Factor XIII Research Articles

Heterozygosity in factor XIII genes and the manifestation of mild inherited factor XIII deficiency

BackgroundThe characterization of inherited mild factor XIII deficiency is more imprecise than its rare, inherited severe forms. It is known that heterozygosity at FXIII genetic loci results in mild FXIII deficiency, characterized by circulating FXIII activity levels ranging from 20% to 60%. There exists a gap in information on 1) how genetic heterozygosity renders clinical bleeding manifestations among these individuals and 2) the reversal of unexplained bleeding upon FXIII administration in mild FXIII-deficient individuals. ObjectivesTo assess the prevalence and burden of mild FXIII deficiency among the apparently healthy German-Caucasian population and correlate it with genetic heterozygosity at FXIII and fibrinogen gene loci. MethodsPeripheral blood was collected from 752 donors selected from the general population with essentially no bleeding complications to ensure asymptomatic predisposition. These were assessed for FXIII and fibrinogen activity, and FXIII and fibrinogen genes were resequenced using next-generation sequencing. For comparison, a retrospective analysis was performed on a cohort of mild inherited FXIII deficiency patients referred to us. ResultsThe prevalence of mild FXIII deficiency was high (∼0.8%) among the screened German-Caucasian population compared with its rare-severe forms. Although no new heterozygous missense variants were found, certain combinations were relatively dominant/prevalent among the mild FXIII-deficient individuals. ConclusionThis extensive, population-based quasi-experimental approach revealed that the burden of heterozygosity in FXIII and fibrinogen gene loci causes the clinical manifestation of inherited mild FXIII deficiency, resulting in ‘’unexplained bleeding’’ upon provocation.

A next generation FVIII mimetic bispecific antibody, Mim8, the impact on non-factor VIII related haemostasis assays.

Mim8 is a next generation bispecific antibody developed for the treatment of haemophilia A (HA). Mim8 has an increased potency compared to first generation molecules. The impact on Mim8 on non-FVIII measuring haemostasis assays was assessed in plasma containing Mim8. Congenital severe HA plasma was spiked with increasing concentrations of Mim8 (0-20μg/mL). 28 routine and specialist haemostasis assays were used to measure activities. These included tests for prothrombin time (PT), fibrinogen, thrombin, D-dimer, anti-Xa, heparin induced thrombocytopenia (HIT), clotting factors II-XII, factor XIII, von Willebrand factor (VWF), thrombophilia and DRVVT. Less than 10 % difference was calculated between plasma without Mim8 and plasma spiked to 15μg/mL Mim8 in all assays except thrombin time (-10.5%), APTT-based factor IX, XI and XII, Werfen VWF:RCo (10.6%) and Siemens LA1 (-26.4%) and LA2 (-16.9%). At the expected therapeutic steady state levels of Mim8 (5-8μg/mL), less than 10% difference was calculated for thrombin time and Werfen VWF:RCo. APTT-based assays of FIX, XI and XII are significantly elevated in the presence of Mim8 and should not be performed. A chromogenic FIX assay could be used to accurately measure FIX activity in the presence of Mim8. There was some interference in the DRVVT method we used so local assessment of other DRVVT methods is advised. Differences in all other tests would not be predicted to affect patient management.

Discovery of plasma proteins associated with ventricular fibrillation during first ST-elevation myocardial infarction via proteomics.

The underlying biological mechanisms of ventricular fibrillation (VF) during acute myocardial infarction are largely unknown. To our knowledge, this is the first proteomic study for this trait, with the aim to identify and characterize proteins that are associated with VF during first ST-elevation myocardial infarction (STEMI). We included 230 participants from a Danish ongoing case-control study on patients with first STEMI with VF (case, n = 110) and without VF (control, n = 120) before guided catheter insertion for primary percutaneous coronary intervention. The plasma proteome was investigated using mass spectrometry-based proteomics on plasma samples collected within 24 h of symptom onset, and one patient was excluded in quality control. In 229 STEMI patients {72% men, median age 62 years [interquartile range (IQR): 54-70]}, a median of 257 proteins (IQR: 244-281) were quantified per patient. A total of 26 proteins were associated with VF; these proteins were involved in several biological processes including blood coagulation, haemostasis, and immunity. After correcting for multiple testing, two up-regulated proteins remained significantly associated with VF, actin beta-like 2 [ACTBL2, fold change (FC) 2.25, P < 0.001, q = 0.023], and coagulation factor XIII-A (F13A1, FC 1.48, P < 0.001, q = 0.023). None of the proteins were correlated with anterior infarct location. Ventricular fibrillation due to first STEMI was significantly associated with two up-regulated proteins (ACTBL2 and F13A1), suggesting that they may represent novel underlying molecular VF mechanisms. Further research is needed to determine whether these proteins are predictive biomarkers or acute phase response proteins to VF during acute ischaemia.

