Donor Body Weight Research Articles

Analysis of Causes and Condition of Blood Donation Reaction Under Collective Emergency Blood Donation

To explore the causes and specific conditions of blood donation reaction under the collective emergency unpaid blood donation, and to provide theoretical basis and decision-making reference for drafting the collective emergency unpaid blood donation and blood donation safety. Through a combination of prospective and retrospective models, and statistical methods were used to analyze the causes and conditions of the blood donation response of 10401 people participating in collective emergency unpaid blood donation during 2016.1-2018.8. A total of 10401 person-times donated blood in a sitting manner, and a total of 293 blood donation reactions occurred. By improving the blood donation services year by year, the moderate blood donation reaction during the year 2017 and 2018 was significantly lower than that in 2016 (P＜0.05). In the actual blood donation group of≤100, 200, 300 and 400 ml, the incidence of blood donation reaction was statistically significant (P＜0.05); the incidence of blood donation reaction in the blood donors for 1,2,3 and ＞3 drnations was also statistically significant (P＜0.05); the blood donation reactions rate of B antigen containers was significantly different from the donors without B antigen (P＜0.05); the incidence of blood donation reaction with related to the weight of the donor. The blood donation reaction of collective emergency unpaid blood donation closely relates with mental factors, blood donation service, blood donation frequency and body weight of the blood donor. The first blood donation is more likely to produce blood donation reaction. The blood donation volum≤ 100 ml from blood donors is resulted mostly from blood donation reactions.

Time for evidence-based, standardized donor size matching for pediatric heart transplantation

BackgroundAccurately predicting cardiac size by other body parameters has long been problematic to determine whether a donor heart will serve a given waitlist candidate, yet hundreds of heart donors are turned down annually for size mismatch. ObjectivesWe sought to describe how donor body weight parameters are currently utilized in cardiac transplantation and its influence on waitlist outcomes. MethodsFrom the United Network for Organ Sharing database, pediatric (age <18 years) heart transplant candidates were divided into lower quartile, interquartile, and upper quartile categories based on final maximum acceptable donor–candidate weight ratio (DCW), expressed as percentage. Baseline characteristics and waitlist outcomes, including monthly offers/candidate and survival were compared. ResultsOverall median DCW was 200% (range, 159%-241%). Patients with congenital heart disease had higher DCW than those with cardiomyopathy (223% vs 203%; P < .001). Number of monthly offers/candidate (5.0, 5.6, and 7.2, respectively; P < .001) increased with quartile of DCW. Posttransplant survival was similar amongst the groups (log-rank P > .05). Subgroup analysis of critically ill children showed a waitlist survival advantage in those listed with a DCW ≥200% (P < .001). ConclusionsDespite substantial practice variation in acceptable donor weight in pediatric heart transplantation, patients listed with variable DCW had similar posttransplant survival. However, in critically ill patients, higher DCW was associated with greater waitlist survival. Better understanding of the importance of donor weight could reduce practice variability and improve organ use and waitlist outcomes for pediatric cardiac transplant candidates.

A new noninvasive mechanical bending test accurately predicts ulna bending strength in cadaveric human arms.

