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.

Postintravenous immunoglobulin stroke in a toddler with Down syndrome: a diagnostic challenge

Children with Down syndrome have a higher risk of stroke. Similarly, intravenous immunoglobulin (IV Ig) is also known to cause a stroke. We reported a 3-year-old boy with Down syndrome who presented with severe pneumonia and received IV Ig. He developed right hemiparesis 60 hours after the infusion. Blood investigations, echocardiography and carotid Doppler did not suggest vasculitis, thrombophilia or extracranial dissection. Brain computerised tomography (CT) showed acute left frontal and parietal infarcts. Initial magnetic resonance angiography (MRA) of cerebral vessels showed short segment attenuations of both proximal middle cerebral arteries and reduction in the calibre of bilateral supraclinoid internal carotid arteries. The boy was treated with enoxaparin and aspirin. He only had partial recovery of the hemiparesis on follow-up. A repeat MRA 13 months later showed parenchymal collateral vessels suggestive of moyamoya disease. We recommend imaging the cerebral vessels in children with a high risk of moyamoya before giving IV Ig.

Factors associated with headache in intravenous immunoglobulin treatment for neurological diseases

OBJECTIVES

To identify possible risk factors influencing the incidence of intravenous immunoglobulin (IVIg) treatment-related cephalalgia in neurological diseases.

MATERIALS & METHODS

Retrospective chart review of neurological patients receiving IVIg treatment between July 13, 2017, and August 14, 2017. Patients with MS receiving natalizumab in the same setting were observed as a reference group.

RESULTS

Patients with headache after IVIg infusion (n = 22 infusions) showed a reduced heart rate (by 6.0 ± 8.5 beats per minute [bpm]), but no significant difference in blood pressure. Patients without headache after IVIg infusion (n = 69 infusions) showed a higher systolic blood pressure increase and a stronger reduction in the heart rate (by 5.7 ± 8.6 bpm), compared to patients with headache after IVIg infusion. The infusion rate was significantly slower and age significantly lower in patients developing headache after IVIg infusion. Body temperature was unchanged in both groups. Binary logistic regression analysis revealed that blood pressure at baseline and age significantly influence the occurrence of cephalalgia. In reference, patients receiving natalizumab (ie, shorter infusions/smaller infusion volume), systolic blood pressure, and heart rate decreased, while body temperature increased. Here, one patient developed headache.

CONCLUSIONS

Intravenous immunoglobulin-associated headache is not associated with an increased blood pressure after infusion but with a reduced heart rate, a slower infusion rate, female sex and seems to be influenced by baseline systolic blood pressure and age. A reaction to immunoglobulin aggregates, stabilizers, or vasoactive mediators are possible explanations. The absence of an association with body temperature does not suggest a systemic immune response as a cause for headache.

A Retrospective Analysis of the Safety Profile of Intravenous Immunoglobulin in 1176 Patients Receiving Home Infusion Therapy

OBJECTIVES

This analysis assessed the safety of intravenous immunoglobulin (IVIg) in the treatment of patients with neuroimmunological and immunological disorders in a home-based setting.

METHODS

Adverse reactions (ARs) were assessed in a retrospective review of 1176 patients receiving 28,677 home-based IVIg infusions between 1996 and 2013.

RESULTS

Of 1176 patients, 648 (55.1%) experienced IVIg-related ARs; 536 (45.6%) were mild, 78 (6.6%) moderate, and 34 (2.9%) severe. Thirty-seven (3.1%) patients were hospitalized because of ARs; of these, headache was most common (51.4%). Mean number of ARs per patient increased from 1.4 (low dose) to 3.6 (high dose). Incidence of ARs increased from 41% in the first 5-year moving average in 2003 to 65% in 2008. The number of ARs correlated with the number of infusions (ρ = 0.24; P < 0.001) and the average IVIg dose (ρ = 0.10; P < 0.001).

CONCLUSIONS

Low- and high-dose IVIg were safe and well tolerated with a few serious ARs in patients with neuroimmunological and immunological disorders.

Two young stroke patients associated with regular intravenous immunoglobulin (IVIg) therapy

We recently experienced 2 young adult patients who developed ischemic stroke after regular intravenous immunoglobulin (IVIg) therapy for agammaglobulinemia with diagnosis of common variable immunodeficiency (CVID) in their childhood. Patient 1 was 26-year-old woman, who developed Wallenberg's syndrome 6 days after the last IVIg therapy, but had no further stroke recurrence with cilostazol later. Patient 2 was 37-year-old man, who developed recurrent cerebral infarction in the territory of bilateral lenticulostriate branches like branch atheromatous disease (BAD) several days after the IVIg therapy. However, he had no further stroke recurrence after bone marrow transplantation (BMT) therapy for his lymphoproliferative disorder. It was suggested that IVIg therapy was associated to these different types of ischemic stroke in our 2 young adult patients with minimal vascular risk factors. Although IVIg therapy is widely used as a relatively safe medication for immunodeficiency disorders or autoimmune diseases, we need to pay more attention to stroke occurrence with regular IVIg therapy.

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.

