Serum antibody titres

Infection can be prevented by immunisation. The vaccine is a recombinant form of the HBsAg and induces strong neutralising antibody responses. High serum antibody titres to HBV are protective in the early stages of infection, effectively preventing establishment of disease. 

The protective efficacy of Engerix B has been demonstrated in a number of trials, in the context of infants, children and adults. Seroprotection rates (measured as serum anti-hepatitis B antibody titres above a value of 10 mlU ml-1) of over 95 per cent were usually recorded. The product was found to be generally well tolerated. The most frequently reported adverse effects were local reactions at the injection sites, fever, headache and dizziness. Special consideration to risk benefit ratio should be given to MS patients, as exacerbations of this condition have been (rarely) reported following administration of hepatitis B and other vaccines. Engerix B is manufactured and marketed by GlaxoSmithKline. 

Locally prepared products such as stabilized human serum are attractive because the donors from whom the plasma is harvested have an antibody spectrum that most closely matches the needs of patients drawn from the same population. This analysis shows that for an approximately equivalent dose of 6 g of immunoglobulins the local product is less expensive on a gram-for basis. Additionally, a comparison of the antibody titres (Jacobs and Wood, unpublished) showed a broader spectrum than some of the commercially available commodities. Exchange rate = R9.50 = R14.35. 

The complete DNA sequence has meanwhile been clarified. HCV binds to the cell surface structure CD 81 via its envelope protein E2 for this reason, HCV can also infect other cell types (apart from hepatocytes). (318) Virus replication can be detected very early (within the first week after exposure). The viral particle load is < 10 /ml serum, which is less than half of an HBV infection. The highest antibody titres are found in the preacute and early acute stages. HCV can replicate extra-hepatically, e. g. in leucocytes and B or T lymphocytes as well as, occasionally, in oral lichen tissue. (284) The spleen serves as a large extrahepatic reservoir for HCV. (280, 288, 313, 318, 334, 342, 355, 358, 377, 383, 404) (s. p. 115)... 

The initial exponential phase of the immune response to intravenously injected SE occurs exclusively in the spleen. The rate of multiplication and differentiation of immunocytes induced by the immunogenic stimulation can be measured, during this phase, by the quantitative study of the number and morphology of RFC . The comparison of the number of RFC and PFC in the spleen with the titre of serum antibody at the end of the exponential phase gives information on the relationships between cellular and humoral aspects of the immune response. 

A third series of experiments was done to check the eventual modifications of the intercellular substance (i.s.) in the Malpighian layer and stratum corneum. The antigenic substrate of five of the ichthyotic subjects was treated with serum with anti-i.s. antibodies (titre 1 320) taken from a pemphigus patient (see Figure 5.1). Each section was treated with two different dilutions of pemphigus serum (1 10 and 1 40) and with an anti-IgG conjugate (same characteristics as above). 

The titre of an antibody in the context of immunoassay is the dilution of serum used in the assay. 

A recent study [42] compared the titre of autoantibodies to malondialdehyde (MDA)-modified LDL and native LDL in baseline serum samples of 30 Eastern Finish men with accelerated two-year progression of carotid atherosclerosis and 30 age-matched controls without progression. Neither group had specific antibody binding to native LDL. A titre was defined as the ratio of antibody... 

Virus RNA is infectious. HAV multiplies within the cytoplasm of hepatocytes. Approximately 2 to 3 weeks after infection, the viruses appear in the stool, but disappear after 4 to 5 weeks, thereby terminating the infec-tivity. As of the 4 week, HAV antibodies (anti-HAV) of the IgM and IgG type appear in the serum as serological markers, (s. fig. 5.5) Acute hepatitis A has a high IgM titre, whereas an infection occurring several months earlier can be recognized by a high IgG titre. Once the infection has been overcome, the elevated IgG titre remains for life. Immunity is permanent. Renewed rises in titre (= booster effect) are possible after reeurrent HAV contacts. The HAV vaccine induces equal IgM and IgG immune responses. By means of quantitative determination of the total anti-HAV, it is possible, for example, to differentiate between passive immunization and (acute or past) HAV infection. HAV RNA can be detected with the help of hybridization tests, and HAV with the help of PCR. (101, 109, 119) (see chapter 22.3 )... 

Clostridial neurotoxins are very toxic. However they are ineffective in individuals immunized with the corresponding toxoids. In most countries children are vaccinated with tetanus toxoid and this is sufficient to provide full protection against tetanus for decades. A booster injection of tetanus toxoid (available from health authorities) before starting research with TeTx is advisable. On the other hand, the vaccine for BoNT/A, B, C, D and E is not commercially available, but can be obtained from the Center for Disease Control (CDC, Atlanta, GA). Due to the rather low efficacy of the BoNTs vaccine, a protective serum anti-BoNT titre is generally, but not always, achieved. Human anti-TeTx antibodies and horse anti-BoNT antibodies are also available from health authorities, and their injection immediately after accidental penetration of the toxin into the circulatory system is sufficient to prevent the disease. 

Anit-Maduramicin Antibody Production. New Zealand white rabbits were hyperimmunized with maduramicin-BSA in Freund s complete adjuvant and boosted biweekly with Freund s incomplete adjuvant four weeks after the initial immunization. Weekly bleeds were performed. Serum titre was monitored by indirect enzyme immunoassay described below. The antibody was produced through a contract with Hazleton Laboratory (Vienna, Virginia). 

A recently developed variant of this method is the class-capture technique useful in the diagnosis of infectious diseases. This method is based on the observation that after the first infection primarily IgM antibodies (Section 5.1.1) are produced which are gradually replaced by IgG antibodies in chronic or recurrent infections. Vari jus laborious methods have been developed to separate IgG from IjM and to establish the relative proportion of antibodies in the two classes. In the very simple but powerful class-capture method, the presence of IgM can be detected by immobilizing an anti-IgM antibody which will capture the IgM from the serum. If the IgM contains antibodies, they will, in turn, be able to capture the antigen, which can be revealed by the methods shown in Figs. 2.2c or 2.2d. The titres of IgM and IgG antibodies can be established in parallel experiments. 

---