Coagulation factor XI is a contaminant in intravenous immunoglobulin preparations

An obvious antinomy, superior sagittal sinus thrombosis in a patient with immune thrombocytopenia: Case report and a review of literatures

RATIONALE

Immune thrombocytopenia (ITP) is an autoimmune disease with an increased risk of bleeding. However, in recent years, it has been reported that patients with this hemorrhagic disease have the risk of thrombosis and embolism.

PATIENT CONCERNS AND DIAGNOSIS

The patient, in this case, was a young female who was diagnosed with ITP. When the platelet count was low, she had skin, mucosa, internal organs, and intracranial hemorrhage. In the process of ITP and hemostatic treatment, superior sagittal sinus thrombosis occurred when she was still bleeding.

INTERVENTIONS

She was given treatments for reducing intracranial pressure and controlling epilepsy.

OUTCOMES

And then the embolectomy operation failed. It was suggested in this case that ITP patients with severe thrombocytopenia and bleeding tendency also have a risk of having thrombotic disease. We reviewed literatures regarding the mechanism of the simultaneous occurrence of 2 antinomy diseases and cerebral venous thrombosis.

LESSONS

There are many factors for ITP patients to have thrombosis involving ITP itself, its treatment and the patients' constitution, medical history, and former medication. ITP is not only a hemorrhagic disease but also a thrombotic disease. Clinicians should be alert to the risk of thrombotic diseases in ITP treatment. Therefore thrombus monitoring and screening should be carried out, and early prevention or appropriate anticoagulant treatment should be selected, especially for patients with high risk.

Alternatives for managing patients with newly diagnosed immune thrombocytopenia: a narrative review

INTRODUCTION

Primary immune thrombocytopenia (ITP) is an acquired bleeding disorder. Conventionally, first-line ITP therapy aims to obtain a rapid response and stop or decrease the risk of bleeding by increasing the platelet count. At this point, the duration of the response, the tolerability, and the long-term safety of pharmacologic interventions are considered less of a priority. Combination treatments that simultaneously address multiple disease mechanisms are an attractive strategy to increase efficacy in acute ITP therapy. In this review, we discuss the treatment of newly diagnosed ITP patients, emphasizing the use of new combinations to benefit from their synergy.

AREAS COVERED

This article summarizes conventional treatment, recent and novel combinations, and COVID-19 management recommendations of newly diagnosed ITP patients.

EXPERT OPINION

The key areas for improvement consider the long-term effects of conventional first-line therapy, reducing relapse rates, and extending responses to achieve long-term remission. Although corticosteroids remain first-line therapy, restricting their use to avoid toxicity and the increasing use of rituximab and TPO-RAs in the first three months after diagnosis open the landscape for future interventions in frontline therapy for ITP. First-line therapy intensification or synergistic drug combination offers a potential and realistic shift in future treatment guidelines.

Renal infarction associated with low dose intravenous immunoglobulin in a kidney transplant recipient with sepsis: a case report and literature review

Background

The use of human intravenous immunoglobulin gamma (IVIG) is associated with thromboembolic events as a complication. There are few reported cases of renal infarction during IVIG use in the general population, but transplant kidney may be more susceptible to thromboembolic events following IVIG use.

Case presentation

A 41-year-old woman visited with fever and pain at the transplant kidney. Six years ago, she underwent kidney transplantation from a deceased donor. Laboratory and radiologic findings were compatible to septic condition, secondary to acute pyelonephritis. We started antibiotics, inotropics, and IVIG. The patient abruptly developed gross hematuria and urine output decreased to 100 cc/day during IVIG administration. Renal doppler and pathologic findings revealed renal infarction. Oliguria and azotemia persisted and she is undergoing maintenance hemodialysis.

Conclusion

Our case shows that infarction of transplant kidney can be caused by IVIG use in a patient with severe infection. Thus, when using IVIG for kidney transplant patients with high risk of thromboembolic events, we may be careful to prevent the thromboembolic events.

Thromboembolic complications following intravenous immunoglobulin therapy in immune-mediated neurological disorders

BACKGROUND

Minor adverse events of intravenous immunoglobulin (IVIg) include flu-like symptoms, eczematous skin reaction, electrolyte disturbance, and transient leukopenia. On rare occasions, serious complications such as aseptic meningitis, arrhythmia, decrease in blood pressure, and thromboembolic complications (TEC) have been described. The current study aimed to understand the frequency and clinical features of TEC related to IVIg administration in patients with immune-mediated neurological disorders.

METHODS

We conducted a retrospective chart review of hospitalized patients with immune-mediated neuromuscular or neuroimmunological disorders treated with IVIg from January 2018 to March 2020 in a single tertiary hospital.

RESULTS

During the study period, 61 patients were treated with a total of 364 IVIg infusions over 84 treatment courses. Among them, we identified 3 TEC cases that occurred during or after the completion of IVIg therapy: two patients with myasthenia gravis (F/60 and F/80) and one patient with Guillain-Barré syndrome (F/79) had undergone arterial TEC (two for ischemic stroke and one for pulmonary thromboembolism). The rates of TEC per patient, per treatment course, and per infusion were 4.91% (3/61), 3.57% (3/84), and 0.82% (3/364), respectively.

CONCLUSION

The risk of developing TEC upon receiving IVIg infusions is generally low in patients with immune-mediated neurological disorders; however, IVIg-related TEC should be cautiously monitored for in critically ill elderly patients with vascular risk factors, especially those suffering from myasthenic crisis.

