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Biomedical subjects

G Dighiero

Publications and source records attributed to G Dighiero.

At least 127 records · Page 7Linked to original sources
PubMed1987

New trends in CLL treatment.

We review here results obtained from the various treatment modalities that have been used in CLL patients: chemotherapy; radiotherapy; splenectomy; leukapheresis; monoclonal antibodies and other immunomodulating agents. We conclude that it is still unclear whether patients in stage A (good prognosis) should be treated; intermediate forms of the disease (stage B) should, in most cases, be treated, but a better treatment than chlorambucil has not emerged; results from the Cooperative Group on CLL of Société Française d'Hématologie indicate that significant progress in the therapy of the advanced stage (stage C) has been achieved with the introduction of the CHOP regimen, using low doses of adriamycin; radiotherapy, splenectomy and immunomodulators such as levamizol, interleukins or interferons, and possibly monoclonal antibodies, are now being actively tested; the results are not yet conclusive.

Antibodies, Monoclonal↗
PubMed1987

Detection of anti-mitochondrial antibodies by ELISA and Western-blot techniques and identification by one and two-dimensional gel electrophoresis of M2 target antigens.

Seven hundred and eleven sera were simultaneously studied by immunofluorescence (IF), complement fixation test (CFT) and ELISA for the detection of anti-mitochondrial antibodies (AMA). One hundred and nineteen of these sera were also studied by Western-blot techniques, while some of them were examined by two-dimensional gel electrophoresis so as to identify the polypeptides recognized by M2 antibodies. The results indicated that: (1) ELISA is a more sensitive technique for detecting type M2 AMA (27 scored positive in 27 primary biliary cirrhosis (PBC), as compared to 21/27 by IF and 16/27 by CFT). (2) Although ELISA appeared to be a promising screening method, some false positive results were observed that necessitated a double confirmation of positive sera by another technique. (3) Western-blot experiments with rat mitochondrial purified preparation indicated that sera from AMA type 2 could recognize eight different polypeptides and that most of them identified 63-60, 48, 44, and 35-33 kD polypeptides, whereas the 54 and 27 kD were less frequently recognized. A trypsin treatment of antigens confirmed the enzyme sensitivity of most of these antigens. These results suggested some heterogeneity among M2 AMA, though this series of PBC was not large enough to relate the heterogeneous pattern noticed in Western-blot to the clinical and histological patterns observed in PBC.

Autoantibodies↗
PubMed1987

Age-related natural antibody specificities among hybridoma clones originating from NZB spleen.

In the studies presented here, age-related natural antibody specificities have been investigated in the autoimmune NZB mouse strain by cell fusion. The monoclonal immunoglobulins (MIg) secreted by productive hybridoma clones were examined for their antibody activities against a panel of antigens, including single- and double-stranded DNA, actin, tubulin, myosin, bromelain-treated mouse red blood cells (BrMRBC) and TNP-BSA, employing both direct and competitive enzyme immunoassays. The antibody specificities against this panel of antigens were strikingly frequent among hybridoma clones from neonatal NZB (49%) mice, compared to normal BALB/c neonates (8.8%) shown earlier. Among neonatal hybridomas with known antigen reactivities, 73% of the clones exhibited polyspecific binding. In contrast, the majority of hybridomas from 5- and 7-month-old NZB spleen reacted monospecifically (76%) with the antigens tested. Such a characteristic reactivity pattern reflects an age-related evolution of B-cell repertoire expression. Unlike normal BALB/c mice, a high frequency of monospecific TNP-hapten-reactive clones (75%) was noticed among hybridomas of known antigen reactivities from 5- and 7-month-old NZB-strain mice, an age when autoimmune haemolytic anaemia sets in. In conclusion, an elevated frequency of autoreactive clones among neonates (49%) and an aberrant expression of TNP-reactive clones in adults seem to be an outward signal of certain discrepancies at the level of B-cell repertoire expression in autoimmune NZB-strain mice.

Aging↗
PubMed1986

Newborn Xid mice carry the genetic information for the production of natural autoantibodies against DNA, cytoskeletal proteins, and TNP.

