Chemotaxis: basic aspects of methodology, mechanisms and pathology.

This review is an attempt to discuss the basic conceptual tools that are a prerequisite for any clinical study of chemotactic defects. They include familiarity with definitions of common terms and with the merits and drawbacks of the several possible in vivo and in vitro assay methods. Cellular mechanisms involved in locomotion are complex. They include basic requirements for cell metabolism as well as receptor recognition, attachment to surfaces and contraction of the cytoskeleton of the cell. Of the many chemotactic factors reported, few are well characterized and universally agreed upon. Similarly, with the use of more stringent criteria, a number of clinical defects of chemotaxis have proven transitory or even artifactual.

Effect of amoxycillin and doxycycline on function of human granulocytes tested in vitro and on chemotaxis of granulocytes from rabbits given the two antibiotics.

The effect of amoxycillin and doxycycline on human granulocyte function was studied in vitro. The antimicrobial agents were added to tests of chemotaxis, random motility, yeast phagocytosis, and killing, at progressing concentrations. The effect was also evaluated in vivo by measuring chemotaxis and random motility (agarose technique) of granulocytes from rabbits injected with these antibiotics. Amoxycillin was shown to have a slightly stimulating effect on chemotaxis, demonstrable only at the highest concentration tested (100 micrograms/ml), and no effect on the other variables. Doxycycline had a dose-related inhibitory effect on chemotaxis, random motility, and phagocytosis, and no effect on killing. Chemotaxis and random motility were slightly, but not significantly, stimulated in vivo when rabbits were given amoxycillin. Chemotaxis (but not random motility) was significantly impaired when the rabbits were given doxycycline.

Evaluation of a new semiquantitative immunodot assay for the screening of specific IgE.

The Immunodot CMG is a new, simple assay for the semiquantitative screening of specific IgE. It does not necessitate any particular equipment. It consists of two nitrocellulose strips on which either five indoor or five outdoor allergens are bound. In the present evaluation, 82 serum samples from allergic patients were tested with the first strip and 101 with the second. The results were compared with those obtained with the CAP System (Kabi Pharmacia). A version using undiluted serum and a short incubation time (short version) appeared to be more sensitive than a long version using serum diluted 1:5. In most cases, the results agreed with those of the CAP System. Discordant results were found in 2-9% of the cases according to the allergen, and were most often negative with Immunodot CMG and positive with the CAP System, indicating a slightly lower sensitivity for the new test. When compared to the CAP System, the Immunodot CMG showed a sensitivity of 84.5% and a specificity of 94%. Readings were found to be reproducible and easy to perform with the naked eye. Our results showed that the Immunodot CMG test is comparable to the CAP System, which is slightly more sensitive but requires much more elaborate and expensive equipment.

[Hepatitis B virus and pathogenesis]. / Hepatitis-B-Virus und Pathogenese.

The hepatitis B virus belongs to the hepadna viruses family. Its genome consists of an incompletely double stranded DNA. The preS/S domain encodes proteins which make up the outer viral coat containing the HBs surface antigen (HBsAg). Other viral genes programme for structures inside the virus and for various regulatory enzymes. HBV mainly infects hepatocytes. The virus replicates in the cytoplasm and is primarily non-cytopathogenic. HBV can also integrate into the host cell. Various stable genotypes and subtypes are known, which have a characteristic geographic distribution. They all share a common HBsAg epitop, which has allowed the development of a vaccine which is efficient world-wide. The protective principle consists of inducing protective anti-HBs. The infected cell has to be destroyed to eliminate the virus. Cellular immune defence mechanisms are mainly relevant, the principle effectors being cytotoxic T lymphocytes, activated monocytes/macrophages and cytokines such as interferon-gamma. The natural course of infection is highly variable, comprising viral elimination with or without acute hepatitis and chronic infection which might lead to chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. This is due to the balance respectively to the inbalance between the viral replication capacity and the immune defence mechanisms.

[Serologic diagnosis and follow-up of hepatitis B]. / Serologische Diagnose und Verlaufsbeurteilung der Hepatitis B.

This paper is a short summary on the usefulness of two antigens (HBsAg and HBeAg), three antibodies (anti-HBc, anti-HBe and anti-HBs) and of HBV DNA, as markers for the diagnosis and the follow-up of hepatitis B. The significance of each of these markers at the various stages of disease history, a few patterns of co-existence of some of these markers and the occurrence of mutations in the core and pre-core regions of the genome are also described. The various indications for measuring HBV DNA, in addition to the classical serological markers, are also mentioned.

[Immune mechanisms in hepatitis B. New aspects and consequent practices]. / Mécanismes immunitaires dans l'hépatite B. Aspects nouveaux et conséquences pratiques

The different types of immune responses occurring during hepatitis B virus infection are reviewed. The responses specific for HBsAg (hepatitis B surface antigen) are important in the pathogenesis of chronic liver disease. The cell-mediated immunity specific for this antigen seems to be responsible for cytolysis occurring when the antigen is located within the hepatocyte (acute and persistent hepatitis). It is also responsible for the subsequent elimination of the virus. Immune complexes in antibody excess probably provoke the lesion of fulminant hepatitis. Complexes in the zone of antigen excess, which are responsible for the extrahepatic lesions of the prodromic phase, may perhaps also play a pathogenetic role in some forms of chronic active hepatitis.

