Paediatric-onset Evans syndrome: Breaking away from refractory immune thrombocytopenia.

Since its first description by Evans in 1951, this syndrome has been linked to chronic immune thrombocytopenia with the concurrent or delayed onset of autoimmune haemolytic anaemia or neutropenia. For decades, the evolution of Evans syndrome (ES) has carried a poor prognosis and often resulted in chronic steroid exposure, multiple immune suppressing medications directed against T or B lymphocytes, and splenectomy. This paper presents a new view of ES based on recent advances in genomics which begin to classify patients based on their underlying molecular variants in previously described primary immune disorders. This has opened up new avenues of targeted therapy or bone marrow transplant at rather than broad long-term immune suppression or splenectomy. Importantly, recent studies of the full lifespan of ES suggest that at least 80% of those paediatric patients will progress to various clinical or biological immunopathological manifestations with age despite the resolution of their cytopenias. Those patients merit long-term follow-up and monitoring in dedicated transition programs to improve outcome at the adult age.

PFA-100 System: A New Method for Assessment of Platelet Dysfunction.

This is a celebratory reprint of a historical paper published in STH in 1998. The original Abstract follows.The PFA-100 system is a platelet function analyzer designed to measure platelet-related primary hemostasis. The instrument uses two disposable cartridges: a collagen/epinephrine (CEPI) and a collagen/ADP (CADP) cartridge. Previous experience has shown that CEPI cartridges detect qualitative platelet defects, including acetylsalicylic acid (ASA)-induced abnormalities, while CADP cartridges detect only thrombocytopathies and not ASA use. In this seven-center trial, 206 healthy subjects and 176 persons with various platelet-related defects, including 127 ASA users, were studied. The platelet function status was determined by a platelet function test panel. Comparisons were made as to how well the defects were identified by the PFA-100 system and by platelet aggregometry. The reference intervals for both cartridges, testing the 206 healthy subjects, were similar to values described in smaller studies in the literature (mean closure time [CT] of 132 seconds for CEPI and 93 seconds for CADP). The use of different lot numbers of cartridges or duplicate versus singleton testing revealed no differences. Compared with the platelet function status, the PFA-100 system had a clinical sensitivity of 94.9% and a specificity of 88.8%. For aggregometry, a sensitivity of 94.3% and a specificity of 88.3% were obtained. These values are based on all 382 specimens. A separate analysis of sensitivity by type of platelet defect, ASA use versus congenital thrombocytopathies, revealed for the PFA-100 system a 94.5% sensitivity in identifying ASA users and a 95.9% sensitivity in identifying the other defects. For aggregometry, the values were 100% for ASA users and 79.6% for congenital defects. Analysis of concordance between the PFA-100 system and aggregometry revealed no difference in clinical sensitivity and specificity between the systems (p > 0.9999). The overall agreement was 87.5%, with a Kappa index of 0.751. The two tests are thus equivalent in their ability to identify normal and abnormal platelet defects. Testing 126 subjects who took 325 mg ASA revealed that the PFA-100 system (CEPI) was able to detect 71.7% of ASA-induced defects with a positive predictive value of 97.8%. The overall clinical accuracy of the system, calculated from the area under the receiver operating characteristic curve, was 0.977. The data suggest that the PFA-100 system is highly accurate in discriminating normal from abnormal platelet function. The ease of operation of the instrument makes it a useful tool to use in screening patients for platelet-related hemostasis defects.

The American Society of Pediatric Hematology Oncology workforce, productivity, and fellowship assessment: Current state of the workforce.

The American Society of Pediatric Hematology Oncology conducted follow-up workforce surveys in 2017 and 2021 as well as a Pediatric Hematology Oncology Fellowship Program Directors Survey in 2020 to provide an updated review of the current workforce. We provide a comprehensive review and analysis of these results with the goal to provide better understanding of the current landscape in pediatric hematology oncology.

Novel manifestations of immune dysregulation and granule defects in gray platelet syndrome.