High error rates in the prediction of fragility fractures by bone mineral density have motivated searches for better clinical indicators of bone strength, and the high incidence of non-hip, non-spine fractures has raised interest in cortical bone. The aim of this study was to assess the accuracy of Cortical Bone Mechanics Technology™. CBMT is a new non-invasive 3-point bending technique for measuring the mechanical properties of cortical bone in the ulnas of living humans. 35 cadaveric human arms were obtained from small women and large men ranging widely in age (17 < Age < 99 years) and body size (14 < BMI < 40 kg/m2). Noninvasive CBMT measurements of the flexural rigidity of the ulna bones within these arms (EICBMT) were compared to measurements of EI by Quasistatic Mechanical Testing in the ulnas excised from those arms (EIQMT). Ulna bending strength was also measured by QMT as the peak moment before fracture (Mpeak). The open source BoneJ plugin to ImageJ image processing software was used to calculate cortical porosity (CP) in micro-computed tomography images of a 2 mm length of the mid-shaft of each fractured ulna, and the interosseous diameter (IOD) of each ulna was also measured in those images. EICBMT measurements (13 < EICBMT < 97 Nm2) explained 99% of the variance in QMT measurements of ulna bending strength (11 < Mpeak < 90 Nm), but EICBMT was biased high by 30% (p < 0.0001) relative to EIQMT (11 < EIQMT < 69 Nm2). After correcting this bias, EICBMT and EIQMT measurements lay along the identity line (y = 1.00x, R2 = 0.99, SEE = 3.1 Nm2). Predictions of Mpeak by EICBMT were less accurate than predictions by EIQMT (both R2 = 0.99; SEECBMT = 5.9 Nm vs SEEQMT = 4.5 Nm, F = 2.92, p = 0.001), but EICBMT predictions were substantially more accurate than those by IOD (R2 = 0.79; SEEIOD = 10.6 Nm, F = 3.30, p < 0.001) and CP (R2 = 0.35; SEECP = 18.9 Nm, F = 10.45, p < 10-9). Predictions by EICBMT were also more accurate than predictions by arm donor height (R2 = 0.63; SEE = 14.3 Nm, F = 5.87, p < 10-6), body weight (R2 = 0.77; SEE = 11.1 Nm, F = 3.54, p < 0.001) and BMI (R2 = 0.64; SEE = 14.1 Nm, F = 2.39, p < 0.01). In forward stepwise multiple regression beginning with EICBMT, only age explained any additional variance in ulna bending strength (ΔR2 = 0.3%, F = 8.03, p = 0.008). Noninvasive CBMT measurements of ulna EI explain 99% of individual differences in QMT measurements of ulna bending strength in cadaveric human arms.

Biomechanical Robustness of a Contemporary Cementless Stem to Surgical Variation in Stem Size and Position.

Successful designs of total hip replacement (THR) need to be robust to surgical variation in sizing and positioning of the femoral stem. This study presents an automated method for comprehensive evaluation of the potential impact of surgical variability in sizing and positioning on the primary stability of a contemporary cementless femoral stem (Corail®, DePuy Synthes). A patient-specific finite element (FE) model of a femur was generated from computed tomography (CT) images from a female donor. An automated algorithm was developed to span the plausible surgical envelope of implant positions constrained by the inner cortical boundary. The analysis was performed on four stem sizes: oversized, ideal (nominal) sized, and undersized by up to two stem sizes. For each size, Latin hypercube sampling was used to generate models for 100 unique alignment scenarios. For each scenario, peak hip contact and muscle forces published for stair climbing were scaled to the donor's body weight and applied to the model. The risk of implant loosening was assessed by comparing the bone-implant micromotion/strains to thresholds (150 μm and 7000 με) above which fibrous tissue is expected to prevail and the periprosthetic bone to yield, respectively. The risk of long-term loosening due to adverse bone resorption was assessed using bone adaptation theory. The range of implant positions generated effectively spanned the available intracortical space. The Corail stem was found stable and robust to changes in size and position, with the majority of the bone-implant interface undergoing micromotion and interfacial strains that are well below 150 μm and 7000 με, respectively. Nevertheless, the range of implant positions generated caused an increase of up to 50% in peak micromotion and up to 25% in interfacial strains, particularly for retroverted stems placed in a medial position.

Continuous Mononuclear Cell Collection (cMNC) protocol impact on hematopoietic stem cell collections in donors with negative collection predictors

BackgroundRecently, novel protocol utilizing Continuous Mononuclear Cell Collection (cMNC) have been introduced for leukapheresis. We compared the efficacy of cMNC with an older protocol – mononuclear cell collection (MNC) for CD34+ cell collection in unrelated donors with negative stem cell collection predictors. Material and methodsRetrospective data from a series of 258 consecutive unrelated hematopoietic stem cell donors was included in this single-center study (80 donors collected with cMNC and 178 with MNC). The donors with poor predictors for collection such as low number of circulating CD34+ cells and/or weight disproportion were assigned to the cMNC arm. ResultsThe cMNC protocol yielded a higher number of CD34 + cells per donor body weight (7.63 × 106/kg vs 6.82 × 106/kg, p = 0.027). One apheresis was sufficient for collection of target cell number in 89% individuals from both groups despite negative predictors in the cMNC group. In donors with CD34 + cell count <100/μL and a body weight disproportion between donor and recipient one apheresis was sufficient in 83% of donors in cMNC group and in 58% in MNC group (p = 0.0345) with collection efficiency CE2% values of 61% for cMNC and 62% for MNC (p = 0.77). ConclusioncMNC protocol is more efficient in donors with low pre-apheresis CD34+ cell count and weight disproportion between donor and recipient. This suggests that the use of cMNC in unrelated donors could possibly further improve the results of HSC collections.

