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Biomedical subjects

F Cassani

Publications and source records attributed to F Cassani.

69 records · Page 4Linked to original sources
PubMed1987

Immune dysfunction in primary biliary cirrhosis (PBC): I. Increased sensitivity of PHA stimulated lymphocyte cultures to indomethacin.

A reduced responsiveness of peripheral blood lymphocytes from PBC patients to phytohaemagglutinin (PHA) was observed. Such an alteration may be related either to an intrinsic defect of T cells to proliferate or to a derangement of endogenously secreted mediators with regulatory functions, i.e., prostaglandins (PG). The role of the PG mediated suppressor system in 14 PBC patients and in 12 age and sex matched controls was evaluated. After the addition of indomethacin, the lymphocyte responsiveness to PHA increased in both controls and in PBC patients. However, this increment was statistically significantly only in PBC patients. The addition of PGE1 and PGE2 to PHA stimulated cultures decreased the lymphocyte proliferative activity. No differential sensitivity to PGEs was detectable in lymphocytes from PBC patients. Our data suggest, that, after polyclonal stimulation, mononuclear cells from PBC patient may release increased levels of PGEs which in turn affect the proliferative activity of mitogen activated lymphocytes.

Adult↗
PubMed1986

Antibodies to dietary antigens in coeliac disease.

Antibodies to gliadin (AGA) were found in 77 (94%) of 82 sera from patients with active coeliac disease (untreated and after gluten challenge). Although IgG AGA had a higher nosological sensitivity than IgA AGA (88% versus 67%), their nosological specificity was lower than that of IgA antibodies (87% versus 100%). The sensitivity of antibodies to casein, beta-lactoglobulin, and ovalbumin in active coeliac disease varied from 36% to 48% without significant difference between IgG and IgA antibodies. IgG and IgA antibodies to milk and egg proteins showed a specificity similar to that of AGA, although some IgA antibodies other than AGA were found in disease controls (Crohn's disease, ulcerative colitis, post-enteritis syndrome).

Adolescent↗
PubMed1985

Mechanically isolated hepatocytes are unsuitable to detect antibodies directed against plasma membrane determinants.

The ultrastructural morphology of mechanically and enzymatically isolated hepatocytes was compared. Plasma membrane integrity was evaluated by electron microscopy, both in the absence and in the presence of ruthenium red, which stains cell coat glycoproteins and makes it possible to identify even partially permeable cells, and by indirect immunofluorescence using experimental antibodies directed against epithelial submembranous components (prekeratin, actin). In order to evaluate the antigenic integrity of the hepatocellular plasma membrane after the isolation procedures, an immuno-electronmicroscopical technique (Staph. pA-colloidal gold) was applied using the IgG fraction from two liver-kidney microsomal antibody (LKM) positive sera, known to react with both plasma membranes and smooth endoplasmic reticulum (SER). Enzymatic procedure made it possible to isolate hepatocytes with a good preservation of both plasma membranes and subcellular organelles. Ruthenium red staining was confined to plasma membranes, thus indicating the preservation of both cell-coat glycoproteins and plasma membrane. Most cells were negative after exposure to experimental antibodies. After exposure to LKM positive sera colloidal gold was strictly confined to the plasma membrane. On the other hand, mechanically isolated hepatocytes showed wide interruptions of the plasma membrane and gross alterations of subcellular organelles. Most cells were stained by ruthenium red, thus confirming the plasma membrane permeability. In addition, a linear peripheral positivity was found in the vast majority of the cells tested with anti-prekeratin and anti-actin antibodies. LKM-colloidal gold complexes were found at the level of both residual plasma membrane and SER.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗
PubMed1985

Antibodies to gliadin detected by immunofluorescence and a micro-ELISA method: markers of active childhood and adult coeliac disease.

