Ideal body weight correlates better with engraftment after PBSC autograft than actual body weight, but is under-estimated in myeloma patients possibly due to disease-related height loss

Ideal body weight is useful for predicting neutrophil engraftment and platelet recovery for overweight and obese recipients in single-unit cord blood transplantation

BACKGROUND

Since cord blood (CB) units are usually selected based on the cell dose /kg, overweight (25 kg/m² ≤ body mass index (BMI) < 30 kg/m²) and obese (30 kg/m² ≤ BMI) recipients tend to have difficulty in getting appropriate CB units. In general, actual body weight (ABW) is used for CB unit selection. However, ideal body weight (IBW) has been reported to be more closely correlated with successful engraftment after autologous, allogeneic bone marrow, and peripheral blood stem cell transplantation than ABW.

OBJECTIVES

We conducted this analysis to clarify the threshold of CD34⁺ cell doses based on ideal body weight (CD34^IBW) and to compare the outcomes among the groups stratified by the threshold according to actual body weight (CD34^ABW) and CD34^IBW for overweight and obese recipients in cord blood transplantation (CBT).

STUDY DESIGN

We retrospectively analyzed 650 overweight and obese recipients who received single-unit CBT. To focus on the recipients who received a low CD34⁺ cell dose /kg, those who received 1.5×10⁵ CD34⁺ cells /ABW or more were excluded. Using a cut-off of 0.8×10⁵ CD34⁺ cells/kg, we compared the outcomes in 3 groups with low CD34^ABW and low CD34^IBW (CD34^Low/Low), low CD34^ABW but high CD34^IBW (CD34^Low/High), and high CD34^ABW and high CD34^IBW (CD34^High/High).

RESULTS

Hematopoietic recoveries were significantly delayed in the CD34^Low/Low group compared with those in the CD34^Low/High group (hazard ratio (HR) 0.67 for neutrophil, P < 0.001; HR 0.72 for platelet, P = 0.014), while those were comparable in the CD34^Low/High and CD34^High/High groups (HR 1.22 for neutrophil, P = 0.16; HR 1.29 for platelet, P = 0.088). Moreover, the CD34^Low/High group demonstrated longer overall survival than the CD34^Low/Low group (HR 1.48, P = 0.011) and comparable survival to the CD34^High/High group (HR 0.93, P = 0.68).

CONCLUSIONS

This finding may address the lack of availability of CB units for some overweight and obese recipients for whom suitable donors are unavailable. Further investigations are warranted to evaluate the appropriateness of ABW and IBW.

Autologous Peripheral Blood Stem Cell Transplantation Among Lymphoproliferative Disease Patients: Factors Influencing Engraftment

Objectives

Autologous peripheral blood stem cells transplantation (APBSCT) is a therapeutic option which can be used in various hematological, neoplastic disorders including lymphoproliferative disease (LPD). Differences in patient populations and treatment modalities in different transplant centers mean it is important to improve the knowledge of the different factors affecting engraftment after APBSCT for the success of this procedure. We sought to determine the factors influencing neutrophil and platelet engraftment after APBSCT in patients with LPD.

Methods

We conducted a retrospective review of 70 patients with LPD (35 with lymphoma and 35 with multiple myeloma) who had undergone APBSCT between January 2008 and December 2016. Data obtained included disease type, treatment, and stem cell characteristics. Kaplan-Meier analysis was performed for probabilities of neutrophil and platelet engraftment occurred and was compared by the log-rank test. The multivariate Cox proportional hazards regression model was used for the analysis of potential independent factors influencing engraftment. A p-value < 0.050 was considered statistically significant.

Results

Most patients were ethnic Malay, the median age at transplantation was 49.5 years. Neutrophil and platelet engraftment occurred in a median time of 18 (range 4–65) and 17 (range 6–66) days, respectively. The majority of patients showed engraftment with 65 (92.9%) and 63 (90.0%) showing neutrophil and platelet engraftment, respectively. We observed significant differences between neutrophil engraftment and patient’s weight (< 60/≥ 60 kg), stage of disease at diagnosis, number of previous chemotherapy cycles (< 8/≥ 8), and pre-transplant radiotherapy. While for platelet engraftment, we found significant differences with gender, patient’s weight (< 60/≥ 60 kg), pre-transplant radiotherapy, and CD34+ dosage (< 5.0/≥ 5.0 × 10⁶/kg and < 7.0/≥ 7.0 × 10⁶/kg). The stage of disease at diagnosis (p = 0.012) and pre-transplant radiotherapy (p = 0.025) were found to be independent factors for neutrophil engraftment whereas patient’s weight (< 60/≥ 60 kg, p = 0.017), age at transplantation (< 50/≥ 50 years, p = 0.038), and CD34+ dosage (< 7.0/≥ 7.0 × 10⁶/kg, p = 0.002) were found to be independent factors for platelet engraftment.

Conclusions

Patients with LPD who presented at an early stage and with no history of radiotherapy had faster neutrophil engraftment after APBSCT, while a younger age at transplantation with a higher dose of CD34+ cells may predict faster platelet engraftment. However, additional studies are necessary for better understanding of engraftment kinetics to improve the success of APBSCT.