Detection of Capsular Polysaccharide in Serum for the Diagnosis of Pneumococcal Pneumonia: Clinical and Experimental Evaluation

To improve diagnostic options for pneumococcal pneumonia, an ELISA system was developed that can detect ⩽6 ng/ml capsular polysaccharide in serum. The test waslimited to 39 serotypes causing >95% of pneumococcal infections. In clinical evaluation the test identified 14 of 15 cases (missing one serotype not included). No false-positive reaction occurred. However, the duration and level of antigenemia were variable (⩾500-2.5 ng/ml) and seemed not to depend solely on the severity of infection. Therefore, the question of whether the extent of antigenemia was determined by a serotype-dependent variation in the elimination rates of polysaccharides was investigated. Clearance rates for 12 serotypes varied in rabbits and rats by a factor of >250. This remarkable variability appeared to affect the extent of clinical antigenemia. Thus, only very sensitive systems can detect circulating antigen from rapidly cleared polysaccharide serotypes. Furthermore, the question arises whether slow polysaccharide clearance contributes to the virulence of some pneumococcal serotype

Oropharyngeal lesions and cervical lymphadenopathy: syphilis is a differential diagnosis that is still relevant

Background Syphilis (lues), a chronic infectious disease caused by Treponema pallidum, has been increasing in incidence during the last few years. Therefore, while clinically it is often not suspected, syphilis is increasingly becoming a differential diagnosis in routine pathology. Aim To report our experience with five cases of cervical lymphadenopathy and/or oropharyngeal lesions, clinically thought to be lymphomas, lymph node metastases or carcinoma, in which we made the mostly clinically unsuspected diagnosis of syphilis. Methods Fine needle aspiration of enlarged cervical lymph nodes was evaluated by cytology and flow cytometry (fluorescence-activated cell sorting analysis), and biopsies were examined by using histology. In addition, all materials were also subjected to immunostaining, silver staining and molecular (PCR) testing. Results Fine needle aspiration cytology revealed follicular hyperplasia in two cases and granulomatous lymphadenitis in one case. In three patients, concomitant biopsy of co-existing oropharyngeal lesions revealed histological findings compatible with syphilis. T pallidum was detected in all cytological and histological samples by immunohistochemistry/immunocytochemistry and PCR. Subsequently, a diagnosis of syphilis was confirmed clinically and by serology. Conclusions Syphilitic lymphadenitis is still a relevant differential diagnosis of cervical lymphadenopathy, and it is clinically often not suspected. Co-exisiting oropharyngeal lesions should alert the physician to this differential diagnosis; and lesions with compatible morphology should be tested with immunohistochemistry and immunocytochemistry and/or molecular analysis to confirm the diagnosis of syphilis