Anti-inflammatory activity of CD44 antibodies in murine immune thrombocytopenia is mediated by Fcγ receptor inhibition

Monoclonal immunoglobulin G (IgG) antibodies to CD44 (anti-CD44) are anti-inflammatory in numerous murine autoimmune models, but the mechanisms are poorly understood. Anti-CD44 anti-inflammatory activity shows complete therapeutic concordance with IV immunoglobulin (IVIg) in treating autoimmune disease models, making anti-CD44 a potential IVIg alternative. In murine immune thrombocytopenia (ITP), there is no mechanistic explanation for anti-CD44 activity, although anti-CD44 ameliorates disease similarly to IVIg. Here, we demonstrate a novel anti-inflammatory mechanism of anti-CD44 that explains disease amelioration by anti-CD44 in murine ITP. Macrophages treated with anti-CD44 in vitro had dramatically suppressed phagocytosis through FcγRs in 2 separate systems of IgG-opsonized platelets and erythrocytes. Phagocytosis inhibition by anti-CD44 was mediated by blockade of the FcγR IgG binding site without changing surface FcγR expression. Anti-CD44 of different subclasses revealed that FcγR blockade was specific to receptors that could be engaged by the respective anti-CD44 subclass, and Fc-deactivated anti-CD44 variants lost all FcγR-inhibiting activity. In vivo, anti-CD44 functioned analogously in the murine passive ITP model and protected mice from ITP when thrombocytopenia was induced through an FcγR that could be engaged by the CD44 antibody's subclass. Consistent with FcγR blockade, Fc-deactivated variants of anti-CD44 were completely unable to ameliorate ITP. Together, anti-CD44 inhibits macrophage FcγR function and ameliorates ITP consistent with an FcγR blockade mechanism. Anti-CD44 is a potential IVIg alternative and may be of particular benefit in ITP because of the significant role that FcγRs play in human ITP pathophysiology.

Enabling accurate measurement of activated factor XI (FXIa) in therapeutic immunoglobulin products

Background and objectives

In 2010, an intravenous immunoglobulin (IVIG) product was removed from the market due to an association with serious thromboembolic events. Investigations revealed that factor XIa (FXIa) was present as a process‐related impurity. This study investigated the ability of two commercial FXIa assays to measure FXIa in immunoglobulin preparations and conducted a survey of FXIa activity in marketed immunoglobulin products.

Materials and methods

Factor XIa assays were modified to include spiking of samples with FXIa before testing. An immunoglobulin product and its excipient were used to assess the ability of the assays to recover the spiked FXIa levels.

Results

The Biophen FXIa assay required a high pre‐dilution of the sample to obtain statistically valid results and complete FXIa recovery. The ROX FXIa assay was more sensitive, giving statistically valid results at a lower sample pre‐dilution and FXIa spike level. This modified ROX FXIa assay was used to assay 17 lots of immunoglobulin products for FXIa. Two product lots had measurable FXIa levels without the need for spiking. A further 3 lots produced detectable but not statistically valid FXIa results when left unspiked. Spiking produced statistically valid assays and recoveries above 100%, demonstrating inherent FXIa.

Conclusion

This study shows marketed immunoglobulin products can contain detectable levels of FXIa. Spiking brings the FXIa levels into the quantifiable range of the assay, allowing measurement of inherent FXIa. Accurate measurement is important to inform on ‘safe’ levels of FXIa in these products and allow future safety guidelines to be set.

Managing syndromic congenital ichthyosis at a tertiary care institute-Genotype-phenotype correlations, and novel treatments

Syndromic congenital ichthyoses (CI) are genetically determined disorders of cornification that are characterized by generalized scaling along with systemic symptoms. Data on congenital syndromic ichthyosis from developing countries are scarce. We aimed to assess the prevalence, phenotype-genotype correlation, and management of syndromic CI patients presenting to our outpatient during the specified period this was a retrospective study of congenital syndromic ichthyosis patients attending a dermatology clinic in a tertiary care center from 2105-2018. We reviewed epidemiological and comorbidities data, phenotype-genotype correlations, and treatments of syndromic congenital ichthyosis patients. Six patients of Syndromic CI were diagnosedamongst 86 patients of CI (8.1%). Amongst these, three patients of Sjogren-Larrson syndrome (SLS), two patients of Netherton syndrome (NS), and one of Chanarin-Dorfman disease (CDD) were reported. Next-generation sequencing (NGS) was performed with novel variants reported in one patient each of SLS, NS, and CDD. An atypical phenotype was observed in a patient with NS with associated growth hormone and adrenocorticotropic hormone deficiency but with favorable clinical response to intravenous immunoglobulin. Our reports point towards the unreported pool of genetic mutations in CI from India. Novel mutations were associated with variable cutaneous and systemic involvement.

Protease: Serpin complexes to assess contact system and intrinsic pathway activation

Mounting evidence suggests that a variety of disease states are pathophysiologically related to activation of the contact system in vivo. The plasma contact system is composed of a cascade of serine proteases initiated by surface activation of factor XII, which can then proceed through a procoagulant pathway by activating the intrinsic coagulation factor XI, or a proinflammatory pathway by activating prekallikrein. Serpins are the primary endogenous inhibitors of the contact system, which irreversibly inhibit their respective protease(s), forming a stable complex. We modified an existing assay strategy for detecting these complexes in plasma using ELISAs and determined the effect of preanalytical variation caused by anticoagulant selection and processing time. The assays were sensitive and specific to inherited deficiency of individual contact factors. We conclude that these assays are robust and represent a relatively simple approach to the assessment of contact factor activation in plasma samples.

