Increased safety level of serotype 3 Sabin oral poliomyelitis vaccine lots by improved seed virus, and tissue culture and virus infection conditions.

The content of 472U to 472C revertant virus in serotype 3 oral poliomyelitis monovalent bulk vaccines can be quantified by MAPREC (Mutant Analysis by PCR and Restriction Enzyme Cleavage). Besides other wildtype reversions identified in propagated type 3 Sabin strain populations, the 472U to 472C reversion correlates most prominently with neurovirulence in the monkey neurovirulence test. Therefore, the results can be used for the discrimination of 'good' and 'bad' vaccines on the molecular level. In international collaborative studies it has been well established that vaccine lots containing revertant genomes below a critical threshold pass the in vivo monkey neurovirulence test (MNVT), while vaccine lots containing more revertants fail the MNVT. In this communication we show that the MAPREC test is a sensitive tool for quality control and the demonstration of consistency in large scale production. Furthermore, MAPREC offers a possibility to assess the effect of changed production conditions on the rate of reversion and to find conditions for consistent production with low reversion rates.

Borna disease virus-specific T cells protect against or cause immunopathological Borna disease.

In this report we show that passive immunization of Lewis rats with viable CD4+, Borna disease virus (BDV)-specific T cells before infection with BDV resulted in protection against BD, whereas inoculation of these T cells after BDV infection induced clinical disease with more rapid onset than seen in BDV control animals. The protective as well as encephalitogenic effector functions of BDV-specific CD4+ T cells were mediated only by viable BDV-specific T cells. The protective situation was obtained by passive transfer of BDV-specific T cells into animals inoculated later with virus, whereas the immunopathological situation was observed when virus-specific T cells developed normally or after adoptive transfer, and appeared on the scene after considerable virus replication in the brain.

[Striated lupus erythematosus following the Blaschko lines]. / Striärer Lupus erythematodes im Verlauf der Blaschko-Linien.

We describe a striated cutaneous lupus erythematosus following the lines of Blaschko. These are lines along which cell populations having a common stem cell spread. If this stem cell is genetically altered, the lines of Blaschko are made visible by linear skin diseases. In the case of striated lupus erythematosus described here this genetic alteration remained unnoticed until, due to the influence of possible injury, the affected cells became antigenic, provoking a localized autoimmune disease.

[Porphyria cutanea tarda and chronic lymphatic leukemia]. / Porphyria cutanea tarda und chronische lymphatische Leukämie (CLL).

We report on a case of porphyria cutanea tarda going with CLL. A review on 21 similar cases in literature warrants our assumption that in our case, too, porphyria cutanea tarda has been triggered by CLL.

Thymus in myasthenia gravis: a light and electron microscopic study of a case with thymic follicular hyperplasia.

The present study has focused mainly on microenvironmental aspects of the thymus from a 17-year-old female patient suffering from myasthenia gravis. The most striking lightmicroscopic feature was again the well known presence of lymphoid follicular hyperplasia. Ultrastructurally, the configuration, cellular composition and fine structure were to a large extent the same as in other, peripheral lymphoid organs. Cells showing the typical morphologic characteristics of fibroblastic reticulum cells, which are most probably precursors of dendritic reticulum cells, were observed within germinal centers. Additionally the morphology of the unaffected medulla and corticomedullary region was studied, thereby paying particular attention to the structural changes of interdigitating cells. These contained frequently Birbeck granules, which have not been described before in human thymus.