Biomedical subjects
Publications and source records attributed to G Angarano.
A case of cryptosporidiosis in a male homosexual man with AIDS is reported. The clinical manifestations were anorexia, mild fever, abdominal pain and profuse watery diarrhea. The diagnosis was made in fecal smears by using a modified Ziehl-Neelsen method and a safranin-methylene blue staining technique.
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A capture enzyme-linked immunosorbent assay for the detection of serum IgA against hepatitis A virus has been developed. The test was highly specific, and the time course of detectability of IgA anti-HAV was longer than six months in 42/42 patients with acute or protracted hepatitis A followed prospectively, but shorter than two years in 14/14 patients tested 21-24 months after diagnosis of acute hepatitis A. IgM anti-HAV were at detectable levels in only 1/42 cases tested six months after the clinical onset. The detection of serum IgA anti-HAV is a simple and specific method to differentiate protracted cases of hepatitis A from non-A, non-B hepatitis.
One-hundred-and-two out of 788 consecutive patients (12.9%) hospitalized for an attack of acute hepatitis fulfilled criteria for non-A, non-B (NANB) hepatitis, and were followed prospectively for 8 to 70 months. Forty-one out of 97 patients showed a monophasic pattern of alanine aminotransferase (ALT), and all recovered completely. In contrast, 22 of 56 (39.2%) subjects with a polyphasic pattern of ALT exhibited persistent hypertransaminasemia for more than 14-18 months, and all of them developed chronic hepatitis. Thus, a polyphasic pattern of ALT seems to characterize one of two forms of NANB hepatitis, more frequently associated with parenteral exposure, absence of jaundice and a high tendency for the development of chronic hepatitis. This suggests distinct immunopathogenetic mechanisms from two unrelated NANB agents. Benign, non-progressive chronic persistent hepatitis is the prevalent form of chronic sequela of NANB hepatitis observed in our patients. Although many of these patients show a tendency to spontaneous remission of the disease, there is the possibility in some of a deterioration of inflammatory activity of the liver that has need of immunosuppressive therapy.
An ELISA for the detection of a Ag/Ab system related to non-A, non-B post-transfusion hepatitis (NANB-PTH) has been developed. A convalescent serum from a patient suffering, 14 month before, of NANB-PTH was used both as capture and detector antibody in a "sandwich" type immunoassay to detect an Ag (Ag-NANB). A "blocking" immunoassay was used, in the same test, to detect the corresponding antibody (Ab-NANB). All patients with NANB-PTH were positive, alternately, for Ag-NANB or Ab-NANB. The Ag was found in the acute phase sera of 3 out of 22 cases of NANB-PTH (13,6%), but in none of 29 acute hepatitis type B,26 acute hepatitis type A,14 NANB sporadic hepatitis, 5 infectious mononucleosis and 8 healthy subjects. 2/3 Ag-NANB positive subjects became chronic carriers of this Ag, whereas the third seroconverted for Ab-NANB after the first two months of their disease. Furthermore, a significant increase of the Ab-NANB titer was observed in the convalescent phase of the disease in 18/20 NANB-PTH. As expected, a relatively high prevalence for Ab-NANB was found in the other groups of patients, suggesting the high diffusion of the agent, but none of these subjects showed a progressive increase of the antibody titer during the course of their disease.
A capture enzyme immuno assay for the detection in the serum of specific IgA antibodies to HAV is described. A total of 203 sera from patients and controls were tested. IgA anti-HAV were present only in sera from patients with recent hepatitis A. 23 patients were followed prospectively and IgA anti-HAV were at detectable levels for at least six months after the onset. The detection of IgA anti-HAV is proposed as an important test to differentiate hepatitis A with persistent hypertransaminasemia from non-A, non-B patients.
