English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Hydroxychloroquine (HCQ) levels can be measured in both serum and whole blood. No cut-off point for non-adherence has been established in serum nor have these methods ever been compared. The aims of this study were to compare these two approaches and determine if serum HCQ cut-off points can be established to identify non-adherent patients.    Methods  HCQ levels were measured in serum and whole blood from 573 patients with systemic lupus erythematosus (SLE). The risk factors for active SLE (SLEDAI score &gt; 4) were identified by multiple logistic regression. Serum HCQ levels were measured in 68 additional patients known to be non-adherent, i.e. with whole-blood HCQ &lt; 200 ng/mL.    Results  The mean (± SD) HCQ levels were 469 ± 223 ng/mL in serum and 916 ± 449 ng/mL in whole blood. The mean ratio of serum/whole-blood HCQ levels was 0.53 ± 0.15. In the multivariate analysis, low whole-blood HCQ levels ( P  = 0.023), but not serum HCQ levels, were independently associated with active SLE.  From the mean serum/whole-blood level ratio, a serum HCQ level of 106 ng/mL was extrapolated as the corresponding cut-off to identify non-adherent patients with a sensitivity of 0.87 (95% CI 0.76–0.94) and specificity of 0.89 (95% CI 0.72–0.98).  All serum HCQ levels of patients with whole-blood HCQ below the detectable level (&lt; 20 ng/mL) were also undetectable (&lt; 20 ng/mL).    Conclusions  These data suggest that whole blood is better than serum for assessing the pharmacokinetic/pharmacodynamic relation of HCQ. Our results support the use of serum HCQ levels to assess non-adherence when whole blood is unavailable.

Hydroxychloroquine levels in patients with systemic lupus erythematosus: whole blood is preferable but serum levels also detect non-adherence