The antibody response of institutionalized Down's syndrome patients to seven microbial antigens.

An earlier cross-sectional study had revealed that institutionalized Down's syndrome (DS) patients possessed much lower titres of hepatitis B surface antibodies (anti-HBs) than did their non-Down's (ND) counterparts. In an attempt to determine whether DS patients were generally deficient in humoral antibody response, the inmates of an institution for the mentally retarded (110 DS, seventy-eight ND) were immunized with tetanus, diphtheria (toxoids), influenza A, influenza B (inactivated vaccines), measles, mumps and rubella (attenuated vaccines), and tested for their antibody responses. The DS and ND groups did not respond differently to any of the seven antigens. Furthermore, there was no general relationship between the anti-HBs titres of inmates and their capacity to respond to the defined antigenic stimulus of any of the seven antigens. From these results it is apparent that a general humoral deficit in the DS group cannot explain their tendency to possess much lower anti-HBs titres than their ND counterparts upon becoming infected with the hepatitis B virus. When the antibody status and responses to immunization of the inmates who possessed anti-HBs were compared with those who had chronic HBsAg antigenaemia, there was no significant difference between the groups.