Spleen cells from 6-day-old unimmunized male and female (CBA/N X BALB/c)F1 mice, fused with the nonsecreting hybrid SP2/0, gave 184 hybrids secreting immunoglobulins (183 IgM class; 115 from males and 69 from females) which were screened for antibody (Ab) activity against actin, tubulin, myosin, TNP-BSA, dsDNA, and denatured DNA. Eleven hybrids from the male series (9.65%) and eight hybrids from the female series (11.55%) secreted immunoglobulins with significant Ab activity against at least one of the six antigens tested. Four of these clones reacted with a single antigen, while 15 others reacted simultaneously with at least two antigens. Three hybrid clones exhibited Ab activity against all of the antigens tested. The monoclonality and specificity of the immunoglobulins from tissue culture supernatants were respectively assessed by two-dimensional gel electrophoresis after biosynthetic labeling and competitive enzyme-linked immunosorbent assay. These results confirm our previous findings with newborn and adult BALB/c mice, demonstrating a high frequency of this auto-Ab repertoire, especially in newborn mice, and widespread polyspecificity found among these natural auto-Ab. Xid mice are characterized by the absence of a Lyb-3+,5+ B cell population; nevertheless, these studies suggest--but do not prove--that the Lyb-3-,5- lymphocyte population seems to carry genetic information for the production of natural auto-Ab, because no marked differences were observed in the secretory patterns of hybrids obtained from male mice bearing the Xid defect and from normal female mice. Hence, we postulate that the Xid gene might be a regulatory gene because Xid mice, in contrast with normal mice, are unable to secrete anti-DNA auto-Ab on mitogenic stimulation, despite carrying the genetic information.

Animals↗
PubMed1986

[Biological aspects of chronic lymphoid leukemia].

The present study is concerned with clinical prognostic classifications of chronic lymphocytic leukemia derived from numerous statistics and multivariate survival analysis. We analyse the prognostic significance of some biological patterns: bone marrow histological studies, lymph node biopsies, size, structure and doubling time of blood lymphocytes, tumoral markers and karyotype analysis. The problem of the monoclonal clone origin is discussed: differentiation abnormality or proliferation of a physiological clone.

Female↗
PubMed1986

[Hashimoto's thyroiditis with intra-thyroid production of a monoclonal antithyroglobulin autoantibody].

A 46-year old man had an Hashimoto's thyroiditis. The disease was particular by the voluminous goiter, associated with pressure symptoms and by the presence of a monoclonal Ig.G Kappa. Because of a possibly associated lymphoma of the thyroid, a total thyroidectomy was performed. Post-operative course showed a rapid and total disappearance of monoclonal Ig.G and antithyroglobulin autoantibodies. There was no pathological feature of thyroid malignancy. We could show that the monoclonal Ig.G bore an antithyroglobulin activity and that this monoclonal antithyroglobulin autoantibody was produced with in the thyroid. This case demonstrate that a monoclonal proliferation can arise from autoreactive B lymphocytes infiltrating the thyroid during Hashimoto's thyroiditis. Such a mechanism could explain, in some cases, the well-known association between lymphomas of the thyroid and Hashimoto's thyroiditis.

Antibodies, Monoclonal↗
PubMed1985

A high incidence of cross-reactive idiotypes among murine natural autoantibodies.

Anti-idiotypic (anti-Id) antibodies were produced in rabbits against two natural monoclonal IgM autoantibodies (NmAb), D23 and E7, which exhibited a broad reactivity and were derived from fusions of spleen cells from adult unprimed BALB/c mice and nonsecreting myeloma cell lines. They were used to test the reactivities of 12 NmAb obtained from adult and newborn unprimed mice. Both anti-Id recognized cross-reactive idiotopes frequently shared by NmAb; 8 out of the 12 NmAb reacted with anti-IdD23, while 5 of them also reacted with anti-IdE7. All of the Id-bearing antibodies possessed widespread reactivity with structurally dissimilar self and nonself antigens. In most cases, their cross-reactive Id determinants seemed to be located outside of their antigen-binding sites. Furthermore, the presence in normal mouse sera of significant levels of D23 and E7 idiotopes correlated with the presence of natural antibody activity and was mainly associated with IgM and IgG2b fractions. Finally, D23 idiotope(s) were also found on induced murine anti-myosin antibodies. The high incidence of cross-reactive idiotopes found among NmAb produced by clones derived from different mice and their presence in normal BALB/c mouse serum Ig fractions suggest that families of germ-line genes may encode for at least a part of them.

Animals↗
PubMed1985

High frequency of natural autoantibodies in normal newborn mice.