The impact of donor and recipient weight incompatibility on renal transplant outcomes.

Donor/recipient size mismatching and correlation to allograft outcome remains poorly defined. This study assessed the impact of donor body weight (DBW) to recipient body weight (RBW) ratio on allograft function and survival. A total of 898 deceased donor renal transplant recipients were included in the study. Patients were divided into quartiles depending on the ratio of DBW/RBW: Q1 (≤0.88), Q2 (0.89-1.00), Q3 (1.01-1.22) and Q4 (>1.22). Donor and recipient characteristics were obtained from the national kidney transplant service database. Serum creatinine and estimated glomerular filtration rate (eGFR) at 1 and 5 years after transplant were compared. Q4 patients had a higher eGFR 1 year post-transplant (median 59.5ml/min, IQR 46.8-76.2) compared to Q1-Q3 which had median eGFRs of 54.3, 54.8 and 55.3ml/min, respectively (p<0.001). At 5 years post-transplant, there were modest differences in the eGFR across the four quartiles, Q1-4 with median eGFRs of 56.9, 61.1, 61.2 and 58.6ml/min, respectively (p=0.02). However, there were no significant differences in 1- and 5-year allograft survival between groups. In the setting of deceased donor renal transplantation, mismatching of donor to recipient weight had no impact on 5-year allograft survival, but a low DBW/RBW ratio is modestly associated with lower eGFR.

Superovulatory responses in cynomolgus monkeys (Macaca fascicularis) depend on the interaction between donor status and superovulation method used.

The current study was performed to investigate the effect of oocyte donor status, including age and body weight, on metaphase II (MII) oocyte recovery using two superovulation methods in cynomolgus monkeys. The use of Method A [recombinant gonadotrophin (75 IU/kg, 3 ×, 3-day intervals) and human chorionic gonadotropin (hCG)] led to great increases in ovary size and the mean number of MII oocytes retrieved in age- and body-weight-dependent manner; in contrast, both the parameters were similar in Method B [recombinant gonadotrophin (60 IU, twice daily, 6 days), recombinant gonadotropin and recombinant human luteinizing hormone (rhLH) (60 IU, twice daily, 3 days), and hCG]. Importantly, Method A showed maximal MII oocyte recovery rate in > 60-month-old or 4.5–5.0-kg female monkeys, whereas Method B was equally effective regardless of the donor age and body weight. These results indicate that superovulatory responses depend on the interaction between oocyte donor status and the superovulation method used in cynomolgus monkeys.

Effect of Calcaneus Fracture Gap Without Step-Off on Stress Distribution Across the Subtalar Joint.

Subtalar arthritis is a common consequence following calcaneal fracture, and its development is related to the severity of the fracture. Previous calcaneal fracture models have demonstrated altered contact characteristics when a step-off is created in the posterior facet articular surface. Changes in posterior facet contact characteristics have not been previously characterized for calcaneal fracture gap without step-off. The contact characteristics (peak pressure, area of contact, and centroid of pressure) of the posterior facet of the subtalar joint were determined in 6 cadaveric specimens. After creating a calcaneal fracture to simulate a Sanders type II fracture, the contact characteristics were determined with the posterior facet anatomically reduced followed by an incremental increase in fracture gap displacement of 2, 3, and 5 mm without a step-off of the articular surface. Peak pressure on the medial fragment was significantly less with a 5-mm gap compared to a 2- or 3-mm gap, or reduced. On the lateral fragment, the peak pressure was significantly increased with a 5-mm gap compared to a 2- or 3-mm gap. Contact area significantly changed with increased gap. In this study, there were no significant differences in contact characteristics between a <3-mm gap and an anatomically reduced fracture, conceding the study limitations including limiting axial loading to 50% of donor body weight. A small amount of articular incongruity without a step-off can be tolerated by the subtalar joint, in contrast to articular incongruity with a step-off present.

