Immunitat und Infektion最新文献

Pregnant women and newborn infants were screened for group B streptococcal (GBS) colonization by obtaining paired swabs from the cervix and urethra for the former group and from the ear, nose, umbilical cord, gastric juice and membranes for the latter. One swab was cultured on blood agar; the other was inoculated into serum-starch broth (GBS medium), which allows identification of GBS by production of a characteristic orange-colored pigment. From the 2105 paired swabs obtained, a total of 158 were GBS positive by either method; of these, 154 (97.5%) were recovered by the GBS medium and 89 (56.3%) by blood agar plate. No false positive color reactions were observed with GBS medium. 75% of the positive GBS media could be read within 24 h of incubation. The use of GBS medium proved to be an easy and reliable method for screening of maternal and neonatal GBS colonization.

Immunoadsorption is an improvement of extracorporeal therapy which differs from plasmapheresis. After plasma perfusion on a special adsorption filter the patient's plasma is reinfused. Meanwhile more than 270 immunoadsorptions have been performed. 7 patients with SLE and glomerulonephritis as well as 3 patients suffering from Wegener's vasculitis and glomerulonephritis had been treated with combined immunoadsorption and IVIG therapy. After three sessions of immunoadsorption (2-3 1 plasma filtrate) the patients received 10 g 7S-immunoglobulin infusions on three consecutive days. Patients with SLE and end-stage kidney involvement (2 patients) did not show any benefit by the above mentioned treatment regimen. Patients with Wegener's vasculitis and glomerulonephritis showed no significant improvement, except in one of three patients who showed a remarkable decrease in proteinuria. On the other hand, patients with SLE and "moderate" kidney involvement (short course of disease, no fixed structural changes) showed improvement on combined immunoadsorption and IVIG therapy.

Vaccination against poliomyelitis remains an absolutely mandatory measure to prevent resurgence of this dreadful viral infection. Today, however, when the chance to get infected is extremely low, one has to reconsider much more the inherent risk of such a living vaccine which is principally able to induce neurologic disease especially in immunocompromised host the number of which is increasing in our population. Since these attenuated vaccine strains multiply largely in the orointestinal tract of a vaccine, those viruses are shed and easily spread into surroundings so that other persons which are not aware of this event are exposed. But also in normal hosts the vaccine strains are able to produce disease because the genetic mutation leading to reduced virulence is not absolutely stable. Back mutations with increased virulence develop during multiplication in the vaccinee and may threaten the vaccinee as well as contact persons. For the sake of security these consequences should be respected much more. Since a dead vaccine of polioviruses is available, one should much more often profit from this choice.

Consistently high tuberculosis rates in many developing nations, the surprising increase in tuberculosis cases in numerous industrialized countries, together with the emergence of multi-drug-resistant strains of Mycobacterium tuberculosis have sharpened public interest in this ancient scourge. Improved tuberculosis control could best be achieved by an efficacious vaccine. The available attenuated vaccine strain, Mycobacterium bovis BCG, has only limited efficiency. This vaccine is capable of protecting against disseminated miliary tuberculosis in the newborn, but it is unable to prevent stable infection and to cause sterile pathogen eradication. Hence, adult tuberculosis, representing the majority of all tuberculosis cases, is not preventable by BCG vaccination. Due to the extraordinarily high rate of asymptomatic M. tuberculosis infection (1/3 of the total world population) any novel vaccination strategy has to fulfil two major tasks: first, prevention of stable infection, second, eradication of already established infection. T lymphocytes represent the major target for any vaccine strategy, because they serve as central mediators of acquired immunity. They segregate into distinct populations, characterized by different activation conditions and biological functions. These T cell populations do not act independently from, but rather interact with, each other mostly through cytokines. Although CD4 T lymphocytes of T helper 1 type are essential for protection, CD8 T cells expressing cytolytic functions are required, in addition. Perhaps other T cell populations, such as gamma/delta T cells and double negative alpha/beta T cells, also participate. An effective vaccine has to stimulate the precise combination of T cells and cytokines required for the different tasks. It remains to be clarified in how far this can be achieved by a single vaccine.

Acellular vaccines against pertussis could be developed because various virulence factors of B. pertussis have been characterized. Acellular pertussis vaccines should retain the efficacy but have lower side effects, as compared to the conventional whole-cell vaccine. Lacking any correlate of antibacterial resistance, the efficacy of the vaccines had to be tested in large field trials. Such trials have been conducted and are being conducted in various European and in one African country. These trials used different designs, and various different vaccines were tested. All available efficacy data show that acellular pertussis vaccine can effectively protect against typical pertussis. It also seems probable that the efficacy of vaccines, which contain more than two pertussis components may be better than a vaccine containing pertussis toxoid or pertussis toxoid with filamentous hemagglutinin. A three-component acellular pertussis vaccine has been licensed for use in primary vaccination in infants in Germany in early 1995.

Using pulsed-field gel electrophoresis, DNA fingerprints of eleven Legionella pneumophila isolates of serogroup 2 were generated. It was shown that two strains from a patient suffering from pneumonia as well as three environmental strains isolated from the shower in the hotel where the patient stayed 5 days before his illness were identical. Six strains of the same serogroup isolated from other sources were clearly separated. Thus, DNA fingerprints by pulsed-field gel electrophoresis are excellent epidemiological markers for the rarely occurring serogroup 2 of Legionella pneumophila.

Inhalation of a variety of organic dusts may cause the onset of hypersensitivity pneumonitis (HP) finally leading to irreversible pulmonary fibrosis in some individuals. So far, the pathogenesis of HP remains partially unclear. Besides patient-related factors this is probably attributable to the complex composition of the causative dusts: in addition to specific antigens that may induce type III and type IV reactions they contain a variety of additional components like particles and toxins with the ability to promote several antigen-independent reactions. During an acute episode of HP a marked alveolitis dominated by polymorphonuclear cells develops. As we showed these polymorphonuclear cells are in an activated state and may therefore cause pronounced damage in the lung interstitium. Based on these and other findings we believe that polymorphonuclear cells are of predominant importance for the pathogenesis of HP.

Idiopathic pulmonary fibrosis or lone cryptogenic fibrosing alveolitis is an interstitial lung disease of unknown origin carrying an unfavorable prognosis. A yet unidentified hazard triggers a chronic inflammatory infiltration of the lung parenchyma characterized by an accumulation of alveolar macrophages, neutrophil and eosinophil granulocytes, and lymphocytes. Cytokines released by the activated cells modulate the inflammatory events. Oxidants and proteases, mainly released by alveolar macrophages and neutrophil granulocytes, mediate the injury to the lung parenchyma, leading to loss of alveolar-capillary units. The ensuing repair process, mesenchymal cell proliferation and up-regulation of synthesis of collagen fibers and other components of connective tissue matrix, replaces lung parenchyma by fibrotic tissue, leading to irreversible pulmonary dysfunction.

Reactive oxygen species (ROS) and cytokines like tumor necrosis factor-alpha (TNF-alpha) play a crucial role as inflammatory mediators in pulmonary sarcoidosis. We examined the antiinflammatory effect of pentoxifylline (POF) on alveolar macrophages (AM) of patients with sarcoidosis in vitro. We could demonstrate that POF (above 4.10(-4) M) inhibited the secretion of superoxide anion and TNF-alpha by AM in a dose-dependent manner via a prostaglandin synthesis-dependent mechanism that was independent of the glucocorticoid receptor. POF is an interesting immunomodulating substance that should be further evaluated in clinical trials.