One patient (4.5%), a 25 12 months old female having a previous history of thiopurine and anti-TNF use, seroconverted at 22 weeks, and, at the time of this analysis, the patient still remained on therapy with stable disease control. DISCUSSION The present study is the first to describe the seroprevalence of JC virus in refractory CD patients, who have been candidates for natalizumab treatment. One hundred and twenty-nine of the individuals (67.5%) tested positive for serum JC computer virus antibody. Multivariate analysis shown that past use of thiopurine was a risk element for screening positive for JC computer virus antibody (odds percentage 7.8; 95% confidence interval [CI], 2.0C30.4; < 0.05 was considered statistically significant. Where indicated, multivariate analysis was performed with factors that showed a positive)<0.05; ?use of the corticosteroid L-Threonine derivative-1 > 3 months at the time of JC computer virus antibody check; #use of natalizumab at the time of JC computer virus antibody check Risk factors for JC computer virus exposure The prevalence of blood anti-JC computer virus antibody in our individuals was 67.5% (129/191) (Table 1). In univariate analysis, prior use of thiopurines was significantly more frequent in individuals who tested positive as compared to those with a negative result (92.1 vs 74.2%, = 0.001). Older age (= 0.05), corticosteroid use (= 0.05), and methotrexate use (= 0.06) showed a strong trend towards a positive serology. Multivariate analysis with all factors that experienced a = 0.003). Methotrexate use and lower CRP level also shown a nonsignificant pattern by multivariate analysis (Table 1). Subsequent natalizumab use and effect on surgery More individuals were treated with natalizumab following a bad JC computer virus antibody test than those with a positive result (Table 1; 35.5% and 12.4%, respectively, = 0.028), history of Crohns surgery L-Threonine derivative-1 (= 0.015), and perianal disease (= 0.048) significantly increased the risk of subsequent surgery, whereas subsequent natalizumab use significantly lowered the risk (= 0.043). Cox regression analysis with these four factors showed that the use of natalizumab was the only element associated with modifying the risk of subsequent surgery (Number 1a; hazard percentage 0.23 (95%CI 0.06C0.98), = 0.048). Number 1b shows the Cox regression analysis of the probability of avoiding surgery in the study population according to the subsequent use (or no use) of natalizumab after JC computer virus testing modified with fistulizing disease, history of Crohns surgery, and perianal disease as the covariates. Open in a separate window Number 1 (a) Cox proportional risks regression analysis was performed to identify risk factors for surgery in the present populace. L-Threonine derivative-1 Fistulizing disease, history of Crohns surgery, natalizumab use after JCV screening, and perianal disease were included in the Cox regression analysis as they shown relevance with increasing/reducing the risk of surgery based on a value of <0.10 on a log-rank test (Kaplan-Meier analysis). Natalizumab use after JCV screening was associated with significantly reducing the risk of surgery (Hazard percentage 0.23, 95%CI 0.06C0.98, = Rabbit polyclonal to PDK4 0.048). (b) Probability of avoiding surgery in the study population according to the use of natalizumab or not after JC computer virus testing modified with fistulizing disease, history of Crohns surgery, and perianal disease as the covariates. Time to surgery treatment after JCV screening was analyzed using Kaplan-Meier estimator. Individuals without follow-up at a certain time point or those who discontinued due to adverse effects were regarded as censored and demonstrated as ticks within the graph. We subcategorized the individuals based on the results of the JC computer virus antibody status and the subsequent natalizumab use, and assessed the risk of surgery. Interestingly, as demonstrated in Number 2, individuals who tested positive for JC computer virus and were treated with natalizumab experienced an excellent end result, followed by those who tested bad and were treated with natalizumab. Regardless of the JC computer virus status, individuals who were not treated with natalizumab were more likely to undergo surgery. None of the individuals who have been treated with natalizumab developed PML. Open in a separate window Number 2 Survival analysis based on the JCV Antibody serology and the subsequent use of natalizumab. Patients were categorized.