Etiology of common childhood acute lymphoblastic leukemia: the adrenal hypothesis.
The pattern of infections in the first years of life modulates our immune system, and a low incidence of infections has been linked to an increased risk of common childhood acute lymphoblastic leukemia (ALL). We here present a new interpretation of these observations--the adrenal hypothesis--that proposes that the risk of childhood ALL is reduced when early childhood infections induce qualitative and quantitative changes in the hypothalamus-pituitary-adrenal axis that increase plasma cortisol levels. This may directly eliminate leukemic cells as well as preleukemic cells for the ALL subsets that dominate in the first 5-7 years of life and may furthermore suppress the Th1-dominated proinflammatory response to infections, and thus lower the proliferative stress on pre-existing preleukemic cells.
Schmiegelow
K
K
The Pediatric Clinic, The University Hospital Rigshospitalet, Copenhagen, Denmark. kschmiegelow@rh.dk
Vestergaard
T
T
Nielsen
S M
SM
Hjalgrim
H
H
D002648:Child; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000276:immunology; D007030:Hypothalamo-Hypophyseal System / Q000276:immunology*; D015994:Incidence; D007239:Infections / Q000453:epidemiology / Q000276:immunology*; D010913:Pituitary-Adrenal System / Q000276:immunology*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology*; D012307:Risk Factors
D006854:Hydrocortisone