Gray platelet syndrome (GPS) is a rare recessive disorder caused by biallelic variants in NBEAL2 and characterized by bleeding symptoms, the absence of platelet α-granules, splenomegaly, and bone marrow (BM) fibrosis. Due to the rarity of GPS, it has been difficult to fully understand the pathogenic processes that lead to these clinical sequelae. To discern the spectrum of pathologic features, we performed a detailed clinical genotypic and phenotypic study of 47 patients with GPS and identified 32 new etiologic variants in NBEAL2. The GPS patient cohort exhibited known phenotypes, including macrothrombocytopenia, BM fibrosis, megakaryocyte emperipolesis of neutrophils, splenomegaly, and elevated serum vitamin B12 levels. Novel clinical phenotypes were also observed, including reduced leukocyte counts and increased presence of autoimmune disease and positive autoantibodies. There were widespread differences in the transcriptome and proteome of GPS platelets, neutrophils, monocytes, and CD4 lymphocytes. Proteins less abundant in these cells were enriched for constituents of granules, supporting a role for Nbeal2 in the function of these organelles across a wide range of blood cells. Proteomic analysis of GPS plasma showed increased levels of proteins associated with inflammation and immune response. One-quarter of plasma proteins increased in GPS are known to be synthesized outside of hematopoietic cells, predominantly in the liver. In summary, our data show that, in addition to the well-described platelet defects in GPS, there are immune defects. The abnormal immune cells may be the drivers of systemic abnormalities such as autoimmune disease.

When Screening for Severe Combined Immunodeficiency (SCID) with T Cell Receptor Excision Circles Is Not SCID: a Case-Based Review.

Newborn screening efforts focusing on the quantification of T cell receptor excision circles (TRECs), as a biomarker for abnormal thymic production of T cells, have allowed for the identification and definitive treatment of severe combined immunodeficiency (SCID) in asymptomatic neonates. With the adoption of TREC quantification in Guthrie cards across the USA and abroad, typical, and atypical SCID constitutes only ~ 10% of cases identified with abnormal TRECs associated with T cell lymphopenia. Several other non-SCID-related conditions may be identified by newborn screening in a term infant. Thus, it is important for physicians to recognize that other factors, such as prematurity, are often associated with low TRECs initially, but often improve with age. This paper focuses on a challenge that immunologists face: the diagnostic evaluation and management of cases in which abnormal TRECs are associated with variants of T cell lymphopenia in the absence of a genetically defined form of typical or atypical SCID. Various syndromes associated with T cell impairment, secondary forms of T cell lymphopenia, and idiopathic T cell lymphopenia are identified using this screening approach. Yet there is no consensus or guidelines to assist in the evaluation and management of these newborns, despite representing 90% of the patients identified, resulting in significant work for the clinical teams until a diagnosis is made. Using a case-based approach, we review pearls relevant to the evaluation of these newborns, as well as the management dilemmas for the families and team related to the resolution of genetic ambiguities.

Evidence of a disability paradox in patient-reported outcomes in haemophilia.

INTRODUCTION: People with inherited and long-term conditions such as haemophilia have been shown to adapt to their levels of disability, often reporting better quality of life (QoL) than expected from the general population (the disability paradox). AIM: To investigate the disability paradox in people with haemophilia in the United States by examining preference differences in health state valuations versus the general population. METHODS: We conducted a discrete choice experiment including duration to capture valuations of health states based on patient-reported preferences. Participants indicated their preferences for hypothetical health states using the EQ-5D-5L, where each participant completed 15 of the 120 choice tasks. Response inconsistencies were evaluated with dominated and repeated scenarios. Conditional-logit regressions with random sampling of the general population responses were used to match the sample of patients with haemophilia. We compared model estimates and derived preferences associated with EQ-5D-5L health states. RESULTS: After removing respondents with response inconsistencies, 1327/2138 (62%) participants remained (177/283 haemophilia; 1150/1900 general population). Patients with haemophilia indicated higher preference value for 99% of EQ-5D-5L health states compared to the general population (when matched on age and gender). The mean health state valuation difference of 0.17 indicated a meaningful difference compared to a minimal clinically important difference threshold of 0.07. Results were consistent by haemophilia type and severity. CONCLUSION: Our findings indicated the presence of a disability paradox among patients with haemophilia, who reported higher health states than the general population, suggesting the impact of haemophilia may be underestimated if general population value sets are used.

Patient preferences and priorities for haemophilia gene therapy in the US: A discrete choice experiment.

