Investigation of bacterial and viral agents and immune status in Behcet's disease patients from Iran.

AIM: Behçet's disease (BD) is an autoimmune disorder associated with HLA-B51 positivity. Serologic/genomic findings have suggested microbes as possible causative agents and the geographical distribution suggests environmental influences. METHODS: We performed comparative analyses of 40 patients with BD or related symptoms not fulfilling BD criteria. Patients originating from different regions of Iran were tested by molecular/serological methods for human herpes viruses and parvovirus B19, two Chlamydiae species, as well as Coxiella, Listeria, Yersinia, Leptospira and Mycobacterium paratuberculosis. Human leukocyte antigen-typing was performed: testing of cytokine profiles and immune mediators representative for the cellular immune system, including neopterin/kynurenine production. RESULTS: No apparent differences in interleukin (IL)-4, 6, 8 and 10 were observed, whereas production of soluble IL-2-receptor and tumor necrosis factor (TNF)-alpha were more pronounced in the BD group. Neopterin/kynurenine production was comparable, although both groups showed twice the levels of healthy people. No significant differences of herpes simplex virus (HSV) antibody titres were observed but higher titres against Chlamydophila pneumoniae were found in the controls. In 20 BD patients and controls neither parvovirus B19 DNA was detected nor bacterial DNA. Viral DNA of Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpes virus (HHV)8 was detected more frequently in the BD group, whereas HSV DNA was only found in the controls, indicating that stomatitis might be caused by HSV. CONCLUSION: Although no significant association of BD was detected with a single pathogen, our findings suggest that detection of HSV DNA or Chlamydiae would rather argue against classic BD. Whether there is a discriminative potential of the tested immune mediators/receptors has to be elucidated in further studies.

Smoking cessation counselling: impact of chart stickers and resident training.

OBJECTIVES: To assess the effect of a training program for smoking cessation combined with chart stickers on resident's (physicians-in-training) practice of counselling smoking patients. SETTING: A single centre prospective observational study at the Basel University Hospital Medical Outpatient Department. METHODS: 456 consecutive outpatients were contacted by phone within 24 hours of their initial consultation. Information concerning questions asked about smoking and/or cessation advice provided by the resident to patients was collected and compared with a historical pre-interventional cohort using the identical questionnaire and study design. RESULTS: Of 272 patients included, 106 (39%) were current smokers, 123 (45%) had never smoked, and 43 (16%) were former smokers. The mean age was 43 +/- 11 (range 16-87) years and 49% were male. Equal proportions of participants were in the pre-contemplation (40%) and contemplation stages (42%), 16% were preparing to quit and 2% had stopped in the previous 6 months. Results related to smoking cessation advice were compared to those obtained during an identical survey one year earlier performed prior to the intervention (pre-interventional). Residents questioned 82% (pre-interventional 81%) of the patients about smoking and inquired about smoking duration in 71% (pre-interventional 44%) of the patients. 46% (pre-interventional 28%) of the patients received information on smoking-related risks, whereas cessation was discussed with 32% (pre-interventional 10%) and offered to 23% (pre-interventional 9%) of the patients. CONCLUSION: Compared with a historical pre-interventional cohort, the rates of patients receiving appropriate counselling approximately doubled following the introduction of systematic training on smoking cessation and chart labels. Extended regular training for physicians on smoking-related issues may have a potentially beneficial effect in improving counselling of smokers and meeting the global tobacco challenge.

Testing for anti-p53 antibodies increases the diagnostic sensitivity of conventional tumor markers.

The aim of this study was to determine whether anti-p53 antibodies are of clinical significance as a serological marker in the diagnosis and monitoring of malignancies. A total of 1874 serum samples from 591 patients with various types of cancer, esophageal, gastric, colorectal, pancreatic, hepatocellular, breast, and urogenital cancer, and 436 control individuals were analyzed by immunoblot for antibodies against p53. The anti-p53 antibody test was correlated with expression of conventional tumor markers, survival and the clinicopathological features of malignant disease. Anti-p53 antibodies were found in 23.4% (138/591) of the sera of patients with malignant disease (range 11.5-34%). The detection of anti-p53 serum antibodies had a specificity of 100% for malignancy (p<0.0001). The overall sensitivity of measuring established tumor markers was 62.9% (372/591). The elevation of conventional tumor markers and the presence of anti-p53 antibodies in the sera of patients with malignant disease turned out to be an independent variable (p<0.05). Combination of established tumor markers with the anti-p53 antibody test led to an increase in diagnostic sensitivity of 8% (49/591) (p<0.01). Thus, the independence of anti-p53 antibodies from established tumor markers allows the serological detection of additional tumor patients. Kaplan-Meier analysis revealed a trend toward a poorer prognosis in hepatocellular carcinoma and breast cancer patients who were anti-p53 serum positive. In conclusion, testing for anti-p53 antibodies can increase the diagnostic sensitivity when used in combination with measurement of conventional tumor markers. This increase is achieved without a parallel decrease in specificity.

