Role of disruptions in O RhD negative donations in Colombia on increasing maternal mortality ratio from haemorrhage

OBJECTIVE

The aim of this work was to evaluate the relationship of the maternal mortality ratio due to obstetric haemorrhage (MMROH) with the national blood donations, particularly O RhD negative (Oneg) before and during COVID-19 pandemic.

BACKGROUND

The maternal mortality ratio is increasing in Colombia, yet little is known regarding the relationship between blood donations and maternal mortality due to obstetric haemorrhage.

MATERIALS AND METHODS

A retrospective cross-sectional study between January 1, 2018, and December 31, 2021, was performed, to assess MMROH compared to the blood donations notified to the Colombian National Haemovigilance System, through non-parametric methods. Because a relationship between blood donations and MMROH was identified, the analysis was expanded from 2009 to 2017.

RESULTS

In 2020, Colombia increased the MMROH by 32% compared to 2019 which coincided with the lockdown period to contain COVID-19. An inversed relationship (SumD2 = 631.0; rs = -0.7335; p 0.01) between blood donations, particularly Oneg (SumD2 = 652.0; rs = -0.7912; p 0.002) and MMROH was identified. For the years 2015-2019 and 2021, the annual mean MMROH was 8.5 ± 0.5 per 100 000 live births when the annual mean blood donations was 18.2 ± 0.4 donations per 1000 people and the Oneg was 1.0 ± 0.0 donations per 1000 people. In contrast, the years 2009-2014 and 2020 displayed an annual MMROH of 12.6 ± 0.8, when the annual collection of blood was 16.4 ± 0.8 donations and the Oneg was 0.9 ± 0.0, p < 0.001.

CONCLUSION

There was an inverse relationship between blood donation, mainly Oneg, and maternal mortality from obstetric haemorrhage. However, we recognise these deaths could be related to other reasons, especially when they occurred in rural areas with limited access to medical services.

Deferral due to low hemoglobin and predictors of permanence in the blood donation system of repeat female blood donors

OBJECTIVES

To evaluate the deferral rate due to low hemoglobin (Hb) in repeat female blood donors and identify the factors affecting their permanence in the blood donation system.

MATERIALS AND METHODS

8,368 repeat female blood donors who donated from January 2012 to December 2018 were included. Bivariate analysis and Kaplan-Meier curves were used to identify the covariates possibly associated with developing low Hb, and Cox proportional hazards modeling was used to adjust for all confounders.

RESULTS

The global deferral rate due to low Hb was 2.4 %. According to baseline Hb, the frequency of low Hb was 0.7-4.1 %, and it was higher in platelet donors (5.8-9.1 %) than in whole blood donors (1.9 %). The main predictors were baseline Hb (compared to the first quartile; hazard ratio [HR] = 0.487 for the second quartile; 0.234 for the third; and 0.095 for the fourth); change in Hb (HR = 2.689 for a >0.49 g/dL change, compared to smaller changes); the type of donation (compared to whole blood donors, HR = 2.317 for platelet donors); and donation interval (compared to >12.5 month intervals; HR = 2.220 for 8.0-12.5 months; HR = 5.658 for 5.4-8.0 months; and HR = 9.452 for <5.4 months).

CONCLUSIONS

In female blood donors at moderate altitude, the probability of developing low Hb increases with a baseline Hb of 13.5-14.0 g/dL, with a change in Hb >0.49 g/dL, in platelet donors, and with donation intervals <12.5 months. These four predictive factors can be used together for early identification of donors at risk of developing low Hb, to institute appropriate measures.

In vitro kinetics of reticulocyte subtypes: maturation after red blood cell storage in additive solution-1 (AS-1)

Background

Reticulocytes are immature red blood cells containing RNA remnants. Their population kinetics has been documented under various in vivo and in vitro conditions, including after storage of red blood cells in blood banks. The purpose of this study was to describe the influence of blood bank storage on the kinetics of reticulocyte disappearance by in vitro culturing.

Method

Samples of reticulocyte-enriched fractions (Percoll density-gradient) were obtained over different storage times from six red blood cell units stored in additive solution-1 (AS-1). Reticulocyte fractions were then cultured in enriched media at 37 °C and analyzed by flow cytometry with thiazole orange taking into account hemolysis.

Results

Density-gradient enriched reticulocyte fractions were obtain from standard red blood cell units with <1% of reticulocytes. An exponential drop of reticulocytes was observed in cultures. The time taken for reticulocyte disappearance in cultures was shorter with increased blood bank storage time (144 ± 46 h at 0.5 weeks of storage and 15 ± 14 h in the sixth week). High fluorescence reticulocytes disappeared completely in 42.5 ± 8.5 h, medium fluorescence reticulocytes in 73.4 ± 20.8 h and low fluorescence reticulocytes in 269.9 ± 98.8 h in red blood cell units stored for half a week. These times significantly decreased in red blood cell units stored for more time.

Conclusion

In vitro reticulocyte disappearance was significantly faster after prolonged storage of red blood cell units at 4 °C. The in vitro half-life at 0.5 weeks of storage was not significantly different from the values reported for fresh venous blood, but after the sixth week of storage, the half-lives were shorter. The possible explanation is that blood bank storage does not cause irreversible damage to the human reticulocyte maturational machinery.

Reticulocyte count in red-blood-cell units stored in AS-1

BACKGROUND AND OBJECTIVES

Previous data that showed maintenance of reticulocyte percentage in whole blood stored in CPDA-1 have led to the assumption that reticulocyte maturation becomes arrested during refrigerated storage. However, reticulocyte behaviour in red-blood-cell units stored in additive solutions has not yet been studied. This study was thus aimed at determining reticulocyte count and reticulocyte subtypes in red-blood-cells units stored in AS-1.

MATERIALS AND METHODS

Reticulocyte percentage and subtypes were determined by flow cytometry with thiazole orange in six red-blood-cells units stored in AS-1.

RESULTS

Reticulocyte count was 26.8 ± 4.6 × 10(9) /l at week 0.5 and 8.2 ± 2.9 × 10(9) /l at week 6. Total haemolysis during storage was 0.19 ± 0.08%. High-fluorescence reticulocytes were 2.0 ± 3.2 × 10(9) /l at week 0.5 and decreased by weeks 2, 4 and 6. Low-fluorescence reticulocytes were 22.1 ± 3.1 × 10(9) /l at week 0.5 and decreased by weeks 4 and 6.

CONCLUSION

A significant decrease in reticulocytes occurred during red-blood-cells units' storage in AS-1. Even if it were assumed that all of haemolysed cells during storage were reticulocytes, there are a number of them whose disappearance cannot be explained by this mechanism. Changes observed in reticulocyte subtypes suggest that they mature during storage.