Background/Objectives: Encouraging results have been reported for Platelet-Rich Plasma (PRP) treatment for knee osteoarthritis (KOA). This study reports the efficacy and safety of a high dose of neutrophile and red-blood-cell-depleted PRP to treat patients with KOA. Methods: A total of 212 consecutive patients diagnosed with Kellgren–Lawrence (KL) grading 1–3 KOA chronic knee pain for at least 1 year were treated with three injections at 15-day intervals with a high dose of neutrophil-depleted PRP (4 billion platelets). Clinical outcomes were retrospectively recorded as the percentage of responders at 3-, 6-, and 12-month follow-up, following the OMERACT-OARSI criteria. Pain, through the VAS score and WOMAC score, was also been recorded. Results: A total of 4 mL of PRP containing 4 × 10⁹ platelets was obtained by single-spin centrifugation and injected intra-articularly into each patient with no preactivation. The overall responder rate of patients responding to the OMERACT-OARSI criteria at 3, 6, and 12 months was 68.9%, 72.7%, and 70.6%, respectively. A significant improvement in VAS and WOMAC scores at 3-, 6-, and 12-month follow-up compared to the pretreatment value (p < 0.01) was observed. The lowest VAS score was observed at 6 months overall and in all three KL-graded groups. The KL2 groups showed the best results regarding pain reduction and their WOMAC score at 6 months (p < 0.01). Conclusions: For KL1–3 KOA, a high dosage of neutrophil-depleted PRP is a successful treatment. It has long-lasting effects that last up to one year, relieves symptoms, and may slow the advancement of the disease.

Plerixafor is widely used as up-front treatment with G-CSF to enhance peripheral blood hematopoietic stem cell output in patients failing previous mobilizations. Less frequently, plerixafor is used to rescue an unsatisfactory mobilization following chemotherapy (CT) and G-CSF. This study investigates if pre-collection factors affect the CD34+ cell harvest in chemotherapy and G-CSF mobilizations rescued by plerixafor. Clinical and hematological data relative to patients, mobilization, and apheresis products were retrospectively examined. The outcome was completing a target cell dose ≥ 2 × 10⁶ CD34+ cells/kg at first apheresis. The effect exerted on the outcome by patient- and disease-related factors was investigated by univariate and multivariate logistic regression analysis. The analysis included data from 42 patients affected by hematological (39 patients) and non-hematological malignancies (three patients). Twenty-nine patients (69%) attained the target cell dose at first apheresis. Twelve out of the remaining 13 patients received an additional plerixafor administration, and all accomplished the transplant dose at a second apheresis procedure. Day -1 CD34+ PB count (OR1.46, 95% CI 1.1–1.9, p = 0.008) and platelet count (OR1.0, 95% CI 1.0–1.0, p = 0.033) predicted the achievement of the target dose at first apheresis, independently of pre-mobilization CT, radiation therapy, and disease status at mobilization. At ROC curve analysis, the best cut-off value predicting the successful collection at first apheresis was 7.5/µL for Day -1 CD34+ cell count (AUC 0.830, 0.69 sensitivity, and 0.92 specificity) and 75 × 10⁹/L for Day -1 platelet count (AUC = 0.736, 0.65 sensitivity and 0.85 specificity). In conclusion, on-demand plerixafor rescue allows a successful stem cell collection, irrespectively of disease type and status, prior CT lines, and radiation exposure. Pre-apheresis CD34+ cells and platelet count predict the need for one or two aphereses.

Background/Objectives: Encouraging results reported of Platelet-Rich Plasma (PRP) treatment for knee osteoarthritis (KOA). The present retrospective study reports the efficacy and safety of a high dose of neutrophile and red blood cell-depleted PRP to treat 212 patients with KOA. Methods: 212 consecutive patients diagnosed with Kellgren-Lawrence (KL) grading 1-3 KOA chronic knee pain for at least 1 year were treated with 3 injections at 15-day intervals with a high dose of neutrophil-depleted PRP (4 billion platelets). Clinical outcomes were retrospectively recorded as a percentage of responders at 3,6, and 12-month follow-up, following the OMERACT-OARSI criteria. Pain through VAS score and WOMAC score have also been recorded. Results: 4ml of PRP containing 4X109 platelets were obtained by single spin centrifugation and injected intra-articular into each patient with no pre-activation. The overall responder rate of patients responding to OMERACT-OARSI criteria at 3,6,12 months was 68.9%, 72,7% and 70,6%. There was a significant improvement in VAS and WOMAC scores at 3-, 6- and 12-month follow-up compared to the pre-treatment value (p< 0.01). The lowest VAS score was observed at 6 months overall and in all three-grade KL groups. KL2 groups showed the best results regarding pain reduction and WOMAC score at 6 months (p< 0.01). Conclusions: a high dose of neutrophil-depleted PRP is an effective treatment for KL1-3 KOA. It provides symptomatic relief, can potentially reduce disease progression, and has sustained effects for up to 12 months.