Combined Omics Approaches Reveal Distinct Mechanisms of Resistance and/or Susceptibility in Sugar Beet Double Haploid Genotypes at Early Stages of Beet Curly Top Virus Infection.

Sugar beet is susceptible to Beet curly top virus (BCTV), which significantly reduces yield and sugar production in the semi-arid growing regions worldwide. Sources of genetic resistance to BCTV is limited and control depends upon insecticide seed treatments with neonicotinoids. Through double haploid production and genetic selection, BCTV resistant breeding lines have been developed. Using BCTV resistant (R) [KDH13; Line 13 and KDH4-9; Line 4] and susceptible (S) [KDH19-17; Line 19] lines, beet leafhopper mediated natural infection, mRNA/sRNA sequencing, and metabolite analyses, potential mechanisms of resistance against the virus and vector were identified. At early infection stages (2- and 6-days post inoculation), examples of differentially expressed genes highly up-regulated in the 'R' lines (vs. 'S') included EL10Ac5g10437 (inhibitor of trypsin and hageman factor), EL10Ac6g14635 (jasmonate-induced protein), EL10Ac3g06016 (ribosome related), EL10Ac2g02812 (probable prolyl 4-hydroxylase 10), etc. Pathway enrichment analysis showed differentially expressed genes were predominantly involved with peroxisome, amino acids metabolism, fatty acid degradation, amino/nucleotide sugar metabolism, etc. Metabolite analysis revealed significantly higher amounts of specific isoflavonoid O-glycosides, flavonoid 8-C glycosides, triterpenoid, and iridoid-O-glycosides in the leaves of the 'R' lines (vs. 'S'). These data suggest that a combination of transcriptional regulation and production of putative antiviral metabolites might contribute to BCTV resistance. In addition, genome divergence among BCTV strains differentially affects the production of small non-coding RNAs (sncRNAs) and small peptides which may potentially affect pathogenicity and disease symptom development.

Factors affecting progressive facial swelling immediately after orthognathic surgery: A retrospective cohort study

The aim of this study was to identify clinical factors associated with progressive facial swelling after orthognathic surgery. Patients diagnosed with jaw deformities and undergoing orthognathic surgery were retrospectively evaluated, and those with surgical site infection, Le Fort I osteotomy, or genioplasty only were excluded. Facial swelling volume was calculated by comparing facial volume preoperatively and three days postoperatively using 3D images and image analysis software (VECTRA H2). FXIII was measured within three days after surgery in only patients with unexplained postoperative bleeding or hematoma. The correlation between facial swelling volume and clinical factors was statistically analyzed. Facial swelling volume was examined in 78 patients. Univariate analysis showed a significant difference between facial swelling volume (mean = 41.6 cm3) and operation time (mean = 209.3 min, r = 0.283, p = 0.012), ΔHb level (mean = 1.18 g/dL, r = 0.235, p = 0.039), as well as decreased factor XIII activity (mean = 75.3%, p = 0.012). Multivariate analysis showed a significant difference between facial swelling volume and FXIII deficiency (standard error = 6.44, p = 0.031).Progressive facial swelling immediately after orthognathic surgery may be due to factor XIII deficiency.

LB 01.3 Factor XIII 24-Hour Trajectory Analysis in Severely Injured Patients: Post-hoc Analysis of the Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) Study

LB 01.3 Factor XIII 24-Hour Trajectory Analysis in Severely Injured Patients: Post-hoc Analysis of the Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) Study

PB0234 Comprehensive Evaluation of Coagulation and Fibrinolysis Parameters in Patients with Congenital Factor XIII Deficiency in Pakistan: Case Control Study

PB0234 Comprehensive Evaluation of Coagulation and Fibrinolysis Parameters in Patients with Congenital Factor XIII Deficiency in Pakistan: Case Control Study

OC 28.5 Exploring Interdomain Interactions Mediated by the Factor XIII Activation Peptide

OC 28.5 Exploring Interdomain Interactions Mediated by the Factor XIII Activation Peptide

