[1] Univ Orange Free State, Fac Hlth Sci, Dept Chem Pathol G3, ZA-9300 Bloemfontein, South Africa
[2] Univ Orange Free State, Univ Acad Hosp, Natl Hlth Lab Serv, Dept Chem Pathol, ZA-9300 Bloemfontein, South Africa
[3] Univ Orange Free State, Dept Haematol & Cell Biol, ZA-9300 Bloemfontein, South Africa
[4] Univ Orange Free State, Dept Internal Med, Metab Res Unit, ZA-9300 Bloemfontein, South Africa