[Virus-host relations in hepatitis infections]. / Virus-Wirts-Beziehungen bei Hepatitisinfektionen.

The hepatitis infections can rather be characterized by an intensive pathogenetic contribution of the most than by a lytic effect of the causative organism, as it is the case for instance in the lymphocytic choriomeningitis of the mouse and perhaps in the chronic polyarthritis.

Long-term evaluation of usefulness of skin and incremental challenge tests in patients with history of adverse reaction to local anesthetics.

A variety of adverse reactions to local anesthetics has been described, some of which are thought to be allergic. Different protocols of prick and intradermal skin tests as well as subcutaneous challenge tests are used to select a local anesthetic which can safely be used. Their long-term effectiveness has not yet been assessed. Twenty-eight patients with a history of adverse reaction to local anesthetics were evaluated over a 3-year period. Loss of consciousness occurred in eight patients, skin reaction in nine, and vagal symptoms in eight. Various reactions were recorded in the remaining three patients. Rapid spontaneous recovery was the rule, suggesting that immediate allergic reaction and, in particular, anaphylactic reaction were unlikely. Investigation allowed the selection of a tolerated anesthetic in all cases. Reexposure occurred in 19 patients 16-50 months after evaluation and 6.8 +/- 5.5 years after the first reaction. No patient presented a second reaction. In conclusion, adverse reactions to local anesthetics seem to be, in most cases, not allergic in nature. Evaluation protocols are effective in selecting an agent susceptible to tolerance, but are time consuming. However, they probably contribute to an important reassurance effect that is likely to increase tolerance to subsequent local anesthetic administration. Simplification of the protocols and better patient selection are proposed.

[Retrospective study of 149 cases of hepatitis B virus infections. Study of markers and of evolution]. / Etude rétrospective de 149 cas d'infection par le virus de l'hépatite B. Etude des marqueurs et de l'évolution.

A retrospective study has been performed in 149 subjects with present or past HBs antigenemia. The group consisted of 8 asymptomatic carriers, 90 with acute hepatitis, 7 with fulminating hepatitis, 27 with chronic hepatitis, 16 with cirrhosis and 1 with hepatoma. The changes from one clinical condition to another, the sources of infection, the percentage of acute hepatitis in the history of chronic hepatitis cases and the working capacity an average of two years after the infection were studied. HBe antigen and the corresponding antibody were detected by immunodiffusion and the results compared with the clinical course.

Influence of (+)-cyanidanol-3 on the leukocyte migration inhibition test carried out in the presence of purified protein derivative and hepatitis B surface antigen.

It has been shown that (+)-cyanidanol-3, therapeutically administered during the course of acute hepatitis B, is able to favor the elimination of hepatitis B surface antigen (HBsAg) from the blood. This observation suggests that (+)-cyanidanol-3 might stimulate the cell-mediated immune response, since it is known that this type of response is responsible for elimination of the virus. In the present study, the possible action of (+)-cyanidanol-3 on this type of immunity was investigated by adding the substance in vitro to leukocyte migration inhibition tests, performed with the antigens purified protein derivative (PPD) and HBsAg and with leukocytes from individuals sensitized to these antigens. In normal individuals sensitized to PPD, the addition of (+)-cyanidanol-3 amplified the inhibition of migration by 7.0% (P less than 0.05). In patients previously infected by hepatitis B virus and sensitized to HBsAg, the addition of (+)-cyanidanol-3 amplified the migration inhibition by 10.5% (P less than 0.05). A trend to a dose-response relation was observed with the antigen PPD. (+)-Cyanidanol-3 did not modify leukocyte migration in the absence of an antigen. (+)-Cyanidanol-3 therefore seems capable of amplifying the cell-mediated immune response as measured by the leukocyte migration inhibition test. It is thus possible that it favors the elimination of HBsAg in patients by this mechanism.

Characterization of antibodies reacting with HIV gag proteins occasionally found in the serum of non-infected subjects.

The use of serological tests for the diagnosis of HIV infection has revealed that some non-infected persons have antibodies that react with HIV-1 gag proteins. Here, the sera of three non-infected subjects reacting with p17 and 11 non-infected subjects reacting with p24 were investigated, using an enzyme immunoassay (EIA) with six recombinant gag antigens and Western blot analysis of proteolytic peptides of two of these gag antigens. The results indicate that whereas all p17-reactive sera could react with an unique epitope, individual p24-reactive sera recognize different epitopes. Investigations by EIA also demonstrated the role of sequences located far from the epitopes in making these epitopes accessible to the antibodies or in providing them with an antigenic conformation. In addition to the 14 subjects mentioned above, another subject was shown to have antibodies reacting with the p9 (NC) gag protein. Several proteins are known as having homology with HIV-1 gag proteins. Their possible role in eliciting cross-reactive antibodies is discussed.

