Clinical and laboratory diagnosis of rare coagulation disorders (RCDs)

Targeted exome analysis in patients with rare bleeding disorders: data from the Rare Bleeding Disorders in the Netherlands study

Background

Rare coagulation factor deficiencies and disorders of fibrinolysis (defined as rare bleeding disorders [RBDs]) present with a heterogeneous bleeding phenotype, and bleeding severity is difficult to predict.

Objectives

Describe underlying rare genetic variants in the Dutch RBD population and investigate the relationship between genotype, laboratory phenotype, and clinical phenotype.

Methods

The Rare Bleeding Disorders in the Netherlands is a cross-sectional, nationwide study conducted between October 1, 2017, and November 30, 2019. Bleeding scores and blood samples were collected during a single study visit. Coagulation factor levels were measured centrally, and targeted exome analysis was performed on 156 genes involved in thrombosis and hemostasis. Pathogenicity was assigned according to the Association for Clinical Genetic Science guidelines.

Results

Rare genetic variants specific to the diagnosed RBD were found in 132 of 156 patients (85%). Of the 214 rare genetic variants identified, 57% (n = 123) were clearly pathogenic, 19% (n = 40) were likely pathogenic, and 24% (n = 51) were variants of unknown significance. No explanatory genetic variants were found in patients with plasminogen activator inhibitor type 1 deficiency or hyperfibrinolysis. A correlation existed between factor activity levels and the presence of a genetic variant in the corresponding gene in patients with rare coagulation factor deficiencies and alpha-2-antiplasmin deficiency. Co-occurrence of multiple genetic variants was present in a quarter of patients, but effect on phenotype remains unclear.

Conclusion

Targeted exome analysis may offer advantages over single-gene analysis, emphasized by a number of combined deficiencies in this study. Further studies are required to determine the role of co-occurring hemostasis gene variants on the bleeding phenotype in RBDs.

Rare bleeding disorders: Real-world data from a Spanish tertiary hospital

INTRODUCTION

Due to their low prevalence, rare bleeding disorders (RBDs) remain poorly characterized.

AIM

To gain insight of RBDs through our clinical practice.

METHODS

Retrospective study of the medical records of RBD patients followed up at the Central University Hospital of Asturias between January 2019 and December 2022.

RESULTS

A total of 149 patients were included. Factor (F) VII (44 %) and FXI (40 %) deficiencies were the most common diagnosed coagulopathies. Most of the patients were asymptomatic (60.4 %) and the most frequent type of bleeding were mucocutaneous and after surgery. All replacement treatments were administered on demand and no patient was on a prophylaxis regimen. Currently available products were safe; allergic reactions after administration of plasma were the most frequent complication. Genetic analysis, carried out on 55 patients (37 %), showed that the most frequent mutations in RBDs are of missense type (71.9 %). We identified 11 different novel genetic alterations in affected genes. The c.802C > T (p.Arg268Cys) variant, previously described, was identified in 71 % (15 of 21) of the patients with FXI deficiency genotyped and none were related (probable founder effect).

CONCLUSION

Our study on an unusual large single center cohort of RBD patients portrays location-dependent distinct genetic drives and clinical practice particularities.

National strategic advocacy to manage patients with inherited bleeding disorders in low and lower-middle income countries

INTRODUCTION

Inherited bleeding disorders (IBDs) including hemophilia, von Willebrand disease, platelet disorders, mucocutaneous bleeding disorders and coagulation factor deficiencies are rarely found and under-recognized in low and lower-middle-income countries. Some patients succumbed to serious bleeding without diagnosis and treatment during childhood.

AREA COVERED

Diagnosis, management, and prevention should be integrated into the existing health care system. Although some countries have not implemented appropriate health care infrastructure, an initiative plan should be set up by cooperation of experienced experts and health care providers. Identification of patients with IBDs should be started in the antenatal setting to search for females at risk of carrier state. The investigations include bleeding assessment, mixing venous clotting time, coagulogram, coagulation factor assay and mutation detection. Genotypic analysis is helpful for confirming the definite diagnosis, carrier detection as well as prenatal diagnosis for females at risk of bearing an offspring with severe bleeding manifestations. Management involves replacement therapy ranging from blood component to virus-inactivated factor concentrate. Appropriate research is an essential backbone for improving patients' care.

EXPERT OPINION

Effective national strategic advocacy to manage patients with IBDs requires intensive collaboration among policy makers, health care providers, patients, and family members.

Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: research priorities for ultra-rare inherited bleeding disorders

BACKGROUND

Ultra-rare inherited bleeding disorders (BDs) present important challenges for generating a strong evidence foundation for optimal diagnosis and management. Without disorder-appropriate treatment, affected individuals potentially face life-threatening bleeding, delayed diagnosis, suboptimal management of invasive procedures, psychosocial distress, pain, and decreased quality-of-life.

RESEARCH DESIGN AND METHODS

The National Hemophilia Foundation (NHF) and the American Thrombosis and Hemostasis Network identified the priorities of people with inherited BDs and their caregivers, through extensive inclusive community consultations, to inform a blueprint for future decades of research. Multidisciplinary expert Working Group (WG) 3 distilled highly feasible transformative ultra-rare inherited BD research opportunities from the community-identified priorities.