On the dark side of therapies with immunoglobulin concentrates: the adverse events

Therapy by human immunoglobulin G (IgG) concentrates is a success story ongoing for decades with an ever increasing demand for this plasma product. The success of IgG concentrates on a clinical level is documented by the slowly increasing number of registered indication and the more rapid increase of the off-label uses, a topic dealt with in another contribution to this special issue of Frontiers in Immunology. A part of the success is the adverse event (AE) profile of IgG concentrates which is, even at life-long need for therapy, excellent. Transmission of pathogens in the last decade could be entirely controlled through the antecedent introduction by authorities of a regulatory network and installing quality standards by the plasma fractionation industry. The cornerstone of the regulatory network is current good manufacturing practice. Non-infectious AEs occur rarely and mainly are mild to moderate. However, in recent times, the increase in frequency of hemolytic and thrombotic AEs raised worrying questions on the possible background for these AEs. Below, we review elements of non-infectious AEs, and particularly focus on hemolysis and thrombosis. We discuss how the introduction of plasma fractionation by ion-exchange chromatography and polishing by immunoaffinity chromatographic steps might alter repertoire of specificities and influence AE profiles and efficacy of IgG concentrates.

[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.

The safety profile of home infusion of intravenous immunoglobulin in patients with neuroimmunologic disorders

OBJECTIVES

To assess the overall safety of high-dose intravenous immunoglobulin (IG) products used to treat patients with neuroimmunological disorders in a supervised home-based setting.

METHODS

The incidence of adverse reactions was assessed in a retrospective chart review of 420 patients who consecutively received 4076, home-based, individual, intravenous immunoglobulin (IVIG) infusions between January 2009 and December 2009.

RESULTS

A total of 90 patients (21.4%) developed adverse reactions related to IVIG administration (2.6% per individual infusion). A total of 95.5% of adverse reactions were mild, and no serious side effects were observed. The incidence of adverse reactions was significantly lower in the subgroup of patients with neuroimmunological disorders who received premedication (18.2% compared with 29.3%, P = 0.02). There was no significant statistical difference in the incidence of side effects among the different brands of IVIG used in this study.

CONCLUSIONS

The combination of premedication and well-defined clinical, IVIG infusion policies may reduce the incidence of high-dose IVIG adverse reactions administered in a home-based setting in patients with neuroimmunological disorders.

Intravenous immunoglobulin increases plasma viscosity without parallel rise in blood pressure

WHAT IS KNOWN AND OBJECTIVE

Intravenous immunoglobulin (IVIg) is a commonly used therapy for autoimmune disease, but may cause chronic hypertension and thrombosis. We determined whether: (i) IVIg systematically affects blood pressure in the short term; (ii) acute changes in plasma viscosity because of IVIg correlate with blood pressure effects; (iii) effects of IVIg on acute blood pressure are related to baseline blood pressure or hypertension status and (iv) IVIg influences plasma markers of inflammation, anticardiolipin antibodies and homocysteine as additional putative prothrombotic risk factors.

METHODS

Twenty adults with autoimmune neurological disease who received a course of IVIg were evaluated immediately before and after each infusion, on every day of the course. Blood pressure, pulse and the following haematological parameters were determined: plasma viscosity, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), haematocrit, fibrinogen, interleukin-6 (IL-6), homocysteine and anticardiolipin positivity.

RESULTS

Intravenous immunoglobulin caused both acute and cumulative rises in plasma viscosity across a treatment course, but no concordant changes in blood pressure. There was also no correlation between individual blood pressure changes and viscosity, baseline blood pressure or hypertension status. Levels of IL-6 rose across the course of therapy, but the acute-phase reactants CRP and fibrinogen did not. One patient developed anticardiolipin antibodies during therapy.

WHAT IS NEW AND CONCLUSION

Individual courses of IVIg do not systematically raise blood pressure. Where IVIg is found to cause hypertension, this does not appear to be due to a direct effect of IVIg on plasma viscosity.

A clinical cardiology perspective of thrombophilias

Thrombophilias, an inherited and/or acquired predisposition to vascular thrombosis beyond hemostatic needs are common in cardiovascular medicine and include systemic disorders such as coronary atherosclerosis, atrial fibrillation, exogenous obesity, metabolic syndrome, collagen vascular disease, human immunodeficiency virus, blood replacement therapy and several commonly used medications. A contemporary approach to patients with suspected thrombophilias, in addition to a very selective investigation for gain-of-function and loss-of-function gene mutations affecting thromboresistance, must consider prevalent diseases and management decisions encountered regularly by cardiologists in clinical practice. An appropriate recognition of common disease states as thrombophilias will also stimulate platforms for much needed scientific investigation.

Common variable immunodeficiency (CVID): case report and review of the literature

Common variable immunodeficiency (CVID) is an immunodeficiency disease characterized by diminished ability to produce immunoglobulins. CVID has an estimated incidence of 1:10,000 to 1:200,000 (male:female 1:1) and usually presents in the second and third decade, although it also has a peak of incidence in childhood. The exact pathophysiology remains unclear. CVID can be associated with autoimmune, granulomatous and gastrointestinal diseases and patients have a predisposition to malignancies (especially non-Hodgkin lymphoma). Since different organ systems can be affected, all clinicians need to be aware of this entity, especially when confronted with patients with recurrent infections and/or multiple autoimmune diseases.

