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T Santantonio

Publications and source records attributed to T Santantonio.

At least 55 records · Page 3Linked to original sources
PubMed1993

Increased frequency of CD8+ CD45R0+ memory T lymphocytes in acute hepatitis B virus infection.

CD8+ lymphocytes of the memory subset (= CD45R0+) encompass antigen-specific effector cells, which are believed to be decisive for virus elimination in several viral infections. To determine whether this can be extended to HBV infection naive and memory T cells were studied among CD(4+)- and CD(8+)-lymphocytes and used monoclonal antibodies in two-color flow cytometric analysis to quantitate functional T cell subsets in peripheral blood of patients with acute hepatitis B (n = 11), chronic hepatitis B (n = 24) and healthy individuals (n = 26). Compared to CD4+ populations of healthy individuals the number of total CD4+ lymphocytes in patients with both acute or chronic hepatitis was significantly reduced. In contrast CD8+ cells did not significantly change in either acute and chronic hepatitis. Analysis of naive and memory subsets demonstrated, however, a significant rise in CD45R0+ memory cells from 5 to 15% (70% of all CD8+ cells) in acute hepatitis. These changes within the CD8+ population were, however, restricted to the acute phase of hepatitis in that the frequency of CD8+CD45R0+ decreased within weeks post infection. Furthermore, patients with chronic hepatitis did exhibit normal values of CD8+ memory cells (30% of all CD8+ cells). These findings suggest that enrichment of CD8+CD45R0+ memory cells reflects an accumulation of functional effector cells, which may be specifically activated by viral antigens and determine the outcome of infection.

Acute Disease↗
PubMed1993

Neutralizing antibodies to recombinant alpha-interferon and response to therapy in chronic hepatitis C virus infection.

Forty-seven patients with chronic hepatitis C were treated with recombinant interferon alpha-2a (rIFN alpha 2a) given subcutaneously in a standard dose of 3 MU thrice weekly for 12 months. Stored baseline sera and monthly samples during treatment were assayed for anti-interferon neutralizing antibodies using the antiviral neutralization bioassay against 5 IU of rIFN alpha 2a. During therapy, 15 of 47 patients (31.9%) developed detectable levels of neutralizing antibodies within 2-8 months after starting treatment. After 12 months of therapy, 26 of 32 antibody-negative patients (81.3%) showed normalization or marked reduction of ALT levels compared to 4 of 15 (26.6%) who developed anti-IFN neutralizing antibodies (p = 0.0009). Four patients demonstrated antiviral response during treatment even in the presence of low levels or late occurrence of neutralizing antibodies. Six of the seven patients who had disease reactivation after an initial response developed high titers of neutralizing antibodies. Our results suggest that reactivation of chronic hepatitis C before completion of therapy seems to be an obvious consequence of anti-IFN neutralizing antibody formation.

Alanine Transaminase↗
PubMed1992

Development of antibody to hepatitis C virus (HCV) in acute and chronic non-A, non-B post-transfusion hepatitis.

The antibody to hepatitis C virus (anti-HCV) was measured by an immunoassay in 507 serum samples from 94 patients with acute and chronic post-transfusion non-A, non-B hepatitis (NANB) and in 436 healthy blood donors. Anti-HCV was found in 70.8 of patients with acute hepatitis, in 78.2 with chronic hepatitis, and in 1.4 of healthy blood donors. In acute hepatitis, anti-HCV appeared in the serum from 4 to 34 weeks after transfusion and from 1 to 30 weeks after the onset of the overt disease. Three patients with resolving hepatitis (21%) and 2 who developed chronic hepatitis (10%) lost anti-HCV during a mean follow-up period of 28 months. Among the 36 patients with chronic hepatitis, 2 (6%) lost anti-HCV after 12 months and 8 years respectively. These data indicate that in recent years HCV has been the major etiologic agent of acute and chronic transfusion-associated hepatitis (TAH) in our geographical area. The late appearance of anti-HCV from the onset of clinical and biochemical signs of acute hepatitis in more than 70% of patients limits the diagnostic utility of this assay for an earlier serological diagnosis of acute NANB hepatitis. Additional studies are required to determine the diagnostic significance of this antibody in chronic NANB hepatitis.

