Japanese encephalitis virus RNA detected in Culex pipiens mosquitoes in Italy.

Mosquitoes collected in northern Italy were screened for flavivirus RNA. Positive amplicons were sequenced and found most similar to insect flavivirus (ISF), Usutu virus (USUV) and surprisingly also to Japanese encephalitis virus (JEV). The sequence (167 bp), obtained from one pool of Culex pipiens, was found identical to JEV strains from bats in China. Unfortunately additional sequence data or virus isolations were not obtained in this study. Confirmation of potential introduction of JEV to Italy and other European countries is urgently needed.

Prevalence and clinical relevance of occult hepatitis B virus infection in patients on the waiting list for kidney transplantation.

BACKGROUND: Occult hepatitis B virus (HBV) infection can be defined as the long-lasting persistence of viral genomes in the liver tissue, and sometimes also in the serum at low levels of viremia in individuals with undetectable HBV surface antigen (HBsAg). Viral replication can be reactivated by immunosuppressive therapies or immunologic diseases, leading to the development of typical hepatitis B. METHODS: All patients on the waiting list for renal transplantation at the only 2 transplant centers in our region (Piemonte, Italy) were checked for the presence of occult HBV infection by an highly sensitive quantitative HBV-DNA polymerase chain reaction (PCR) assay (nested PCR); the only exclusion criterion was HBsAg-positivity. The enrollment lasted from October 1, 2006, to May 31, 2007. The prospective follow-up will continue for 5 years. RESULTS: HBV-DNA sequences were detected in blood samples from 10 of 300 cases examined (3.3%), being more frequent among Asian (1/3; 33.3%) and African (1/16; 6.25%) subjects as compared with the Caucasians (8/281; 2.8%; P = .011), among anti-hepatitis C virus (HCV) positive versus HCV negative patients (3/32 [9.3%] vs 7/268 [2.6%]; P = .004) and mainly among patients with a previous history of overt liver diseases (3/22 [14%] vs 7/278 [2.5%]; P = .019). HBV-DNA sequences became undetectable at 1 month after renal transplantation in 3 patients; the follow-up is in progress for these and the other patients. CONCLUSION: Occult HBV infection occurs in patients undergoing renal transplantation. Longer observation and prospective studies will clarify the clinical impact of this occult infection on transplant outcomes and the possibility of viral reactivation related to immunosuppressive therapy.

Unsuspected strongyloidiasis in hospitalised elderly patients with and without eosinophilia.

The prevalence and associated factors of chronic uncomplicated strongyloidiasis were estimated among 200 consecutive elderly patients (aged >or= 60 years) admitted to a general hospital in northern Italy. One-hundred patients had a peripheral eosinophil concentration >or= 500 cells/microL (group A), and 100 were age- and gender-matched controls (group B). Measurements included serum IgG anti-Strongyloides antibody titre by an indirect immunofluorescence assay, combined with faecal culture for Strongyloides stercoralis. Anti-Strongyloides antibodies were detected in 28 patients (at high titre in 11 patients). Seropositivity was significantly more common among group A than among group B patients (OR 4.85). Strong seropositivity for anti-Strongyloides antibodies was associated with farm work (p < 0.001), but not with other patient characteristics or with signs and symptoms of strongyloidiasis. In conclusion, strongyloidiasis was relatively common among elderly in-patients; eosinophilia and a history of farm work were the most useful indications for this diagnosis.

Response to sequential treatment with lymphoblastoid interferon-alpha in patients with Ph+ chronic myeloid leukemia unresponsive to recombinant interferon-alpha (rIFN alpha 2a) and neutralizing-rIFN alpha 2a antibodies negative.

