Secretor state and immunoglobulin levels among women with recurrent urinary tract infections.

In this study we tested the hypothesis that the increased susceptibility of non-secretors of blood group antigens to recurrent urinary tract infections might be due, in part, to lower levels of IgA reported for non-secretor Caucasian women. Total serum IgA and IgG levels of 200 women in a retrospective study group monitored by the local pyelonephritis unit for 20 yr was compared with those of 100 women from a prospective group recently referred to the clinic. Immunoglobulin levels of the retrospective group were analyzed with reference to the secretor state of the patient, improvement over the 20 yr and presence or absence of renal scars. Total IgA and IgG levels were significantly higher in the sera of non-secretors with or without renal scars and also among patients who had clinically improved over the 20-yr period. Most women appeared to improve regardless of age of onset of infections or treatment prescribed. It was suggested that improvement might be associated with a self-immunization phenomenon. The significantly higher levels of IgA and IgG found among the women in the retrospective study compared with the levels found in the sera of age-matched women in the prospective study is evidence for this hypothesis. The implications of these findings for further investigations of the pathogenesis of urinary tract infections are discussed.