Factor I-mediated processing of complement fragments on HIV immune complexes targets HIV to CR2-expressing B cells and facilitates B cell-mediated transmission of opsonized HIV to T cells.

Our study demonstrates that binding of complement-opsonized HIV to complement receptor type 1 on human erythrocytes (E) via C3b fragments is followed by a rapid normal human serum-mediated detachment of HIV from E. The release was dependent on the presence of factor I indicating a conversion of C3b fragments to iC3b and C3d on the viral surface. This in turn resulted in an efficient binding of opsonized HIV to CR2-expressing B cells, thus facilitating B cell-mediated transmission of HIV to T cells. These data provide a new dynamic view of complement opsonization of HIV, suggesting that association of virus with E might be a transient phenomenon and the factor I-mediated processing of C3b to iC3b and C3d on HIV targets the virus to complement receptor type 2-expressing cells. Thus, factor I in concert with CR1 on E and factor H in serum due to their cofactor activity are likely to be important contributors for the generation of C3d-opsonized infectious HIV reservoirs on follicular dendritic cells and/or B cells in HIV-infected individuals.

C-type lectin-independent interaction of complement opsonized HIV with monocyte-derived dendritic cells.

HIV directly activates the complement cascade and is, therefore, opsonized with C3-cleavage products in vivo. This cloud of C3 fragments on the viral surface may impair the interaction of the HIV envelope glycoproteins gp120/gp41 with C-type lectins expressed on immature dendritic cells (iDC). Therefore, we determined the accessibility of gp120 after opsonization and compared the interaction of DC with non-opsonized or complement-opsonized HIV. The recognition of native gp120 was drastically impaired when the virus was covered by complement. Independent of opsonization, similar amounts of HIV bound to DC. The interaction of iDC and the infection of DC-PBL co-cultures with non-opsonized virus was significantly reduced by mannan and antibodies which inhibit the ICAM-1-CR3 interaction. The binding of opsonized virus to iDC was reduced by an anti-CR3-antibody, which interferes with the binding of C3 fragments, but was not affected by mannan. Complement enhanced the HIV infection of DC and DC-PBL co-cultures significantly. Mannan did not inhibit the complement-dependent enhancement of infection. Thus, non-opsonized and opsonized HIV interacted with iDC, although the binding mechanisms seemed to differ. As HIV is opsonized in vivo, the C-type lectin-independent interaction of opsonized viruses with iDC has to be taken into account.

Two human ULBP/RAET1 molecules with transmembrane regions are ligands for NKG2D.

We characterized two novel members of the RAET1/ULBP gene cluster, RAET1E and RAET1G. The encoded proteins were similar to the ULBP in their class I-like alpha1 and alpha2 domains, but differed in that, instead of being GPI-anchored, their sequences were type 1 membrane-spanning molecules. Both proteins were capable of being expressed at the cell surface. Both proteins bound the activating receptor NKG2D, and RAET1G bound the human CMV protein UL16. The expression of diverse NKG2D-binding molecules in different tissues and with different properties is consistent with multiple modes of infection- or stress-induced activation.

Low tetrahydrobiopterin biosynthetic capacity of human monocytes is caused by exon skipping in 6-pyruvoyl tetrahydropterin synthase.

Biosynthesis of (6 R )-5,6,7,8-tetrahydro-L-biopterin (H(4)-biopterin), an essential cofactor for aromatic amino acid hydroxylases and NO synthases, is effectively induced by cytokines in most of the cell types. However, human monocytes/macrophages form only a little H(4)-biopterin, but release neopterin/7,8-dihydroneopterin instead. Whereas 6-pyruvoyl tetrahydropterin synthase (PTPS) activity, the second enzyme of H(4)-biopterin biosynthesis, is hardly detectable in these cells, PTPS mRNA levels were comparable with those of cell types containing intact PTPS activity. By screening a THP-1 cDNA library, we identified clones encoding the entire open reading frame (642 bp) as well as clones lacking the 23 bp exon 3, which results in a premature stop codon. Quantification of the two mRNA species in different cell types (blood-derived cells, fibroblasts and endothelial cells) and cell lines showed that the amount of exon-3-containing mRNA is correlated closely to PTPS activity. The ratio of exon-3-containing to exon-3-lacking PTPS mRNA is not affected by differential mRNA stability or nonsense-mediated mRNA decay. THP-1 cells transduced with wild-type PTPS cDNA produced H(4)-biopterin levels and expressed PTPS activities and protein amounts comparable with those of fibroblasts. We therefore conclude that exon 3 skipping in transcription rather than post-transcriptional mechanisms is a major cause of the low PTPS protein expression observed in human macrophages and related cell types.