The clinical management of factor XI deficiency in pregnant women

INTRODUCTION

Factor XI (FXI) deficiency is associated with highly variable bleeding, including excessive gynecologic and obstetrical bleeding. Since approximately 20% of FXI-deficient women will experience pregnancy-related bleeding, careful planning and knowledge of appropriate hemostatic management is pivotal for their care.

AREAS COVERED

In this manuscript, authors present our current understanding of the role of FXI in hemostasis, the nature of the bleeding phenotype caused by its deficiency, and the impact of deficiency on obstetrical care. The authors searched PubMed with the terms, 'factor XI', 'factor XI deficiency', 'women', 'pregnancy', and 'obstetrics' to identify literature on these topics. Expectations of pregnancy-related complications in women with FXI deficiency, including antepartum, abortion-related, and postpartum bleeding, as well as bleeding associated with regional anesthesia are discussed. Recommendations for the care of these women are considered, including guidance for management of prophylactic care and acute bleeding.

EXPERT COMMENTARY

FXI deficiency results in a bleeding diathesis in some, but not all, patients, making treatment decisions and clinical management challenging. Currently available laboratory assays are not particularly useful for distinguishing patients with FXI deficiency who are prone to bleeding from those who are not. There is a need for alternative testing strategies to address this limitation.

Effect of storage of plasma in the presence of red blood cells and platelets: re-evaluating the shelf life of whole blood

BACKGROUND

There is renewed interest in administering whole blood (WB) for the resuscitation of patients with bleeding trauma. The shelf life of WB was established decades ago based on the viability of red blood cells. However, plasma quality during WB storage is not established.

STUDY DESIGN AND METHODS

White blood cell- and platelet-reduced WB (WB-PLT) was prepared using standard processes and compared to WB processed using a platelet-sparing WBC reduction (WB + PLT) filter. WB (± PLT) was held at 2 to 6°C for 35 days alongside control units of red blood cells (RBCs) in saline, adenine, glucose, and mannitol and liquid plasma. A series of assays explored the coagulation potential and RBC quality.

RESULTS

While fibrinogen and α2-antiplasmin remained unaffected by storage, other factors varied between components or over time at 2 to 6°C. At 14 days factor V, factor VII, α₂ -antiplasmin and free protein S antigen remained on average greater than 0.50 IU/mL or 50%, as appropriate, in WB ± PLT. Factor VIII was on average 0.49 IU/mL in WB+PLT, and 0.56 IU/mL for WB-PLT. Free protein S activity decreased significantly in all arms but remained on average greater than 40% at Day 14. Contact activation was not demonstrated before Day 14. Thrombin generation in plasma remained relatively stable to Day 35 in all arms.

CONCLUSIONS

Clotting factor activity remained at or above a mean of 0.5 IU/mL, or 50%, at Day 14 for factor V, factor VII, factor VIII, free protein S, fibrinogen, and α2-antiplasmin in all arms. Further data on platelet function in WB+PLT is needed to inform its shelf life.

Safety considerations with current and emerging antiviral therapies for cytomegalovirus infection in transplantation

Introduction: Human cytomegalovirus (HCMV) is a major contributor of morbidity and mortality, and its management is essential for the successful outcome of solid organ and hematopoietic stem cell transplantation. Areas covered: This review discusses the safety profiles of currently available and emerging antiviral drugs and the other strategies for HCMV prevention and treatment after transplantation. Expert opinion: Strategies for management of HCMV rely largely on the use of antiviral agents that inhibit viral DNA polymerase (ganciclovir/valganciclovir, foscarnet, and cidofovir/brincidofovir) and viral terminase complex (letermovir), with different types and degrees of adverse effects. An investigational agent, maribavir, exerts its anti-CMV effect through UL97 inhibition, and its safety profile is under clinical evaluation. In choosing the antiviral medication to use, it is important to consider these safety profiles in addition to overall efficacy. In addition to antiviral drugs, reduction of immunosuppression is often generally needed in the management of HCMV infection, but with a potential risk of allograft rejection or graft-versus-host disease. The use of HCMV-specific or non-specific intravenous immunoglobulins remains debated, while adoptive HCMV-specific T cell therapy remains investigational, and associated with unique set of adverse effects.

Complications of Immunoglobulin Therapy and Implications for Treatment of Inflammatory Neuropathy: A Review

BACKGROUND

Intravenous Immunoglobulin (IVIg) forms a cornerstone of effective treatment for acute and chronic inflammatory neuropathies, with a class I evidence base in Guillain-Barré Syndrome (GBS), Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). It is generally considered to be a safe therapy however there are several recognised complications which are reviewed in this article.

DISCUSSION AND CONCLUSION

Most adverse events are immediate and mild such as headache, fever and nausea although more serious immediate reactions such as anaphylaxis may rarely occur. Delayed complications are rare but may be serious, including thromboembolic events and acute kidney injury, and these and associated risk factors are also discussed. We emphasise the importance of safe IVIg administration and highlight practical measures to minimise complications of this therapy.

Estimating the Reliability of Low-Abundant Signals and Limited Replicate Measurements through MS2 Peak Area in SWATH

Sequential windows acquisition of all theoretical fragment ions mass spectrometry (SWATH-MS) provides large-scale protein quantification with high accuracy and selectivity. Nevertheless, reliable quantification of low-abundant signals in complex samples remains challenging, as recently illustrated in a multicenter benchmark study of different label-free software tools. Here, the SWATH Replicates Analysis 2.0 template from Sciex is used to highlight that the relationship between the MS2 peak area and the variability can be described by a function. This functional relationship appears to be largely insensitive to variation in samples or acquisition conditions, suggesting a device-intrinsic property. By using a power regression, it is shown that the MS2 peak area can be used to predict the quantification repeatability without relying on replicate injections, thus contributing to high-throughput confident quantification of low-abundant signals with SWATH-MS.

