Absence of association between the incidence of BK virus and sporadic creutzfeldt-jakob disease

Background: Many studies suggest that the virus-like particles are required for the infection of Creutzfeldt-Jakob disease (CJD). Objective: To determine the relationship between BK polyomavirus (BKV) and sporadic CJD. Materials and Methods: We investigated the prevalence of BKV in urine samples from 94 sporadic CJD patients and 54 other neurological disease (OND) patients using polymerase chain reaction. Results: BKV DNA was detected in 16 (17%) and 9 (16.7%) urine samples from sporadic CJD and OND patients, respectively. There was no significant difference in the incidence of BKV infection between Korean sporadic CJD and OND patients (p = 0.9558). In order to investigate the genotypes of BKV, we analyzed 22 BKV isolates obtained from Korean patients by DNA sequencing and nucleotide sequence analysis. Three distinct subtypes, namely I, III, and IV, were found in 66.7, 22.2, and 11.1% of 9 BKV isolates from OND patients, whereas subtypes I and IV were detected in 76.9 and 23.1% of 13 BKV isolates from sporadic CJD patients. Interestingly, subtype III was not detected in sporadic CJD patients. Significant differences in the frequency of BKV genotypes were not observed between sporadic CJD and OND patients. Conclusions: These results indicate that BKV may not play an important role in the pathogenesis of prion diseases.