Interaction effect of donor age and body weight on superovulation and embryo production performance in goats

The experiment was conducted to evaluate the interaction effect of age and body weight (BW) on ovarian responses in follicle stimulating hormone (pFSH) superovulated doe. Does (40) were divided into groups 1 (2–4 years old and 15–25 kg BW), 2 (2–4 years old and 26–35 kg BW), 3 (5–7 years old and 15–25 kg BW) and 4 (5–7 years old and 26–35 kg BW). Oestrus was synchronized by inserting a controlled internal drug release (CIDR) and a single injection of prostaglandin F2α. Does were administered 5 mg pFSH/kg BW, twice a day through 6 decreasing dosages. All does of Group 2 showed oestrus signs, while 70, 70 and 80% of does of group 1, 3 and 4 showed oestrus, respectively. Natural mating was carried out when does showed oestrus. Ovarian responses were evaluated on Day 7 after CIDR removal. Group 2 produced higher number of corpus luteum than other groups. Average number of embryo production was higher in group 2 than that in groups 1, 4 and 3. Transferable embryo production was higher in group 2 than in groups 4 and 1. Group 3 did not produce any transferable embryos. Numbers of anovulatory follicles per doe were similar in group 2 and 4, but higher than that in group 1 and 3 and did not show any differences. Does in group 2 gave higher number of embryos than other groups, indicating that donor age and BW interaction is an important consideration for superovulation in goats.

Autologous endothelial progenitor cells improve allograft survival in porcine lung transplantation with prolonged ischemia.

As endothelial progenitor cells (EPCs) attenuated acute lung injury (ALI) in rabbit model, we hypothesized that autologous EPCs preserved lung graft function during the acute reperfusion period of lung transplantation and tested the therapeutic potential of EPCs in a porcine model of lung transplantation with prolonged graft ischemia. Day-7 EPCs isolated from the recipient subjects or plain culture media were administered into the left pulmonary artery immediately before restoration of pulmonary blood flow in a porcine lung allotransplantation model, with the transplantation surgeons blinded to the content of injection. Hemodynamics and arterial blood gas were recorded, and the right pulmonary artery was occluded 30 min after reperfusion to evaluate the lung graft function. The lung grafts were sectioned for histological examination at the end of experiments. The total ischemic time for lung graft was approximately 14 h. All animals receiving plain medium died within 40 min after reperfusion, but 3 out of 5 (60%) piglets receiving EPCs survived up to 4 h after diversion of the entire cardiac output into the lung graft (P<0.01). The donor body weight, recipient body weight, cold ischemic time, and time for anastomosis were comparable between the EPC and control group (P=0.989, 0.822, 0.843, and 0.452, respectively). The mean aortic pressure decreased, and the cardiac output and mean pulmonary artery pressure elevated after right pulmonary artery occlusion. All these parameters were gradually compensated in the EPC group but decompensated in the control group. Better preservation of gas exchange function, reduced thrombi formation in the terminal pulmonary arterioles, and attenuated interstitial hemorrhage of the lung graft were observed in the EPC group. We concluded autologous EPCs significantly enhanced the function of lung allograft and improved survival in a porcine model of lung transplantation with prolonged ischemia.

Ad Integrum Functional and Volumetric Recovery in Right Lobe Living Donors: Is It Really Complete 1 Year After Donor Hepatectomy?

