Serum IgA concentrations in children undergoing tonsillectomy for recurrent sore throats were lower than those of a control population. Haemophilus influenzae was usually grown from children with lower IgA concentrations, near to and below 2 SD below the control mean. Their values were significantly lower than those from patients from whom β haemolytic streptococci were grown. Some of the children with low IgA had low antistreptolysin titres and little or no lymphocyte response to PHA. There was no relationship between the immunological findings and the pre-operative severity of symptoms, but there was with the incidence of infection in the post-operative year. These findings will necessitate reappraisal of surgery and prophylactic antibiotics in the two groups separately.
These findings suggest that tonsils from children presenting with indistinguishable syndromes are infected with different bacteria, depending on the immunological function of the child. Since tonsillectomy is common, there appears to be clinical relevance for the range of immunological function near to or within the `normal limits'.