Associations of HLA genotypes with antithyroid drug-induced agranulocytosis: A systematic review and meta-analysis of pharmacogenomics studies

Aims: Antithyroid drug (ATD)-induced agranulocytosis is a life-threatening adverse drug reaction. Previous studies suggested that HLA genotypes may play an important role in ATD-induced agranulocytosis. To examine the associations between HLA genotypes and ATD-induced agranulocytosis, we conducted a systematic review and meta-analysis of pharmacogenomics studies. Methods: We searched the MEDLINE, Embase and CENTRAL databases on 16 June 2018 for case–control studies on the associations between HLA genotypes with ATD-induced agranulocytosis. The Newcastle–Ottawa scale was used to evaluate the risk of bias of included studies. We conducted random-effects model meta-analysis to obtain pooled odds ratios (ORs) with 95% confidence intervals (CIs) to determine the associations between HLA genotypes and ATD-induced agranulocytosis. Results: We included 5 studies with 142 ATD-induced agranulocytosis cases, 1529 matched ATD-tolerant controls and 5945 healthy controls. The risk of bias of included studies was generally low. ATD-induced agranulocytosis was associated with HLA-B*27:05 (OR 10.97; 95% CI 0.75–159.99), HLA-B*38:02 (OR 19.85; 95% CI 7.94–49.57) and HLA-DRB1*08:03 (OR 5.29; 95% CI 3.44–8.14). After excluding propylthiouracil, the associations of ATD-induced agranulocytosis with HLA-B*27:05 and HLA-B*38:02 were strengthened (OR being 20.61 (95% CI 5.21–81.58) and 40.59 (95% CI 13.24–124.47), respectively). The associations of ATD-induced agranulocytosis with HLA-B*27:05, HLA-B*38:02 and HLA-DRB1*08:03 remained significant when compared to population controls (OR being 7.37 (95% CI 3.86–14.07), 36.43 (95% CI 12.80–103.70) and 5.42 (95% CI 2.36–12.47), respectively). HLA-B*27:05, HLA-B*38:02, and HLA-DRB1*08:03 alleles were associated with ATD-induced agranulocytosis, especially in carbimazole/methimazole-induced agranulocytosis. Conclusions: HLA-B*27:05, HLA-B*38:02 and HLA-DRB1*08:03 alleles were associated with ATD-induced agranulocytosis, especially in carbimazole/methimazole-induced agranulocytosis.