[1] Constantiaberg Medi Clin, Searll Res Lab Cellular & Mol Biol, Dept Haematol, ZA-7800 Cape Town, South Africa
[2] Constantiaberg Medi Clin, Searll Res Lab Cellular & Mol Biol, Bone Marrow Transplant Unit Incorporating, ZA-7800 Cape Town, South Africa
[3] Groote Schuur Hosp, Div Infect Dis & HIV Med, ZA-7925 Cape Town, South Africa
[4] Univ Stellenbosch, Tygerberg Acad Hosp, Fac Hlth Sci, ZA-7600 Stellenbosch, South Africa
[5] Univ Nebraska Med Ctr, Coll Med, Omaha, NE 68198 USA
[6] Univ Cape Town, Groote Schuur & Red Cross Hosp, Dept Anat Pathol, ZA-7700 Rondebosch, South Africa