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Biomedical subjects

G Balestrieri

Publications and source records attributed to G Balestrieri.

At least 73 records · Page 4Linked to original sources

Use of monoclonal antibodies to identify shared idiotypes on anticardiolipin and anti-DNA antibodies in human sera.

Using hybridoma technology we produced monoclonal antibodies (MoAb) to idiotypic determinants on human anti-cardiolipin antibodies purified from a patient with SLE. Hybridomas were screened by inhibition of cardiolipin binding activity of sera from patients with SLE. Seven hybridomas were selected, two of which were studied extensively. Sera from a number of patients with SLE were found to share idiotypic determinants. This cross-reacting idiotype was not detectable on anti-cardiolipin antibodies in syphilis sera. The cross-reacting idiotype was present in sera with anti-ssDNA antibodies even though some of these sera had no anti-cardiolipin antibodies. We propose that these MoAb may recognize a regulatory idiotype.

Animals↗

Anti-mitochondrial type M5 and anti-cardiolipin antibodies in autoimmune disorders: studies on their association and cross-reactivity.

In a series of 42 positive sera, anti-mitochondrial type M5 antibodies (AMA-M5) were found most frequently in patients with SLE (24) and SLE-like syndromes. Patients with AMA-M5 displayed a higher prevalence of thrombocytopenia, thrombosis, biological false positive seroreactions for syphilis, lupus-like anticoagulant activity and anti-cardiolipin antibodies in comparison with a group of 43 SLE AMA-M5 negative patients. The strong association between anti-phospholipid and AMA-M5 antibodies cannot be explained entirely by cross-reactivity between these two groups of antibodies, as indicated by absorption experiments and studies using affinity purified antibody preparations. However, cardiolipin liposomes were able to reduce partially the titres of AMA-M5 sera, suggesting that a small population of AMA-M5 antibodies exists that cross-reacts with cardiolipin. The existence of this population was further substantiated by our demonstration that an IgM monoclonal antibody, from a patient with Waldenström's macroglobulinaemia, displayed both anti-cardiolipin and AMA-M5 activity, and AMA-M5 activity was completely inhibited by cardiolipin.

Adult↗

Inhibitory effect of IgM rheumatoid factor on immune complex solubilization capacity and inhibition of immune precipitation.

Purified IgM rheumatoid factors (RF; 3 monoclonal and 2 polyclonal) were shown to inhibit, in a dose-dependent manner, 2 complement-mediated functions, i.e., the immune complex solubilization capacity and the inhibition of immune precipitation. Inhibition of immune complex solubilization capacity occurred only if RF was added at the same time as, but not after, addition of the complement source. Experimental evidence suggests that the effects of RFs were not related to their anticomplementary activity, but rather required the attachment of RF to the Fc region of the IgG molecule. Although no clinical data are available so far, it might be plausible that these newly described properties of RF have biologic relevance.

Antigen-Antibody Complex↗

Comparison of pathologic and normal sera by immune complex determination: five disease groups within 190 samples are discriminated by computer-selected combinations of 13 methods. Report of the Italian committee for the study of immune complexes (WIC).

Pathological (190) and normal (33) sera were tested for their content of circulating immune complexes (CIC) by a battery of 13 assays performed in 11 laboratories. Statistical processing was done both by pooling all pathological samples and by extracting those falling into well-defined disease groups, i.e., rheumatoid arthritis, diabetes, lupus, melanoma, and glomerulonephritis. Highly significant correlations between methods--taken two at a time--for each disease differed in proportion (ranging from 6 to 30%) and in the pattern displayed on a checkerboard. Disease-linked patterns were also found when a function maximizing discrimination between pathological and normal samples was derived by combining the information from all methods. Here the order and the weight attributed by the computer to the methods differed for each of the disease groups. Taken together these results are interpreted as an indication that all assays may not determine the same classes of CIC, and thus vary in sensitivity depending on the prevailing properties of the complexes present in the serum, which in turn may depend on the etiology, pathogenesis, and stage of the disease.

Antigen-Antibody Complex↗

Detection of circulating immune complexes in acute non-lymphatic leukaemia: is it reliable?

The in vivo and in vitro phagocytic ability of leukaemic cells and the serum levels of circulating immune complexes (CIC) have been evaluated in 11 patients affected by acute non-lymphatic leukaemia (ANLL). High levels of serum CIC were detected in 17% of the cases showing phagocytic ability and in 80% of the cases lacking phagocytic ability (p less than 0.05). In 3 patients serum CIC determinations were negative while immunoglobulins with complement-fixing ability were detected in the cytoplasm of leukaemic cells indicating in vivo phagocytosis of CIC. These results suggest that leukaemic cells may sometimes interfere through their phagocytic ability on the detection of CIC in the serum. Therefore, the clinical and prognostic value of serum CIC in ANLL seems questionable.

Antigen-Antibody Complex↗

Con A suppressor cell assay: a further characterization.

