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Biomedical subjects

J F Bach

Publications and source records attributed to J F Bach.

At least 433 records · Page 24Linked to original sources

Prophylactic use of OKT3 monoclonal antibody in cadaver kidney recipients. Utilization of OKT3 as the sole immunosuppressive agent.

We describe the first clinical trial of OKT3, a monoclonal anti-T-cell antibody, for prevention of kidney transplant rejection. 13 patients receiving a first cadaveric kidney transplant were randomly assigned to conventional treatment with azathioprine and high-dose steroids (7 patients) or to treatment with daily injection of OKT3 alone (6 patients). The first OKT3 injection resulted in a dramatic decrease in T3+, T4+, and T8+ cells, while patients simultaneously experienced fever, chills, and diarrhea. These symptoms did not recur with subsequent injections. All six OKT3-treated patients had a rejection necessitating introduction of steroids 12.8 +/- 2.9 days after surgery. Rejection was related to appearance of anti-OKT3 antibodies leading to disappearance of detectable OKT3 in the serum. Modulating (T3-, T4+ or T3-, T8+) cells were observed in all patients but were functionally inactive. As no rejection was observed before day 9 posttransplant, despite the lack of additional immunosuppressive agents, we conclude that OKT3 is a powerful, well-tolerated immunosuppressive agent. However, it is highly immunogenic and anti-OKT3 antibodies lead to loss of clinical effectiveness in this protocol. The use of OKT3 alone for prevention of kidney graft rejection cannot be recommended until a method for reducing the effects of anti-OKT3 immunization is developed.

Acute Disease↗

HLA antigens in 88 cases of rheumatic fever observed in Martinique.

HLA-A, B, C and DR antigens were studied in 88 patients from Martinique. A modest but significant reduction of B14 and Bw42 antigens was noted as well as an increase in B35 (p less than 0.05) and DR1 antigens (corrected p less than 0.05), two antigens known to be in linkage disequilibrium. These data, which corroborate a previous study for B35, suggest that the unusual antistreptococcal response mounted by rheumatic fever patients is under HLA control.

France↗

T-lymphopenia and T-cell imbalance in diabetic db/db mice.

The diabetic db/db mice of the C57 BL/KsJ strain display anti-islet immunity, thymic dysfunction, and lymphopenia. In the present work, lymphocytes, T-cells, and T-cell subsets were enumerated in thymus and spleen from diabetic db/db mice and their db/ + heterozygote littermates from the 10th day to the 10th month of life. A significant lymphopenia was detected in thymus and spleen from the second month on, involving specifically the T-cell compartment, as assessed by use of a monoclonal anti-Thy1 antibody in indirect fluorescence. The study of T-cell subsets by monoclonal anti-Lyt1 and anti-Lyt2 antibodies revealed a significant increase in Lyt1+ cells and a decrease in Lyt2+ cells, with a corresponding increase of the Lyt1+/Lyt2+ ratio. These anomalies appeared early in life, and were apparently linked neither with the degree of hyperglycemia nor with weight loss or infection. The T-cell depletion in thymus was more pronounced in young male (less than 3 mo) than in young female db/db mice. These alterations may correspond to an increase in the helper/suppressor-cytotoxic ratio and could be linked with the thymic anomalies present in these mice, contributing to the development of anti-islet autoimmunity.

Animals↗

Specificity of acebutolol-induced antinuclear antibodies.

Treatment with the beta blocker acebutolol may trigger antinuclear antibody (ANA) production. We retrospectively studied 97 sera from 47 patients who developed ANA during acebutolol treatment. Anti-histone and anti-denatured (ss) DNA antibodies were found in 53% and 66% respectively of the sera tested. The activities of these two antibodies correlated well with the total ANA titer. Anti-native (ds) DNA were absent or present at low titer. This immunochemical pattern of acebutolol-induced ANA is similar to that reported for other drug-induced ANA. To date, the presence such isolated ANA is not known to expose patients to any particular risk other than exceptional and minor clinical manifestations of lupus which are rapidly reversible following therapy cessation.

Acebutolol↗

The wasted mutant mouse. II. Immunological abnormalities in a mouse described as a model of ataxia-telangiectasia.