Spleen cells from 6-day-old nonimmunized BALB/c and BALB.B10 mice were fused with the nonsecreting hybridoma cell line Sp2/0. Three hundred and eighty-four immunoglobulin-secreting hybrids were screened for antibody activity against mouse actin, tubulin, and myosin, and against TNP, peroxidase, renin, DNA, and neurofilaments. At least 24 hybridomas in the collection (6.25%) exhibited antibody activity against this panel of antigens. Ten of these hybrids were cloned, were propagated, and the corresponding monoclonal IgM protein was isolated from ascitic fluids and was further characterized. At least four groups of antibody specificities were identified: 1) one clone reacting with TNP only; 2) one clone reacting with both actin and tubulin; 3) two clones which bound to both TNP and actin; and 4) a fourth group, comprising the six other clones, which all exhibited widespread reactivity and bound to actin, tubulin, myosin, and TNP. These results indicate: 1) B cell clones directed against self antigens are activated in the internal environment and are recovered consequently by somatic cell hybridization; 2) the widespread antibody specificities found for these newborn mouse antibodies are very similar to those previously characterized with human natural antibodies and human monoclonal Ig; and 3) the frequency of B cells binding to cytoskeletal proteins and TNP is very high (at least 6.25%).

Animals↗
PubMed1983

Thirty-six human monoclonal immunoglobulins with antibody activity against cytoskeleton proteins, thyroglobulin, and native DNA: immunologic studies and clinical correlations.

Six hundred and twelve monoclonal Ig (MIg) were studied for their antibody activity against the following autoantigens: actin, tubulin, thyroglobulin, myosin, myoglobin, fetuin, albumin, transferrin, and double-stranded DNA (dsDNA). Of these 612 MIg, 36 (i.e., 5.75%) were shown to possess antibody activity. Thirty-two of these 36 (5.22% of the total) were mainly directed against actin. The four others were directed, respectively, against tubulin, myosin, thyroglobulin, and dsDNA. The interaction of the MIg with the respective antigen was demonstrated by immunoenzymatic methods with monospecific antisera and by blotting experiments. Furthermore, this interaction in the 12 cases studied was mediated by the dimeric fragment F(ab')2 of the MIg. The MIg with antitubulin, antithyroglobulin, and anti-dsDNA activities were exclusively inhibited by their homologous antigens. Those with antiactin activity were predominantly inhibited by actin and also by tubulin and thyroglobulin. The one binding to myosin was, for the most part, inhibited by myosin and also significantly by actin and tubulin. Retrospective clinical analysis was possible for 31/36 patients. Twenty-six of 31 had malignant lymphoplasmocytic disorders. The five others were followed for miscellaneous disorders without overt signs of multiple myeloma (MM) or Waldenström's macroglobulinemia (WM). The correlation between the antibody activity of the MIg and the clinical features is discussed. These results indicate that a high proportion of MIg possess antibody activity against actin (5.22%). This incidence contrasts sharply with the positive reactions found toward all the other antigens tested: only one each for dsDNA, tubulin, thyroglobulin, and myosin, and none against myoglobin, fetuin, albumin, and transferrin. The significance of these results and the relationship between MIg and natural antibodies are discussed.

Actins↗
PubMed1983

Murine hybridomas secreting natural monoclonal antibodies reacting with self antigens.

Spleen cells from nonimmunized BALB/c mice were fused with two nonsecreting myeloma lines. The hybrids were selected in HAT medium and screened for Ig production and for antibody activity against actin, tubulin, myosin, thyroglobulin, myoglobin, spectrin, dsDNA, fetuin, and transferrin. Among 161 hybrids secreting Ig, three were found to react with DNA, one with thyroglobulin, and one mainly with myosin. Two of these hybrids could be propagated and further characterized. On the basis of inhibition experiments, one was found to be directed against dsDNA; the other was directed mainly against myosin but at the same time reacted significantly with actin, tubulin, spectrin, and dsDNA. Reactivity with myosin seemed to be concentrated in the light meromyosin subfragment, known to be rich in alpha-helical structure. These results indicate: 1) There are reactive B cell clones directed against self antigens. 2) The antibody specificities found for these antibodies are very similar to those found for natural antibodies in normal human serum and for human monoclonal Ig. 3) The widespread reactivity found for the clone mainly reacting with myosin raises the possibility that the determinant recognized by this antibody is a conformational structure that possibly is associated with alpha-helical structures.

Actins↗
PubMed1982

Automated recognition of B and T lymphocytes by immunoperoxidase on the hemalog D system and its applications.