INTRODUCTION: Gene therapy has shown promise in clinical trials for patients with haemophilia, but patient preference studies have focused on factor replacement treatments. AIM: We conducted a discrete choice experiment (DCE) to investigate the relative importance and differential preferences patients provide for gene therapy attributes. METHODS: We surveyed male adults with haemophilia in the United States recruited from patient panels including the National Hemophilia Foundation Community Voices in Research platform using an online survey over 4 months in 2020/21. Participants indicated preferences for gene therapy attributes including dosing frequency/durability, effect on annual bleeding, uncertainty related to side effects, impact on daily activities, impact on mental health, and post-treatment requirements. The relative importance of each attribute was analysed overall and for subgroups based on haemophilia type and severity. RESULTS: A total of 183 males with haemophilia A (n = 120) or B (n = 63) were included. Half (47%) had severe haemophilia; most (75%) were White. Overall, participants gave effect on bleeding rate the greatest relative importance (31%), followed by dose frequency/durability (26%), uncertainty regarding safety issues (17%), and impact on daily activities (11%). Dose frequency/durability had the greatest importance for those with haemophilia B (35%). CONCLUSION: People with haemophilia prioritised reduced bleeding and treatment burden; the former was more important in haemophilia A and the latter in haemophilia B, followed by safety and impact on daily life in this DCE of gene therapy attributes. These findings and differences can inform clinical and health policy decisions to improve health equity for people with haemophilia.

Achieving the unimaginable: Health equity in haemophilia.

Historically, treatment based on the availability of clotting factor replacement has resulted in an arcane guideline for the correction of factor deficiencies in people with haemophilia (PwH). While all other disease entities seek to restore function to a normal level, PwH are restricted to factor nadirs still equivalent to mild or moderate disease, resulting in continued risk of bleeding. A new treatment paradigm is needed based on the defined needs of PwH. A treatment model was developed by a panel of haemophilia providers, patient advocates and health economists to establish specific treatment milestones and targeted outcomes. The panel defined a series of treatment milestones to characterize the activity and outcomes linked to level of factor deficiency correction. All agreed that the ultimate goal should be 'functional cure' and 'health equity'. Seven levels to achieving a functional cure were identified, (a) Sustain life; (b) Minimal joint impairment; (c) Freedom from any spontaneous bleeds; (d) Attainment of 'normal' mobility; (e) Able to sustain minor trauma without additional intervention; (f) Ability to sustain major surgery or trauma; and (g) Normal haemostasis. A parallel set of patient-reported outcomes to achieve health equity was identified. These guidelines are now comparable with other disorders where the goal is to replace missing proteins to attain normal activity levels. As we are no longer limited by plasma supply due to the manufacture of recombinant factors, mimetics, and the early success of gene therapy, health equity is now achievable.

Rubella Virus-Associated Cutaneous Granulomatous Disease: a Unique Complication in Immune-Deficient Patients, Not Limited to DNA Repair Disorders.

The association of immunodeficiency-related vaccine-derived rubella virus (iVDRV) with cutaneous and visceral granulomatous disease has been reported in patients with primary immunodeficiency disorders (PIDs). The majority of these PID patients with rubella-positive granulomas had DNA repair disorders. To support this line of inquiry, we provide additional descriptive data on seven previously reported patients with Nijmegen breakage syndrome (NBS) (n = 3) and ataxia telangiectasia (AT) (n = 4) as well as eight previously unreported patients with iVDRV-induced cutaneous granulomas and DNA repair disorders including NBS (n = 1), AT (n = 5), DNA ligase 4 deficiency (n = 1), and Artemis deficiency (n = 1). We also provide descriptive data on several previously unreported PID patients with iVDRV-induced cutaneous granulomas including cartilage hair hypoplasia (n = 1), warts, hypogammaglobulinemia, immunodeficiency, myelokathexis (WHIM) syndrome (n = 1), MHC class II deficiency (n = 1), Coronin-1A deficiency (n = 1), X-linked severe combined immunodeficiency (X-SCID) (n = 1), and combined immunodeficiency without a molecular diagnosis (n = 1). At the time of this report, the median age of the patients with skin granulomas and DNA repair disorders was 9 years (range 3-18). Cutaneous granulomas have been documented in all, while visceral granulomas were observed in six cases (40%). All patients had received rubella virus vaccine. The median duration of time elapsed from vaccination to the development of cutaneous granulomas was 48 months (range 2-152). Hematopoietic cell transplantation was reported to result in scarring resolution of cutaneous granulomas in two patients with NBS, one patient with AT, one patient with Artemis deficiency, one patient with DNA Ligase 4 deficiency, one patient with MHC class II deficiency, and one patient with combined immunodeficiency without a known molecular etiology. Of the previously reported and unreported cases, the majority share the diagnosis of a DNA repair disorder. Analysis of additional patients with this complication may clarify determinants of rubella pathogenesis, identify specific immune defects resulting in chronic infection, and may lead to defect-specific therapies.