Nine Ph+ CML patients in chronic phase who were hematologically and/or karyotypically unresponsive to recombinant-IFN alpha 2a (rIFN alpha 2a) and neutralizing-rIFN alpha 2a Abs negative were shifted from rIFN alpha 2a to lymphoblastoid-IFN alpha (IFN alpha-Ly) therapy. After 3 months of IFNa-Ly treatment, the hematologic response was reinduced in 3 out of the 6 pts who were resistant to previous rIFN alpha 2a therapy, and was maintained in 2 out of 3 patients who were hematologically but not karyotypically responsive to rIFN alpha 2a. After 6 and 12 months, the hematologic response was progressively lost, being present only in 3 out of 7 and in 2 out of 3 evaluable patients respectively. None of the hematologically responsive patients achieved a karyotypic response (Ph neg. metaphases-0%). One patient, who was hematologically responsive, continued being treated with IFN alpha-ly for 36 months but he did not achieve any karyotypic response. The results of this study suggest that in the unresponsive and neutralizing-rIFN alpha 2a Abs negative CML patients a change in therapy, by using a non cross-reactive type of IFN alpha, would not be advantageous.

Neutralizing anti-interferon-alpha antibodies and response to treatment in patients with Ph+ chronic myeloid leukaemia sequentially treated with recombinant (alpha 2a) and lymphoblastoid interferon-alpha.

Neutralizing anti-IFN alpha antibodies (nIFN alpha Abs) occur in a significant proportion of patients with hairy cell leukaemia, hepatitis or solid tumours treated with recombinant IFN alpha (IFN alpha 2a or IFN alpha 2b), but information on their incidence in chronic myeloid leukaemia (CML) is scanty and their clinical relevance is not yet completely defined. By using an IFN alpha antiviral neutralization bioassay, the frequency of nIFN alpha 2a Abs was evaluated in 67Ph+ CML patients during IFN alpha 2a therapy at doses ranging from 6 to 9 MU/d. 15 patients (22%) developed nIFN alpha 2a Abs (titre ranging from 1:40 to 1:20480) and 11/15 (73%) were haematologically and/or karyotypically unresponsive to treatment. 52 patients did not develop antibodies and 11 of them (21%) were unresponsive. The negative relationship between the positivity for nIFN alpha 2a Abs and the response to treatment was highly significant (P = 0.0001). In nine nIFN alpha 2a Abs positive patients, treatment was changed from recombinant IFN alpha 2a to lymphoblastoid IFN alpha (IFN alpha-ly), at the same dose and schedule. After 9 months of IFN alpha-ly treatment a haematological response was achieved in 4/7 cases who were non-responsive to prior IFN alpha 2a therapy and was maintained in the other two patients previously responsive to IFN alpha 2a. However, no karyotypic response was observed. This data shows that a significant proportion of Ph+ CML patients receiving treatment with IFN alpha 2a can develop neutralizing antibodies and that these antibodies are associated with a loss of IFN alpha 2a efficacy. Changing the patients to treatment with lymphoblastoid IFN alpha may restore haematological response but it is not likely to induce a karyotypic response.

Role of structural and extracellular virulence factors in gram-negative anaerobic bacteria.

Gram-negative anaerobic bacteria belonging to the genera Bacteroides, Prevotella, and Porphyromonas represent the most common cause of endogenous, usually mixed, infections occurring after abdominal or gynecologic surgery. Anaerobes are important pathogens in oral-cavity infections as well as in systemic infections that originate from the mouth. Clinical interest in these organisms is linked to the therapeutic problems usually encountered in treating mixed infections. Despite their clinical relevance, very little is known about the pathogenetic mechanism of anaerobic infections. In Bacteroides species, the capsule has been thought to be important, and initially it was considered unique to Bacteroides fragilis, the most common pathogen. It has been claimed that the capsule is involved in adhesion, abscess formation, and impaired phagocytosis. However, other structures such as pili and extracellular substances, including metabolic by-products (e.g., short-chain fatty acids), have to be considered as potentially relevant pathogenetic mechanisms in anaerobic infections. Several extracellular enzymes have been investigated, but no clear evidence is available for establishing their relevance in disease mechanisms. Special attention should be devoted to enzymes able to digest IgA (IgA proteases), a first-line defense mechanism that is active in the mucosal membranes.