RESULTS

WG3 identified three focus areas with the potential to advance the needs of all people with ultra-rare inherited BDs and scored the feasibility, impact, and risk of priority initiatives, including 13 in systems biology and mechanistic science; 2 in clinical research, data collection, and research infrastructure; and 5 in the regulatory process for novel therapeutics and required data collection.

CONCLUSIONS

Centralization and expansion of expertise and resources, flexible innovative research and regulatory approaches, and inclusion of all people with ultra-rare inherited BDs and their health care professionals will be essential to capitalize on the opportunities outlined herein.

Embracing enzyme promiscuity with activity-based compressed biosensing

The development of protease-activatable drugs and diagnostics requires identifying substrates specific to individual proteases. However, this process becomes increasingly difficult as the number of target proteases increases because most substrates are promiscuously cleaved by multiple proteases. We introduce a method-substrate libraries for compressed sensing of enzymes (SLICE)-for selecting libraries of promiscuous substrates that classify protease mixtures (1) without deconvolution of compressed signals and (2) without highly specific substrates. SLICE ranks substrate libraries using a compression score (C), which quantifies substrate orthogonality and protease coverage. This metric is predictive of classification accuracy across 140 in silico (Pearson r = 0.71) and 55 in vitro libraries (r = 0.55). Using SLICE, we select a two-substrate library to classify 28 samples containing 11 enzymes in plasma (area under the receiver operating characteristic curve [AUROC] = 0.93). We envision that SLICE will enable the selection of libraries that capture information from hundreds of enzymes using fewer substrates for applications like activity-based sensors for imaging and diagnostics.

Association between PT, PT-INR, and in-hospital mortality in critically ill patients with tumors: A retrospective cohort study

Objectives

Prothrombin time (PT) and PT-INR are independent predictors of mortality in patients with cancer. The PT and PT-INR of cancer patients are independent predictive variables of mortality. However, whether the PT or PT-INR is related to in-hospital mortality in severely ill patients with tumors remains unknown.

Design

This was a case-control study based on a multicenter public database.

Settings

This study is a secondary analysis of data extracted from 2014 to 2015 from the Electronic Intensive Care Unit Collaborative Research Database.

Participants

The data relevant to seriously ill patients with tumors were obtained from 208 hospitals spread throughout the USA. This research included a total of 200,859 participants. After the samples were screened for patients with combination malignancies and prolonged PT-INR or PT, the remaining 1745 and 1764 participants, respectively, were included in the final data analysis.

Primary and secondary outcome measures

The key evaluation methodology was the PT count and PT-INR, and the main outcome was the in-hospital mortality rate.

Results

After controlling for confounding variables, we found a curvilinear connection between PT-INR and in-hospital mortality (p < 0.001), and the inflection point was 2.5. When PT-INR was less than 2.5, an increase in PT-INR was positively associated with in-hospital mortality (OR 1.62, 95% CI 1.24 to 2.13), whereas when PT-INR was greater than 2.5, in-hospital mortality was relatively stable and higher than the baseline before the inflection point. Similarly, our study indicated that the PT exhibited a curvilinear connection with in-hospital mortality. On the left side of the inflection point (PT <22), a rise in the PT was positively linked with in-hospital mortality (OR 1.08, 95% CI 1.04 to 1.13, p < 0.001). On the right side of the inflection point, the baseline PT was above 22, and the in-hospital mortality was stable and higher than the PT count in the prior range (OR 1.01, 95% CI 0.97 to 1.04, 0.7056).

Conclusion

Our findings revealed that there is a curved rather than a linear link between the PT or PT-INR and in-hospital mortality in critically ill cancer patients. When these two laboratory results are below the inflection point, comprehensive therapy should be employed to reduce the count; when these two laboratory results are above the inflection point, every effort should be made to reduce the numerical value to a value below the inflection point.

Corpus luteum hemorrhage with acquired hemophilia A: a case report and literature review

Background

The rupture of the corpus luteum (CL) may occur at all stages of a woman’s reproductive life. Bleeding of the ruptured CL varies from self-limiting hemorrhage to massive hemoperitoneum, causing the shock and subsequent emergency surgery. But hemoperitoneum secondary to ruptured CL is a rare complication and situation for women with bleeding disorders.

Case presentation

We here describe a case of severe CL hemorrhage with factor VIII deficiency. We chose conservative management instead of surgery for the abnormal hemostatic condition. With blood product and factor concentrate support, conservative management was successful in avoiding surgery in the episode of bleeding.

Conclusion

Gynecologist should be alert for the patients with abnormal hemostatic condition. Selective patients presenting with CL hemoperitoneum association with bleeding disorders may undergo conservative management and avoid the risk of surgery.

Diagnosing rare bleeding disorders

Rare bleeding disorders (RBDs) comprise the inherited deficiencies of coagulation factors such as fibrinogen, factor (F)II, FV, FV fl FVIII, FVII, FX, FXI, and FXIII, and are usually transmitted as autosomal recessive disorders. Given the low prevalence of these coagulopathies, information about their genetic, clinical and laboratory characteristics is limited. The clinical symptoms of RCDs are extremely diverse in terms of bleeding type, site, severity, age at onset, and duration. The weak association between residual coagulant activity and clinical bleeding severity, or at times inexistent, correlation between the factor's residual levels and clinical manifestations in some RBDs makes it difficult to use a single criterion to classify such conditions. Standardization and customization of coagulation assays, full genome sequencing, and global clotting assays will significantly improve diagnosis of patients with RBDs.