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Biomedical subjects

F B Bianchi

Publications and source records attributed to F B Bianchi.

At least 145 records · Page 8Linked to original sources

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↗

Relationship between smooth muscle and cytoskeleton antibodies in neuroblastoma.

The previously reported high prevalence of smooth muscle antibodies in neuroblastoma has been found to be associated with a similarly elevated prevalence of anti-cytoskeleton antibodies. The most relevant finding is related to anti-microfilaments (anti-actin) and anti-microtubules antibodies, which were detected with highly significantly different prevalences when compared with a disease control group (p less than 0.001 and p less than 0.000001, respectively). The correspondence between smooth muscle antibodies and anti-cytoskeleton antibodies is incomplete, and it is more relevant for anti-microfilaments. It is concluded that antigen specificities of smooth muscle antibodies in neuroblastoma are as complex as documented in other diseases. Possible pathogenetic and clinical implications emerging from these data are discussed.

Antibodies↗

Sequential behaviour of extracellular matrix glycoproteins in an experimental model of hepatic fibrosis.

The behaviour of extracellular matrix glycoproteins (fibronectin, laminin, basement membrane heparan-sulphate proteoglycan, type III, IV and V collagens) has been investigated in a sequential model of experimental hepatic fibrosis, using an immunofluorescence technique. The presence of some basement membrane macromolecules (such as type IV and V collagens, laminin and basement membrane heparan-sulphate proteoglycan) is detectable only in the early stages of septa formation, while type III collagen and fibronectin persist in late septa. These data suggest that hepatic fibroplasia proceeds through different steps in which stromal glycoproteins are preferentially engaged, as happens during organogenesis.

Animals↗

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↗

Patterns of lacrimal dysfunction in primary biliary cirrhosis.

The lacrimal function has been evaluated in 23 patients suffering from primary biliary cirrhosis by rose bengal test, the Schirmer test 1, and the tear breakup time. Ocular dryness was present in 78% of cases studied. No difference was found with respect to the length or severity of the hepatic involvement between patients with and without lacrimal dysfunction, but in patients with signs of hypolacrimation the changes in the lacrimal tests increased with the duration and histological progression of liver disease.

Adult↗

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↗

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↗

Antibodies to the cytoskeleton components and other autoantibodies in inflammatory bowel disease.

A high prevalence of antibodies to cytoskeleton components (anti-CYTO) and of anti-smooth muscle (SMA) and antinuclear (ANA) antibodies has been found in inflammatory bowel disease (IBD). In particular, a significant correlation has been documented between anti-CYTO and activity of the disease in ulcerative colitis and anti-fibroblast intermediate filaments (anti-vimentin) antibodies and Crohn's disease. The antibodies are detectable in the three major immunoglobulin classes, including IgA. While titres of anti-CYTO did not exceed 1:40, ANA and SMA were of high titres (up to 1:1,280). Antibodies to epithelial cells intermediate filaments (anti-cytokeratin) were detected only occasionally. The significance of these findings in IBD is discussed.

Adolescent↗

Non-organ-specific autoimmunity in alopecia.

A significantly high prevalence (41%) of non-organ-specific autoantibodies, tested in immunofluorescence with sera diluted 1:40, is reported in sera from 86 alopecia patients. No correlation was found with extension and duration of the disease, topical treatment with contact agents or response to it. The relevance and significance of these findings, with particular reference to anti-smooth muscle and anti-basal cell layer antibodies, is discussed.

Adolescent↗

Aberrant expression of HLA-DR antigens on bileduct epithelium in primary biliary cirrhosis: relevance to pathogenesis.

Direct immunofluorescence with an avidinbiotin system was used to investigate the expression of MHC molecules HLA-DR and HLA-A,B,C on bileducts in cryostat sections from 10 primary biliary cirrhosis (PBC) patients. Needle biopsy specimens from 55 patients with various chronic liver disorders, surgical biopsy specimens from 2 patients with recurrent secondary cholangitis, and 4 normal livers were used as controls. Normal bileducts did not express DR whereas in 8/10 PBC biopsy specimens there were varying degrees of cytoplasmic DR staining in septal or interlobular bileduct epithelium. In the early histological stages of PBC the aberrant DR expression was multifocal, but in late-stage specimens whatever ducts remained were all positive. This pattern resembles that in focal thyroiditis and suggests that DR expression is an early manifestation of autoimmune cholangitis. In 6/61 control biopsies only weak staining was detected in occasional small interlobular ducts. The class I HLA-A,B,C expression normally seen on biliary epithelium was increased in 8/10 PBC cases and in 19/61 non-PBC biopsies. Perhaps the aberrant expression of HLA-DR antigens on bileduct epithelium in PBC enables these cells to present "self antigens" to sensitised T-lymphocytes and to promote autorecognition, possibly in response to several environmental triggers; the increased HLA-A,B,C, expression may be a means of amplifying T-cell cytotoxic responses.

Adult↗

Steroid treatment lowers hepatic fibroplasia, as explored by serum aminoterminal procollagen III peptide, in chronic liver disease.

Serum aminoterminal type III procollagen peptide (sPIIIP) has been proposed as an index of hepatic fibroplasia. sPIIIP was retrospectively evaluated in 34 treated and five untreated patients affected by chronic active hepatitis with or without cirrhosis by an RIA test. Serum samples taken before and after 6 months of treatment were tested in all cases. In 15 of the treated and all untreated patients, 6-20 (median 13) sera, corresponding to a median follow-up of 43 months were studied. Before treatment, the sPIIIP median value was 18.6 ng/ml; after 6 months of treatment, it decreased to 13.6 ng/ml (p less than 0.005). Follow-up sPIIIP levels were significantly lower in treated than in untreated patients (p less than 0.05), at each interval considered, except for the last control (39 months). In seven patients, treatment was discontinued: sPIIIP rose rapidly in six; four of them were retreated and this was followed by a new decrease. In four patients, sPIIIP was tested weekly from the onset of the treatment: it reverted to normal values within the first week in all cases, while GOT decreased later. sPIIIP is significantly and rapidly reduced by steroids. Steroid withdrawal is generally followed by a rebound, with a new decrease when treatment is restarted. Since sPIIIP is more rapidly lowered than GOT levels, the above data support the hypothesis that steroids can directly affect collagen metabolism.

Adolescent↗

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↗