To evaluate the behaviour of the Theophylline-sensitive T lymphocytes subpopulation some modifications of the standard procedure are proposed. Lymphoprep purified lymphocytes were counted in a Neubauer hemocytometer after Acridine Orange stain, viability was evaluated by Ethidium Bromide counterstain and monocytes contamination was evaluated by the peroxidase stain. Sheep red blood cells were treated with AET, Theophylline was used at 3 mM (final concentration) and the results compared with untreated lymphocytes; the enumeration of the rosetting lymphocytes was facilitated by adding Acridine Orange prior to the resuspension. The modifications described were able to increase the % of rosetting T lymphocytes, to eliminate differences depending by different lots of sheep red blood cells and to decrease differences depending by subjective evaluation of the rosetting T lymphocytes.
The pathogenesis of the hepatic damage in hepatitis is not well understood but an imbalance in immunoregulatory T lymphocytes is probable. We tested the Theophylline-sensitive T lymphocytes in acute and protracted cases of hepatitis A, in hepatitis B and non-A, non-B. A delayed increment of such cells was demonstrated in hepatitis B suggesting a positive role in the recovery from the disease. The results were indicative for a direct action of the HAV and nAnB on the lymphocytes. Theophylline-sensitive lymphocytes were increased in the course of protracted hepatitis A whereas were progressively decreasing in nAnB hepatitis. This behaviour of suppressor cells in nAnB hepatitis may explain the high frequency of evolution in chronic liver disease.
Three enzyme-linked immunosorbent assays which use commercially available reagents are presented as alternatives to the complement fixation procedure for large-scale detection of rotavirus antibodies. Comparison of results in 75 sera tested by indirect, competition and blocking ELISA and by complement fixation demonstrated that the ELISA techniques were rapid, easy to perform and 26 to 29 times more sensitive than complement fixation; furthermore the ELISA techniques permitted extrapolation of an approximate titer from a single dilution test. Although it could detect class-specific antibodies, the indirect assay was less sensitive, specific and reproducible than competition and blocking assays; furthermore the titer extrapolated from a single dilution test in the indirect assay had a lower correlation with the end-point titer than in the other two methods. Competition ELISA was easier to perform whereas blocking ELISA had better reproducibility and serotype studies were possible with it using faecal rotavirus isolates. The respective ELISA technique can be recommended for use in seroepidemiologic surveys according to the study needs.
A new test principle for the simultaneous detection of total approximate titers and immunoglobulin M antibodies has been developed and applied to the detection of antibody to hepatitis B core antigen. The method is based on the combination of a competition radioimmunoassay, for the determination of total antibody titer, with an indirect enzyme-linked immunosorbent assay for the determination of single class antibodies. The interference of the rheumatoid factor was avoided by including heat-aggregated immunoglobulin G in the dilution buffer. The specificity, sensitivity, and clinical application of the test are discussed. The results presented suggest that the simultaneous detection of total and immunoglobulin M antibody to hepatitis B core antigen might be helpful in the differentiation between previous and recent or ongoing hepatitis B infection, as well as in the differential diagnosis of acute hepatitis, in monitoring viral activity in chronic infections, and in helping to differentiate acute from chronic infections. The test principle appears applicable in the accurate diagnosis of other infectious diseases by a single test on only one serum sample.
Soluble (free) and insoluble (IgG-bound) hepatitis B e antigen (HBeAg) activities in 1,33 M ammonium sulfate solution was evaluated serially in sera from 12 patients with acute type B hepatitis followed up to 60 days. In three cases preclinical sera were available. In patients who showed clinical and biochemical resolution of hepatitis within 60 days, HBeAg free was the prevalent form of circulating HBeAg during the incubation period of disease, then gradually shifting to the IgG-bound form at the onset of jaundice. Finally HBeAg-bound was no longer demonstrable, followed by detection of anti-HBe antibody. On the contrary, in all patients with unresolved hepatitis both HBeAg-free and HBeAg-bound were detected with prevalence of HBeAg-free ratio. These data suggest a striking correlation between synthesis of HBeAg and HBV replication and may indicate that HBeAg-free and IgG-bound ratio reflects the stage and prognosis of acute HBV infection.
