Susceptibility to Creutzfeldt-Jakob disease after human growth hormone treatment in France

Abstract

To identify, among the available data concerning host characteristics and exposure, risk factors influencing the susceptibility for developing iatrogenic Creutzfeldt-Jakob disease (iCJD) in a cohort of patients treated with human cadaver-sourced growth hormone (hGH) in France. This study included all 1,443 individuals treated in France with hGH from January 1982 to December 1985, out of which 119 cases of hGH-iCJD have been identified so far. We applied a 3 sequential step Cox analysis involving univariable, stepwise, and nonstepwise multivariable procedures. The variables studied were sex, age at hGH treatment initiation, and treatment characteristics (batches and doses). While no effect of age at treatment initiation was observed, a significant effect of sex on disease susceptibility was unexpectedly evidenced with a 2-fold increase of disease occurrence in male patients. This effect did not depend on differences of exposure between male and female patients. We identified 4 categories of hormone batches from high risk to no association with susceptibility. A relationship between the dose received from at-risk hormone batches and the attack rate (number of patients developing the disease among exposed individuals) was demonstrated. Studying the hGH-exposed patients in France provides epidemiologic evidence of a relationship between dose of inoculum and disease occurrence in humans and suggests an unexpected effect of sex on individual susceptibility.