Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SEROTHERAPY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed1982

Serum levels of antibody to toxoid during tetanus and after specific immunization of patients with tetanus.

Levels of serum antibody to toxoid in patients with tetanus who were immunized with toxoid differed from those in immunized healthy persons in two respects. (1) Base-line levels preceding immunization were higher among patients with tetanus than among young or elderly healthy person, even though the patients with tetanus were evaluated before specific serotherapy. This observation suggests the occurrence of immunostimulation, whether specific or not, by disease during the incubation period. (2) No significant increase in levels of antibody to toxoid was detected among patients with tetanus from the first to the last evaluable serum sample, whereas a significant increase was observed among healthy persons. Specific immunosuppression induced by tetanus toxoid or serotherapy could account for this ineffectiveness of immunization among patients with tetanus, although nonspecific immunosuppression induced by prolonged and severe illness cannot be excluded. Among healthy persons, active immunization is less effective in elderly persons than in young persons [2]. However, age cannot, by itself, account for the type of antibody production observed in patients with tetanus.

Adult↗
PubMed1994

Effects of combined antigrowth factor receptor treatment on in vitro growth of multiple myeloma.

BACKGROUND: Although passive serotherapy for cancer with monoclonal antibodies is an attractive concept, it has unfortunately had limited efficacy in clinical trials. An alternative approach to passive serotherapy is targeting cell surface growth factor receptors with monoclonal antibodies. With some limitations, anti-growth factor receptor antibodies can limit cell growth by blocking stimulatory or trophic growth factor receptors and by marshaling in vivo antitumor immune responses. PURPOSE: The purpose of our study was to determine the extent to which anti-interleukin-6 (IL-6) and anti-transferrin (Tf) receptor antibodies, when used individually or combined, could limit myeloma cell growth. METHODS: The four myeloma cell lines studied varied in IL-6 responses from factor independence (myeloma cell lines 8226 and U266) to strict factor dependence (OCI-My4 myeloma cells and human acute myelogenous leukemia [AML] cell line UCSD/AML1). IL-6 RNA was detected using reverse transcriptase-polymerase chain reaction. IL-6 protein was detected in U266 supernatant by growth stimulation of UCSD/AML1 cells and by enzyme-linked immunosorbent assay. For cell growth assays, cell lines were plated with various concentrations of IL-6 and anti-receptor antibodies and [3H]thymidine uptake determined after 3 days. Cells were grown in varying concentrations of IgG1 monoclonal anti-Tf receptor antibodies E2.3 and A27.15 or antibodies PM1, AUK 146-15, AUK 64-7, or AUK 12-20 to the human IL-6 receptor-alpha protein. Tf and IL-6 receptors were detected by immunofluorescence staining. RESULTS: Using short-term proliferation assays, anti-Tf receptors and anti-IL-6 antibodies caused dose-dependent growth inhibition of varying degrees, and, in one of three cell lines, a combination of anti-Tf and anti-IL-6 antibodies showed supra-additive growth inhibition. IL-6-independent cells were inhibited by anti-Tf receptor antibodies, while IL-6-dependent cells were resistant to these antibodies but sensitive to anti-IL-6 receptor. Factor-dependent myeloma cells exposed to either anti-Tf or anti-IL-6 receptor antibodies for 48 hours lost colony-forming capability. A combination of anti-Tf and anti-IL-6 antibodies increased elimination of colony-forming cells at 24 hours. CONCLUSIONS: Anti-receptor antibodies have distinct patterns of myeloma cell growth inhibition and inhibit in vitro growth of factor-dependent myeloma cells. Combinations of anti-growth factor receptor antibodies also increase toxicity for IL-6-dependent myeloma colony-forming units.

Antibodies, Monoclonal↗
PubMed1994

Retrospective study of 108 cases of botulism in Poitiers, France.

