Table 4.

Common conditioning regimens used in PID HSCT, adapted from (17).

Conditioning regimens∧	Drug combination	+/–	Engrafment rate	Toxicity
Myeloablative Conditioning (MAC)*	Bu (90 ± 5 mg × h/L iv) + Flu (160 mg/m2)	Alemtuzumab or ATG	High	High
Reduced Intensity Conditioning (RIC)	Bu (60 ±5 mg × h/L iv) + Flu (180 mg/m2)	Alemtuzumab or ATG	Variable	Low
	Flu (150 mg/m2) + Melphalan (140 mg/m2)	Alemtuzumab
	Treosulphan (42 g/m2) + Flu (150 mg/m2)°	None or Alemtuzumab

^∧Thiotepa can be used in addition to current conditioning regimen when more myelosuppression is needed.

^*Bu/CY conditioning is associated with increased risk of VOD and no longer recommended.

^°Regimen also assessed as reduced toxicity conditioning. Bu, busulfan; Flu, fludarabine; ATG, antithymocyte globulin; CY, cyclophosphamide; VOD, veno-occlusive disease.