caused by the G‐CSF the donors receive to mobilize the PBSCs. Almost all donors experience some side effect [73]. The most common of these is bone pain, but headache, fatigue, and flu‐like symptoms also occur. In response to G‐CSF, the donor’s leukocyte count increases to 30,000–40,000 per microliter, and the platelet count decreases by about 40% [120, 121]. The leukocyte and platelet counts return to normal by about day 16, or about 10 days after the apheresis donation and discontinuation of G‐CSF. There is an increase in alkaline phosphatase, alanine aminotransferase, lactate dehydrogenase, and sodium, and a decrease in glucose, potassium, bilirubin, and blood urea nitrogen. In donors who receive G‐CSF, the spleen size increases [122] and splenic rupture has been reported [123]. Although most donors experience some side effects, these are mild and should interfere with PBSC donation only rarely.
Recently, it has been suggested that platelet and MNC donors may experience prolonged lymphopenia after repeated donations [124]. It is unclear whether this effect is instrument dependent and/or related to other factors such as donor age, and studies are ongoing. Thus far, there appear to be no reports of medical complications associated with this apparent lymphopenia.
Characteristics of the peripheral blood stem cell concentrates
Large quantities of CD34+ cells can be collected from normal donors given G‐CSF for 5 days. G‐CSF doses of 7.5 or 10 mg/day provide a greater yield than 5 mg/day [115], but it is not clear whether there are statistically significant differences in the CD34+ cell yield between 7.5 and 10 mg/day. Because the donor side effects increase with increasing doses of G‐CSF, we recommend that donors be given 7.5 mg/kg/day of G‐CSF to mobilize peripheral blood CD34+ cells [115]. The composition of the PBSC component is shown in Tables 6.3 and 6.4. Most PBSC components contain only a small volume of red cells (mean, 7 mL) but a rather large total number of neutrophils and platelets [115]. This number of platelets is similar to the number of platelets ordinarily provided in a platelet transfusion, and if transfused fresh (i.e., allogeneic transplant) this may provide an additional benefit from the PBSC transfusion. The PBSC concentrate usually has a volume of about 200 mL and contains approximately 3 × 1010 MNCs and 4 × 108 CD34+ cells.
Quality control of peripheral blood stem cell concentrates
Because there is no definitive test for the primordial hematopoietic stem cell, quality control of these PBSC concentrates is not standardized. Cell culture techniques can be used to determine CFU‐GM, BFU‐E, and CFU‐MIX colonies, and the number of CD34+ cells can be determined by flow cytometry. In practice, the dose for transplantation is usually based on cell counting to obtain at least 3 × 108 mononuclear or 5 × 106 CD34+ cells per kilogram of the recipient’s body weight. The results of progenitor assays are not available for about 2 weeks and thus can be used only in retrospect for research purposes. Many centers do not even determine progenitor content because they do not believe there is a correlation with engraftment, although we believe this can be a valuable quality‐control test.
Table 6.3 Effects of 10 μg/kg G‐CSF dose on the quantity of cells collected by one apheresis procedure from healthy people treated with G‐CSF for 5 days (number of cells collected).
Source: Stroncek DF, Clay ME, Smith J, et al. Composition of peripheral blood progenitor cell components collected from healthy donors. Transfusion 1997; 37:411–417. © 1997 John Wiley & Sons. Reproduced with permission of John Wiley & Sons.
| All components (n = 150) | |||
|---|---|---|---|
| Cell type | Mean ± SD | Median | Range |
| WBCs (× 109) | 39.8 ± 21.8 | 36.0 | 15.6–163.3 |
| MNCs (× 109) | 38.1 ± 19.4 | 34.5 | 15.6–139.7 |
| CD34+ cells (× 108) | 452 ± 294 | 383 | 78–1,380 |
| CD34+ cells (× 106 per L processed) | 53.2 ± 33.1 | 46.5 | 9.3–146.3 |
| RBC (mL) | 7.2 ± 3.5 | 7.6 | 0–15.5 |
| Neutrophils (× 109) | 1.77 ± 3.37 | 1.05 | 0–23.68 |
| Platelets (× 1011) | 490 ± 100 | 490 | 250–740 |
MNC, mononuclear cell; RBC, red blood cell; WBC, white blood cell.
Table 6.4 Quantity of cells in the PBSC components.
Source: Stroncek DF, Clay ME, Smith J, et al. Comparison of two blood cell separators in collecting peripheral blood stem cell components. Transfus Med 1997; 7:95–99. © 1997 John Wiley & Sons. Reproduced with permission of John Wiley & Sons.
| Cell type | CS‐3000 (n = 15) | Spectra (n = 14) | P |
|---|---|---|---|
| WBCs (× 109) | 40.9 ± 21.7 | 33.1 ± 10.7 | 0.24 |
| Neutrophils (× 109) | 1.38 ± 1.88 | 5.53 ± 8.71 | 0.001 |
| Mononuclear cells (× 109) | 39.6 ± 21.9 | 26.9 ± 5.6 | 0.02 |
| Platelets (× 109) | 507 ± 98 | 531 ± 116 | 0.54 |
| CD34+ cells (× 106) | 470 ± 353 | 419 ± 351 | 0.69 |
WBC, white blood cell.
There is considerable variation in the number of CD34+ cells collected (Figure 6.3). In our early experience [115], a single‐cytapheresis procedure yielded a median dose of 780–1,658 × 106 CD34+ cells. In approximately 42% of the procedures, this would be an adequate cell dose to transplant 5 × 106 CD34+ cells/kg to a 75‐kg recipient.
In 86% of donors,