Botulism, a food-borne toxin-mediated disease caused by Clostridium botulinum is still a common disease, which is most frequent in the rural environment; 108 cases, 66 males and 42 females, average age 32 years, were recorded from 1965 to 1990 in the infectious disease department of the University Hospital of Poitiers (France). In 83% of patients, the food responsible was home-cured ham. Mean incubation time was 3.4 days; digestive symptoms were observed in 93% of cases, ocular symptoms in 92% and urinary tract dysfunction in 22%. A scale of severity was used to classify the patients into those suffering from severe (6), intermediate (50) and mild (52) forms of the disease. Botulinum toxin type B was found in 36 (52%) of 69 blood samples and in 41 (51%) of 81 samples of the suspected food. From 1965 to 1976, 44 patients were treated with both toxoid and heterologous equine serotherapy. Since 1976, 29 patients have been treated with guanidine hydrochloride (35 mg/kg daily) and 35 patients with guanidine hydrochloride plus heterologous serotherapy. All 108 patients recovered without any sequelae.

Adolescent↗
PubMed2005

[The anti-diphtheria serum and the case of Langerhans].

An eighteen-month old boy called Ernst Langerhans died shortly after being injected with a prophylactic dose of anti-diphtheria serum in April 1896. The father, a well-known pathologist in Berlin, claimed, in the obituary notice, that his son had been poisoned by Behring's anti-diphtheria serum. This paper describes the tragic events of Spring 1896: the death of Ernst Langerhans, the official investigations that followed as well as the reactions in the daily newspapers and the medical journals. The death of Ernst Langerhans afforded the opponents of the new serotherapy an opportunity to call into question the whole immunological concept. Supporters of the serotherapy, in turn, defended it against these attacks. The spectacular nature of Ernst Langerhans's death combined with the fact that he came from a prominent family of physicians made the event a public scandal. The tuberculine affair which had happened only a few years earlier was another reason for the public concern. Finally, the "Langerhans case" was a scandal because of the way in which Robert Langerhans published the death notice also causing resentment within the scientific community. Indeed, the publication of the accusation was one of the reasons why the "Langerhans case" failed to provoke a crisis with respect to the new therapy, as the central argument was displaced onto wider ethical questions. Furthermore, the medical administration had learned from the tuberculine affair, and had subsequently implemented a large confidence-inspiring system of quality control. The "official" cause of death, following the investigations into the case, was proclaimed to be an accident; a tragic piece of bad luck.

Diphtheria Antitoxin↗
PubMed1989

[Physician, state and public health: the campaign against diphtheria in Belgium (1894-1914)].

On 100 deaths caused by diphtheria in Belgium at the end to the 19th century, 90% had not reached the age of 6. In the beginning of the nineties an antitoxin had been developed against the so called "terror of mothers". Very slowly, the production of sera took place, first of all in Germany, after 1894 in our country too. The battle against diphtheria became the subject of parliamentary debates (in the years 1894-1895 and 1900) and of several comments and articles in the Belgian medical press. The authorities followed the evolution of morbidity closely, commissions were charged with the study of the effectiveness of sera and of the foundation, if necessary, of an institution for serotherapy. As a result of an intensive campaign of serotherapy, the decrease of mortality rates due to diphtheria was sensational after 1910.

Belgium↗
PubMed1984

[Reversible paraplegia following intrathecal injection of high doses of human gammaglobulins in the treatment of low-grade tetanus. 4 cases].

Intrathecal serotherapy appears to be effective in the treatment of tetanus, and it has been claimed that human immune globulins are innocuous. In the 4 cases reported here reversible paraplegia developed a few hours after intrathecal injection of 1500 to 2000 UI of human immune globulins prepared by the French Blood Transfusion Centre. We believe that paraplegia was related to the high doses administered. The fact that intrathecal serotherapy is normally used in severely ill patients whose impaired consciousness precludes motricity and sensitivity testing may explain why this complication has not previously been reported. The need for high doses of intrathecal immune globulins is discussed. It has recently been suggested that high doses are superior to low doses. We consider that this form of treatment is justified, even in the least severe forms of tetanus, but we feel that doses higher than 1000 IU are not without danger.

Aged↗
PubMed1993

Cell growth regulation in epithelial ovarian cancer.

