For determining treatment options of tonsillar diseases, the authors c
ompared immunohistochemical differences for IgA immunocytes and measur
ed the changes in concentrations of the serum immunoglobulin A and sal
ivary secretory immunoglobulin A before and after tonsillectomy accord
ing to age in 126 cases (60 control cases, 66 tonsillectomee cases). T
he serum IgA and salivary SIgA concentrations of the control group rea
ched to adult's level at the age of 11 to 13. In the tonsillectomees,
the serum IgA concentrations below the age of 10 were higher than that
of controls and were decreased to the levels of the controls after to
nsillectomy in all ages and the salivary SIgA concentrations were decr
eased to the levels of the controls at the 30th postoperative day, esp
ecially at the age of 5 to 7 and 8 to 10. Morphometric features of ton
sils in the group below the age of 8 were more active than those in th
e group above the age of 8 in the controls. In the tonsillectomees, mo
rphometric features of the tonsils were similar to those in the group
above the age of 8, but the reticular part of the crypt epithelium rem
ained significantly. Total number of IgA immunocytes was the highest a
t the age of 5 to 7 with a decline by age, especially at the age of 19
in the controls. In the tonsillectomee group, the number of IgA immun
ocytes of the extrafollicular area and the reticular part of crypt epi
thelium decreased below the levels of the control group. In conclusion
, tonsils in preschool children are important as a local immunologic d
efense mechanism, but no significant changes in the immunologic system
occurs after tonsillectomy.