Cytolocation of prosome antigens on intermediate filament subnetworks of cytokeratin, vimentin and desmin type.

Analysis by double-label indirect immunofluorescence of PtK1 and HeLa cells had previously demonstrated that prosome* antigens form networks that superimpose on those of the intermediate filaments of the cytokeratin type. We show here that in PtK1 cells various prosomal antigens also reside to a variable extent on intermediate filaments subnetworks of the vimentin type. In proliferating human fibroblasts the prosome and vimentin networks were found to coincide, while in proliferating myoblasts of the C2.7 mouse myogenic cell line the prosomal antigens seem to superimpose on the intermediate filaments of the desmin type. Thus, the prosomes, which are RNP particles of variable composition and subcomplexes of untranslated mRNP, and carry a multicatalytic proteinase activity, seem to co-localize with the specific kind of cytoplasmic intermediate filament in relation to the cell type. These results, which generalize the previous data, are discussed in view of possible role(s) for prosomes in mRNA metabolism and/or intermediate filaments remodelling.

Evaluation of an automated system for identification of anaerobic bacteria.

A fully automated computer-assisted system (ATB system, bioMérieux, France) which uses disposable microenzymatic panels was evaluated for its ability to identify 215 strains of anaerobic bacteria (clinical isolates and reference strains). All strains were examined using conventional identification protocols and by gas chromatographic analysis of short-chain fatty acids. Automated reading of Rapid ID32A test kits (bioMérieux, France) by the ATB system gave correct identification for 195 strains (90.7%): 92.25% of gram-negative anaerobes (116 strains) and 89% of gram-positive anaerobes (99 strains) were correctly identified. Twelve strains (5.6%) were incorrectly identified and 8 strains (3.7%) were not identified by the system. For some strains in the Bacteroides fragilis group, for Clostridium difficile and for the Fusobacterium genus, additional tests suggested by the ATB software were necessary to reach a final identification at the species or genus level. On the basis of the high incidence of correct identifications and the comparison of these results with those obtained previously using other commercially available kits, the ATB system was found to be a reliable method for identification of anaerobic bacteria in clinical laboratories.

Patterns of cytodistribution of prosomal antigens on the vimentin and cytokeratin networks of monkey kidney cells.

Prosomes were found as mRNA-associated ribonucleoprotein particles (RNP) and cofactors of untranslated (ribosome-) free mRNP. Previous data have shown the presence of prosomal networks in the cytoplasm of PtK1 and HeLa cells and their superposition onto the intermediate filaments (IF) of cytokeratin type but little if any of vimentin type. Here it is shown that in LLC-MK2 cells various prosomal antigens are present on both, vimentin and cytokeratin networks, individual prosomal antigens superposing to variable degrees onto the IF subnetworks. Some prosomal antigens in variable relative concentrations were also observed in the nuclei of these cells. We suggest the existence of prosomal subnetworks specific for each prosomal antigen superposing to a variable extent onto the IF of both types.

Evaluation of some immunological parameters in interstitial lung disease by discriminant analysis.

In 37 subjects affected by interstitial lung diseases (19 patients with pulmonary sarcoidosis, 11 with hypersensitivity pneumonitis, 7 with idiopathic pulmonary fibrosis), we have compared by discriminant analysis (Statistical Package for the Social Sciences, version 8.3) 17 biological parameters derived from bronchoalveolar lavage analysis, gallium-67 scanning and lung biopsy. The aim of the study was to analyze the parameters of these three groups by forming one or more linear combinations of the discriminant variables. In particular, we tried to define the ability of such parameters to define these interstitial lung diseases and the relative importance of the data examined. The functions obtained are highly discriminant, so that the three groups are well distinguished among themselves; it means that the variables employed discriminate among the diseases studied. Among the variables considered, differential cell count, immune complex determination, gallium-67 lung scanning have the most important discriminant capacity. Discriminant analysis emphasizes that the three diseases are mediated by different immune mechanisms and underlines the role of each mechanism in determining the disease.