Including AZT in the initial ART regimen was not associated with an increased risk of early severe anaemia compared with initiation of a d4T-based regimen OR1.33 (95% CI 0.85 - 2.07), when adjusted for age, gender, BMI, WHO stage, baseline CD4 T cell count, baseline Hb, MCV, and incident TB. Here, GSTM1 is linked to anemia (phenotype).