Vertebral Artery Thrombosis in Chronic Idiopathic Thrombocytopenic Purpura

INTRODUCTION

Immune thrombocytopenic purpura (ITP) is an autoimmune hematological disorder that causes decreased production and destruction of platelets leading to thrombocytopenia. Although thrombocytopenia usually causes hemorrhagic problems, thrombotic events like strokes, although rare, can still occur. Management of thrombotic events in patients with ITP differs from that of patients with normal platelet count function and count.

CASE DESCRIPTION

A 32-year-old female with a history of ITP presented with ischemic stroke. The patient was treated in the hospital with IV immunoglobulin, discharged to a rehabilitation facility, and had complete resolution of symptoms when examined at a follow-up visit 3 months later.

CONCLUSION

Although stroke in patients with ITP is very rare due to thrombocytopenia, it has been reported in several other published cases and is likely associated with increased platelet microparticle levels, a byproduct of platelet destruction. While usage of antiplatelet therapy in such patients is debated, immunosuppression therapy has been the mainstay treatment in all published cases.

Ischemic stroke in Kawasaki disease

Pediatric stroke is considered to be rare. Stroke resulting from cerebral vasculitis is also uncommon in young children. With the increasing prevalence of Kawasaki disease (KD) diagnosis, this acquired vasculitis has been reported with various clinical presentations including neurological symptoms. Herein we describe the case of a KD patient presenting with stroke. A 15-month-old boy was referred due to stroke that occurred on the fifth day of febrile illness. He was initially admitted to another hospital due to fever and diarrhea. He was discharged and re-admitted 2 days afterward due to left hemiplegia. During the 10 days of the second hospitalization, he had a presumptive diagnosis of encephalomeningitis. Upon referral to the present hospital, he was found to have right middle cerebral artery branch stenosis and fusiform aneurysms of the coronary arteries. Retrospectively, the patient had the full clinical criteria for KD diagnosis. Therefore, stroke could be considered as one of the uncommon clinical manifestations of KD.

Cerebral Venous Thrombosis after Intravenous Immunoglobulin Therapy in Immune Thrombocytopenic Purpura

A common misconception is that immune thrombocytopenic purpura (ITP) causes only bleeding diathesis. From this case vignette of a young male with ITP who had cerebral venous thrombosis, we highlight the importance of considering venous thrombosis in such patients when they present with focal cerebral signs.

Proposed Relationship Between Intravenous Immunoglobulin and Thrombosis in Renal Transplant Recipients

Objective:

To report 2 cases of intravenous human immunoglobulin (IVIG)–associated thrombosis in kidney transplant patients.

Case Summary:

Both cases involved female patients presenting to Henry Ford Hospital in Detroit for renal transplantation. Patient 1 presented with systemic lupus erythematosus, positive for both anticardiolipin and anti-DNA antibody. Patient 2, post nephrectomy, was found to have moderate hyperhomocysteinemia, with a total plasma homocysteine level of 3.9 mg/L. Both patients were considered highly sensitized and at high risk for rejection due to the presence of either high panel reactive antibody or a positive B cell flow cytometry crossmatch, in addition to other risk factors. Therefore, IVIG was considered a viable treatment option to be included in induction therapy. IVIG was administered both peri- and postoperatively, and both patients experienced immediate graft function with good urine output. Within 24 hours following transplantation, elevations in serum creatinine and decreases in urine output were seen. Subsequently, kidney exploration was performed and palpable thrombi in renal arteries and veins were detected. Immediate nephrectomy was performed in both cases.

Discussion:

Currently, evidence derived from case reports highlights numerous risk factors for IVIG-associated thrombosis, one of which appears to be a hypercoagulable state. It has also been reported that some IVIG products contain amounts of anticardiolipin antibodies; these antibodies may potentiate thrombosis in the presence of hypercoagulable states, such as hyperhomocysteinemia or antiphospholipid syndrome, in these 2 patients, the Naranjo probability scale indicated that there was a possible association between the thrombotic events and the use of IVIG.

Conclusions:

Prospective trials evaluating the safety of IVIG in highly sensitized transplant patients are scarce. Therefore, it is imperative that the benefits and risks be weighed when considering the use of IVIG in highly sensitized transplant patients.

Synergy Between Tissue Factor and Exogenous Factor XIa in Initiating Coagulation

OBJECTIVE

Recent evidence suggests involvement of coagulation factor XIa (FXIa) in thrombotic event development. This study was conducted to explore possible synergies between tissue factor (TF) and exogenous FXIa (E-FXIa) in thrombin generation.

APPROACH AND RESULTS

In thrombin generation assays, for increasing concentrations of E-FXIa with low, but not with high TF concentrations, peak thrombin significantly increased whereas lag time and time to peak significantly decreased. Similar dependencies of lag times and rates of thrombin generation were found in mathematical model simulations. In both in vitro and in silico experiments that included E-FXIa, thrombin bursts were seen for TF levels much lower than those required without E-FXIa. For in silico thrombin bursts initiated by the synergistic action of TF and E-FXIa, the mechanisms leading to the burst differed substantially from those for bursts initiated by high TF alone. For the synergistic case, sustained activation of platelet-bound FIX by E-FXIa, along with the feedback-enhanced activation of platelet-bound FVIIIa and FXa, was needed to elicit a thrombin burst. Furthermore, the initiation of thrombin bursts by high TF levels relied on different platelet FIX/FIXa binding sites than those involved in bursts initiated by low TF levels with E-FXIa.