Origins and organization of the NHLBI State of the Science Workshop: Generating a national blueprint for future research on factor VIII inhibitors.

INTRODUCTION: The major complication of protein replacement therapy for haemophilia A is the development of anti-FVIII antibodies or inhibitors that occur in 25%-30% of persons with severe haemophilia A. Alternative therapeutics such as bypassing agents or immune tolerance induction protocols have additional challenges and are not always effective. AIM: Assemble a National Heart, Lung and Blood Institute (NHLBI) State of the Science (SOS) Workshop to generate a national blueprint for research on inhibitors to solve the problem of FVIII immunogenicity. METHODS: An Executive Steering Committee was formed in October 2017 to establish the scientific focus and Scientific Working Groups for the SOS Workshop in May 2018. Four working groups were assembled to address scientific priorities in basic, translational and clinical research on inhibitors. RESULTS: Working Group 1 was charged with determining the scientific priorities for clinical trials to include the integration of non-intravenous, non-factor therapeutics including gene therapy into the standard of care for people with haemophilia A with inhibitors. Working Group 2 established the scientific priorities for 21st-century data science and biospecimen collection for observational inhibitor cohort studies. The scientific priorities for acquiring an actionable understanding of FVIII immunogenicity and the immunology of the host response and FVIII tolerance were developed by Working Group 3. Working Group 4 designed prospective pregnancy/birth cohorts to study FVIII immunogenicity, inhibitor development and eradication. CONCLUSION: The NHLBI SOS Workshop generated a focused summary of scientific priorities and implementation strategies to overcome the challenges of eradicating and preventing inhibitors in haemophilia A.

Promising biomarkers for the prediction of catheter-related venous thromboembolism in hospitalized children: An exploratory study.

BACKGROUND: Pediatric venous thromboembolism (VTE) has increased over the past 10 years, with central venous catheters (CVC) being the strongest risk factor. Current tools are not sufficient to predict VTE risk. The utility of biomarkers in predicting CVC-related VTE has been minimally explored. Our objective is to determine the utility of microparticles (MPs), factor VIII (FVIII) activity, and thrombin generation (TG) in prospectively predicting VTE occurrence in hospitalized children with CVCs. PROCEDURE: In this nested case-control pilot study, consecutive hospitalized children needing CVC placement (1 month to 21 years) were enrolled. Venous samples were collected prior to or within 24 h of CVC placement. MPs were measured using factor Xa initiated clot-based assay. FVIII was measured using a one-stage clot-based assay. TG was measured using calibrated automated thrombogram. RESULTS: There were three CVC-related VTE events (7%) in our cohort of 42 subjects. Xa clotting time (XaCT) ratio was lower (0.68 ± 0.07 vs 0.95 ± 0.21, P = .4), while FVIII (461 ± 120 vs 267 ± 130, P = .02), peak thrombin (418 ± 89 vs 211 ± 101, P = .001), endogenous thrombin potential (ETP) (1828 ± 485 vs 1282 ± 394, P = .03), and velocity index (VI) (182 ± 28 vs 75 ± 53, P = .001) were higher in subjects with CVC-related VTE compared to those without CVC-related VTE. Sensitivity/specificity analysis revealed optimal cutoff values for XaCT ratio (0.75), FVIII (370), ETP (1680), peak (315), and VI (130), with receiver operating characteristic area under the curve values >0.9. CONCLUSION: MPs, FVIII, and TG can potentially predict pediatric CVC-related VTE in a prospective fashion. Stratification according to VTE risk may aid in guiding preventative efforts in future studies.

Parent proxy assessment of sibling quality of life following pediatric hematopoietic cell transplantation.

