Lower risk of Creutzfeldt-Jakob disease in pituitary growth hormone recipients initiating treatment after 1977.

Context: Creutzfeldt-Jakob disease (CJD) caused by contaminated cadaveric pituitary-derived human GH (hGH) has been responsible for hundreds of deaths worldwide. Studies of U.S. National Hormone and Pituitary Program (NHPP) hGH recipients have found CJD only in patients treated before 1977, when a new purification procedure with column chromatography was implemented for hGH extraction.

Objective: Our objective was to provide updated information on transmission of CJD to NHPP hGH recipients and determine whether recipients of hGH produced after 1977 had a significantly lower CJD risk than pre-1977 recipients.

Patients: A total of 5570 NHPP hGH recipients were included in the study: 2099 in the pre-1977 cohort and 3471 in the post-1977 cohort.

Main Outcome Measure: We used probability distribution functions to determine whether the observed number of CJD cases in the post-1977 cohort was significantly fewer than expected if the CJD risk was equal to that of the pre-1977 cohort, controlling for treatment duration and follow-up time.

Results: All 22 CJD cases (diagnosed from 1984-2009) occurred in the pre-1977 hGH recipients. Almost half (47.9%) of pre-1977 recipients had a treatment duration of at least 5 yr compared with only 13.8% for post-1977 recipients. Based on the rates present in the pre-1977 cohort, the probability of observing no cases in the post-1977 cohort by chance alone was low (P = 0.0019).

Conclusions: Risk of acquiring CJD was significantly lower for post-1977 NHPP hGH recipients than for pre-1977 recipients, suggesting that the new purification procedure in 1977 may have greatly reduced or eliminated CJD agent in hGH.