Antibodies to gliadin have been detected by immunofluorescence (IFL-AGA) and a micro-ELISA method (ELISA-AGA) in 45 out of 47 (96%) sera from patients with active childhood and adult coeliac disease. The two methods were more sensitive than R1-reticulin antibodies (R1-ARA) which were found only in 28 of the same patients (60%). R1-ARA were always negative in the 26 sera from patients with childhood coeliac disease and adult coeliac disease after gluten free diet, while IFL- and ELISA-AGA were respectively found in three (12%) and in four (15%) out of these patients. Moreover, while R1-ARA and IFL-AGA were strictly confined to coeliac disease. ELISA-AGA were occasionally found in patients with control diseases. These 'false positive' antibodies were all of IgG class and had low titres. In our experience IFL- and ELISA-AGA of IgA class were strictly confined to active childhood coeliac disease and adult coeliac disease. The detection of AGA is useful in monitoring the diet and in the follow up of coeliac disease. IFL- and ELISA-AGA, then, are to be preferred to R1-ARA for the screening of coeliac patients.

Adult↗
PubMed1985

Immunomorphological characterisation of antinuclear antibodies in chronic liver disease.

Two immunofluorescence procedures to evaluate antinuclear antibodies were compared in a series of 221 patients with chronic liver disorders of various aetiologies. The use of HEp-2 cells allowed us to discriminate with more confidence between the homogeneous and speckled patterns, to show the presence of associated patterns in the same serum, and, above all, to identify two specificities, unrecognizable on tissue sections. The anticentromere antibody was found in 10% of cases of primary biliary cirrhosis and occasionally in other conditions; the antibody staining multiple nuclear dots was strictly confined to primary biliary cirrhosis (17%). With the exception of autoimmune chronic active hepatitis the prevalence of antinuclear antibodies increased in all groups, particularly in primary biliary cirrhosis. Homogeneous antinuclear antibody was associated by both immunofluorescence procedures with autoimmune chronic active hepatitis. The multiple nuclear dot antinuclear antibody turned out to be an additional marker of primary biliary cirrhosis, helpful for the positive diagnosis of primary biliary cirrhosis in a proportion of cases negative for antimitochondrial antibody. Absorption experiments showed that multiple nuclear dot and antimitochondrial antibody are antigenically distinct. Moreover, multiple nuclear dot antinuclear antibody was associated with the finding of a dry Schirmer's test.

Antibodies, Antinuclear↗
PubMed1984

Antibodies to gliadin in adult coeliac disease and dermatitis herpetiformis.

Antibodies to gliadin, searched for by indirect immunofluorescence and a micro-ELISA, were detected in 16 (64%) of 25 sera from patients with adult coeliac disease and in 13 (45%) of 29 with dermatitis herpetiformis. Although the sensitivity of the two tests was relatively low in the whole groups, it increased when only cases with severe jejunum abnormalities were considered (93% for coeliac disease and 81% for dermatitis herpetiformis). A significant correlation was found between antigliadin antibodies and the severity of jejunum damage in both diseases. Moreover, most coeliac and dermatitis herpetiformis patients with antigliadin antibodies were on normal diet. The specificity of the tests was 100% for the immunofluorescence and fairly good for the micro-ELISA, as only 5 (11%) of the 46 disease control patients (Crohn's disease, ulcerative colitis) were positive for antigliadin antibodies. R1-reticulin antibody test was equally specific but less sensitive in both groups. We conclude that antigliadin antibodies are useful in the diagnosis of patients with active adult coeliac disease and dermatitis herpetiformis with gluten-sensitive enteropathy. Moreover, the two tests make it possible to monitor the compliance to gluten-free diet in both diseases.

Adolescent↗
PubMed1984

Liver cell surface expression of the antigen reacting with liver-kidney microsomal antibody (LKM).

To test the hypothesis that liver membrane antibodies, found in all liver-kidney microsomal antibody (LKM) positive sera from patients with chronic active hepatitis, were directed against antigens shared by both hepatocellular endoplasmic reticulum and plasma membranes, absorption experiments have been performed using viable isolated hepatocytes and liver microsomes as antigens. Results are in agreement with the above hypothesis, LKM, which displays a restricted organ specificity, is thus able to react with antigenic determinants expressed on the liver cell surface, as it has been demonstrated for strictly organ specific antibodies directed against thyroid, adrenal and gastric parietal cell microsomes.

Animals↗
PubMed1983

A microELISA assay to detect anti-liver-specific protein antibodies in the sera of patients with liver diseases.