To evaluate the effective role of hepatitis viruses in thalassemic (Th) liver disease, we carried out a long-term study in 42 subjects with nontransfusion-dependent Th minor hospitalized for an episode of acute viral hepatitis. 10 patients had serologic evidence of hepatitis A, 23 of hepatitis B and 9 of hepatitis non-A, non-B. In the follow-up chronic hepatitis was detected histologically in 5/23 patients with hepatitis B and 5/9 with hepatitis non-A, non-B. All hepatitis A patients recovered completely. The prevalence in 7 out of 10 patients with chronic hepatitis of piecemeal necrosis and of inflammatory changes over hepatic siderosis and fibrosis evidenced a determinant role of chronic viral infection in the development of liver damage in these patients. Thus, heterozygous nontransfusion-dependent Th patients seem to have a high risk of developing a chronic inflammatory liver disease especially after an episode of non-A, non-B hepatitis. Therefore, in our geographical area, chronic hepatitis of viral origin should be taken into account, among other pathogenetic factors, in many cases of cryptogenic thalassemic liver disease.
The composition of immune complexes (IC) found in 28 patients with HBsAg positive and negative acute and chronic hepatitis was analysed. Components were defined in PEG-precipitated material isolated by preparative ultracentrifugation on linear sucrose density gradients and analysed by the Ouchterlony plate technique and by the radioimmunoassay of hepatitis B virus markers. Sedimentation rate ranged from 8 to 19s in the serum of patients with chronic hepatitis, whereas heavier IC (greater than 19s) were present in the active phase of the disease. The participation of hepatitis B virus in acute hepatitis was shown by the presence of its antigens. In contrast, a low incidence of vital components was seen in IC of chronic active hepatitis and liver cirrhosis. Thus, other causes must contribute to the formation of IC in chronic liver disease.
58 fecal specimens from 14 patients (10 hepatitis A, 2 hepatitis B and 2 infectious mononucleosis) were tested for the hepatitis A virus (HAV) and IgA anti-HAV by micro-solid-phase-radioimmunoassay. Only patients with hepatitis A were positive for HAV and/or IgA anti-HAV. In the first days of the disease we found HAV in the feces of 4 patients but it was never present after the sixth day. In all hepatitis A we found IgA anti-HAV in at least one fecal specimen and the titer of the antibodies increased in most cases during the course of the disease. The duration and the peak of the IgA response in the feces were strongly similar to other enterovirus infections. Some methodologic improvement both for HAV and IgA anti-HAV detection are suggested.
The serological markers of hepatitis B virus and serum alpha-fetoprotein (AFP) levels have been studied in 28 consecutive cases of fulminant hepatitis, correlating the data with survival. On admission, 20 patients were found to be positive for HBsAg and eight for anti-HBs. All anti-HBs-positive cases showed high titers of anti-HBc, and six patients were positive for specific anti-HBc-IgM. DNA polymerase activity was detected in serum of 11 HBsAg-positive (55%) and four anti-HBs-positive (50%) patients. HBeAg was detected in six (21.4%) subjects (five HBsAg-positive and one anti-HBs-positive), whereas anti-HBe was present in nine (32.1%) subjects (six HBsAg-positive and three anti-HBs-positive). AFP levels greater than 60 ng/ml were found in sera of 14 patients (50%). No significant difference was evidenced in the survival rate between HBsAg-positive and anti-HBs-positive and between HBeAg-positive and HBe Ag-negative patients. However, a statistically significant difference (P less than 0.05) in the survival rate was found in patients positive and negative for DNA polymerase activity and in those with AFP levels higher and lower than 60 ng/ml (P less than 0.005). Pathogenetic and prognostic significance of these findings are discussed.
Sera from 28 HBsAg chronic carriers were tested for the presence of HBeAg, anti-HBe and Dane particle-associated DNA-polymerase activity, in order to evaluate the relationship between the presence of these markers and the spread of HBV infection in their family contacts. A highly significant prevalence of HBV infection was observed in the relatives of HBsAg carriers who were positive for either HBeAg or DNA-polymerase activity or both. These observations support the inference of a striking correlation between the presence of these markers and the infectivity of HBsAg carriers. Therefore, serological determination of HBeAg and DNA-polymerase activity may be considered in the epidemiological control of HBV infection