BACKGROUND: As in the case of other epithelial neoplasms, most ovarian cancers arise from single clones of cells that have undergone multiple genetic alterations. A comparison of normal and malignant ovarian epithelium has identified several differences in growth regulation by peptide growth factors, protooncogenes, and tumor suppressor genes. METHODS: Recent articles and abstracts have been reviewed. RESULTS: The malignant ovarian epithelial phenotype has been associated with (1) autocrine growth stimulation by transforming growth factor-alpha, (2) loss of autocrine growth inhibition by transforming growth factor-beta, (3) mutation or amplification of ras in 2-12% of cases, (4) amplification of myc in 23% of specimens, (5) expression of fms in 56% of cases with potential autocrine stimulation by macrophage colony stimulating factor, (6) paracrine stimulation by macrophage products including interleukin-1, interleukin-6 and tumor necrosis factor, (7) overexpression of c-erbB-2 (HER-2/neu) in 30% of cases, and (8) mutation with consequent overexpression of p53 in 50% of advanced ovarian cancers. A poor clinical prognosis is associated with expression or overexpression of the epidermal growth factor receptor, fms, and HER-2/neu. Antibodies against the extracellular domain of the HER-2/neu gene product p185 inhibit the growth of tumor cells that overexpress HER-2/neu and are associated with marked decreases in diacylglycerol levels. The intracellular kinase domain is required for growth inhibition. Antibodies that inhibit growth stimulate phosphorylation of intracellular substrates. Ricin A chain monoclonal antibody conjugates that react with p185 also inhibit the growth of tumor cells that overexpress p185. The intracellular kinase region is not required for immunotoxin-mediated killing. Coexpression of HER-2/neu and the epidermal growth factor receptor has been observed in 65% of epithelial ovarian cancers and in a limited number of normal tissue from a fraction of donors. CONCLUSIONS: Multiple alterations in growth factors, protooncogenes and growth factors have been detected in different epithelial ovarian cancers. Inappropriate signalling from receptor tyrosine kinases may be particularly important for ovarian oncogenesis. Drugs that affect tyrosine kinase and phosphatase activity deserve attention as potential therapeutic agents for ovarian cancer. The extracellular domains of the HER-2/neu gene product p185 and the epidermal growth factor receptor may provide useful targets for serotherapy.

Carcinoma↗
PubMed1987

CD4 monoclonal antibody pairs for immunosuppression and tolerance induction.

A pair of rat anti-mouse CD4 monoclonal antibodies (mAb) have been selected which bind to different epitopes of the molecule. Both the mAb are rat IgG2b and show clear synergistic activity in complement lysis in vitro. When injected together in vivo, they exhibit an improved immunosuppressive effect, compared to each antibody alone, on allogeneic graft rejection, humoral responses and on tolerance induction. Limiting dilution analysis indicates that the in vivo depletion of interleukin 2-producing cells is improved using both mAb by 2-3-fold over that obtained with the individual antibodies. As little as 60 ng per mouse of the CD4 antibody pair was sufficient to allow the induction of tolerance to human gamma-globulin, even without elimination of the CD4+ cells. The results suggest that appropriate antibody pairs may be good candidates for effective immunosuppressive serotherapy in man.

Animals↗
PubMed1990

Antigen density on target cells determines the immunosuppressive potential of rat IgG2b monoclonal antibodies.

The current studies were designed to determine the relevance of T cell antigen density, besides antibody isotype, with regard to the success of antibody serotherapy. We compared the immunosuppressive effects of two rat IgG2b monoclonal anti-Thy-1 antibodies, RmT1 and 30-H12, with distinct binding sites in a graft-vs.-host disease (GVHD) model of fully H-2 and I-A region-mismatched bone marrow transplantation, making use of the difference in Thy-1.2 antigen density between homozygous (BALB/c) and heterozygous (BALB/c X AKR/J)F1 GVHD-promoting donor cells. Antibodies RmT1 (directed against a monomorphic determinant on mouse Thy-1) and 30-H12 (reactive with the Thy-1.2 allele-specific determinant) did not differ in their anti-GVHD activity with regard to Thy-1.2 homozygous grafts. However, in the region of a critical number of binding sites a small difference in the amounts of the two antibodies bound (about 8 X 10(3) IgG molecules/cell) obviously accounts for a great difference in anti-GVHD activity. This is shown in a two haplotype host-graft disparity between C57BL/6 recipients treated with either RmT1 or 30-H12 before challenging them with (BALB/c X AKR/J)F1 grafts, where the Thy-1.2 antigen concentration is approximately 50% compared to the density on BALB/c lymphocytes. Here, mAb 30-H12 loses its remarkable in vivo immunosuppressive quality, whereas RmT1 treatment protects mice against lethal GVHD. Binding sites were quantitated using a computerized approach for the analysis of data from ligand binding experiments of the respective mAb, RmT1 and 30-H12, coated to LN cells of BALB/c and F1 hybrid origin. Furthermore, the in vivo immunosuppressive activity of rat IgG2b antibodies directed against Thy-1 was found to correlate with their ability to generate stable antibody-C1q complexes on the cell surface of immunocompetent T cells.

