GSTM1 and alpha thalassemia spectrum: In bivariate models, Hb concentration was negatively associated with HbSS genotype, homozygous α+thalassemia, malaria, CRP, AGP, vitamin A deficiency (low inflammation-adjusted RBP), and iron deficiency (low inflammation-adjusted ferritin) and positively associated with plasma folate and vitamin B-12 concentrations (Table 3).