CONCLUSIONS

Low concentrations of TF and exogenous FXIa, each too low to elicit a burst in thrombin production alone, act synergistically when in combination to cause substantial thrombin production. The observation about FIX/FIXa binding sites may have therapeutic implications.

Frequency of Adverse Events Associated with Intravenous Immunoglobulin Therapy in Patients with Pemphigus or Pemphigoid

Background:

Intravenous immunoglobulin (IVIG) therapy is widely used in immune-mediated diseases as an immunomodulatory agent and is considered to be a safe biologic agent.

Objective:

To determine the frequency of adverse events associated with IVIG therapy in patients with pemphigus and pemphigoid.

Methods:

We retrospectively reviewed data on patients treated with IVIG for pemphigus and pemphigoid over a 10 year period. Patients had pemphigus vulgaris, pemphigus foliaceus, mucous membrane pemphigoid, or bullous pemphigoid. IVIG was given according to a published protocol at a dose of 2 g/kg administered over 3–5 days at prescribed intervals. Patient records were reviewed for information on sex, age, duration of treatment, number of cycles given, number of days each patient received IVIG, weight of each patient, IVIG dose each patient received per infusion, and early or delayed adverse effects reported by patients or observed by healthcare providers.

Results:

We identified 9892 infusions given to 174 patients. Headaches were the most common adverse effects; they were observed during 886 (8.9%) infusions and involved 123 (70.6%) patients. The incidence of other minor adverse effects, including fatigue, nausea, vomiting, chills, urticaria, swollen glands, hoarseness, thoracic discomfort, and palpitations, was 0.57–3.4% per infusion and 0.04–1,3% per patient. Hoarseness of voice and swelling of cervical lymph nodes have not been previously reported. Acute renal failure occurred in one patient and was the only major adverse effect observed. None of the patients required hospitalization, and there were no deaths.

Conclusions:

Adverse events associated with IVIG therapy are usually mild and self-limiting. The incidence of serious adverse events is low. Identification of risk factors and close monitoring of high-risk patients throughout the therapy are likely to decrease the occurrence of rare serious and less likely fatal adverse effects.

A new manufacturing process to remove thrombogenic factors (II, VII, IX, X, and XI) from intravenous immunoglobulin gamma preparations

Coagulation factors (II, VII, IX, X, and particularly XIa) remaining in high concentrations in intravenous immunoglobulin (IVIG) preparations can form thrombi, causing thromboembolic events, and in serious cases, result in death. Therefore, manufacturers of biological products must investigate the ability of their production processes to remove procoagulant activities. Previously, we were able to remove coagulation factors II, VII, IX, and X from our IVIG preparation through ethanol precipitation, but factor XIa, which plays an important role in thrombosis, remained in the intermediate products. Here, we used a chromatographic process using a new resin that binds with high capacity to IgG and removes procoagulant activities. The procoagulant activities were reduced to low levels as determined by the thrombin generation assay: <1.56 mIU/mL, chromogenic FXIa assay: <0.16 mIU/mL, non-activated partial thromboplastin time (NaPTT): >250 s, FXI/FXIa ELISA: <0.31 ng/mL. Even after spiking with FXIa at a concentration 32.5 times higher than the concentration in normal specimens, the procoagulant activities were below the detection limit (<0.31 ng/mL). These results demonstrate the ability of our manufacturing process to remove procoagulant activities to below the detection limit (except by NaPTT), suggesting a reduced risk of thromboembolic events that maybe potentially caused by our IVIG preparation.

Treatment of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is one of the acquired demyelinating neuropathies and is considered to be immune mediated. Diagnosis is typically based on clinical history, neurologic examination, electrophysiologic studies, CSF studies, and pathologic examination. Early diagnosis and treatment is important to prevent irreversible axonal loss and optimize improvement in function. The first-line agents for treatment are intravenous immunoglobulin (IVIg), corticosteroids, and plasmapheresis, which have all been demonstrated to be effective in controlled studies. Studies have not shown a significant difference between these three treatments, and the initial choice of therapy is often based on availability, cost, ease of administration, and side effect profile. If patients do not respond to one of these agents, they may respond to one of the others and sometimes in combination. If the first-line agents are not effective, chemotherapeutic or immunosuppressive agents may be considered. There are limited controlled studies of these modalities, and they are often used in conjunction with a first-line treatment. The majority of patients require long-term therapy to maintain a response and to prevent relapse.

Intravenous immune globulin and thromboembolic adverse events in patients with hematologic malignancy

In patients with hypogammaglobulinemia secondary to chronic lymphocytic leukemia (CLL) or multiple myeloma (MM), intravenous immune globulin (IVIg) may be administered to reduce the risk of infection. Since 2013, IVIg products have carried a boxed safety warning about the risk of thromboembolic events (TEEs), with TEEs reported in 0.5% to 15% of patients treated with IVIg. In this retrospective cohort study of older patients with CLL or MM identified from the Surveillance, Epidemiology, and End Results-Medicare Linked Database, we assessed rates of clinically serious TEEs in 2724 new users of IVIg and a propensity-matched comparison group of 8035 nonusers. For the primary end point, arterial TEE, we observed a transient increased risk of TEE during the day of an IVIg infusion and the day afterward (hazard ration = 3.40; 95% confidence interval [CI]: 1.25, 9.25); this risk declined over the remainder of the 30-day treatment cycle. When considered in terms of absolute risk averaged over a 1-year treatment period, the increase in risk attributable to IVIg was estimated to be 0.7% (95% CI: -0.2%, 2.0%) compared with a baseline risk of 1.8% for the arterial TEE end point. A statistically nonsignificant risk increase of 0.3% (95% CI: -0.4%, 1.5%) compared with a baseline risk of 1.1% was observed for the venous TEE end point. Further research is needed to establish the generalizability of these results to patients receiving higher doses of IVIg for other indications.

