[Evaluation of biochemical, serological and antibiotic-sensitivity characteristics of Pseudomonas aeruginosa for epidemiological purpose].
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Biomedical subjects
Publications and source records attributed to M Crovatto.
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BACKGROUND: Several reports showed that mixed cryoglobulinemia (MC) is closely associated with hepatitis C virus (HCV) infection. Since several authors reported the efficacy of alpha-interferon in the treatment of MC, we investigated the long-term effects of this drug on clinical, hematological and virological parameters in a group of 18 patients (13 women and 5 men, mean age 56 +/- 11 years) affected by MC. METHODS: A bone marrow biopsy was performed in all patients, and a liver biopsy was obtained in those with biochemical signs of chronic liver disease. The presence of HCV-RNA in serum was assessed by detection of anti-HCV antibodies and by PCR amplification of the 5' untranslated region of HCV. All patients followed the same treatment schedule: three million units of recombinant interferon alpha-2b s.c., three times a week for 1 year. RESULTS: In 5 cases bone marrow histology showed the presence of a monoclonal lymphocytic infiltrate. Liver biopsies were performed in 13 (72%) of the patients and a chronic liver disease was found in all 13. Anti-HCV antibodies were present in 17 (95%) subjects. HCV-RNA was detected in all cases (100%) before therapy. Five (28%) patients achieved a complete response and 9 (50%) a partial response, while the others (4 cases, 22%) showed minor responses. Four patients cleared the virus and obtained a complete remission of the MC. CONCLUSIONS: HCV may be a cause of MC. The disease is associated with a high incidence of monoclonal lymphocytic infiltrate of the bone marrow. Alpha-interferon seems to be an effective agent for the treatment of MC.
METHODS: Genomic and replicative forms of HCV-RNA in B lymphocytes were detected by RT-PCR, and HCV genotyping was performed using universal and type-specific primers for the core region. Immunoglobulin gene rearrangement was detected by RT-PCR. RESULTS: The presence of genomic and replicative forms of HCV-RNA in the 5'NC region was investigated on total RNA extracted from subpopulations of PBMC. The frequency of HCV-RNA was higher in the B lymphocytes than in other PBMC. In two patients a larger sized band was present in the B lymphocytes and PMN; this band could represent either another form of HCV-RNA or a cross-reaction between cellular RNA and HCV primers. HCV-RNA detected using primers for the core region was negative in the patients examined. Immunoglobulin monoclonal gene rearrangement was present on the cDNA in all of the HCV and type II cryoglobulinemia positive samples except two; in contrast, it was absent in the HCV positive and cryoglobulinemia negative samples. The analysis of immunoglobulin monoclonal gene rearrangement on DNA showed the presence of new positive samples among the HCV positive, type II cryoglobulinemia negative patients, who had been negative when PCR was performed on cDNA. Denaturing sequencing gel showed clearer results than agarose gel. CONCLUSIONS: The early detection of immunoglobulin monoclonal gene rearrangement and expression is very important because it could provide evidence of the possible lymphoproliferative evolution of HCV infection. In addition, these investigations together with PCR product sequencing could show us the steps in the clonal selection of B lymphocytes towards malignant transformation, in which HCV plays a direct and/or indirect role.
OBJECTIVE: To evaluate the HCV genotype distribution in subjects affected by cryoglobulinemia in order to verify its possible role in the pathogenesis of the disease and to provide the clinician with a useful datum for therapy. METHODS: Nested PCR with universal and type-specific primers was used for the genotyping. RESULTS: Genotype I (1a) was never present in cryoglobulinemia, while it was present in 7 (4.3%) patients with chronic hepatopathy and in 4 (10.8%) asymptomatic patients. Type II (1b) was present in 28 (58.3%) and in 8 (47.1%) cryoglobulinemic patients with and without hepatopathy, respectively, in 106 (64.6%) patients with chronic hepatitis; in one patient with acute hepatitis; and in 14 (37.9%) asymptomatic patients. Type III (2a) was present in 2 (4.2%) and 2 (11.8%) cryoglobulinemic patients with and without hepatopathy, respectively; in 1 (0.6%) patient with chronic hepatopathy; and in 2 (5.4%) asymptomatic subjects. Type IV (2b) was present in 1 (2.1%) and in 2 (11.8%) cryoglobulinemic patients with and without hepatopathy, respectively; in 5 (3%) patients with chronic hepatopathy; and in 1 (2.7%) asymptomatic subject. Coinfections were present in 42 cases: 6 (12.5%) cryoglobulinemia with hepatopathy, 4 (23.5%) cryoglobulinemia without hepatopathy, 25 (15.3%) chronic hepatopathy, and in 7 (18.9%) asymptomatic subjects. For 41 (15.4%) strains typing was not possible. Eight of the "untypable" strains and 3 strains from patients with coinfection proved to belong to a new genotype. CONCLUSIONS: Genotype II (1b) was the most frequent in patients with and without cryoglobulinemia; genotype I (1a) was absent in all 65 patients with cryoglobulinemia, in whom, however, as in the subjects without cryoglobulinemia, all the other genotypes could be found. An interferon-resistant genotype characterized by an elevated homology with Simmonds' type 2c (rare genotype) was present.