The partial liver's ability to regenerate both as a graft and remnant justifies right lobe (RL) living donor liver transplantation. We studied (using biochemical and radiological parameters) the rate, extent of, and predictors of functional and volumetric recovery of the remnant left liver (RLL) during the first year in 91 consecutive RL donors. Recovery of normal liver function (prothrombin time [PT] ≥70% of normal and total bilirubin [TB] ≤20 µmol/L), liver volumetric recovery, and percentage RLL growth were analyzed. Normal liver function was regained by postoperative day's 7, 30, and 365 in 52%, 86%, and 96% donors, respectively. Similarly, mean liver volumetric recovery was 64%, 71%, and 85%; whereas the percentage liver growth was 85%, 105%, and 146%, respectively. Preoperative PT value (p = 0.01), RLL/total liver volume (TLV) ratio (p = 0.03), middle hepatic vein harvesting (p = 0.02), and postoperative peak TB (p < 0.01) were predictors of early functional recovery, whereas donor age (p = 0.03), RLL/TLV ratio (p = 0.004), and TLV/ body weight ratio (p = 0.02) predicted early volumetric recuperation. One-year post-RL donor hepatectomy, though functional recovery occurs in almost all (96%), donors had incomplete restoration (85%) of preoperative total liver volume. Modifiable predictors of regeneration could help in better and safer donor selection, while continuing to ensure successful recipient outcomes.

Status on Heart Transplantation in China.

Status on Heart Transplantation in China.

Bone Marrow Harvesting of Allogeneic Donors in an Outpatient Setting: A Single-Center Experience

The aim of this retrospective study was to assess the safety and efficacy of bone marrow (BM) harvesting of allogeneic donors in an outpatient setting. Data of 226 related and unrelated donors who underwent BM harvest under general anesthesia at our institution from 2002 to 2014 were analyzed. Sixteen patients were a priori planned for admission for social reasons and 210 patients underwent BM harvesting with the intention to perform this procedure on an outpatient basis. To identify factors that predispose for hospital admission, we retrospectively analyzed donor characteristics and collection parameters. Outpatient treatment was performed in 178 of 210 donors (85%), whereas 32 donors (15%) required admission for clinical reasons (mainly clinically relevant anemia and circulatory problems). These individuals were not significantly different in sex distribution, age, donor's body weight, and the proportion of related donors from those who were not admitted. However, we found a significantly higher collection volume per kilogram donor's body weight in inpatients compared with volume for outpatients (16 versus 13 mL/kg body weight, P < .001). Severe adverse events or deaths occurred neither in the inpatient nor in the outpatient setting. Our study demonstrated that BM harvest in an outpatient setting is safe and feasible for the majority of allogeneic donors. A high volume of BM represented a major risk factor for inpatient admission.

Islet Product Characteristics and Factors Related to Successful Human Islet Transplantation From the Collaborative Islet Transplant Registry (CITR) 1999–2010

The Collaborative Islet Transplant Registry (CITR) collects data on clinical islet isolations and transplants. This retrospective report analyzed 1017 islet isolation procedures performed for 537 recipients of allogeneic clinical islet transplantation in 1999–2010. This study describes changes in donor and islet isolation variables by era and factors associated with quantity and quality of final islet products. Donor body weight and BMI increased significantly over the period (p < 0.001). Islet yield measures have improved with time including islet equivalent (IEQ)/particle ratio and IEQs infused. The average dose of islets infused significantly increased in the era of 2007–2010 when compared to 1999–2002 (445.4 ± 156.8 vs. 421.3 ± 155.4 ×103 IEQ; p < 0.05). Islet purity and total number of β cells significantly improved over the study period (p < 0.01 and <0.05, respectively). Otherwise, the quality of clinical islets has remained consistently very high through this period, and differs substantially from nonclinical islets. In multivariate analysis of all recipient, donor and islet factors, and medical management factors, the only islet product characteristic that correlated with clinical outcomes was total IEQs infused. This analysis shows improvements in both quantity and some quality criteria of clinical islets produced over 1999–2010, and these parallel improvements in clinical outcomes over the same period.

Prediction of Renal Allograft Function at POD 7 With Pre/Peri-Operative Clinical Data.