Adult↗
PubMed1992

Hepatitis B virus genomes that cannot synthesize pre-S2 proteins occur frequently and as dominant virus populations in chronic carriers in Italy.

The heterogeneity of hepatitis B virus (HBV) pre-S sequences coding for envelope proteins was tested by DNA amplification and direct sequencing of viral genomes from sera of 22 unselected chronic carriers resident in Southern Italy. The sequences of the dominant viral genome populations from 15 carriers were very similar to known published "wildtype" HBV genomes and showed no deletions. In contrast, in the HBV populations of six patients, deletions in the pre-S region, mainly clustered at the amino terminal end of the pre-S2 region, were found. Four of these mutant genome populations and those from another patient cannot express pre-S2 proteins due to deletions or a mutation of the translation initiation codon. Emergence of the pre-S mutant viruses either during the natural course of infection or after interferon treatment was found in follow-up sera of one and two patients, respectively. These data indicate a high prevalence of pre-S mutant viruses which cannot express pre-S2 and normal-size pre-S1 proteins. This has important implications for the usefulness of diagnostic pre-S protein assays and possibly for interferon treatment and the efficacy of new vaccines containing pre-S proteins.

Amino Acid Sequence↗
PubMed1992

Anti-HBe-positive chronic hepatitis B with HBV-DNA in the serum response to a 6-month course of lymphoblastoid interferon.

Eighteen heterosexual HBsAg carriers with anti-HBe- and HBV-DNA-positive chronic hepatitis B (CHB) were randomly assigned to receive human lymphoblastoid interferon (ly-IFN) at a dose of 5 MU/m2 i.m. three times a week for 6 months (ten cases) or no treatment (eight cases). All patients were followed for 24 months after IFN discontinuation and received a second liver biopsy. During the 6 months of treatment all patients had a progressive reduction of serum HBV-DNA levels, and at the end of therapy nine out of ten were HBV-DNA-negative and had normal ALT values. None of the untreated patients became persistently HBV-DNA-negative or showed significant variations of ALT levels. During the post-treatment follow-up, from 1 to 17 months after ly-IFN discontinuation, eight of the nine responders (89%) had recurrent or persistent reappearance of HBV-DNA in the serum and reactivation of the liver disease activity, with an ALT peak in four of them. On the post-trial liver biopsy seven of the eight relapsed patients showed persistence of HBcAg reactivity with no significant difference in the percentage of positive cells with respect to the pre-treatment liver specimen. Histological features improved in four treated patients, worsened in one untreated case and were unchanged in the remaining patients. These results indicate that ly-IFN shows a transient antiviral effect in the therapy of anti-HBe- and HBV-DNA-positive CHB. The 6-month treatment regimen employed in this study seems insufficient for eradicating the replicating virus from the liver cells in the majority of patients and consequently does not appear to prevent HBV reactivation after IFN discontinuation.

Adult↗
PubMed1991

Lack of HBV and HDV replicative activity in HBsAg-positive intravenous drug addicts with immune deficiency due to HIV.

The effects of HIV infection on HBV and HDV replication and liver damage were evaluated by comparing the findings from 48 anti-HIV-positive HBsAg chronic carriers with those from 22 matched anti-HIV-negative subjects. The state of HBV/HDV infection was also related to the degree of immunodeficiency of the anti-HIV-positive patients. Most patients were intravenous drug addicts (IVDA) (84.2%); male homosexuals represented only a small proportion (7.1%). Serum HBV-DNA was detected more frequently in anti-HIV-negative than in anti-HIV-positive patients (50% vs. 35%) despite evidence of HDV replication in the anti-HIV-negative group (P = 0.02). Seroconversion from ongoing to inactive HBV infection occurred in 45% of anti-HIV-negative patients as well as in 23% of anti-HIV-positive patients (P = ns). The difference in severity of liver damage between the two groups was not statistically significant (P = 0.84). Furthermore, in the anti-HIV-positive subjects, HBV and/or HDV activity was detected in 63% of patients with mild immunodeficiency (CDC groups II and III with a total CD4 count greater than 400/mm3) and also in 75% of ARC-AIDS patients (CDC groups IV A-IV C) (P = ns). Severe hepatic disease occurred in subjects with CD4 counts above or below 400/mm3 (13 vs. 6, respectively). In conclusion, the data do not demonstrate that HBV or HDV infections are modified by HIV. The epidemiological background of the patients investigated and the extensive spread of hepatitis viruses in Italy before the appearance of HIV may account for the lack of relationship between HIV and HBV/HDV infections.

