[1] Univ Stellenbosch, Div Anat Pathol, Dept Pathol, Fac Med & Hlth Sci, ZA-7505 Tygerberg, South Africa
[2] Tygerberg Acad Hosp, NHLS, Tygerberg, South Africa
[3] NHLS, Port Elizabeth, South Africa
[4] Univ Stellenbosch, Div Pulmonol, Dept Med, Fac Med & Hlth Sci, ZA-7505 Tygerberg, South Africa
[5] Univ Stellenbosch, Div Med Physiol, Dept Biomed Sci, Fac Med & Hlth Sci, ZA-7505 Tygerberg, South Africa