BACKGROUND: When a child undergoes hematopoietic cell transplantation (HCT), the impact extends to the entire family, including siblings. Assessment of the quality of life (QoL) of siblings is challenged by their general lack of availability for regular assessment by clinical providers. Thus, the use of parent proxy reporting may be useful. Our aim was to describe the QoL of siblings of HCT survivors, as reported by their parents, as well as to identify parent and family factors associated with lower sibling QoL. METHODS: A cross-sectional study was utilized to assess parent-reported QoL of the HCT recipient's sibling (Short Form (SF)-10 Health Survey for Children and the Pediatric Symptom Checklist (PSC)-17). Parent QoL was assessed using the SF-12. Multivariable linear regression was used to explore hypothesized predictors of sibling QoL, including parent QoL, family impact/function (Impact on Family Scale, Family Adaptability and Cohesion Evaluation Scales, IV, and a question asking about financial problems) while adjusting for demographic and HCT characteristics. RESULTS: Ninety-seven siblings (55% males) with a mean age of 12 years (standard deviation [SD] 4 years) were assessed, representing HCT survivors, who were an average of 5 years (SD 4 years) post-HCT. Neither sibling psychosocial (mean 49.84, SD 10.70, p = 0.87) nor physical health scores (mean 51.54, SD 8.42, p = 0.08) differed from norms. Parent proxies reported behavioral/emotional problems (PSC-17 total score > 15) in 24% of siblings. While parental ratings of their own physical health (SF-12 were higher than norms (mean 53.04, SD 8.17, p = 0.0005), mental health scores were lower (mean 45.48, SD 10.45, p < 0.0001). In multivariable analysis, lower parent emotional functioning and adverse family function were associated with lower sibling QoL, as reported by parents. CONCLUSIONS: While proxy-reported QoL of siblings did not differ significantly from normative data, both parent QoL and family function were associated with sibling QoL. Future research is needed to understand how siblings themselves perceive their QoL following HCT.

Value of prophylaxis vs on-demand treatment: Application of a value framework in hemophilia.

INTRODUCTION: Therapeutic advances over the past 30 years have led to longer life expectancy and improved quality of life (QOL) for persons with hemophilia. Access to innovative therapy may be compromised if treatment decisions are driven solely by cost. New strategies are needed to assess true therapeutic values, along with financial cost, as physicians, policymakers, payers and manufacturers work together to improve patient care. AIM: To provide an evidence-based assessment of the value of prophylaxis vs on-demand therapy for hemophilia, based on a widely recognized three-tiered value framework approach for assessing a range of therapeutic interventions. METHODS: Data from six randomized clinical trials (ESPRIT, Joint Outcomes Study, SPINART, LEOPOLD II, ADVATE and POTTER) and four observational studies comparing primary and secondary prophylaxis vs on-demand therapy were applied to a hemophilia value framework. RESULTS: Both primary and secondary prophylaxis showed advantages in Tier 1 "Degree of health/recovery" outcomes, including measures of bleeding, musculoskeletal complications, pain, function/activity and QOL. Tier 2 "Process of Recovery" outcomes, also favoured prophylaxis, including measures of recovery time, return to normal activities, orthopaedic intervention and venous access. In Tier 3 "Sustainability of Health Recovery," measures of breakthrough bleeds, joint preservation, sustained productivity and QOL showed significant improvement with prophylaxis. CONCLUSION: The hemophilia value framework affirmed value of primary and secondary prophylaxis vs on-demand therapy, with clinical benefit demonstrated in all three tiers. This analysis also demonstrates clinical utility of the value framework process in the determination of optimal and cost-effective hemophilia care for all stakeholders.

Clinical Challenges: Identification of Patients With Novel Primary Immunodeficiency Syndromes.

Novel primary immunodeficiency disorders are being identified with next generation sequencing technologies. We describe 1 patient with cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) haploinsufficiency who had recurrent enhancing brain lesions, nodular pulmonary infiltrates, hepatosplenomegaly, immune cytopenias, as well as progressive hypogammaglobulinemia and lymphopenia. We describe a second patient with activated p110δ syndrome (APDS)/p110δ activating mutation causing senescent T cells, lymphadenopathy, and immunodeficiency (PASLI) in association with recurrent respiratory tract infections, Epstein-Barr virus infection, lymphadenopathy, elevated serum IgM, and progressive lymphopenia. These presentations highlight the need for astute clinical judgment in the evaluation of patients with potential primary immunodeficiency disorders.

