A previous meta-analysis suggested that 6-thioguanine nucleotides levels are associated with clinical remission in inflammatory bowel disease.
It was criticized because of the relatively small number of patients included in this meta-analysis and heterogeneity between studies. Recent studies provided conflicting results, and the source of those discrepancies has yet to be explored.
Dr Amelie Carla Moreau and colleagues conducted a comprehensive, computerized literature search in Medline, ISI Web of Science, and EMBASE until 2012.
A combined odd ratio with its 95% confidence interval was calculated using a fixed effects model based on the Mantel–Haenszel method.
|The lack of standardization in 6-thioguanine nucleotides assays is responsible for recent contradictory results|
|Inflammatory Bowel Diseases|
Between-study heterogeneity was assessed using Cochran's Q statistic.
The research team analyzed 17 studies enrolling 2049 patients with inflammatory bowel disease.
The team found significant heterogeneity in the overall analysis.
As heterogeneity among studies could be explained by differences in metabolite assay methods, an analysis including only studies using the reference method by Lennard et al was performed, and the pooled odds ratio for clinical remission among patients with 6-thioguanine nucleotides levels over a cut-off value between 230 and 260 pmol/8.10^8 RBC was 3.15.
Dr Moreau's team concludes, "This meta-analysis clearly establishes an association between 6-thioguanine nucleotides levels and clinical remission rates in patients with inflammatory bowel disease, and explains the heterogeneity of results among selected studies."
"The lack of standardization in 6-thioguanine nucleotides assays is responsible for recent contradictory results."
"Whether therapeutic drug monitoring of thiopurines should be systematically used in clinical practice in inflammatory bowel disease to improve disease outcomes will require further investigation."