Animals↗
PubMed1979

Antibody-dependent cell-mediated cytotoxicity against Epstein-Barr virus membrane antigen in African Burkitt's lymphoma.

Serial samples of sera from patients with African Burkitt's lymphoma were tested for antibody against Epstein-Barr virus (EBV)-specific membrane antigen (MA) by the antibody-dependent cell-mediated cytotoxicity assay (ADCC). Titers of patients in the long-term survivor group were generally higher than those found in the sera of patients in the short-term survivor group. Although ADCC titers to EBV-MA were not useful in predicting which patients would relapse there was a definite relationship between ADCC titer and prognosis. The individual differences in ADCC titers in patients in remission may explain the variability of responses that have been reported in studies on serotherapy with remission plasma.

Antibodies, Viral↗
PubMed1985

Murine monoclonal antibody LAM2 defines cell membrane determinant with preferential expression on human lung small-cell carcinoma and squamous-cell carcinomas.

Murine monoclonal antibodies (MAbs) were generated against a human undifferentiated lung carcinoma cell line. The hybridoma designated LAM2 produced an IgM kappa MAb with reactivity to the cell membrane. Indirect immunofluorescence staining and radioimmunoassay showed LAM2 antibody to react preferentially with lung small-cell carcinoma (SCC) cell lines and squamous-cell carcinoma (SQC) cell lines. LAM2 antibody also stained primary cultures of normal bronchial epithelial cells, but was unreactive with human erythrocytes and nucleated marrow cells. Indirect immunofluorescent staining with LAM2 antibody was performed on frozen sections of human tumor tissues and normal tissues. LAM2 antibody stained all 8 SCC carcinomas, 4 of 5 SQC of the lung and head and neck region, and 2 or 4 lung large-cell carcinomas. No staining was seen on lung adenocarcinomas, breast carcinomas, ovarian carcinomas, renal cell carcinomas, colon carcinomas, or mesotheliomas. Staining was present on sections of normal bronchus, but not on normal lung parenchyma, liver, kidney, adrenal or skin. While LAM2 antibody was highly reactive with all SCC examined, its antigenic determinant was not expressed in other cell lines and tumors of presumed neuroectodermal origin, including neuroblastoma, melanoma, and bronchial carcinoid. Radioimmunoprecipitation showed the antigen defined by LAM2 antibody to have two major bands of approximate molecular weights of 45,000 and 125,000. The selective reactivity of LAM2 antibody with SCC and SQC, but not with most other tumor tissues and normal tissues, makes it a good candidate for use in clinical diagnosis and possibly serotherapy.

Antibodies, Monoclonal↗
PubMed1993

Antibody-induced growth inhibition is mediated through immunochemically and functionally distinct epitopes on the extracellular domain of the c-erbB-2 (HER-2/neu) gene product p185.

Over-expression of the c-erbB-2 (HER-2/neu) gene product p185 occurs in 30% of breast and ovarian cancers. The p185 protein might serve as a target for serotherapy in that antibodies against different epitopes on the extracellular domain of p185 can inhibit growth of tumor cells in the absence of cellular or humoral effector mechanisms. To define epitopes of functional relevance, 11 monoclonal antibodies (MAbs) were evaluated for their ability to bind to the extracellular domain of p185. Results of competition studies with 125I-labeled and non-labeled antibodies indicated that 10 of 11 epitopes were grouped in a linear array. Antibodies against 7 epitopes inhibited anchorage-independent growth and antibodies against 2 of these epitopes also inhibited anchorage-dependent growth of SKBr3 breast-cancer cells that over-expressed p185. Treatment with antibodies exerted cytotoxic rather than cytostatic effects. When antibodies were used in combination, additive or supra-additive inhibition of anchorage-independent and anchorage-dependent growth was observed between pairs of antibodies. Growth inhibition did not relate to the affinity of the antibody or its isotype. Two antibodies that inhibited both anchorage-dependent and anchorage-independent growth also blocked binding of the HER-2/neu ligand, whereas 5 antibodies that inhibited only anchorage-independent growth had no effect on ligand binding. Inhibition of cell growth did not correlate with internalization of p185 or down-regulation of p185 on the cell surface. Fab fragments of active antibodies could also inhibit anchorage-independent growth of SKBr3. Thus, murine MAbs and their fragments recognized both immunochemically distinct and functionally distinct epitopes on the p185 molecule. Whereas inhibition of anchorage-dependent growth correlated with the ability of antibodies to block ligand binding, inhibition of anchorage-independent growth did not correlate with effects on ligand binding, internalization, cell-surface expression or cross-linking of p185.