PB0574 Severe Bleeding in an Acquired Factor XIII Deficiency in an Otherwise Healthy Patient

PB0574 Severe Bleeding in an Acquired Factor XIII Deficiency in an Otherwise Healthy Patient

PB1200 Evaluation of the Association of Factor XIII at Hospital Arrival and Outcomes in a Cohort of Severely Injured Patients

PB1200 Evaluation of the Association of Factor XIII at Hospital Arrival and Outcomes in a Cohort of Severely Injured Patients

PO08 Factor XIII Deficiency as Underlying Cause of Unexplained Intracranial Hemorrhage

PO08 Factor XIII Deficiency as Underlying Cause of Unexplained Intracranial Hemorrhage

Tackling the Root Cause of Surface-Induced Coagulation: Inhibition of FXII Activation to Mitigate Coagulation Propagation and Prevent Clotting.

Factor XII (FXII) is a zymogen present in blood that tends to adsorb onto the surfaces of blood-contacting medical devices. Once adsorbed, it becomes activated, initiating a cascade of enzymatic reactions that lead to surface-induced coagulation. This process is characterized by multiple redundancies, making it extremely challenging to prevent clot formation and preserve the properties of the surface. In this study, a novel modulatory coating system based on C1-esterase inhibitor (C1INH) functionalized polymer brushes, which effectively regulates the activation of FXII is proposed. Using surface plasmon resonance it is demonstrated that this coating system effectively repels blood plasma proteins, including FXII, while exhibiting high activity against activated FXII and plasma kallikrein under physiological conditions. This unique property enables the modulation of FXII activation without interfering with the overall hemostasis process. Furthermore, through dynamic Chandler loop studies, it is shown that this coating significantly improves the hemocompatibility of polymeric surfaces commonly used in medical devices. By addressing the root cause of contact activation, the synergistic interplay between the antifouling polymer brushes and the modulatory C1INH is expected to lay the foundation to enhance the hemocompatibility of medical device surfaces.

Histidine-rich glycoprotein attenuates catheter thrombosis.

Factor XII (FXII) knockdown attenuates catheter thrombosis in rabbits. Because histidine-rich glycoprotein (HRG) modulates FXIIa activity, we hypothesized that HRG depletion would promote catheter thrombosis. To test this, rabbits were given either antisense oligonucleotides (ASOs) against HRG or FXII, a control ASO, or saline. The activated partial thromboplastin time (aPTT), prothrombin time (PT), and catheter-induced thrombin generation were determined in blood collected before and after treatment. Compared with the controls, the HRG- and FXII-directed ASOs reduced hepatic messenger RNA and plasma levels of HRG and FXII, respectively, by >90%. Although HRG knockdown shortened the aPTT by 2.5 fold, FXII knockdown prolonged it by fourfold; neither of the ASOs affected the PT. Catheter segments shortened the lag time and increased peak thrombin in the plasma from control rabbits; effects were significantly enhanced and attenuated in the plasma from rabbits given the HRG- and FXII-directed ASOs, respectively. Catheters were then inserted into the right external jugular vein of the rabbits, and the time for catheter occlusion was determined. The catheter occlusion times with the control ASO or saline were 62± 8minutes and 60± 11minutes, respectively. The occlusion time was significantly reduced to 34± 9minutes, with HRG knockdown and significantly prolonged to 128± 19minutes with FXII knockdown. HRG levels are decreased with sepsis or cancer, and such patients are prone to catheter thrombosis. Because HRG modulates catheter thrombosis, our findings suggest that HRG supplementation may prevent this problem.

Fibrinogenolysis and fibrinolysis in vaccine-induced immune thrombocytopenia and thrombosis

BackgroundVaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare syndrome associated with adenoviral vector vaccines for COVID-19. The syndrome is characterized by thrombosis, anti-platelet factor 4 (PF4) antibodies, thrombocytopenia, high D-dimer, and hypofibrinogenemia. ObjectivesTo investigate abnormalities in fibrinolysis that contribute to the clinical features of VITT. MethodsPlasma samples from 18 suspected VITT cases were tested for anti-PF4 by ELISA and characterized as meeting criteria for VITT (11/18) or deemed unlikely (7/18; non-VITT). Antigen levels of PAI-1, factor XIII (FXIII), plasmin-α2antiplasmin (PAP), and inflammatory markers were quantified. Plasmin generation was quantified by chromogenic substrate. Western blotting was performed with antibodies to fibrinogen, FXIII-A, and plasminogen. ResultsVITT patients 10/11 had scores indicative of overt disseminated intravascular coagulation, while 0/7 non-VITT patients met the criteria. VITT patients had significantly higher levels of inflammatory markers, IL-1β, IL-6, IL-8, TNFα, and C-reactive protein. In VITT patients, both fibrinogen and FXIII levels were significantly lower, while PAP and tPA-mediated plasmin generation were higher compared to non-VITT patients. Evidence of fibrinogenolysis was observed in 9/11 VITT patients but not in non-VITT patients or healthy controls. Fibrinogen degradation products were apparent, with obvious cleavage of the fibrinogen α-chain. PAP complex was evident in those VITT patients with fibrinogenolysis, but not in non-VITT patients or healthy donors. ConclusionVITT patients show evidence of overt disseminated intravascular coagulation and fibrinogenolysis, mediated by dysregulated plasmin generation, as evidenced by increased PAP and plasmin generation. These observations are consistent with the clinical presentation of both thrombosis and bleeding in VITT.

Comparison of coagulation parameters associated with fibrinogen concentrate and cryoprecipitate for treatment of bleeding in patients undergoing cytoreductive surgery for pseudomyxoma peritonei: Subanalysis from a randomized, controlled phase 2 study.

The FORMA-05 study compared the efficacy and safety of human fibrinogen concentrate (HFC) versus cryoprecipitate for hemostasis in bleeding patients undergoing cytoreductive surgery for pseudomyxoma peritonei (PMP). This subanalysis explores coagulation parameters in the FORMA-05 patients, with a focus on the seven patients who developed thromboembolic events (TEEs). FORMA-05 was a prospective, randomized, controlled phase 2 study in which patients with predicted blood loss ≥2 L received HFC (4 g) or cryoprecipitate (two pools of five units), repeated as needed. Plasma fibrinogen, platelet count, factor (F) XIII, FVIII, von Willebrand Factor (VWF) antigen and ristocetin cofactor activity levels, EXTEM A20, FIBTEM A20, and endogenous thrombin potential (ETP) were measured perioperatively. Fibrinogen, platelet count, EXTEM and FIBTEM A20, FXIII, FVIII, VWF levels, and ETP were maintained throughout surgery in both the HFC group (N = 21) and the cryoprecipitate group (N = 23). Seven TEEs were observed in the cryoprecipitate group. The two patients developing deep vein thromboses (DVT) appeared to have a procoagulant status preoperatively, with distinctively higher fibrinogen level, FIBTEM A20, and platelet levels, all of which persisted perioperatively. The five patients developing pulmonary embolism (PE) had slightly higher VWF levels preoperatively, with a disproportionate increase intraoperatively (postcryoprecipitate administration) and postoperatively. Patients treated with HFC versus cryoprecipitate showed broad overlaps in coagulation parameters. Patients with PE experienced a disproportionate VWF rise following cryoprecipitate administration, whereas patients developing DVT displayed a procoagulant status before and following surgery. Preoperative testing may allow these patients to be identified.

Differences in coagulation-relevant parameters: Comparing cryoprecipitate and a human fibrinogen concentrate.

Variable fibrinogen content within cryoprecipitate makes accurate dosing challenging in patients with coagulopathic bleeding, in addition to pathogen transmission risks associated with its administration. Purified and standardized human fibrinogen concentrates (HFCs) represent reliable alternatives. Full cryoprecipitate characterization is required to inform selection of an appropriate fibrinogen source for supplementation therapy. Extended biochemical comparison of pooled cryoprecipitate and HFC (Fibryga, Octapharma) was performed using commercially available assays to determine levels of variability in cryoprecipitate and HFC. In addition to standard procoagulant factors, measurements included activities of platelet-derived microparticles (PMPs) and plasminogen, and levels of fibrin degradation products. Cryoprecipitate contains lower fibrinogen levels than HFC (4.83 vs.19.73 g/L; p<0.001), translating to approximately half the amount of fibrinogen per standard cryoprecipitate dose (two pools, pre-pooled from five donations each) vs. HFC (2.14 vs. 3.95 g; p<0.001). Factor XIII (FXIII) levels were also lower in cryoprecipitate vs. HFC (192.17 vs. 328.33 IU/dL; p = 0.002). Levels of procoagulants in cryoprecipitate, such as von Willebrand Factor (VWF) and factor VIII (FVIII), were highly variable, as was PMP activity. A standard cryoprecipitate dose contains significantly higher levels of measured plasminogen and D-dimer fragments than a standard HFC dose. The tested HFC is a more reliable fibrinogen and FXIII source for accurate dosing compared with cryoprecipitate. Cryoprecipitate appears considerably less predictable for bleeding management due to wide variation in pro- and anticoagulation factors, the presence of PMPs, and the potential to elevate VWF and FVIII to prothrombotic levels.

