Development of a mucosal challenge test for leprosy using leprosin A.

There is little information about the mucosal immune response in leprosy. We have developed a nasal provocation test with leprosin A which will be used to investigate mucosal immunity to Mycobacterium leprae. Initial studies were performed with increasing doses of leprosin A (1.0 pg/ml-10 micrograms/ml) to determine the optimal safe dose of leprosin A. Anti-M. leprae IgA antibody and normal IgA concentrations were measured in the saliva of leprosy contacts and controls before and after instillation of leprosin A. Nasal leprosin A was well tolerated up to a concentration of 10 micrograms/ml without side effects. None of the six subjects who had not been exposed to leprosy had salivary IgA against whole M. leprae, whereas IgA was detected from 64 h to 140 h following instillation of leprosin A in all of the leprosy hospital workers and in 15 out of 18 healthy household contacts tested. There was no correlation between serum and salivary anti-M. leprae IgA levels before and after testing. Salivary IgA anti-lipoarabinomannan responses were seen in 12 out of 20 household contacts. Normal salivary IgA concentrations varied from 8 to 240 mg/l. The leprosin A nasal provocation test appears to be a safe method for the investigation of the role of mucosal immunity in the pathogenesis of leprosy.

Methods of selection for adenoidectomy in childhood otitis media with effusion.

We have examined the implications of selecting children with otitis media with effusion (OME) for adenoidectomy using different criteria. Data were collected pre-operatively on 125 consecutive cases of OME. Ages 1-13 years, mean = 4.9 years; 68 males and 57 females. The criteria used were: (1) obstructive nasal symptoms, (with three sub-categories); (2) age: and (3) nasopharyngeal airway size. The three sub-categories of obstructive nasal symptoms were based on the clinical practices of colleagues in the UK. Thus we analysed five criterion groups in all. These were: (1) snoring; (2) snoring + mouth breathing; (3) snoring + nasal obstruction; (4) age = 4-8 years and (5) nasopharyngeal airway < 4 mm. We found that applying each criterion separately to the group of children would result in widely differing numbers of children being selected for adenoidectomy. Of the 125 children, the percentage selected by each method varied considerably, ranging from 35-70%. In addition, there was only limited overlap, (43-71%) between the composition of the groups. This helps to explain the variations in surgical rates in different centres. In the absence of any universally acceptable guidelines, therefore, the importance of individual assessment of children can not be overemphasised.