Eng M. Tan

Bio: Eng M. Tan is an academic researcher from Scripps Research Institute. The author has contributed to research in topics: Antigen & Autoantibody. The author has an hindex of 47, co-authored 71 publications receiving 30110 citations. Previous affiliations of Eng M. Tan include University of Pittsburgh & University of Vermont.

Plasma complement and histamine changes in atopic dermatitis.

Abstract: Fifteen patients with atopic dermatitis were investigated to evaluate the total of complement and histamine. In five patients total serum complement haemolytic activity (CH50) was significantly decreased as was the haemolytic activity of complement components C2 (C2H50) and C3 (C3H50). By counter immunoelectrophoresis split products of C3 were detected. There was no evidence for alternative pathway activation or the presence of an activator of the alternative pathway. In three patients plasma histamine concentrations were elevated. The intensity of the complement and histamine changes observed seemed to be correlated to the severity of the disease.

Relative paradigms between autoantibodies in lupus and autoantibodies in cancer.

Abstract: Autoantibodies which are reactive with intracellular antigens have been studied extensively in autoimmune rheumatic diseases such as systemic lupus erythematosus (lupus), Sjogren's syndrome, scleroderma, dermatomyositis/polymyositis, and other related diseases [1]. Autoantibodies are being recognized with increasing frequency in other illnesses including type I diabetes [2], the paraneoplastic neurological disease syndromes [3,4], liver diseases [5], bullous skin diseases, inflammatory bowel diseases, thyroid and other endocrinopathies, haematopoietic disorders and many others [6]. Autoantibody to p53 was detected in breast cancer [7] but for a time the main interest was in T cell-mediated autoimmunity [8], until it became evident that humoral immunity was also a prominent response in many different types of cancer [9–11]. In this paper, we will review and discuss the special features of spontaneously occurring autoantibodies and in the case of cancer, how some patients’ immune systems appear to be sensing aberrant cellular mechanisms related to tumorigenesis and reporting these events in the form of the contemporaneous appearance of neo-antibodies. There are some similarities between autoantibodies in lupus (and other autoimmune diseases) and autoantibodies in cancer and there are some differences, but important insights into aetiology, pathogenesis and therapeutic strategies could be gained by careful analysis of the deeper implications of autoimmune responses in both lupus and cancer.

Non-muscle myosin as target antigen for human autoantibodies in patients with hepatitis C virus-associated chronic liver diseases.

Abstract: Three patients with hepatitis C virus (HCV)-related chronic liver disease were shown to have autoantibodies strongly reacting with cytoskeletal fibres of non-muscle cells. The heavy chain of non-muscle myosin microfilament was the main target for those autoantibodies, as determined by (i) cell and tissue immunofluorescence studies showing colocalization with an anti-myosin antibody prototype; (ii) primary reactivity in immunoblotting with a 200-kD protein, using either MOLT-4 cells, human platelets, or affinity-purified non-muscle myosin as antigen extract; and (iii) immunoblotting of similar immunoreactive fragments in papain-digested MOLT-4 cell extracts, by using those human sera and antibody prototype. Autoantibodies to non-muscle myosin heavy chain were not previously reported in patients with chronic liver diseases, especially in those associated with HCV infection.

Autoantibody to DNA topoisomerase II in primary liver cancer

Abstract: A patient with chronic hepatitis associated with hepatitis C virus infection was observed to convert from antinuclear antibody-negative to antinuclear antibody-positive status at the time when liver cancer was detected. The newly recognized antibodies reacted with a nuclear protein doublet of 170 and 180 kDa in immunoblotting, and in fluorescence-activated flow cytometry the antigens were shown to vary in expression level in a cell cycle-related manner: minimum in G1, increasing in S, and maximum in G2 and M. In synchronized HeLa and HEp-2 cells, immunofluorescence microscopy showed uniformly distributed staining of the nucleoplasm in S-phase, with increased intensity of nucleoplasmic staining in G2, at which time nucleolar staining was also present. In M, condensed chromosomes were uniformly stained. Using previously characterized polyclonal antibodies to DNA topoisomerase II (topo II) as reference markers, the antigens recognized by the patient's serum were shown in Western blotting to have the same mobilities as DNA topo IIalpha (170 kDa) and beta (180 kDa) isoforms. The patient's serum was also highly efficient in inhibiting DNA topo II in an in vitro functional assay. Antibody to DNA topo II appeared de novo in close association with transformation to cancer, and since dysregulation of DNA topo II is considered to be involved in some forms of tumorigenesis, the observed antibody response in this patient could conceivably be an immune reaction to the abnormally regulated protein.

Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.

Abstract: A method has been devised for the electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets. The method results in quantitative transfer of ribosomal proteins from gels containing urea. For sodium dodecyl sulfate gels, the original band pattern was obtained with no loss of resolution, but the transfer was not quantitative. The method allows detection of proteins by autoradiography and is simpler than conventional procedures. The immobilized proteins were detectable by immunological procedures. All additional binding capacity on the nitrocellulose was blocked with excess protein; then a specific antibody was bound and, finally, a second antibody directed against the first antibody. The second antibody was either radioactively labeled or conjugated to fluorescein or to peroxidase. The specific protein was then detected by either autoradiography, under UV light, or by the peroxidase reaction product, respectively. In the latter case, as little as 100 pg of protein was clearly detectable. It is anticipated that the procedure will be applicable to analysis of a wide variety of proteins with specific reactions or ligands.

Updating the American College of Rheumatology revised criteria for the classification of systemic lupus erythematosus.

Abstract: In 1982, the Diagnostic and Therapeutic Criteria Committee of the American College of Rheumatology (ACR)published revised criteria for the classification of systemiclupus erythematosus (SLE) (1). During the ensuing decade several investigators, including Drs. Graham Hughes and Donato Alarcon-Segovia, among others, have described the presence and clinical associations or antiphospholipid antibodies in patients with SLE, as well as the occurrence of theprimary antiphospholipid syndrome (2-5). In 1992, Piette and colleagues suggested that the ACR revised criteria be reevaluated in light of the above discoveries (6).

Development of criteria for the classification and reporting of osteoarthritis: Classification of osteoarthritis of the knee

Abstract: For the purposes of classification, it should be specified whether osteoarthritis (OA) of the knee is of unknown origin (idiopathic, primary) or is related to a known medical condition or event (secondary). Clinical criteria for the classification of idiopathic OA of the knee were developed through a multicenter study group. Comparison diagnoses included rheumatoid arthritis and other painful conditions of the knee, exclusive of referred or para-articular pain. Variables from the medical history, physical examination, laboratory tests, and radiographs were used to develop sets of criteria that serve different investigative purposes. In contrast to prior criteria, these proposed criteria utilize classification trees, or algorithms.

Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria.

Abstract: The New York and the Rome diagnostic criteria for ankylosing spondylitis (AS) and the clinical history screening test for AS were evaluated in relatives of AS patients and in population control subjects. The New York criterion of pain in the (dorso) lumbar spine lacks specificity, and the chest expansion criterion is too insensitive. The Rome criterion of low back pain for more than 3 months is very useful. Our study showed the clinical history screening test for AS to be moderately sensitive, but it might be better in clinical practice. As a modification of the New York criteria, substitution of the Rome pain criterion for the New York pain criterion is proposed.