A new automated immunoperoxidase assay for the recognition of B and T lymphocytes on the Hemalog system is proposed. Lymphoïd cells are incubated with peroxidase labeled antibodies, and after manual washing, cells are run through the flow system of the machine which automatically stains the cells for peroxidase and, according to their staining for this enzyme, separates positive from negative cells. Using this method we have been able to recognize B and T lymphocytes and to count them as accurately as by routine immunological methods. Very preliminary results, concerning a few cases of chronic lymphocytic leukemia, prolymphocytic leukemia and Waldenström's macroglobulinemia are also reported. The usefulness of this new method which allows processing of 60 samples per hour is discussed.

Animals↗
PubMed1981

A new prognostic classification of chronic lymphocytic leukemia derived from a multivariate survival analysis.

Survivals of two series of CLL patients (99 from a retrospective series and 196 from a prospective series) were studied separately. The three main staging systems (Rai, Binet, Rundles) agreed well, but as far as survival is concerned, too many stages are defined. The authors performed a Cox multivariate analysis of survival in order to isolate important prognostic factors at diagnosis and to use them to build a simple three-stage classification. Thrombopenia and anemia appeared as the most important risk factors. Among the nonanemic and nonthrombopenic patients, the number of involved areas was clearly related to prognosis in the authors' two series. This study allowed the authors to propose a new classification in three prognostic groups. Group C: anemia (Hb less than 10 g) and/or thrombopenia (platelets less than 100,000/mm3); about 15% of the patients; median of 2 years. Group B: no anemia, no thrombopenia, three or more involved areas (counting as one each of the following: axillary, cervical, inguinal, lymph nodes, whether unilateral or bilateral, spleen and liver); about 30% of patients; median of 7 years. Group A: no anemia, no thrombopenia, less than three involved areas; about 55% of patients; the survival of this group does not seem different from that of the French population of the same age and sex distribution. This three-stage classification only requires clinical examination and routine hemogram, has a good prognostic value which was confirmed on the series of Montserrat and Rozman (146 patients), and should therefore be helpful in planning new clinical trials.

Aged↗
PubMed1981

Differentiation ability of the CLL lymphocyte: an immature lymphocyte or an abnormal leukemic cell?

The present study is concerned with the patterns of cell differentiation in chronic lymphocytic leukemia. Most cases correspond to the proliferation of a B-cell clone. In contrast to the normal B-lymphocyte, the B-cell CLL lymphocyte is characterized by: (1) very low amounts of monoclonal surface Ig; (2) the presence of receptors for mouse red blood cells; (3) the presence in a high percentage of cases of dual B and T markers. T-cell CLL is a rare event and is defined by a peculiar clinical and hematological picture including the presence of receptors for sheep erythrocytes, the reactivity with anti-T sera, and negative or very low values of terminal transferase. Different studies have conflicted in their findings on the incidence of null-cell CLL; however, these cases appear to be rare. Perhaps more sensitive methods of study must be employed before concluding that the null-cell CLL exists and before establishing its incidence. Even though great progress has been made in the understanding of this disease, two main questions remain unresolved: 1. Does the proliferating clone correspond to an immature B-lymphocyte, or does it merely represent an abnormal leukemic cell? 2. What is the role of T cells in B-cell CLL?

B-Lymphocytes↗
PubMed1980

Individual cell-by-cell quantitation of lymphocyte surface membrane Ig in normal and CLL lymphocyte and during ontogeny of mouse B lymphocytes by immunoperoxidase assay.

A new quantitative immunoperoxidase method is presented for determining absolute amounts of peroxidase and, consequently, surface antigen densities of individual cells in B lymphocytes from normal individuals, from subjects with CLL and prolymphocytic leukemia, and during ontogeny of B lympocytes in the mouse. The following results were observed: (1) The density of B antigenic sites were lower on CLL than on normal B lymphocytes. (2) The B antigens density of leukemic lymphocytes varied less from cell to cell, forming a homogeneous peak on histograms. (3) In a very rare case of CLL, the antigen density was measured at the time of initial diagnosis (22,500 sites or 647 U) and during the development of a blastic crisis (135,000 sites or 2576 U). The cell by cell distribution changed from a homogeneous peak with a low number of antigenic sites per cell to a heterogeneous peak with a high number of antigenic sites per cell. (4) In prolymphocytic leukemia, the density of B antigenic sites was greater than on normal B lymphocytes and much more heterogeneous than on CLL lymphocytes. (5) During ontogeny of B lymphocytes in the mouse, maturation is associated with the appearance of a population of cells of intermediate to high Smig density. The finding of a decrease in, and altered distribution of, surface markers in CLL is compared with these ontologic findings in the mouse, and the concept that a monoclonal B lymphocyte in CLL may be arrested at a particular stage in its differentiation is discussed.

Animals↗