A microELISA to detect anti-liver-specific protein (LSP) antibodies in human sera is described. Rabbit LSP was used as antigen. Optimal conditions for antigen concentration, serum dilution, substrate incubation time and reproducibility with time were established. The microELISA is specific, as assessed by testing anti-LSP positive sera with another lipoprotein from rabbit plasma (VLDL), although a weak cross-reactivity between LSP and VLDL was observed. The test was applied to patients with HBsAg-positive and -negative chronic active hepatitis (CAH). Ten of 26 (38%) patients were positive for anti-LSP antibodies, in comparison with healthy controls used to determine the threshold of positivity. Such a percentage is comparable with that reported for radioimmunoassay (RIA) procedures.

Antibody Specificity↗
PubMedDate not supplied

Antiperinuclear factor in an Italian series of patients with rheumatoid arthritis.

Serum samples from 90 cases of rheumatoid arthritis (RA), 218 control patients and 100 healthy controls were tested by indirect immunofluorescence for the presence of the antiperinuclear factor (APF), an autoantibody to the keratohyaline granules of human buccal mucosal cells. The sensitivity and specificity of the APF test for RA were 82 and 90%, respectively, slightly higher than those obtained when the same serum samples were tested for rheumatoid factor (RF) using a latex agglutination method. The diagnostic gain of APF in the RF-negative RA cases was greater than that of RF in the APF-negative cases (54% vs. 37%). In spite of a few technical disadvantages, the APF test should be therefore performed in the serological routine examination of rheumatic diseases. As APF was also found in 11% of degenerative joint disease (DJD) cases and the estimated prevalence ratio RA/DJD is, in Italy, 1/11, the predictive value of a negative APF test proved to be much higher than that of a positive test (98% vs. 40%) for the diagnosis of RA. APF was significantly associated with other autoantibodies (RF and antinuclear antibody).

Antibodies, Antinuclear↗
PubMedDate not supplied

Clinical subsets of scleroderma: relevance of fluorescent and precipitating antinuclear antibodies.

Sera from 7 patients with localized and 35 with systemic scleroderma were studied for the presence of fluorescent antinuclear antibodies (FANA) (by indirect immunofluorescence on HEp-2 cells) and antibodies to extractable nuclear antigens (anti-ENA) (by immunodiffusion - ID - and counterimmunoelectrophoresis - CIE). In localized disease, antinuclear autoimmunity was limited to 1 FANA positive serum (14%); in systemic disease, the prevalence of FANA was 94% and that of anti-ENA ranged from 29% to 49% (by ID and CIE, respectively). The commonest ENA system, Scl-70, could be easily detected by CIE, in spite of the reported basic nature of the antigen. The anticentromere antibody occurred only in patients with acrosclerosis (7/26-27%), whereas the association of nucleolar + homogeneous FANA, as well as the anti-Scl-70, were found more frequently in diffuse scleroderma (9/9-100% and 6/9-67%, respectively). The presence of the anticentromere antibody excluded that of any anti-ENA, while a close association was found between nucleolar + homogeneous FANA and the anti-Scl-70. Pulmonary involvement was significantly more frequent in nucleolar + homogeneous FANA positive patients; moreover, in two cases the same pattern proved to predict the development of diffuse scleroderma.

Antibodies, Antinuclear↗
PubMedDate not supplied

Antibodies to cardiac conducting tissue in progressive systemic sclerosis.

Cardiac conducting tissue antibodies (CCTA) were detected, using indirect immunofluorescence, in 8 (25%) out of 32 sera from patients with progressive systemic sclerosis (PSS) and in 39 (35%) out of 110 with rheumatoid arthritis (RA). Conduction abnormalities, namely right bundle branch block, were present in 19 (59%) of the PSS patients and in 37 (32%) of the RA cases. No significant correlation was found between the prevalence of CCTA and conduction abnormalities in PSS patients, while this was present in RA patients (p less than 0.001). CCTA were always negative in 18 patients with systemic lupus erythematosus and were found in one out of 8 cases with Sjögren's syndrome, also positive for rheumatoid factor without clinical RA. These data suggest that CCTA are evoked when involvement of cardiac conducting tissue (as in RA) or working myocardium (as in PSS) is present. Whether CCTA should be mainly regarded as an expression of the immunological derangement underlying these pathological conditions or whether they are secondary to myocardial tissue damage, must still be clarified.

Adolescent↗