Antibodies, Monoclonal↗
PubMed1987

Standardization of a plaque assay for Lassa virus.

The plaque reduction neutralization test (PRNT) has been used routinely in serological studies with such arenaviruses as Junin, Machupo, and Parana. However, difficulties have been encountered in using the PRNT for LCM virus, while conflicting views have been expressed about the reliability and efficacy of the test with Lassa virus. We have therefore investigated and evaluated the plaque assay for Lassa virus. In addition, the suitability of the PRNT for determining the potency of a serum and its efficacy in passive immunization for the treatment of Lassa fever was also investigated. The Lassa virus plaque assay satisfied the criteria proposed by Cooper [1961] for determining satisfactory plaque technique. Lassa virus plaques appear within 3 days of inoculating Vero cell cultures. By day 5, the plaques are clearly defined, discrete, and measure 1.5 to 2.0 mm. In the plaque reduction neutralization test, the use of native non-inactivated serum was required for a reliable and reproducible determination of serum antibody titer. The potency and suitability of a serum for Lassa fever serotherapy was determined by the use of a constant serum-varying virus (CS-VV) and/or a constant virus-varying serum (CV-VS) PRN technique.

Animals↗
PubMed1998

Effect of some variables on the in vivo determination of scorpion and viper venom toxicities.

An adequate assessment of scorpion and snake venom LD50 is an important step for accurate evaluation of antivenom sera potencies and the optimization of serotherapy. The LD50 variation of Tunisian scorpion (Androctonus australis garzonii: Aag and Buthus occitanus tunetanus: Bot) venoms with body weight, sex and strain (Swiss or C57BI/6) of mice used, the route of venom injection, the venom-milking procedures (manually or electrically) and the venom batches have been studied over a 7-year period (1990-1996). Aag venom is 3-4 times more toxic than Bot venom. However for both venoms, the LD50 determined in C57BI/6 mice, in small body weight animal or by intraperitoneal route were respectively significantly lower than those determined in Swiss mice, in high body weight or by subcutaneous route. Significant LD50 variations (25-50%) were also seen from one electrically prepared batch to another. A good correlation (r = 0.982) was observed between the concentrations of the crude venom toxic fraction determined by ELISA and LD50 values when assessed in vivo. The LD50 variation of Tunisian viper (Cerastes cerastes: Cc and Vipera lebetina: VI) venoms with the strain (Swiss or BALB/c), sex and body weight of mice used, the season and the year of venom milking were also investigated over a 3-year period (1990-1992). No significant LD50 variations were observed with the mouse strain, the sex or the season of venom milking. However, LD50 varies significantly with the year of the venom collection and the body weight of mice used. Furthermore, SDS-PAGE analysis shows annual variation for VI venom composition where no such variations were observed for Cc venom. These results stress the need either for the standardization of the venom LD50 evaluation or of the venom quality used for the development of an efficient antivenom.

Animals↗
PubMed2000

Antibody modeling: implications for engineering and design.

Our understanding of the rules relating sequence to structure in antibodies has led to the development of accurate knowledge-based procedures for antibody modeling. Information gained from the analysis of antibody structures has been successfully exploited to engineer antibody-like molecules endowed with prescribed properties, such as increased stability or different specificity, many of which have a broad spectrum of applications both in therapy and in research. Here we describe a knowledge-based procedure for the prediction of the antibody-variable domains, based on the canonical structures method for the antigen-binding site, and discuss its expected accuracy and limitations. The rational design of antibody-based molecules is illustrated using as an example one of the most widely employed modifications of antibody structures: the humanization of animal-derived antibodies to reduce their immunogenicity for serotherapy in humans.

