NIH and Italian scientists develop nasal test for human prion disease

A nasal brush test can rapidly and accurately diagnose Creutzfeldt-Jakob disease (CJD), an incurable and ultimately fatal neurodegenerative disorder, according to a study by National Institutes of Health (NIH) scientists and their Italian colleagues. The study appears in the current issue of the New England Journal of Medicine.

CJD is a prion disease. These diseases originate when normally harmless prion protein molecules become abnormal and gather in clusters. Scientists have associated the accumulation of these clusters with tissue damage that leaves sponge-like holes in the brain. Human prion diseases include variant, familial, and sporadic CJD.

An easy-to-use diagnostic test would let doctors clearly differentiate prion diseases from other brain diseases, according to Byron Caughey, PhD, the lead NIAID scientist involved in the study. Although specific CJD treatments are not available, prospects for their development and effectiveness could be enhanced by early and accurate diagnoses. Further, a test that identifies people with various forms of prion diseases could help to prevent the spread of prion diseases. It is known that human prion diseases can be transmitted via medical procedures such as blood transfusions, transplants, and the contamination of surgical instruments.

The NIAID study involved 31 nasal samples from patients with CJD and 43 nasal samples from patients who had other neurologic diseases or no neurologic disease at all. These samples were collected primarily by researchers at the University of Verona in Italy, who developed the technique of brushing the inside of the nose to collect olfactory neurons connected to the brain. Caughey’s lab then correctly identified 30 of the 31 CJD patients (97% sensitivity) and correctly showed negative results for all 43 of the non-CJD patients (100% specificity). By comparison, tests using cerebral spinal fluid—currently used to detect sporadic CJD—were 77% sensitive and 100% specific, and the results took twice as long to obtain. Read the article preview.