D. L. Klein

The development of vaccines to prevent infectious diseases has been one of the most important contributions of biomedical science. Recent advances in the basic sciences are now fueling the development of a new generation of vaccines that will be based on rational design approaches. Two factors are making this possible: an improved understanding of the microbial factors required for virulence and the nature of the immune response to infection. The status of new vaccine technologies is summarized here.

Unlike the elderly, healthy middle aged adults are at relatively low risk of acquiring serious pneumococcal disease. An explanation that has been proposed is that people in this age group have significant amounts of serum antibody (primarily IgG2) that react with any pneumococcal capsular polysaccharide serotypes. The level of antibody can be as high as several hundred micrograms per milliliter of blood for some serotypes. A significant component of this reactivity is directed toward the conserved C-polysaccharide depletion. Even after C-polysaccharide depletion, which is included as a routine part of the assay to determine antibody levels, resting antibody levels in a normal healthy adult population can vary widely. We have analyzed the reactivity of serum from 76 people to 16 pneumococcal capsular polysaccharide serotypes. The antibody reactivities to 13 of 16 serotypes are highly correlated with one another. Depletion of serum with C-polysaccharide and purified capsular polysaccharide inhibited antibody binding to type specific capsular polysaccharide. Cross-serotype inhibition of antibody binding was also observed. This indicates that there are materials contained within the pneumococcal polysaccharides that contribute to the cross-reactivity of serum antibodies in people that have not been vaccinated with the pneumococcal vaccine.

An account is given of a family from the Canton of Valais suffering from hereditary adenocarcinomatosis. The pedigree extends over four generations; the first three comprised 47 individuals (28 males, 19 females), of whom 21 (16 males and 5 females), i.e. 44.6%, have malignant tumors. Of the 32 people in the fourth generation, only one individual is affected to date (a girl age 21, IV/4). There were 27 tumors in all: 16 adenocarcinomas of the colon, two gastric adenocarcinomas, one duodenal adenocarcinoma, one rectal adenocarcinoma, one papillary carcinoma of the ovary, one osseous sarcoma, one cutaneous fibrosarcoma, a multiform glioblastoma of the basal nuclei of the brain, a basocellular epithelioma, a cerebral metastasis from an adenocarcinoma, the origine of which has not been established, and a tumor invading the biliary tract. Three members of the family had multiple tumors. In three of the patient the colonic adenocarcinoma was accompanied by one or two polyps. The average age at onset for all tumors was 45 years. It was definitely lower in the third than the second generation (anticipation). The transmission was autosomal dominant, with predilection for the male sex (57.1% male and 26.3% female patients). The penetrance was about 80%. Finally, the diagnostic criteria for hereditary adenocarcinoma are discussed and the different familial forms of cancer are reviewed.