Bombyx batryticatus extract activates coagulation factor Ⅻ to promote angiogenesis in rats with cerebral ischemia/reperfusion injury

Ethnopharmacological relevanceBombyx batryticatus is traditionally used to treat patients with stroke, but its mechanism remains unclear. Aim of the studyTo explore the interventional effect of Bombyx batryticatus extract as an activator of FⅫ on angiogenesis of rats with cerebral ischemia/reperfusion injury. Materials and methodsFirstly, the mechanism of Bombyx batryticatus interfering with IS was predicted by systematic pharmacology method, and then it was further verified by animal experiments. The effects of Bombyx batryticatus extract on plasma coagulation were detected, and the activation of coagulation factor Ⅻ (FⅫ) and its downstream substrate kallikrein kinase (KK) was detected in vitro. The brain morphology and expressions of FXII, KK, vascular endothelial growth factors (VEGF), CD31, Brdu/von Willebrand Factor (vWF) were detected. The morphological changes, cell proliferation and VEGF expression of brain microvascular endothelial cells were detected by oxygen glucose deprivation model. The pharmacodynamic substances of Bombyx batryticatus extract were identified by Liquid Chromatography - Mass Spectrometry (LC-MS). ResultsThe results of systematic pharmacology found that the treatment of IS by Bombyx batryticatus may be related to blood coagulation and other processes. In vitro, Bombyx batryticatus extract prolonged the activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) (P < 0.05), activated FⅫ and promoted the production of downstream substrate KK, with dose-dependent (P < 0.05). Bombyx batryticatus extract improved the neuronal damage of rats, activated FXII and increased the production of KK and the expressions of VEGF, CD31, Brdu/vWF (P < 0.05). Bombyx batryticatus extract also increased the proliferation of brain microvascular endothelial cells and expression of VEGF in rats (P < 0.05). A total of 809 metabolites in Bombyx batryticatus extract were identified by LC-MS. ConclusionBombyx batryticatus extract may ameliorate the injury of nerve function in rats with cerebral ischemia/reperfusion injury.

Novel function of transglutaminase 2 in extracellular histone-induced acute lung injury

Extracellular histones induce endothelial damage, resulting in lung haemorrhage; however, the underlying mechanism remains unclear. Factor XIII, as a Ca2+-dependent cross-linking enzyme in blood, mediates fibrin deposition. As another isozyme, transglutaminase 2 (TG2) has a catalytic activity distributing in most tissues. Herein, we investigated whether TG2 promotes fibrin deposition and mediates the adhesion of platelets to ECs in histone-induced acute lung injury (ALI). We evaluated the lung histology and the adhesion of platelets to endothelial cells (ECs) after injecting histones to wild-type (WT) C57BL/6J and TG2 knockout (TG2−/−) mice, and administered a TG2 inhibitor (NC9) to WT mice. Pulmonary haemorrhage was more severe in TG2−/− mice than that in WT mice. The area of fibrin deposition and the proportion of CD41+CD31+ cells were lower in TG2−/− mice than in WT mice. Pre-treatment of NC9 decreased the area of fibrin deposition and the proportion of CD41+CD31+ cells in WT mice. These results suggest that TG2 prevents from pulmonary haemorrhage in ALI by promoting the adhesion of platelets to ECs and the fibrin deposition.