Biophysical properties and morphology of purified antigen associated with non-A, non-B hepatitis.

The antigen from a non-A, non-B antigen-antibody system previously described was purified and, when tested by immunodiffusion, was shown to produce patterns of identity with all antigen-positive sera of the system. The sedimentation coefficient S20,w of the antigen was estimated by rate zonal ultracentrifugation to be 48. Isopycnic ultracentrifugation in CsCl gradient of non-A, non-B antigen generated a single sedimentation peak at the density of 1.28. SDS-polyacrylamide-agarose gel electrophoresis showed that I125-labelled antigen migrated as a single band (molecular weight 3.0 X 10(6)); in addition, labelled material also migrated to the albumin region. With SDS-PAGE under reducing conditions, the antigen was shown to consist of seven polypeptides. Spherical particles of 23 nm in diameter, demonstrated by electron microscopy, could be aggregated by purified non-A, non-B antibody. They probably represent the antigen and not a complete viral particle. The characteristics of this antigen associated with non-A, non-B hepatitis appear therefore to be close to those of hepatitis B surface antigen.

Presence of low levels of anti-HBs antibody in so-called 'anti-HBc alone' subjects.

BACKGROUND/AIMS: The 'anti-Hbc alone' pattern could sometimes be that of subjects who produced anti-HBs after recovery, but at a lower level than that detectable using commercial assays. This study aimed to test this hypothesis. METHODS: A total of 104 'anti-HBc alone' serum samples, i.e.positive for the anti-HBc antibody but not for HBsAg nor for anti-HBs antibody, were recruited when routine testing a broad population of employees, patients and pregnant women from a university hospital. A possible subliminal anti-HBs production, that would have escaped detection by commercial EIAs, was investigated by comparing the optical densities (ODs) obtained in vaccinees (commercial anti-HBs EIA) to those of a control group of 100 nonimmunised and nonvaccinated subjects. RESULTS: The median OD was significantly higher (p<0.0001) in the 'anti-HBc alone' subjects (OD=0.035) than in the controls (OD=0.023). Thirty-six percent of the 'anti-HBc alone' subjects had an anti-HBs OD higher than the median OD of the controls+2SD. 'Anti-HBc alone' subjects with anti-HBe antibody had higher anti-HBs ODs (0.041) than had those without anti-HBe (0.029). In 'anti-HBc alone' subjects, the anti-HBs ODs, although under the cut-off value of the EIA, were found to be higher than in the controls. CONCLUSION: Our results show low anti-HBs production in some of the subjects studied.

Demonstration of a single antigen-antibody system in 26 patients with non-A, non-B viral hepatitis.

26 patients with viral hepatitis were selected on the basis of negative responses to serological tests for hepatitis B virus and hepatitis A virus infections. The illness was acute in 19 patients and chronic persistent in the remaining 7. Immunodiffusion tests showed a single antigen-antibody system in the sera of all 26 patients. Each patient had at least one serum sample positive for antigen or antibody. In 1 post-transfusion case, the corresponding immunological marker was found in the donor. This system was considered specific for the disease, since the markers could not be detected in sera from patients with other liver conditions or immune complex diseases, or in sera from healthy blood donors without a history of hepatitis. The antigen could be separated from contaminating serum proteins. The purified preparation showed immunological identity with all our antigen-containing sera and with samples of a study already published. These results suggest the existence of an antigen associated with non-A, non-B, viral hepatitis and probably related to an infectious agent responsible for all the cases in this study.

Identification of monoclonal gammopathies: a comparison of immunofixation, immunoelectrophoresis and measurements of kappa- and lambda-immunoglobulin levels.

We study whether immunoelectrophoresis (IE) could be replaced by immunofixation (IF) for the routine diagnosis of monoclonal gammopathies and/or by a quantitative measurement of kappa-resp. lambda-Ig levels in serum. The values of these measurements, together with the level of each Ig class, were used to calculate two ratios. IF, IE and calculation of both ratios were simultaneously applied to 153 serum samples. A monoclonal gammopathy (MGP) was found with all three methods in 51 cases and by none of them in another 51 cases. The first two techniques were positive and the third one negative in 16 cases. In 15 cases, IF showed the presence of a MGP, which was not or incompletely identified with IE, these results being associated with normal (7x) or abnormal ratios (8x). Nineteen cases with normal IF and IE had one or two abnormal ratios. After comparison with clinical data and outcome, we conclude that IF revealed 15 cases of MGP, which were not or only partially shown by IE. IE did not show any case of MGP not detected by IF. One of the ratios appeared as an interesting adjunct to the diagnostic procedure, but insufficient to be used as a single test. The other appeared to be of no diagnostic help. We conclude that immunofixation is the test of choice in the routine diagnosis of monoclonal gammopathies.