Adult↗
PubMed1991

Prevalence and type of pre-C HBV mutants in anti-HBe positive carriers with chronic liver disease in a highly endemic area.

The sequence variability in the pre-C region of the hepatitis B virus (HBV) genome in the serum of 42 anti-HBe antibody positive carriers with chronic hepatitis B was studied by PCR and direct sequencing to determine prevalence and type of HBV pre-C mutants in a highly endemic area. Except for one, all patients were infected with viruses containing mutations in the pre-C region which prevent precore and e-antigen (HBeAg) expression: 33 were infected predominantly or exclusively with variants containing a stop codon; two had a mixture of wild-type and a pre-C stop codon mutant virus; three had precore variants with mutations of the pre-C initiation codon and two of them an additional stop codon; four had a frameshift mutation; and one had two stop codons. One patient was infected with viruses which contained a mutation creating an amino acid exchange which should not prevent precore and HBeAg expression. These data demonstrate that in an endemic area a higher prevalence and even broader spectrum of pre-C HBV mutants are found than has been recognized previously in anti-HBe positive patients with chronic hepatitis B.

Adult↗
PubMed1991

High prevalence and heterogeneity of HBV preC mutants in anti-HBe-positive carriers with chronic liver disease in southern Italy.

In this study we have investigated the prevalence and type of preC mutants in anti-HBe/HBV-DNA-positive patients with chronic hepatitis B in an endemic area. HBV-DNA from sera of 42 anti-HBe chronic HBV carriers was amplified by PCR and the preC region was directly sequenced. With one exception, all patients tested were found to be infected with viruses containing mutations in the preC region that predictably prevent precore and e antigen expression. Thirty-one patients were infected with HBV containing a stop codon; two had a mixture of wild-type and preC stop codon mutant; three had preC mutants with mutations in the translation initiation codon and two of them an additional stop codon; four had a frameshift mutation, and one had two stop codons. One patient was infected with a virus showing a mutation creating only an amino acid exchange which could not prevent HBeAg expression. The data obtained indicate a higher prevalence and heterogeneity of preC mutants in our geographical area than recognized so far in anti-HBe-positive carriers with chronic hepatitis B.

Base Sequence↗
PubMed1991

Selection for a pre-C stop codon mutation in a hepatitis B virus variant with a pre-C initiation codon mutation during interferon treatment.

Hepatitis B virus (HBV) variants with a stop codon, a mutated translation initiation codon or other mutations in the pre-C region which prevent e-antigen expression are highly prevalent in anti-HBe chronic carriers and can be positively selected from a mixed virus infection. Our laboratories recently described pre-C variants with two pre-C mutations which prevent HBeAg expression. Here we have investigated whether there is a selective pressure for acquisition of the second pre-C mutation. By direct sequencing of amplified HBV DNA from sera of a chronic carrier taken during a 6-year follow-up, we found that genomes of a virus population virtually all had a pre-C translation initiation codon mutation and about 50% had an additional stop codon mutation. With the onset of interferon treatment, the genomes with the stop codon mutation increased to more than 95% while the frequency of the translation initiation codon mutation in all genomes remained constant. These data indicate positive selection (possibly immune-mediated and HBeAg-targeted) for a second pre-C mutation. This putative enhancement of negative translational control may be present because a pre-C translation initiation codon mutation cannot totally prevent HBeAg expression and is therefore less frequent.

Adult↗
PubMed1991

Conserved core protein sequences in hepatitis B virus infected patients without anti-HBc.

The absence of detectable anti-HBc antibodies in some hepatitis B virus (HBV) infected patients may be due to altered core-protein (HBc) sequences. To investigate this possibility we sequenced the pre-C/C-region of HBV isolated from 12 juvenile cancer patients who incurred a nosocomial infection of HBV during chemotherapy but did not develop anti-HBc antibodies or acute cytolytic episodes. The sequences demonstrated the highest sequence homology to the pre-C/C region of a previously cloned HBV genome (subtype ayw) and no deletions or striking mutations were detected. Up to 7 years after infection almost all the survivors developed low titers of anti-HBc antibodies but no clinical signs of hepatic damage. These results suggest that chemotherapy may induce a tolerance status to HBcAg, the most immunogenic HBV protein.