Managing patients with side effects and adverse events to immunoglobulin therapy

Immunoglobulin therapy has not only served as a lifesaving approach for the prevention and treatment of infections in primary and secondary immunodeficiency diseases, but has also been used as an immunomodulatory agent for autoimmune and inflammatory disorders and to provide passive immunity for some infectious diseases. Most of the adverse effects associated with immunoglobulin therapy are mild, transient and self-limiting. However, serious side effects also occur. Therefore, to minimize the adverse events of immunoglobulin therapy, specialist review of patient clinical status and immunoglobulin products, in addition to selection of appropriate treatment strategy for the management of patients with associated side effects and adverse events, are crucial.

Management of adverse events in the treatment of patients with immunoglobulin therapy: A review of evidence

Immunoglobulin (IG) therapy is actually used for a broad range of diseases including primary and secondary immunodeficiency disorders, and autoimmune diseases. This therapy is available for intravenous (IV) and subcutaneous (SC) administration. The efficacy of the IG therapy has been demonstrated in numerous studies and across different diseases. Generally, IG infusions are well tolerated; however some well-known adverse reactions, ranging from mild to severe, are associated with the therapy. The most common adverse reactions including headache, nausea, myalgia, fever, chills, chest discomfort, skin and anaphylactic reactions, could arise immediately during or after the infusion. Delayed events could be more severe and include migraine headaches, aseptic meningitis, haemolysis renal impairment and thrombotic events. This paper reviews all the potential adverse events related to IG therapy and establishes a comprehensive guideline for the management of these events. Moreover it resumes the opinions and clinical experience of expert endorsers on the utilization of the treatment. Published data were classified into levels of evidence and the strength of the recommendation was given for each intervention according to the GRADE system.

Deep Venous Thrombosis with Pulmonary Embolism Related to IVIg Treatment: A Case Report and Literature Review

IVIg therapy has potentially been related to arterial and venous therapy. We performed an Ovid review focusing on IVIg and thrombotic events. While a few case reports were reviewed case series and case control studies were particularly reviewed in relation to thrombotic events. Outcomes demonstrate a correlation between underlying cardiovascular risk factors with predominately arterial events which typically occurred within 4–24 hours of infusion. While venous events occurred less commonly they were associated with traditional risk factors and occurred later, typically, 1–7 days following infusion of IVIg. Potential causation of thrombotic events was discussed.

Manufacture of immunoglobulin products for patients with primary antibody deficiencies - the effect of processing conditions on product safety and efficacy

Early preparations of immunoglobulin (Ig) manufactured from human plasma by ethanol (Cohn) fractionation were limited in their usefulness for substitution therapy in patients with primary antibody deficiencies (PAD), as Ig aggregates formed during manufacture resulted in severe systemic reactions in patients when given intravenously. Developments in manufacturing technology obviated this problem through the capacity to produce concentrated solutions of intact monomeric Ig, revolutionizing PAD treatment and improving patient life expectancy and quality of life. As the need for Ig has grown, manufacturers have refined further manufacturing technologies to improve yield from plasma and produce therapies, which are easier and less expensive to deliver. This has led to the substitution, partly or wholly, of ethanol precipitation by other techniques such as chromatography, and has also stimulated the production of highly concentrated solutions capable of rapid infusion. Ig products have been associated, since their inception, with certain adverse events, including infectious disease transmission, hemolysis, and thromboembolism. The introduction of standardized manufacturing processes and dedicated pathogen elimination steps has removed the risk of infectious disease, and the focus of attention has shifted to other problems, which appear to have increased over the past 5 years. These include hemolysis and thromboembolism, both the cause for substantial concern and the subject of recent regulatory scrutiny and actions. We review the development of manufacturing technology and the emerging evidence that changes for the optimization of yield and convenience has contributed to the recent incidents in certain adverse events. Industry measures under development will be discussed in terms of their potential to improve safety and optimize care for patients with PAD.

Intravenous immunoglobulin treatment in chronic neurological diseases: do we have maintenance dose right?

Objectives. We tried to define, on individual basis, minimal effective maintenance dose of intravenous immunoglobulins (IVIG) in 26 patients with chronic neurological conditions requiring long-term IVIG treatment. Methods. Clinical criteria were reviewed in individual cases (Phase 1) followed by titration phase (Phase 2, 12 months) and posttitration/follow-up phase (Phase 3, 3 months). Objective neurological examination and patient self-reports were used for clinical follow-up. Results. 69.2% of patients reported condition as stable, 26.9% as better, and 3.9% as mildly worse. Original mean monthly dose was 1 g/kg; over the period of 12 months we reduced dose of IVIG to mean dose 0.67 g/kg (range 0.3–2.5 g/kg, P < 0.0001) which meant reduction by 36.4%. We identified 4 nonresponders and diagnosis in one case was reclassified to degenerative disease. In follow-up phase we reduced dose further to 0.60 g/kg. Cumulative monthly dose dropped from 2040 g to 1298 g and to 991 g, respectively. Financial expenses were reduced significantly (by −36.4% during titration phase and by −51.4% during follow-up phase) (comparing with baseline) (P < 0.0001). Conclusion. Individual dose titration leads to significant maintenance IVIG dose reduction with preserved clinical efficacy. Maintenance dose below 1 g/kg (in our study around 0.7 g/kg) has acceptable risk/benefit ratio.

