Risk prediction of iron deficiency for plasmapheresis donors in China: Development and validation of a prediction model.

BACKGROUND AND OBJECTIVES: The present study aims to evaluate the iron stores in plasmapheresis donors and develop and validate an iron deficiency (ID) risk prediction model for plasmapheresis donors with potential or existing ID. MATERIALS AND METHODS: We assessed plasmapheresis donors' serum ferritin (SF) and haemoglobin (Hb) levels. The candidate factors showing significant differences in the multivariate logistic regression analysis were used to establish a risk prediction scoring system. The participants were divided into a training cohort and an internal validation cohort in a 7:3 ratio. Additional plasmapheresis donors from a different station were recruited for external validation. RESULTS: The SF levels in both male and female donors in the high-frequency group were significantly lower than those of new donors (male: p < 0.001; female: p = 0.008). The prevalence of ID in female regular donors with a high frequency was significantly higher than that in new donors (33.1% vs. 24.6%; odds ratio = 1.209 [95% CI: 1.035-1.412]). Donation frequency, age, Hb, body mass index and being pre-menopausal were identified as independent risk factors for ID (p < 0.05). The developed model exhibited good discrimination ability (area under the receiver operating characteristic curve >0.7) and calibration (p > 0.05) in development, internal validation cohorts and external validation cohorts. CONCLUSION: A higher donation frequency has been associated with reduced SF levels and an increased risk of ID in women. The developed ID risk prediction model demonstrates moderate discriminative power and good model fitting, suggesting its potential clinical utility.

Development and validation of a nomogram for predicting the risk of vasovagal reactions after plasma donation.

BACKGROUND AND OBJECTIVES: Vasovagal reactions (VVRs) are the most common adverse reactions and are frequently associated with serious donor adverse events. Even mild VVRs can lead to a significant reduction in the likelihood of subsequent donations. The purpose of this study is to explore the factors related to the occurrence of VVRs after plasma donation and to construct a nomogram to identify individuals at risk for VVRs to improve the safety of plasma donors. MATERIALS AND METHODS: We collected the donation data from July 2019 to June 2020 from a plasma center in Sichuan, China, to explore the independent risk factors for vasovagal reactions. From these data, we constructed and validated a predictive model for vasovagal reactions. RESULTS: VVRs after plasma donation occurred 737 times in 120 448 plasma donations (0.66%). Gender, season, donor status, weight, pulse, duration of donation, and cycle were independent risk factors for VVRs (P< 0.05). The concordance index (C-index) of a logistic model in the derivation cohort was 0.916, with a Hosmer-Lemeshow goodness-of-fit probability of 0.795. The C-index of a logistic model in the validation cohort was 0.916, with a Hosmer-Lemeshow goodness-of-fit probability of 0.224. The calibration curve showed that the predicted results were in good agreement with the actual observed results. CONCLUSION: This study preliminarily constructed and verified a prediction model for VVRs after plasma donation. The model nomogram is practical and can identify high-risk donors.

The risks of low hemoglobin deferral in a large retrospective cohort of plasmapheresis donors and the influence factors of return for a subsequent donation in China.

Background: According to the Technical Operation Procedures for Plasmapheresis Collection Station (2019) in China, plasmapheresis donors with low hemoglobin (Hb) levels (men <12.0 g/dL; women <11.0 g/dL) were deferred for at least 2 weeks. The purpose of this retrospective study was to survey the demographic characteristics of plasmapheresis donors with low Hb deferral (LHD) and identify at-risk LHD donors, so as to enhance donor safety and improve donation service management. Methods: From 2018 to 2020, a multi-center study involving plasmapheresis donors from 18 plasmapheresis centers in three provinces (Sichuan, Yunnan and Hunan) of China was conducted. Donor demographics (age, sex) and donation information (date of donation, first-time donors vs. repeat donors, the number of lifetime donations, the number of donations in the last 12 months, and whether the LHD donor returned for a subsequent donation) were collected. The Cochran-Mantel-Haenszel method was used to explore the risk factors for LHD while adjusting for the different provinces. Logistic regression analysis was used to investigate the factors influencing the return for a subsequent donation after LHD. Results: A total of 497,039 plasmapheresis donors were included. Female donors' LHD rate was 0.15% on average, while male donors' LHD rate was 0.01%. Female donors aged 41-50 years old (OR: 2.276, 95% CI [1.333-3.887], p = 0.002) were more likely to experience LHD temporarily than those aged 18-30 years old. For female donors, compared with donations in the winter, they had a higher risk for LHD in the summer (OR: 2.217, 95% CI [1.670-2.943], p < 0.001), spring (OR: 2.402, 95% CI [1.806-3.196], p < 0.001), and fall (OR: 2.002, 95% CI [1.500-2.673], p < 0.001). Among the LHD donors, those who had donated more frequently in the past were more likely to return for a subsequent donation (p = 0.012). Conclusions: Female donors were at a higher risk of LHD, particularly between the ages of 41 and 50. A clear seasonal pattern in the rate of LHD was observed. In the winter, the risk of LHD was the lowest; thus, it was advised to recruit plasmapheresis donors throughout the winter and to make the required adjustments for recruitment measures during other seasons. The number of previous donations was correlated with the return rate after LHD. Our observations could have practical implications for plasmapheresis donor management.