Base Sequence↗
PubMed1990

Hepatitis B virus clearance from serum and liver after acute hepatitis delta virus superinfection in chronic HBsAg carriers.

Clinical, virological, and histological findings in four HBsAg chronic carriers who cleared HBV markers from both serum and liver following HDV superinfection are described. The patients were long-term HBsAg carriers and all were HBV-DNA/HBeAg positive. Liver biopsy, obtained from three of the patients between 5 and 15 months prior to HDV superinfection, showed chronic persistent hepatitis in two and chronic active hepatitis in one. During the follow-up of 9-19 months, the patients completely recovered from acute delta hepatitis with termination of HBsAg carriage and regression of the histological feature of chronic liver damage. These data demonstrate that sometimes HDV is able to induce a permanent inhibition of its helper virus. HDV superinfection probably enhances the immune clearance of infected cells during the replicative phase of chronic HBV infection.

Acute Disease↗
PubMed1990

Problems in the management of chronic hepatitis B with interferon: experience in a randomized, multicentre study.

In a multicentre trial, 82 patients known to be hepatitis B e antigen and hepatitis B virus DNA positive for at least 1 year, with elevated serum alanine aminotransferase levels and chronic liver lesions on biopsy, were randomized to receive either recombinant interferon alfa-2a at a dose of 4.5 million units thrice weekly for 4 months or no treatment. At the end of therapy, viral DNA clearance and aminotransferase normalization were significantly (p less than 0.05) more frequent in treated patients than in controls. After 16 months' follow up, the difference was still significant for hepatitis B e antigen clearance and transaminase normalization. Hepatitis B virus DNA reactivation was observed during follow up in 43% of treated patients and 50% of controls. Improvements in liver inflammation were observed in patients on interferon. High pre-treatment serum aminotransferase levels, female sex and a low score for fibrosis in the initial biopsy were predictive factors significantly (p less than 0.05) associated with termination of hepatitis B virus replication in treated cases. These results indicate that interferon is effective in inducing clearance of HBV from serum and improvement of biochemical and histological parameters of liver disease. However, a more prolonged regimen of therapy may be required to obtain stable suppression of hepatitis B virus replication.

Adult↗
PubMed1988

Effects of HIV superinfection on HBV replication in a chronic HBsAg carrier with liver disease.

A case of HIV superinfection observed in an HBsAg/HBeAg-positive male homosexual with chronic persistent hepatitis is described. Soon after the appearance of clinical and serological features of acute HIV infection, a rapid fall to a normal value of ALT was noted with simultaneous recrudescence of HBV replication lasting for several months as detected by an increase of the HBV-DNA concentration in the serum. Our observations suggest that the reduction of hepatocyte necrosis and the increase in HBV replication were a consequence of impaired T cell function during acute HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Permanent inhibition of viral replication induced by low dosage of human leukocyte interferon in patients with chronic hepatitis B.

Fourteen out of 28 HBsAg/HBeAg-positive carriers with chronic persistent and active hepatitis were randomly assigned to human leukocyte interferon (a-IFN) treatment for three months. The remaining 14 patients served as controls. Each treated subject received a standard i.m. dose of 0.7-1.0 X 10(5)/kg/day reference units of a-IFN for 28 consecutive days, and then the same dose twice a week for two months. This treatment regimen was well tolerated, and no remarkable side effects were recorded. At six months the number of patients who permanently lost HBV-DNA from serum was significantly higher in the treated group (p = 0.006) than in the untreated group. These results suggest that a less expensive and well tolerated treatment regimen based on low dosage of a-IFN may be as effective in producing permanent inhibition of hepatitis B virus replication as a treatment regimen based on larger dosage.

Adult↗
PubMed1985

Serum IgA anti-hepatitis A virus as detected by enzyme-linked immunosorbent assay. Diagnostic significance in patients with acute and protracted hepatitis A.

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.

Enzyme-Linked Immunosorbent Assay↗