The minimum CD34 threshold depends on prior chemotherapy in autologous peripheral blood stem cell recipients.
We analysed 57 patients with non-myeloid malignancies who received a non-purged autologous PBSCT. All had similar mobilisation and conditioning regimens. A high prior chemotherapy score and the number of chemotherapy lines used (P = 0.015 and P = 0.01, respectively) were adverse predictors of CD34 cell yields. Lower CD34 values (P = 0.002) were seen in patients treated with potent stem cell toxins (BCNU, melphalan, CCNU and mustine), designated toxicity factor 4 agents (TF4). All patients infused with grafts containing CD34 cell doses between 1.0 and 2.0 x 10(6)/kg (range 1.25-1.90) engrafted by day 51. The only variable associated with slow platelet recovery was exposure to TF4 (P = 0.007). The majority of patients with CD34 >1.0 x 10(6)/kg achieved rapid and sustained engraftment and the only predictive factor of delayed recovery is prior exposure to stem cell toxins. Potential PBSCT candidates should if possible avoid first line and salvage chemotherapy containing TF4 drugs. We therefore advocate a minimum CD34 threshold of >1.0 x 10(6)/kg in patients without extensive prior chemoradiotherapy, and > or = 2.0 x 10(6)/kg in all other patients.
Department of Haematology and Bone Marrow Transplantation, Addenbrooke's Hospital, Cambridge, UK.
M K
MK
Gandhi
K
K
Jestice
M A
MA
Scott
D
D
Bloxham
G
G
Bass
R E
RE
Marcus
D000293:Adolescent; D000328:Adult; D018952:Antigens, CD34; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology / Q000627:therapeutic use*; D001772:Blood Cell Count; D002330:Carmustine / Q000494:pharmacology / Q000627:therapeutic use; D003131:Combined Modality Therapy; D005260:Female; D019337:Hematologic Neoplasms / Q000097:blood / Q000628:therapy*; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000473:pathology*; D006801:Humans; D008130:Lomustine / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008466:Mechlorethamine / Q000494:pharmacology / Q000627:therapeutic use; D008558:Melphalan / Q000494:pharmacology / Q000627:therapeutic use; D008875:Middle Aged; D014182:Transplantation, Autologous
D018952:Antigens, CD34; D008466:Mechlorethamine; D008130:Lomustine; D008558:Melphalan; D002330:Carmustine