Human plasma-derived immunoglobulin G fractionated by an aqueous two-phase system, caprylic acid precipitation, and membrane chromatography has a high purity level and is free of detectable in vitro thrombogenic activity

BACKGROUND AND OBJECTIVES

Instituto Clodomiro Picado has developed an immunoglobulin G (IgG) plasma fractionation process combining a polyethylene glycol/phosphate aqueous two-phase system (ATPS), caprylic acid precipitation and anion-exchange membrane chromatography. We evaluated the purity and in vitro thrombogenicity of such IgG, in line with current international requirements.

MATERIALS AND METHODS

Contributions of the different production steps to reduce thrombogenicity were assessed at 0·2 l-scale, and then the methodology was scaled-up to a 10 l-scale and final products (n = 3) were analysed. Purity, immunoglobulin composition, and subclass distribution were determined by electrophoretic and immunochemical methods. The in vitro thrombogenic potential was determined by a thrombin generation assay (TGA) using a Technothrombin fluorogenic substrate. Prekallikrein activator (PKA), plasmin, factor Xa, thrombin and thrombin-like activities were assessed using S-2302, S-2251, S-2222, S-2238 and S-2288 chromogenic substrates, respectively, and FXI by an ELISA.

RESULTS

The thrombogenicity markers were reduced mostly during the ATPS step and were found to segregate mostly into the discarded liquid upper phase. The caprylic acid precipitation eliminated the residual procoagulant activity. The IgG preparations made from the 10 l-batches contained 100% gamma proteins, low residual IgA and undetectable IgM. The IgG subclass distribution was not substantially affected by the process. TGA and amidolytic activities revealed an undetectable in vitro thrombogenic risk and the absence of proteolytic enzymes in the final product.

CONCLUSIONS

Fractionating human plasma by an ATPS combined with caprylic acid and membrane chromatography resulted in an IgG preparation of high purity and free of a detectable in vitro thrombogenic risk.

Quantifying the thrombogenic potential of human plasma-derived immunoglobulin products

Polyvalent immunoglobulin G (IgG) products obtained by fractionation of human plasma are used to treat a broad range of conditions, including immunodeficiency syndromes and autoimmune, inflammatory, and infectious diseases. Recent incidences of increased thromboembolic events (TEEs) associated with intravenous (IV) IgG (IVIG) led to recalls of some products and increased regulatory oversight of manufacturing processes in order to ensure that products are essentially free of procoagulant/thrombogenic plasma protein contaminants. Laboratory investigations have now identified activated factor XI (FXIa) as the likely causative agent of IVIG-related TEEs. Quantification of the thrombogenic potential is becoming a requirement made to fractionators (a) to validate the capacity of IVIG and subcutaneous IgG manufacturing processes to remove procoagulant contaminants and (b) to establish the safety of the final products. However, in the absence of a recommended test by the main regulatory authorities, several analytical approaches have been evaluated by fractionators, regulators, and university groups. This review focuses on the scientific rationale, merits, and applications of several analytical methods of quantifying the thrombogenic potential of IgG products and intermediates to meet the latest regulatory requirements.

Cerebral infarctions after intravenous immunoglobulin therapy for ITP in a child

BACKGROUND

Intravenous immunoglobulin is the favored therapy in childhood immune thrombocytopenic purpura. It is usually well tolerated with manageable side effects, but venous and arterial thrombosis following its administration have been described, mostly in adults.

METHODS

We describe a 3-year-old girl with immune thrombocytopenic purpura and intracranial hemorrhage who received intravenous immunoglobulin therapy and subsequently developed multifocal cerebral infarctions.

RESULTS

Product specific as well as other factors may play a role in the development of this complication of intravenous immunoglobulin therapy. This is the only reported case of intravenous immunoglobulin-related thrombosis in a child with immune thrombocytopenic purpura and intracranial hemorrhage.

CONCLUSIONS

Thrombotic complications are associated with intravenous immunoglobulin administration and this includes cerebral infarcts.

Evidence for factor IX-independent roles for factor XIa in blood coagulation

BACKGROUND

Factor XIa is traditionally assigned a role in FIX activation during coagulation. However, recent evidence suggests this protease may have additional plasma substrates.

OBJECTIVE

To determine whether FXIa promotes thrombin generation and coagulation in plasma in the absence of FIX, and to determine whether FXI-deficiency produces an antithrombotic effect in mice independently of FIX.

METHODS

FXIa, FXIa variants and anti-FXIa antibodies were tested for their effects on plasma coagulation and thrombin generation in the absence of FIX, and for their effects on the activation of purified coagulation factors. Mice with combined FIX and FXI deficiency were compared with mice lacking either FIX or FXI in an arterial thrombosis model.

RESULTS

In FIX-deficient plasma, FXIa induced thrombin generation, and anti-FXIa antibodies prolonged clotting times. This process involved FXIa-mediated conversion of FX and FV to their active forms. Activation of FV by FXIa required the A3 domain on the FXIa heavy chain, whereas activation of FX did not. FX activation by FXIa, unlike FIX activation, was not a calcium-dependent process. Mice lacking both FIX and FXI were more resistant to ferric chloride-induced carotid artery occlusion than FXI-deficient or FIX-deficient mice.

CONCLUSION

In addition to its predominant role as an activator of FIX, FXIa may contribute to coagulation by activating FX and FV. As the latter reactions do not require calcium, they may make important contributions to in vitro clotting triggered by contact activation. The reactions may be relevant to FXIa's roles in hemostasis and in promoting thrombosis.