Developing the First Recombinant Factor XIII for Congenital Factor XIII Deficiency: Clinical Challenges and Successes.

Congenital factor XIII (FXIII) deficiency is a rare, autosomal recessive bleeding disorder with potentially life-threatening consequences. FXIII is composed of two subunits (A and B), and a deficiency or dysfunction of either can result in FXIII deficiency. Traditionally, FXIII deficiency has been managed by infusing plasma-derived products containing FXIII (fresh frozen plasma, cryoprecipitate, and plasma-derived FXIII concentrates), all of which contain both subunits. Despite the increased safety of plasma-derived products, concern remains regarding potential viral safety issues. This review describes the development, from concept to clinical use, of a recombinant FXIII molecule (containing subunit A only; rFXIII-A2) for congenital FXIII-A subunit deficiency. Unmet needs and ongoing challenges in congenital FXIII deficiency are also discussed. Despite the challenges in developing a product for a very rare bleeding disorder, the information gathered on efficacy, safety, and pharmacokinetics of FXIII replacement therapy represents the largest dataset on congenital FXIII-A subunit deficiency in the world. It also provides evidence for the safety and efficacy of monthly prophylaxis with 35 IU/kg of rFXIII-A2 in patients with FXIII-A subunit deficiency. The issues encountered and overcome, along with lessons learned, may be applied to and encourage the development of new recombinant products for other rare bleeding disorders.

Platelet genomics: the role of platelet size and number in health and disease.

Taken together, there is ample evidence of the association of cardiovascular disease, cerebrovascular, and inflammatory disease with single nucleotide variants (SNV) due to their impact on platelet size, number, and function. With the use of electronic medical record (EMR) or other phenotypic-linked bioinformatics sources, the more important "functional" variants are emerging and provide valuable information on their specific role in promoting early onset of disease or poor response to therapeutic measures. This review will focus upon the recognized common polymorphisms or gene variants with small, but functional effects, as it is becoming clear that these contribute to hyper- or hypo-responsive platelet phenotypes. The impact of these gene variants is distinguishable among normal individuals, and they are suspected contributors to increased risk of adverse outcomes in patients with underlying disease. There are thousands of gene variants and environmental factors that may mitigate risk or amplify the potential for disease within each of us. When combined with the environment and epigenetic influences, it is clear that whole-genome sequencing and bioinformatics alone will not be enough to truly predict "risk" or probability, but awareness of their potential influence may be a starting point in selective screening and generating prevention strategies to promote a healthy lifestyle or fine-tune therapeutic choices in the future.

Unrelated Hematopoietic Cell Transplantation in a Patient with Combined Immunodeficiency with Granulomatous Disease and Autoimmunity Secondary to RAG Deficiency.

The use of HLA-identical hematopoietic stem cell transplantation (HSCT) demonstrates overall survival rates greater than 75 % for T-B-NK+ severe combined immunodeficiency secondary to pathogenic mutation of recombinase activating genes 1 and 2 (RAG1/2). Limited data exist regarding the use of HSCT in patients with hypomorphic RAG variants marked by greater preservation of RAG activity and associated phenotypes such as granulomatous disease in combination with autoimmunity. We describe a 17-year-old with combined immunodeficiency and immune dysregulation characterized by granulomatous lung disease and autoimmunity secondary to compound heterozygous RAG mutations. A myeloablative reduced toxicity HSCT was completed using an unrelated bone marrow donor. With the increasing cases of immune dysregulation being discovered with hypomorphic RAG variants, the use of HSCT may advance to the forefront of treatment. This case serves to discuss indications of HSCT, approaches to preparative therapy, and the potential complications in this growing cohort of patients with immune dysregulation and RAG deficiency.

Expanding the Mutation Spectrum Affecting αIIbß3 Integrin in Glanzmann Thrombasthenia: Screening of the ITGA2B and ITGB3 Genes in a Large International Cohort.