(Background) Serum creatinine (s-Cr) level reaches its nadir around POD 7 after renal transplant. Although it is an important marker of allograft function, systematic formula to predict it is lacking. (Method) We retrospectively analyzed a correlation of recipient's s-Cr with clinical data of a donor and a recipient through symbolic regression. We used 176 pairs of live renal transplantations (LRTx) that showed eventless peri/post-operative courses as a training set to construct a prediction formula of recipient's s-Cr at POD 7. Then we took other 70 pairs of LRTx that also had uncomplicated courses as a future set to validate the efficacy of the formula. (Results) In the course of constructing a formula, body weight, gender, age were significant factors in the prediction. A donor's s-Cr/2hr-Cr clearance, ischemic time and graft weight were also significant. ABO-incompatibility, HLA mismatch, dialysis period, immunosuppression protocol and blood pressure were not. Average error of absolute values between observed s-Cr and predicted one using the training set was 0.18±0.16mg/dl. 61.9% of such errors were <0.2mg/dl and 91.4% were <0.4mg/dl. The same formula was applied to the future set and average error was 0.22±0.19mg/dl while in 78.6% of them the predicted level was higher than the observed one.Figure: No Caption available.Then 11 cases (15.7%) showed prediction errors of >0.4mg/dl and their background revealed significantly lighter body/graft weight of a donor and heavier body weight of a recipient than the rest. (Conclusion) We conclude that it was possible to predict the POD7 s-Cr of a recipient with an error of 0.22±0.19mg/dl as long as the clinical course was uneventful. It was also revealed that s-Cr was not affected so much in uneventful cases by ABO-incompatibility, HLA mismatch, regimen and blood pressure as by age, body weigh, graft weight, donor's renal function and ischemic time. Since in 78.6% of the future cases predicted s-Cr was nearly equal or higher than the observed one, it could be used as an upper threshold of s-Cr for standard renal graft function.

Hepatic Pathologic Change After Donor Weight Reduction in Potential Living Liver Donors With Fatty Liver.

Background Fatty liver is critical for donor selection, which has been associated with a risk of complication for both donor and recipient after liver transplantation. After living donor weight reduction for a short-term, the change of liver fat percentile and pathologic findings were investigated. Methods A total of 356 living donor candidate were between January 2011 and November 2013 at a single center. Of them, 18 donors tried to lose their weight reduction. Fat fraction was estimated on preoperative non-invasive MR spectroscopy. And liver biopsy findings were analyzed before and after weight reduction. Results Eighteen donor candidates lose mean 3.6 ± 3.1 kg of their weight for mean 43.9 ± 31.0 days (range 7-107 days) and BMI was significantly decreased to 25.9 ± 3.1 kg/m2 from 27.1 ± 3.2 kg/m2 (p < 0.001). Their fat fractions were also significantly decreased to 6.8 ± 4.5% from 11.4 ± 4.7% (p < 0.001). Although preoperative liver biopsy showed that ballooning change (n=3, 23.1%), inflammation (n=9, 69.2%), fibrosis (n=2, 15.4%) and necrosis (n=3, 16.7%) before weight reduction, intraoperative biopsy showed no fibrosis, no necrosis, decreased inflammation (n=2, 17.6%) and improved ballooning change of hepatocyte (n=1, 5.9%) after weight reduction.Table: No Caption available.Although one candidate could not donate his liver finally because of steatohepatitis, the others recovered uneventfully. Conclusions Donor body weight reduction can expand donor pool and contribute to donor safety.

Feasibility of marrow harvesting from pediatric sibling donors without hematopoietic growth factors and allotransfusion.

We retrospectively studied 108 marrow harvests from 105 pediatric sibling donors. The median age of donors was 8 years (range: 1-15) and the median body weight was 27 kg (range: 10-100). The volumes of aspirated marrow were 5.0-23.8 mL/kg donor body weight, and harvested bone marrow volume exceeded 15 mL/kg in 42% of the donors. A total of 100 autologous blood donations were performed, and eight donors had red cells salvaged from their harvests reinfused. The median Hb levels before and after harvests were 12.3 g/dL (range: 10.0-14.7) and 11.0 g/dL (range: 8.9-13.8), respectively. None of the donors received allogeneic blood transfusions or hematopoietic growth factors such as EPO and G-CSF before or after collection. Transplanted dose was 1.4-10.8 × 10(8) cells/kg recipient body weight without differences due to donor age. Higher concentrations of nucleated and CD34(+) cells were obtained from younger donors. All donors tolerated the procedures well, with no serious complications. Thus, children may safely donate marrow for allogeneic transplantation, and the yields of nucleated cells for engraftment are substantial.