Con A induced suppressor cell assay was further characterized in this study. Significant lower mitogenic responses of autologous fresh cells cocultured with Con A-activated cells were found when compared with the response of cocultures of responders plus control cells preincubated in medium alone. However, Con A-activated cells did not express a real suppression, since no difference was found between responses of fresh responders alone and responses of cocultures with Con A-activated cells. So, Con A activation seemed to block the expression of the enhancement provided by control cells to autologous responders, rather than to induce a real suppressor activity. The induction of the Con A suppressor cell activity required cell proliferation but it was not proportional to the degree of DNA synthesis. Monocyte depleted cell populations exhibited lower Con A suppressor cell activity compared to unfractionated cells, suggesting a cooperative role of monocytes in the Con A induction step. The expression of this activity was not due to a cytotoxicity against the responders and was dependent on the number of activated cells added. Mononuclear cells from active lupus erythematosus (SLE) patients, but not from inactive SLE patients differed from normal controls in showing a significant loss of suppression index.

Adult↗

Solubilization of immune complexes and inhibition of immune precipitation in SLE sera.

The ability of serum to in vitro process immune complexes both preformed (ICSC) and during their formation (ICPIC) has been evaluated in 37 patients affected by systemic lupus erythematosus (SLE). ICSC was found to be significantly lower in these patients than in normal controls (p less than 0.001), and strictly related to the phase of the disease. Correlations were evidenced between ICSC and haemolytic activity of the classical and alternative pathways of complement, levels of the complement components C3 and C4, and incidence of circulating immune complexes. Low values of ICPIC were demonstrated almost only in sera of patients with active SLE; in fact, ICPIC was impaired in 6 sera only, and five of them were collected in the acute phase. All sera with decreased ICPIC also displayed a very low level of the C4 complement component.

Antigen-Antibody Complex↗

[Evaluation of T suppressor activity in systemic lupus erythematosus].

Con A induced suppressor cell activity was evaluated in 10 patients with Systemic Lupus Erythematosus and in 20 normal subjects. The suppressor activity, calculated according to Shou et al. (1976), was markedly reduced in SLE patients (mean value 45.2% vs 72.9% P less than 0,01). No statistical difference was evidentiated between the patients with mild and those with severe disease, though the last ones showed the lowest values. Low degree of suppression was found related to low hemolytic complement activity (P less than 0.02) but not to anti-DNA antibody titre or immune complex presence.

Adolescent↗

Circulating immune complexes in human acute leukaemia.

Circulating immune complexes (CIC) in the sera of 60 newly diagnosed leukaemic patients were investigated by two methods, 125I-C1q binding test (C1q-BA) and conglutinin binding assay (KgB-SP). Positivity percentages were respectively 20.0% (C1q-BA) and 28.3% (KgB-SP). The small overlap between the results of the two methods suggests the occurrence of different types of CIC. The presence of CIC was found to be related only to clinical haemorrhage and thrombocytopenia; it did not prove to affect the prognosis and the survival of leukaemic patient.

Acute Disease↗

[Immune complexes DNA-anti-DNA during the course of mixed cryoglobulinemia].

Plasma and isolated cryoglobulins from ten patients with mixed cryoglobulinemia were studied for the presence of DNA using the diphenylamine reagent test. DNA-like material was detected in all the plasmas tested and it was also present in nine of the isolated cryoglobulins. IgM and IgG components of three cryoglobulins were purified by gel-filtration: anti-DNA activity was detected in IgG fraction (two cases), in IgM and IgG (one case); antigammaglobulin activity was always found in IgM fraction.

Antibodies, Anti-Idiotypic↗

Familial clustering of hepatitis B antigen and liver diseases in families with a high incidence of viral hepatitis.

In each of 23 families in which two or more cases of acute hepatitis-like jaundice (index cases) occurred, all family members were studied to evaluate HBAg clustering and the incidence of asymptomatic liver disease. There were 49 "index cases" of hepatitis-like jaundice: 38 cases of acute viral hepatitis, 5 of chronic agressive hepatitis and 6 of active cirrhosis. The overall number of members in these families (excluding index cases) was 170 and 155 of which were tested by clinical examination, laboratory tests and needle liver biopsy. In 27 out of the 155 subjects there was evidence of liver diseases (10 non icteric hepatitis cases, 12 CAH cases and 5 cirrhosis cases). HBAg was present in the serum of 19 of these patients, and twof the cirrhotic patients were positive. Furthermore, 33 of the 155 cases were healthy HGAg carriers showing no abnormality in liver function tests. In the majority of these carriers liver histology showed slight damage (pin-head necrosis or portitis) sometimes compatible with resolving viral hepatitis. A long-term follow-up of the HGAg carriers showed that three of these subjects progressed to acute viral hepatitis.

Acute Disease↗

Anti-IgA antibodies in two brothers with selective serum IgA deficiency.

A selective serum IgA deficiency with anti-IgA antibodies at high titer were found in a patient who suffered severe transfusion reactions. The same abnormalities were detected in his brother, a 72-year-old-man in good general condition. Anti-IgA antibodies were found in the IgG fraction and were directed against alpha-chains. A deficiency of isoagglutinins and an absence of heteroagglutinins in the propositus' serum could be shown.

Aged↗