We report the largest international study on Glanzmann thrombasthenia (GT), an inherited bleeding disorder where defects of the ITGA2B and ITGB3 genes cause quantitative or qualitative defects of the αIIbß3 integrin, a key mediator of platelet aggregation. Sequencing of the coding regions and splice sites of both genes in members of 76 affected families identified 78 genetic variants (55 novel) suspected to cause GT. Four large deletions or duplications were found by quantitative real-time PCR. Families with mutations in either gene were indistinguishable in terms of bleeding severity that varied even among siblings. Families were grouped into type I and the rarer type II or variant forms with residual αIIbß3 expression. Variant forms helped identify genes encoding proteins mediating integrin activation. Splicing defects and stop codons were common for both ITGA2B and ITGB3 and essentially led to a reduced or absent αIIbß3 expression; included was a heterozygous c.1440-13_c.1440-1del in intron 14 of ITGA2B causing exon skipping in seven unrelated families. Molecular modeling revealed how many missense mutations induced subtle changes in αIIb and ß3 domain structure across both subunits, thereby interfering with integrin maturation and/or function. Our study extends knowledge of GT and the pathophysiology of an integrin.

Identification of patients with RAG mutations previously diagnosed with common variable immunodeficiency disorders.

PURPOSE: Combined immunodeficiency (CID) presents a unique challenge to clinicians. Two patients presented with the prior clinical diagnosis of common variable immunodeficiency (CVID) disorder marked by an early age of presentation, opportunistic infections, and persistent lymphopenia. Due to the presence of atypical clinical features, next generation sequencing was applied documenting RAG deficiency in both patients. METHODS: Two different genetic analysis techniques were applied in these patients including whole exome sequencing in one patient and the use of a gene panel designed to target genes known to cause primary immunodeficiency disorders (PIDD) in a second patient. Sanger dideoxy sequencing was used to confirm RAG1 mutations in both patients. RESULTS: Two young adults with a history of recurrent bacterial sinopulmonary infections, viral infections, and autoimmune disease as well as progressive hypogammaglobulinemia, abnormal antibody responses, lymphopenia and a prior diagnosis of CVID disorder were evaluated. Compound heterozygous mutations in RAG1 (1) c256_257delAA, p86VfsX32 and (2) c1835A>G, pH612R were documented in one patient. Compound heterozygous mutations in RAG1 (1) c.1566G>T, p.W522C and (2) c.2689C>T, p. R897X) were documented in a second patient post-mortem following a fatal opportunistic infection. CONCLUSION: Astute clinical judgment in the evaluation of patients with PIDD is necessary. Atypical clinical findings such as early onset, granulomatous disease, or opportunistic infections should support the consideration of atypical forms of late onset CID secondary to RAG deficiency. Next generation sequencing approaches provide powerful tools in the investigation of these patients and may expedite definitive treatments.

Use of Factor XIII (FXIII) concentrate in patients with congenital FXIII deficiency undergoing surgical procedures.

BACKGROUND: Patients with congenital Factor XIII (FXIII) deficiency have impaired fibrin stabilization and are at high risk for surgical bleeding. Data regarding the use of FXIII concentrates before and during surgery are lacking. The objective of this study was to report the use of plasma-derived FXIII concentrate (Corifact in the United States; Fibrogammin P in other countries) in patients with congenital FXIII deficiency undergoing surgical procedures. STUDY DESIGN AND METHODS: FXIII concentrate at preoperative doses ranging from 25 to 40 U/kg was administered to six patients with congenital FXIII deficiency undergoing major or minor surgeries. RESULTS: FXIII concentrate was administered immediately before surgery for five surgical cases; three of these patients achieved excellent hemostasis during and after surgery, while two had intraoperative bleeding. In one surgical case, a regular prophylactic dose of FXIII concentrate was administered to the patient 1 week before minor surgery. FXIII concentrate provided rapid replacement of FXIII activity. In all but one of the patients given a dose of FXIII designed to increase FXIII levels more than 50%, there was satisfactory intraoperative and postoperative hemostasis. One patient undergoing aortic valve replacement on cardiopulmonary bypass (CPB) was the exception. Intraoperative bleeding in this patient was associated with lower-than-expected blood levels of FXIII. CONCLUSION: Preoperative plasma-derived FXIII concentrate allowed for sufficient hemostasis in most patients with FXIII deficiencies. Additional doses were necessary to achieve hemostasis in one patient who underwent a CPB procedure.