Antibodies↗
PubMed2002

Non-myeloablative stem cell transplantation for congenital immunodeficiencies.

Allogeneic haematopoietic stem cell transplantation (HSCT) can be a highly successful treatment option for individuals with congenital immunodeficiency states. The strategy for HSCT is varied but in cases where there is preservation of residual T cell function, conditioning regimes have been used and have been based around a combination of busulphan and cyclophosphamide with or without serotherapy. In patients with coexisting organ damage this has resulted in significant morbidity and mortality. We have therefore used a low-intensity conditioning regime for transplantation in this group of immunodeficiency patients. Twenty-one patients with a variety of different immunodeficiencies were treated using the following conditioning regimes: (1) fludarabine/melphalan/ATG or Campath 1H (n=16), (2) fludarabine/cyclophosphamide/Campath 1H (n=1), (3) TBI/CyA/MMF (n=1), (4) fludarabine/melphalan/busulphan/ATG (n=3). In 13 cases matched (n=9) and 1 Ag mismatched (n=4) unrelated donors were used and in eight cases transplants from matched siblings (n=4), 1 Ag mismatched sibling (n=1), matched parent (n=1) and haploidentical parents (n=3) were performed. At a median follow-up of 13 months, 19 of 21 (90%) patients were still alive following the transplant procedure. Despite a T cell replete graft and the use of unrelated donor grafts in the majority of patients studied there was no evidence of significant organ disease. Immune reconstitution in terms of CD3+ and CD4+ T cell recovery and function was equivalent in comparison with a historical cohort. We believe that this low-intensity approach has significant implications for transplantation of individuals with immunodeficiency states with established organ disease.

Adolescent↗
PubMed1992

In vivo neutralization of tumor necrosis factor-alpha and interferon-gamma abrogates resistance to Yersinia enterocolitica infection in mice.

Cytokines are important mediators of the inflammatory host response against infectious agents. In this study, the role of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in the elimination of a primary infection with highly virulent Yersinia enterocolitica serotype 0:8 strain WA-P has been investigated in C57BL/6 mice. The injection of anti-TNF-alpha or anti-IFN-gamma antibodies ("serotherapy") prior to the intravenous challenge of a sublethal dose of Y. enterocolitica caused an increased bacterial net-growth in the spleens, although this effect was more pronounced for anti-TNF-alpha treatment. The later treatment with anti-TNF-alpha or anti-IFN-gamma antibodies on day 3 post infection likewise abrogated resistance to Y. enterocolitica and, subsequently, led to death from progressive infection. Our data demonstrate for the first time that the endogenous production of both the cytokines TNF-alpha and IFN-gamma is required for the restriction of a primary Y. enterocolitica infection in mice.

Animals↗
PubMed1985

Complexes prepared from protein A and human serum, IgG, or Fc gamma fragments: characterization by immunochemical analysis of ultracentrifugation fractions and studies on their interconversion.

Protein A of Staphylococcus aureus is an Fc receptor for IgG that has been used as a therapeutic reagent to treat cancer in humans and experimental animals. We used ultracentrifugation combined with analysis of isolated fractions by radioimmunoprecipitation and competitive radioimmunoassay with chicken antibodies that bind free protein A or protein A in complexes but do bind free immunoglobulin reagents to localize and characterize the types of complexes formed with different molar ratios of 125I-protein A and human 131I-IgG alone or in serum, and 131I-Fc gamma fragments. This approach offers a distinct advantage over direct counting of radioactivity in the fractions because resolution of complexes and free reagents is much improved. With excess 131I-IgG or 131I-Fc, all the 125I-protein A is present only in complexes that contained 4 molecules of immunoglobulin reagent and 2 molecules of protein A (4:2 complexes), whereas with excess 125I-protein A the stoichiometry of the complexes was 1:1. We have also shown the preformed 4:2 and 1:1 complexes will interconvert in the presence of added excess protein A or IgG, respectively, and that fresh IgG will exchange with IgG or Fc gamma in preformed complexes. Because protein A has been found to elute from an immobilized reagent used in serotherapy of human cancer and is present in a large excess of IgG, the 4:2 complexes may play an active role in the tumoricidal or toxic reactions observed.

Antigen-Antibody Complex↗