Tuberculosis II: the failure of the BCG vaccine

The use of tularemia live vaccine in clinical oncology

The review of literature on the use of tularemia live vaccine in clinical oncology is presented. The results of the investigation of tularemia live vaccine as a non-specific stimulator of natural immune and antitumor resistance of patients with endometrial cancer and inoperable lung cancer and its influence on the immunological status of these patients after immunization, during the process of combined treatment, and on long-term (up to 5 years) follow-up after vaccination are shown. A single immunization with tularemia live vaccine increases the main immunological indices in patients with endometrial cancer and inoperable lung cancer already in 2 to 3 weeks after vaccination and they remain during the whole term of follow-up. Moreover, the vaccine shows not only immunostimulating but immunomodulating effect as well and does not give any serious local or general complications. It is shown that due to these effects immunization of patients with tularemia live vaccine in 15 to 20 days before surgery or chemotherapy is followed by a significantly decreased frequency of postoperative complications and better survival. On the basis of the data obtained the authors recommend to use tularemia live vaccine in the complex treatment of those cancer patients who have deep decrease of immunological reactivity.

Tuberculosis

Approximately one-third of the world population is infected with Mycobacterium tuberculosis, the organism that causes tuberculosis (TB). After a brief resurgence beginning in the mid-1980s, the incidence of TB is once again declining in the United States. Health care workers, including dentists and their staff, however, remain at risk for occupational acquisition of the disease. This risk can be managed by educating dental health care workers about the oral and systemic manifestations of TB and the mechanisms by which it is spread so that appropriate measures may be taken in the office to minimize the opportunity for disease transmission.

Bacillus Calmette-Guerin down-regulates CD1b induction by granulocyte-macrophage colony stimulating factor in human peripheral blood monocytes

Non-peptide antigens (e.g. glycolipids of microbial origin) presented by monocyte-associated CD1 molecules to T cells appear to play an important role in host immunity against tuberculosis and other pathogenic bacteria. Since vaccination with Bacillus Calmette-Guerin (BCG) has limited efficacy, the influence of viable BCG organisms on the induction of CD1b antigen by granulocyte macrophage-colony stimulating factor (GM-CSF) has been tested in adherent mononuclear cells obtained from peripheral blood of healthy donors. The results indicate that the vaccine reduces substantially CD1b induction by GM-CSF. On the other hand, BCG was found to promote a slight increase in the expression of this molecule on target cells not exposed to GM-CSF. Attempts to reverse the antagonistic effects of BCG on GM-CSF with high concentrations of GM-CSF, alone, or associated with IL-4, were unsuccessful. Moreover, mycobacteria suppression by 10 microg/ml of rifampin, did not affect BCG influence on CD1b induction. The present results suggest that mycobacterium-induced impairment of the CD1 system could play a role in the unsatisfactory results obtained with BCG vaccination.

Ocular tuberculosis

Despite the use of highly sensitive molecular tools, such as polymerase chain reaction, for the detection of Mycobacterium tuberculosis, ocular tuberculosis remains a subject of controversy. The diagnosis is often presumptive in the absence of ocular biopsies. Choroiditis is the most common ocular manifestation in patients with pulmonary and systemic tuberculosis. Indocyanine green angiography seems to be an interesting method to determine choroidal involvement. PCR technology is proposed to evaluate the presence of the tubercule bacillus DNA in ocular fluids and tissues when conventional microbiologic methods fail to confirm a bacterial etiology. Most of the presumed cases of ocular tuberculosis should be treated with associations of antituberculous drug, especially when a systemic steroid regimen is required.