Differential impact of pegfilgrastim, a recombinant human granulocyte colony stimulating factor, on the neutrophil count of male and female deer mice (Peromyscus maniculatus bairdii).

BACKGROUND: An increasing body of research implicates inflammatory processes, including alterations in the neutrophil-lymphocyte ratio (NLR), in the pathophysiology of psychiatric illness. The deer mouse (Peromyscus maniculatus bairdii) is commonly studied for its naturalistic expression of compulsive-like behaviour. Towards future efforts to gain an understanding of how innate and adaptive immune processes might be involved in this model, we aimed to study the effects of pegfilgrastim, a pegylated recombinant human granulocyte colony-stimulating factor (g-CSF) analogue, on the NLR of both male and female deer mice. METHODS: Briefly, 54 deer mice (equally distributed between sexes) were exposed to a single injection with either control or pegfilgrastim (0.1 or 1 mg/kg) (n = 18 per group). Six mice of each group (three per sex) were euthanized on days two, four and seven post-administration, their blood collected and the NLR calculated. Data were analysed by means of ordinary three-way ANOVA, followed by Bonferroni post-hoc testing. RESULTS: Irrespective of dose, pegfilgrastim resulted in higher NLR values in mice of both sexes at days four and seven of testing. However, female mice exposed to the higher dose, presented with significantly higher NLR values irrespective of time, compared to male mice exposed to the same. CONCLUSION: The data generated from this work highlight important dose- and sex-specific aspects of pegfilgrastim with female mice showing heighted elevation of the NLR in response to high-dose pegfilgrastim administration only. Since the innate immune components of male and female deer mice is differentially sensitive to g-CSF stimulation, our results provide a useful basis for further study of sex-specific immunological processes in deer mice.

CD34+ cell yield among healthy donors: Large-scale model development and validation.

BACKGROUND: Successful engraftment in hematopoietic stem cell transplantation necessitates the collection of an adequate dose of CD34+ cells. Thus, the precise estimation of CD34+ cells harvested via apheresis is critical. Current CD34+ cell yield prediction models have limited reproducibility. This study aims to develop a more reliable and universally applicable model by utilizing a large dataset, enhancing yield predictions, optimizing the collection process, and improving clinical outcomes. MATERIALS AND METHODS: A secondary analysis was conducted using the Center for International Blood and Marrow Transplant Research database, involving data from over 17 000 healthy donors who underwent filgrastim-mobilized hematopoietic progenitor cell apheresis. Linear regression, gradient boosting regressor, and logistic regression classification models were employed to predict CD34+ cell yield. RESULTS: Key predictors identified include pre-apheresis CD34+ cell count, weight, age, sex, and blood volume processed. The linear regression model achieved a coefficient of determination (R2) value of 0.66 and a correlation coefficient (r) of 0.81. The gradient boosting regressor model demonstrated marginally improved results with an R2 value of 0.67 and an r value of 0.82. The logistic regression classification model achieved a predictive accuracy of 96% at the 200 × 106 CD34+ cell count threshold. At thresholds of 400, 600, 800, and 1000 × 106 CD34+ cell count, the accuracies were 88%, 83%, 83%, and 88%, respectively. The model demonstrated a high area under the receiver operator curve scores ranging from 0.90 to 0.93. CONCLUSION: This study introduces advanced predictive models for estimating CD34+ cell yield, with the logistic regression classification model demonstrating remarkable accuracy and practical utility.

Comparison of biosimilar filgrastim and originator filgrastim for peripheral blood stem cell mobilization for allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Nivestym, a biosimilar granulocyte colony-stimulating factor (G-CSF) to the originator filgrastim (Neupogen), is now being used for the mobilization of peripheral blood stem cells (PBSC) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). We aim to compare the efficacy of Nivestym and Neupogen for PBSC mobilization in healthy allogeneic donors. METHODS: We conducted a retrospective single-center study including 541 adult allo-HSCT donors receiving Nivestym (January 2013-July 2020), or Neupogen (July 2020-June 2023) for donor PBSC mobilization. Bivariate analysis was conducted using SPSS version 28. Statistical significance was determined at a p-value <.05. RESULTS: Our study included 541 allo-HSCT donors who received Neupogen (n = 345, 64%) or Nivestym (n = 196, 36%) for PBSC mobilization. The median age was 47 years (range 17-76). The median donor weight was 86 kg (95% confidence interval [CI]: 87-91). Donors receiving Neupogen had similar pre-G-CSF white blood cell count, CD34+ percentages, and circulating CD34+ count compared with donors receiving Nivestym. The Neupogen group had similar median PBSC product total neutrophil count, CD34+ percentage, absolute CD34+ count, and infused CD34+ dose compared with the Nivestym group. For donors aged 35 years or younger, the median CD34+ dose was higher in donors who received Neupogen compared with Nivestym (6.9 vs. 6.3 million cells/kg, p = .044). CONCLUSIONS: Nivestym demonstrated similar efficacy for PBSC mobilization compared with Neupogen among allo-HSCT donors. In donors aged 35 years or younger, a slightly lower PBSC product CD34+ count was noted with Nivestym compared with Neupogen.

A global assessment of hemostatic function of healthy allogeneic stem cell donors undergoing apheresis by rotational thromboelastometry.

INTRODUCTION: Peripheral blood stem cell (PBSC) collection via apheresis requires the administration of granulocyte colony-stimulating factor (filgrastim) to stem cell donors. Several reports have shown that filgrastim administration and apheresis procedure induce a hypercoagulable state across PBSC collection, which might predispose certain donors to thrombotic complications. METHODS: We evaluated the hemostatic functions of healthy allogeneic stem cell donors by rotational thromboelastometry (ROTEM). Blood samples from healthy donors (n = 30) were collected at defined time points: before filgrastim (baseline), on the day of apheresis before and after the procedure, and 1 week after apheresis. RESULTS: The results indicated that hemostatic changes are temporary since all parameters in both EXTEM and INTEM assays are restored to their initial values 1 week after the apheresis. CONCLUSION: We concluded that stem cell apheresis does not induce a hypercoagulable state in healthy donors. This is the first study evaluating the hemostatic functions of stem cell donors by ROTEM.

Biological potency evaluation and characterization of rhG-CSF in pharmaceutical products / Avaliação biológica da potência e caracterização de rhG-CSF em produtos farmacêuticos

Realizou-se a identificação do fator estimulador da colônia de granulócitos humanos recombinante em produtos farmacêuticos por eletroforese em gel de poliacrilamida não redutora e imunodetecção com anticorpos específicos, que apresentaram banda única na região de, aproximadamente, 19 kDa. A avaliação de potência baseada na contagem do número de neutrófilos em camundongos com neutropenia forneceu valores entre 88,4 ù 122,4 % em relação à potência declarada. A precisão expressa pela ponderação, calculada nos ensaios independentes, forneceu valores entre 141 e 432. As amostras lote-a-lote cumpriram os requisitos dos testes de toxicidade e endotoxinas bacterianas. Os resultados dos ensaios biológicos e imunológicos demonstram a qualidade dos produtos farmacêuticos em uso clínico, e as especificações sugeridas contribuem para assegurar a inocuidade e eficácia terapêutica dos produtos biológicos.