Pneumococcal antibodies in maxillary sinus secretion.

Resistance to and recovery from mucosal surface infections may be better correlated to the presence of local antibodies than to serum antibodies. In 14 patients with maxillary sinusitis due to pneumococci, IgA, IgG and IgM antibodies to the isolated pneumococci were quantified in sinus secretion and serum by indirect immunofluorescence technique. Most secretions contained type specific pneumococcal antibodies, mainly of IgA class. The frequent lack of demonstrable type specific IgA antibodies in serum indicates their local synthesis. After drainage of purulent sinus secretion, as in 5 patients, a local increase of antibodies was observed.