Endothelial dysfunction, thrombophilia, and nailfold capillaroscopic features in livedoid vasculopathy

BackgroundLivedoid vasculopathy (LV) is a rare, disabling disease characterized by painful ulcers, livedo reticularis and atrophy blanche. Hypercoagulation, endothelial, and microcirculatory dysfunction are believed to be responsible for the pathogenesis of this difficult-to-treat disease. ObjectivesThis study sought to investigate the frequency of endothelial dysfunction, hypercoagulability, and nailfold capillaroscopic features in LV patients to shed light on its etiology. MethodsThis case-control study included 16 patients with LV, 24 with systemic sclerosis (SSc), and 23 control subjects. Serum markers of endothelial dysfunction soluble endoglin, endocan, endothelin-1, lipoprotein a, plasminogen activator inhibitor-1 (PAI-1), soluble thrombomodulin, and von Willebrand factor were measured using enzyme-linked immunosorbent assays. Flow-mediated dilation and carotid intima-media thickness were examined as markers of endothelial dysfunction, and microcirculation was assessed with nailfold capillaroscopy. Thrombophilia-related parameters, including gene polymorphisms of factor V Leiden, prothrombin, PAI-1 genes, methylenetetrahydrofolate reductase (MTHFR) and factor XIII mutation and serum levels of protein C, protein S, antithrombin, homocysteine, D-dimer and antiphospholipid antibodies were investigated in LV patients. ResultsPlasminogen activator inhibitor-1 and soluble thrombomodulin levels were significantly higher in LV patients compared to control subjects (2.3 [2.05–2.79] ng/ml vs. 1.89 [1.43–2.33] ng/ml, p = 0.007; 1.15 [0.88–1.4] ng/ml vs. 0.76 [0.56–0.9] ng/ml, p = 0.004, respectively). Flow-mediated dilation was 25.4 % lower in the LV patients compared to the control group (14.77 % [11.26–18.26] vs. 19.80 % [16.47–24.88], p = 0.034). Capillaroscopic features, including ramifications (75 % vs. 8.7 %, p < 0.001), avascular areas (25 % vs. 0 %, p = 0.011) and dilatations (33.2 % vs. 0 %, p = 0.016), were significantly higher in LV patients than in controls. LV patients had multiple biochemical or genetic abnormalities related to thrombophilia, including heterozygous factor V Leiden mutations (6.3 %), MTHFR (C677T) mutations (heterozygous 43.8 %, homozygous 18.8 %), MTHFR (A1298C) mutations (heterozygous 37.5 %, homozygous 12.5 %), factor XIII heterozygous mutation (12.5 %), antithrombin deficiency (31.3 %), protein S deficiency (12.5 %), hyperhomocysteinemia (31.3 %), D-dimer elevation (25 %), anti-β2-glycoprotein I (12.5 %), lupus anticoagulant antibodies (6.3 %), and anticardiolipin antibodies (6.3 %). ConclusionsIn conclusion, LV patients were characterized by an increased presence of thrombophilia-related parameters, and also exhibited vascular endothelial and microcirculatory dysfunction, resembling SSc. These findings support the complex interaction of thrombophilia, endothelial dysfunction, and microcirculation dysregulation in the pathogenesis of LV. Thus, the treatment of LV patients should be individualized, based on the identification of the predominant pathological pathways.

A comparative evaluation of the quality of cryoprecipitate prepared from 350ml versus 450ml of whole blood and different methods of thawing of plasma: A prospective observational study.

Cryoprecipitate is used in conditions like hypofibrinogenemia, massive transfusion with bleeding, and factor XIII deficiency. The current guidelines support the preparation of cryoprecipitate from 450ml whole blood. But 350ml of whole blood collection is expected from low body weight (<55kg) donors. However, no standardized criteria exist for preparing cryoprecipitate from 350ml of whole blood. This study compared the fibrinogen and factor VIII levels in cryoprecipitate units prepared from 350ml versus 450ml whole blood collection. The study also compared the fibrinogen and factor VIII levels prepared by circulating water bath versus blood bank refrigerator (BBR) thawing method. A total of 128 blood bags were equally divided into groups A and B for 450 and 350ml whole blood collection further subdivided into subgroups based on thawing methods. The fibrinogen and factor VIII yield were analyzed in the cryoprecipitates prepared from both groups. The factor VIII levels were significantly higher in cryoprecipitate made from 450ml whole blood collection (P=0.02). The BBR method of plasma thawing resulted in better fibrinogen recovery than the cryo bath method. Whereas vice versa in the case of factor VIII recovery. A weak but significant positive correlation was noted in factor VIII levels with the plasma volume. Over 75% of the cryoprecipitates prepared from 350ml whole blood passed the fibrinogen and factor VIII quality control criteria. So, 350ml whole blood collection from low body weight (<55kg) donors could be utilized to prepare cryoprcipitates. However, future clinical studies should focus on the cryoprecipitate's clinical efficacy prepared from 350ml of whole blood.