RELATIONSHIP BETWEEN IMMUNOLOGICAL RESPONSIVENESS CONTROLLED BY T-HELPER-2 LYMPHOCYTES AND INFECTIONS WITH PARASITIC HELMINTHS

It should have been difficult until relatively recently for immunologi sts to ascribe a sound biological reason for the continued possession of the allergic phenotype in human populations. Nevertheless, for the past 20 years or so textbooks of immunology have routinely exhibited f anciful and perhaps exaggerated diagrams as to how IgE and eosinophils killed all helminth parasites. These diagrams were largely based on p erhaps selective in vitro observations, and it is only now that immuno parasitologists, working on human populations under arduous conditions in the field, are able to provide data to corroborate these findings, and perhaps ascribe a useful purpose for a generally pathological imm une response termed Type I hypersensitivity. The present paper reviews much of this recent literature, and asks a number of pertinent questi ons relating to the relationship between what we now know to be T-help er 2 lymphocyte-driven immunological responsiveness and infections wit h parasitic helminths.