose melphalan, might improve the prognosis for these patients.

Phenotypical and functional characterization of the idiotype-positive blood B cells in multiple myeloma.

In this study the idiotype-positive B cells of one patient with smouldering multiple myeloma (IgG kappa) and of one patient with multiple myeloma (IgG lambda) were analysed phenotypically and functionally. As regards the expression of B cell-associated differentiation antigens and size distribution, the idiotype-positive B cells resembled normal IgG-bearing blood B cells. In functional studies the lymphocytes were cultured in vitro with Staphylococcus aureus, pokeweed mitogen, T-cell factors, or combinations of these. After culture, proliferation and differentiation of the idiotype-positive B cells were measured by autoradiography, an idiotype-specific ELISA, and a spot ELISA. The results show that idiotype-positive B cells of both patients are able to proliferate after stimulation in vitro. In contrast to their normal counterparts, however, almost no increase in the amount of secreted idiotype IgG could be induced. This suggests that the idiotype-positive blood B cells have lost some of their ability to respond to exogenous stimuli.

Radioresistant pseudo-colony formation in the PHA-leukocyte feeder colony assay.

In the PHA-leukocyte feeder colony assay--a fluid assay on top of an agar underlayer--colonies might not be the product of clonogenic cells but rather from aggregates, as was already shown for hairy cell leukemia (Leukemia Res. 11, 911 (1987)). To study the role of aggregation in this colony assay in other B-cell malignancies, we irradiated cells from B-chronic lymphocytic leukemia, B-non-Hodgkin's lymphoma and multiple myeloma. In nearly all cases, viable "colonies" were seen after irradiation, albeit in lower numbers. These data indicate that in the PHA-leukocyte feeder colony assay, a considerable percentage of colonies from a large variety of B-cell malignancies originate from aggregating rather than from proliferating cells.