Ataxia-telangiectasia (AT) is a complex multiparametric disease associating oculocutaneous telangiectasias, cerebellar ataxia, elevated chromosomal aberration frequency and varied degrees of immunodeficiency. Recently a wasted mutant mouse (wst) has been described as an animal model of AT. We have looked in the wasted mutants for the presence of immune and endocrine abnormalities characteristic of AT. In contrast to the T cell immunodeficiency in AT, wasted mutants had a marked hypoplasia of all lymphoid organs, which affected both T and B lymphocyte subsets. The marked thymic atrophy appearing at the final stage of their disease did not modify the endocrine function of the thymic epithelium which produced normal levels of the thymic hormone thymulin. Although in vitro interleukin 2 (IL-2) production by splenic T cells in response to Con A was markedly diminished, these mice presented normal T and B cell proliferative responses to mitogens. Finally, no significant increase in serum alpha-fetoprotein level (a typical marker of AT) was found throughout the course of the disease. Although by many aspects, i.e. neurological disorder, chromosomal aberrations and early death, wasted mice presented similarities with human AT, major discrepancies in the typical features of immune abnormalities were found between the mouse model and the human disease.

Animals↗

[Hormonal modulation in disseminated lupus erythematosus: the preliminary results with danazol and cyproterone acetate].

In an open prospective study, we have tested clinical efficacy and tolerance of two antigonadotropic drugs, that is danazol (D) and cyproterone-acetate (CA). This study was performed in 11 female patients ranging in age from 19 to 47 years, who suffered from midly-active SLE, during 12 therapeutic periods on the whole (that is 6 for each drug), the minimum period of which was one year. Because of side-effects, D had to be early withdrawn in 2 patients, whereas (the) AC appeared to be well-tolerated in all of them. On the whole, 16 clinical exacerbations of DLE were observed during the 12 months pre-treatment period, versus 9 exacerbations during the 12 months treatment period (p less than 0.05, Wilcoxon test), whereas the average dose of prednisone was reduced from 9.6 to 3.5 mg/day. A dramatic improvement was then observed in 3 patients suffering from mucous ulcerations. Increased plasma testosterone level without any change in estradiol level was observed in patients treated with D. Conversely, plasma estradiol decreased without any change in testosterone level in patients treated with CA. Both drugs induced reduction in plasma sex-hormone binding protein. These preliminary results suggest that D and CA may both reduce lupus disease activity, in parallel with an hormonal environment modification, towards a lower estrogen-androgen balance, along with a better tolerance as for CA.

Adult↗

Autoimmune disorders in diabetes.

The development of IDDM correlates with the presence of biologic markers pointing to the involvement of the immune system in the disease process. In addition to clinical observations of association of IDDM with other autoimmune disease and morphologic evidence of a mononuclear cell infiltration of the islets of Langerhans at the onset of the disease, anti-islet cell antibodies are detected in the serum of IDDM patients. Moreover, a strong genetic association with HL-A DR3 and DR4 identifies a genetic background compatible with autoimmune phenomena. Whether autoimmune phenomena are primary or secondary to an initial damage of the islets by infectious agents or other environmental factors is unknown. Whether or not the autoimmune response participates in the selective destruction of insulin-secreting cells has been a major issue in the past five years. The presence of T lymphocytes and anti-islet cell antibodies, which selectively inhibit or lyse insulin-secreting cells in vitro, strongly suggests that it may be the case. A definitive demonstration is difficult to provide in human IDDM. The development of animal models for IDDM has allowed useful insight into the pathogenetic mechanisms responsible for IDDM. In both the BB rat and the low-dose streptozotocin mouse model, the role of the immune system in the destruction of the islets of Langerhans is supported by the prevention of the disease by treatments interfering with the immune system. The BB rat develops a spontaneous autoimmune disease on a genetic background defined by the association with a major histocompatibility complex allele without any evidence for a role in initial damage of islets of a triggering infectious or chemical process. The low-dose streptozotocin model is an autoimmune IDDM secondary to the selective damage of islet cells by a toxin. The present scheme of an islet cell target and specific autoreactive T and B lymphocyte clones raises two major issues: what is the target antigen on islet cells and what is the role at the molecular level of class II major histocompatibility complex genes in susceptibility for IDDM? The first issue is presently being addressed in several laboratories using the hybridoma technology. The second issue is addressed at the biochemical level by studying restriction site polymorphism of major histocompatibility genes in susceptible individuals and IDDM patients, and at the functional level by studying the action of monoclonal antibodies to class II antigen on the development of IDDM in animal models. These steps are likely to be a prerequisite to antigen-specific immunotherapy in IDDM.

Animals↗

[Pathogenic antibodies in systemic lupus erythematosus: anti-LAMP antibodies].

We recently demonstrated that a monoclonal anti-DNA antibody, spontaneously produced in lupus B/W mice, recognizes the same protein(s) at the surface of several human cell types involved in lupus pathogenesis including normal human erythrocytes, normal platelets and rat neuronal tissue. This cell-surface protein(s) cross-react(s) with double-stranded DNA. We suggest to call this protein(s) LAMP [lupus associated membrane protein(s)]. Here we show that: immunoglobulins eluted from kidneys of autoimmune MRL/lpr/lpr mice strongly react with LAMP. Anti-LAMP antibodies are present in large amount in MRL/lpr and B/W mice sera. Anti-LAMP are present in 25 out of 25 human SLE sera ranged as SLE on the basis of revised American Rheumatism Associated classification. Interestingly, two of these sera did not display anti DNA anti-body activity. Taken together, these results strongly suggest a role of LAMP in the pathogeny of SLE.