Hyperimmune globulins and same-day thrombotic adverse events as recorded in a large healthcare database during 2008-2011

Thrombotic events (TEs) are rare serious complications following administration of hyperimmune globulin (HIG) products. Our retrospective claims-based study assessed occurrence of same-day TEs following administration of HIGs during 2008-2011 and examined potential risk factors using HealthCore's Integrated Research Database (HIRD(SM) ) and laboratory testing of products' procoagulant Factor XIa activity by U.S. Food and Drug Administration. Multivariable regression was used to estimate same-day TE risk for different products. Of 101,956 individuals exposed to 23 different HIG product groups, 86 (0.84 per 1,000 persons) had a TE diagnosis code (DC) recorded on the same day as HIG administration. Unadjusted same-day TE DC rates (per 1,000 persons) ranged from 0.4 to 148.9 for different products. GamaSTAN S/D IG >10 cc had statistically significantly higher same-day TE DC risk compared to Tetanus IG (OR = 57.57; 95% CI = 19.72-168.10). Increased TE risk was also observed with older age (≥45 years), prior thrombotic events, and hypercoagulable state(s). Laboratory investigation identified elevated Factor XIa activity for GamaSTAN S/D, HepaGam B, HyperHep B S/D, WinRho SDF, HyperRHO S/D full dose, and HyperTET S/D. Our study, for the first time, identified increase in the same-day TE DC risk with GamaSTAN S/D IG >10 cc and suggests potentially elevated TE risk with other HIGs.

[Treatments with immunoglobulin and thrombotic adverse events]

Treatments with intravenous or subcutaneous immunoglobulin (Ig) are used in a broad variety of disorders. Tolerance of Ig is usually good but adverse events, including some serious ones, have been reported and may differ among different Ig preparations. Thrombotic complications occur in 0.6 to 13% of cases and can involve arterial or venous circulation, rarely both. Deep venous thrombosis with or without pulmonary embolism, stroke or myocardial infarction remained the most frequent thrombotic complications. Some risk factors have been identified, mainly old age, multiple cardiovascular risk factors, and past history of thrombo-embolic manifestations. Several mechanisms are suggested to explain this increased risk of thrombotic complications. Indeed, Ig treatments increase the plasma viscosity, increase and activate platelets, can trigger the coagulation cascade through the presence of activated factor XI in some Ig preparations, and release vasoactive molecules responsible for vasospasm. Patients have to be carefully monitored and risk factors to be identified as soon as possible. The role of antiplatelets or anticoagulation is not well determined but should probably be proposed to patients with high risk.

Adverse effects of human immunoglobulin therapy

Human immunoglobulin (IG) is used for IgG replacement therapy in primary and secondary immunodeficiency, for prevention and treatment of certain infections, and as an immunomodulatory agent for autoimmune and inflammatory disorders. IG has a wide spectrum of antibodies to microbial and human antigens. Several high-titered IGs are also available enriched in antibodies to specific viruses or bacterial toxins. IG can be given intravenously (IGIV), intramuscularly (IGIM) or by subcutaneous infusions (SCIG). Local adverse reactions such as persistent pain, bruising, swelling and erythema are rare with IGIV infusions but common (75%) with SCIG infusions. By contrast, adverse systemic reactions are rare with SCIG infusions but common with IGIV infusions, occurring as often as 20% to 50% of patients and 5% to 15% of all IGIV infusions. Systemic adverse reactions can be immediate (60% of reactions) occurring within 6 hours of an infusion, delayed (40% of reactions) occurring 6 hours-1 week after an infusion, and late (less than 1% of reactions), occurring weeks and months after an infusion. Immediate systemic reactions such as head and body aches, chills and fever are usually mild and readily treatable. Immediate anaphylactic and anaphylactoid reactions are uncommon. The most common delayed systemic reaction is persistent headache. Less common but more serious delayed reactions include aseptic meningitis, renal failure, thromboembolism, and hemolytic reactions. Late reactions are uncommon but often severe, and include lung disease, enteritis, dermatologic disorders and infectious diseases. The types, incidence, causes, prevention, and management of these reactions are discussed.

In vitro and in vivo properties differ among liquid intravenous immunoglobulin preparations

Objective To compare in vitro and in vivo biological and biochemical properties of five liquid intravenous immunoglobulin (IVIg) preparations licensed for therapeutic use in Europe.

Methods ClairYg® was compared in a blinded manner to four other liquid IVIg preparations licensed in Europe (Octagam®, Kiovig®, Gamunex®, Privigen®). Three batches of each preparation were tested, except for the IgG repertoires and the animal model.

Results Levels of anti-A and anti-B antibodies were lower in ClairYg® (0·11/0·11) relative to a positive EDQM standard and Octagam® (0·11/0·08) than in other preparations (0·33–0·69/0·42–0·46). IgG in ClairYg® recognized 365 and 416 protein spots in HEp-2 cell and Escherichia coli protein extracts vs. 230–330 and 402–842 protein spots, respectively, for IgG in other preparations. IgA content (301 vs. 165–820 ng/mg of IgG), Factor XI and Factor XII antigen (0·46 vs. 0·85–2·40 mU/mg of IgG and 7·8 vs. 20·0–46·2 lU/mg of IgG) C1q binding (0·42 vs. 0·67–1·89 arbitrary units) and C5a uptake (0·41 vs. 0·45–0·66% of activation) were lower in ClairYg® than in other preparations. Finally, intravenous infusion of ClairYg®, Gamunex® and Privigen® had no major effect on arterial blood pressure in spontaneously hypertensive rats.

Conclusions Our results evidence some differences in the biological and biochemical properties among licensed liquid IVIg preparations.