Large donors transfer more sperm, but depletion is faster in a promiscuous hermaphrodite

Males are limited in sperm and seminal fluid, which can lead to prudent sperm allocation across consecutive matings. While sperm depletion is usually considered a population characteristic, we investigated an individual size-related variation in sperm depletion in the promiscuous sea slug Chelidonura sandrana. We found that sperm counts substantially declined across four successive copulations, indicating sperm depletion. Sperm depletion occurred at a disproportionally fast rate in larger sperm donors. Based on our finding of body size-dependent sperm depletion, we further investigated whether this translates into prudent sperm allocation across ejaculates. We found no evidence that slugs adjusted the number of delivered sperm in response to partner body weight, a tight proxy of fecundity. Instead, sperm counts increased with sperm donor body weight. Sperm donation independent of partner body size and—as found in previous work—partner novelty leaves scope for currently unidentified traits like the sperm competition environment to affect male sperm allocation. Alternatively, we propose that, in C. sandrana, a low optimal male mating rate close to the female optimum as indicated by our data may ultimately render indiscriminate sperm allocation the most beneficial male mating strategy.

Peripheral blood stem cell yield calculated using preapheresis absolute CD34+ cell count, peripheral blood volume processed, and donor body weight accurately predicts actual yield at multiple centers.

Accurate prediction of stem cell yield is important for planning leukapheresis procedures. A formula has been published (Pierelli et al., Vox Sang 2006;91:126-34) to estimate the CD34+ dose collected on the first day of leukapheresis that was based on the preapheresis peripheral blood (PB) CD34+ counts, the blood volume processed, and the donor's weight. The aim of this study was to assess the predictive value of this formula. Data were retrospectively collected on 1126 consecutive PB stem cell harvests conducted at five institutions. Information on age, sex, diagnosis, weight, preapheresis absolute peripheral CD34+ count, total blood volume processed, and CD34+ cells harvested per kilogram of body weight on the first day of apheresis was collected. Among donors at least 18 years old, Pearson's correlation coefficient (r) between actual yield (AY) and predicted yield (PY) was 0.76. To characterize this correlation, AY and PY were classified as being within the conventionally acceptable CD34+ doses (>2 × 10(6) -5 × 10(6) cells/kg), below this range (≤2 × 10(6) cells/kg), or above it (>5 × 10(6) cells/kg). The positive predictive value (PPV) of PY was estimated considering the distribution of AY as the "gold standard." PPV was relatively high for PY of more than 5 × 10(6) cells/kg (85%), moderate for PY of not more than 2 × 10(6) cells/kg (72%), and low for PY more than 2 × 10(6) to 5 × 10(6) cells/kg (56%). A consistent pattern was observed within institutions. The formula of Pierelli et al. is associated with a PPV that is high, moderate, and relatively low for the corresponding predicted CD34+ doses.

Prediction model for CD34 positive cell yield in peripheral blood stem cell collection on the fourth day after G-CSF administration in healthy donors

Allogeneic peripheral blood stem cell transplantation (PBSCT) is an indispensable treatment option for hematological malignancy. The optimal collection day after granulocyte colony-stimulating factor (G-CSF) administration should be determined by peripheral blood pre-apheresis CD34 positive (CD34⁺) cell percentage. However, pre-apheresis CD34⁺ cell analysis is not available for most institutions in Japan. Prediction of the optimal collection day based on objective parameters, other than direct CD34⁺ cell count, is thus an important matter for investigation. To identify potential predictive factors, clinical parameters in 79 related donors who received allogeneic peripheral blood stem cell (PBSC) collection were analyzed. Eight factors were significantly correlated with the number of CD34⁺ cells per donor body weight on the fourth day (day 4) after G-CSF administration in univariate analysis. Using multi-regression analysis, we made a simple scoring system comprising age, sex, LDH on day 4 and RBC count at the baseline, which significantly predicted CD34⁺ cell yield (P = 0.048). This system allows us to determine the optimal PBSC collection day. When the score is 0 or 1 on day 4, starting apheresis on day 5 potentially helps avoiding the need for multiple harvests. Score 3 or 4 on day 4 is indicative of better performance if apheresis is started on day 4.