Animals↗

Idiotypes of monoclonal anti-DNA antibodies produced in autoimmune B/W mice are expressed in normal mice.

An anti-idiotypic antiserum was prepared in a rabbit immunized against a pool of six monoclonal anti-DNA antibodies generated in B/W mice. This antiserum detected idiotypic determinants in four of the six monoclonal anti-DNA antibodies but also in the serum of several non autoimmune strains (BALB/c, NZB X BALB/c) F1 hybrids & CBA/LH). The antiserum also reacted, but only to a weak degree, with B/W mouse sera. These results indicate that some idiotypes of anti-DNA antibodies produced by autoimmune B/W mice are present in normal mouse sera.

Animals↗

Thymic epithelium in AIDS. An immunohistologic study.

The authors investigated by immunofluorescence the thymic epithelium from AIDS patients, using several structural and functional markers of this tissue. In AIDS thymus, the epithelial reticular pattern was lost; and instead, clusters of round or spindle-shaped cells (assessed by their keratin content) were found. In addition, regions of epithelial necrosis, with loss of cell limits, were frequently observed. Thymulin content was decreased, and a partial loss of differentiation antigens of the thymic epithelium was also detected. The authors showed the presence of immunoglobulins and elements of the complement system directly bound to AIDS thymic epithelium, but not in any of the controls studied, including thymuses from patients who died after a long period of agony. These data suggest that the thymic epithelium can be included among the target tissues in AIDS, possibly by an indirect mechanism of autoimmune destruction.

Acquired Immunodeficiency Syndrome↗

Cutaneous pheomorphic T cell lymphoma. Immunologic, virologic, and T-cell receptor gene rearrangement studies in one European case with initial pseudolymphoma presentation.

An unusual case of cutaneous nodular T cell lymphoma evolving for 4 years with massive eosinophilia and greatly increased IgE levels is discussed. Repeated histologic and immunohistologic examinations could not ascertain malignancy because tumors were composed of a granuloma-like, highly polymorphic cellular infiltrate with mature immunotype and no significant nuclear abnormalities nor epidermotropism. T cell lymphoma was evidenced by the T cell receptor beta-chain gene study, which showed a clonal rearrangement. Final histologic classification was "pleomorphic T cell lymphoma" because further biopsy samples displayed numerous lymphoid cells with pleomorphic convoluted nuclei. The T-cell receptor gene probe is a major tool for the early diagnosis of some T cell lymphomas. The case we report shares many features with the smoldering type of human T cell lymphotropic virus type I-associated Japanese endemic pleomorphic T cell lymphoma. Our virologic study confirms that in nonendemic Western countries, pleomorphic T cell lymphomas do not show evidence of a retrovirus association.

Antibodies, Monoclonal↗

Feedback regulation of the secretion of a thymic hormone (thymulin) by human thymic epithelial cells in culture.

The production of the thymic hormone, thymulin (FTS), was studied in primary cultures of human thymic epithelium by immunofluorescence using monoclonal anti-thymulin antibodies. The number of thymulin-containing cells and the thymulin level in the culture supernatant increased gradually during the culture. Addition of synthetic thymulin to the culture medium reduced significantly the increase of thymulin-containing cells. Conversely, addition of monoclonal anti-thymulin antibody from the beginning of the culture exacerbated the spontaneous increase of thymulin-containing cells and abrogated the effects of thymulin. Combined with similar data previously reported in vivo, these results demonstrate that thymulin is actively produced by cultured thymic epithelial cells and that its synthesis can be down-regulated by the hormone itself.

Antibodies, Monoclonal↗

[Myasthenia induced by D-penicillamine. Study of immuno-clinical correlations in 23 cases].

Sera from 23 patients with D-penicillamine-induced myasthenia gravis (MG) contained antibodies directed against the human muscle acetylcholine receptor (anti-AChR) in 83% of the cases at the onset of the disease. Twenty-one were patients with rheumatoid arthritis. The anti-AChR antibody titers were comparable to those of sera from ocular MG patients and were related to the presence of clinical signs but not to their severity. The anti-AChR antibodies persisted in autonomous MG (5 cases) and disappeared in the other cases. The same phenomenon occurred for antinuclear antibodies detected in sera from 13 patients at the onset of the disease: anti-ss DNA 9/13, antinuclear 4/13 and anti-histones 7/13. The latter antibodies seem to result from, and follow the D-penicillamine treatment.

Adult↗