Global sources of cryoprecipitate demonstrate variability in coagulant factor levels and functional hemostasis

Overestimation of fibrinogen concentration in cryoprecipitate by repeated freeze-thawing with long thawing period as used in the Clauss method

BACKGROUND

Cryoprecipitate (CRY) is widely used for treating acquired hypofibrinogenemia. During our study to determine an optimal preparation method, we noticed that the measurement of fibrinogen concentration in CRY had a risk of overestimation. We analyzed this condition and mechanism.

STUDY DESIGN AND METHODS

CRY was prepared from fresh frozen plasma (FFP) under four conditions: A, 30 h thawing time, 2 cycles; B, 24 h thawing time, 2 cycles; C, 30 h thawing time, 1 cycle; and D, 24 h thawing time, 1 cycle. Then, fibrinogen concentrations in CRY and cryosupernatant (CS) were measured by the Clauss method.

RESULTS

Purification (CRY/CRY+CS) and recovery (CRY/FFP) rates in CRY prepared under 2-cycle conditions were higher than those under 1 cycle. However, recovery rates often exceeded 100%, particularly in the case of CRY prepared under A condition, and fibrinogen concentrations calculated by direct measurement were higher than those indirectly calculated from FFP and CS, suggesting an overestimation of fibrinogen values. The level of soluble fibrin monomer complex was considerably higher in CRY prepared under A than under D condition, indicating that CRY adopted a hypercoagulated state. We further found that repeated thawing/freezing increased fibrinogen values as measured by the Clauss method while mechanical vortexing did not.

DISCUSSION

Our findings suggest that direct assessment of fibrinogen contents in CRY prepared by repeated freeze-thawing with a longer thawing period presents a higher risk of overestimation. For the purpose of quality control, we propose an alternative method to indirectly estimate fibrinogen concentrations in CRY from those of CS and FFP.

Differential proteomic of plasma provides a new perspective on scientific diagnosis and drug screening for dampness heat diarrhea in calves

Dampness heat diarrhea (DHD) is one of the most common syndromes of calf diarrhea. Its complex etiology and lack of objective diagnostic criteria bring great challenges to the diagnosis and treatment of this disease. This study aims to screen some prospective diagnostic biomarkers or therapeutic targets for calves with DHD by investigating the differential protein profiles of plasma between DHD calves and clinically healthy calves by mass spectrometry-based proteomic. A total of 120 DHD calves and 90 clinically healthy calves were divided into two groups randomly, 30 DHD calves and 30 clinically healthy calves in the test group, and 90 DHD calves and 60 clinically healthy calves in the validation group. In the test group, a total of 52 proteins were differentially expressed between calves with DHD and clinically healthy calves, 13 proteins were significantly increased and 39 proteins were significantly decreased. The differentially expressed proteins were associated with the intestinal immune network of IgA production, caffeine metabolism, purine metabolism, and PI3K signaling pathway. In the validation group, 13 proteins were selected from 52 differential expression proteins for parallel reaction monitoring validation to verify their associations with DHD calves. The targeted proteomic results showed that fibronectin precursor (FN1) and apolipoprotein C-IV precursor (APOC4) were significantly associated with DHD in calves, and they were downregulated in sick calves. In conclusion, the differential expression of plasma proteins was associated with DHD pathogenesis in calves, and the FN1 and APOC4 might be the potential clinical biomarkers for diagnosis of DHD in calves, and the intestinal immune network of IgA production, caffeine metabolism, purine metabolism, and PI3K signaling pathway are the candidate targets to treat DHD in calves. Our finding provides a reference for further investigating the pathogenesis, developing techniques of diagnosis, and screening treatment drugs for DHD in calves.

Cryoprecipitated anti-hemophiliac factor manufactured from plasma frozen within 24 h after phlebotomy meets AABB quality standards

BACKGROUND

Cryoprecipitated antihemophiliac factor (CryoAHF) manufacturing in the US has not kept pace with the increasing demand for hospital transfusion services. Association for Advancement of Blood and Biologics (AABB) and Food and Drug Administration (FDA) require that CryoAHF be manufactured from fresh frozen plasma within 8 h (FFP). We evaluated whether CryoAHF manufactured from plasma frozen within 24 h (PF24) met regulatory quality control (QC) requirements to increase available plasma for CryoAHF.

STUDY DESIGN AND METHODS

In a "worst-case scenario" feasibility study, we produced 21 single units of CryoAHF from type-O whole blood-derived PF24 frozen between 20 and 24 h after collection. A follow-up QC validation was conducted wherein 69 PF24 units across three sites were manufactured into CryoAHF. Factor VIII (FVIII) and fibrinogen levels were measured.

RESULTS

CryoAHF manufactured in our feasibility study from PF24 contained FVIII levels of 208 ± 61 IU (mean ± SD) and 509 ± 152 mg of fibrinogen levels per unit. CryoAHF manufactured in our QC validation from PF24 yielded FVIII levels of 214 ± 58 IU and 607 ± 176 mg of fibrinogen levels per unit. The coagulation factor levels from each of the individual CryoAHF units exceeded the minimum AABB and FDA requirement of ≥80 IU of FVIII per unit and ≥150 mg of fibrinogen per unit. There was no decrease in FVIII or fibrinogen levels in CryoAHF produced from PF24 as compared to historic QC results of CryoAHF produced from FFP.

CONCLUSION

These studies demonstrated that CryoAHF produced from PF24 meets AABB and FDA QC requirements. FDA approved the American Red Cross request to manufacture CryoAHF singles and pools from PF24 as source material.