Adverse effects of treatment with intravenous immunoglobulins for neurological diseases

Therapy with intravenous immunoglobulins (IVIg) is considered to be a safe treatment for a number of immune-mediated neurological diseases. Published data about prevalence of adverse effects range from 11 to 81%. The purpose of our study was to preserve a representative view on adverse effects by analysis of a large cohort of patients treated by IVIg. A recent prospective study reported 42.7% adverse events. The majority of patients presented with minor adverse effects, mostly asymptomatic laboratory changes. Rash or mild headache occurred especially when IVIg was administered with an infusion flow higher than 10 g/h. Severe complications like deep vein thrombosis or others are rare. In addition to its efficacy, IVIg therapy appears to be a safe therapy in immune-mediated neurological diseases. Most patients show no or minor adverse effects. Patients with pre-existent disorders like heart or renal insufficiency or immobilized patients, however, may be at higher risk for complications.

Intravenous immunoglobulins contain naturally occurring antibodies that mimic antineutrophil cytoplasmic antibodies and activate neutrophils in a TNFα-dependent and Fc-receptor–independent way

Intravenous immunoglobulin (IVIg) preparations are increasingly used for therapy of several neuroimmunologic diseases. IVIg therapy is considered safe, although serious side effects like aseptic meningitis, cerebral vasospasm, or ischemic encephalopathy have been reported. These side effects are frequently associated with neutrophilic pleocytosis in the cerebrospinal fluid (CSF), suggesting a neutrophil-mediated mechanism. To elucidate the potential role of neutrophil activation, we analyzed IVIg preparations from 5 different commercial sources for the presence of antineutrophil cytoplasmic antibody (ANCA)–like immunoglobulins against ethanol-fixed peripheral-blood neutrophils, purified human antigens, and a panel of human and nonhuman tissues. All IVIg batches tested (n = 13) contained atypical ANCAs (IgG titer up to 1:2048, IgA up to 1:512). Moreover, all preparations were capable of inducing hydrogen peroxide production in TNFα-primed human neutrophils, with a significant correlation (P < .005) between atypical ANCA titers in IVIg preparations and neutrophil activation. Fc-mediated binding and activation was ruled out by the use of IVIg-F(ab′)2 fragments. Our findings strongly suggest that in vivo activation of TNFα-primed neutrophils by atypical ANCAs of IVIg may contribute to the side effects of IVIg therapy and for the first time demonstrate that the activation of neutrophil granulocytes by IVIg occurs in an Fc receptor (FcR)–independent, hence antigen-dependent, way.

Developing practice guidelines for the administration of intravenous immunoglobulin

As the use of intravenous immunoglobulin (IGIV) continues to expand, infusion nurses have a greater need for a comprehensive understanding of the product, patient risk factors, and comorbidities when developing guidelines for administering IGIV. Because immunoglobulin therapy is a blood derivative product, many nurses may not have as much experience administering this type of infusion. This article provides an in-depth overview of immunoglobulin therapy and helps to define the infusion nurse's major role in coordinating, assessing, and ensuring patient safety during IGIV administration.

High-dose immunoglobulin during pregnancy for recurrent neonatal haemochromatosis

BACKGROUND

Neonatal haemochromatosis is a rare disease of gestation that results in severe fetal liver injury. We hypothesised an alloimmune aetiology for the disorder on the basis of its high recurrence rate in sibships. In this study, we assessed the effectiveness in preventing or changing the severity of recurrent neonatal haemochromatosis of administering during pregnancy high-dose intravenous immunoglobulin (IVIG) derived from pooled serum of multiple donors.

METHODS

Women whose most recent pregnancy ended in documented neonatal haemochromatosis were treated with IVIG, 1 g/kg bodyweight, weekly from the 18th week until the end of gestation in their subsequent pregnancy. The outcomes of treated pregnancies were compared with those of randomly selected previous affected pregnancies for each woman, which were used as historical controls.

FINDINGS

15 women were treated through 16 pregnancies. All pregnancies progressed uneventfully and resulted in live babies with normal physical examinations and birthweights that were appropriate for gestational age. 12 babies had evidence of liver involvement with neonatal haemochromatosis: 11 had higher than normal concentrations of serum alpha-fetoprotein and ferritin or serum alpha-fetoprotein alone, including four with coagulopathy (international normalised ratio >1.5), and one had coagulopathy alone. All babies survived with medical or no treatment and were healthy at follow-up within the past 6 months. In analysis on a per-mother basis comparing outcomes of treated gestations with those of randomly selected previous affected gestations, gestational IVIG therapy was associated with better infant survival (15 good outcomes vs two in previous pregnancies; p=0.0009).

INTERPRETATION

Treatment with high-dose IVIG during gestation appears to have modified recurrent neonatal haemochromatosis so that it was not lethal to the fetus or neonate. These results further support an alloimmune mechanism for recurrent neonatal haemochromatosis.

Effets immunomodulateurs des immunoglobulines intraveineuses

Intravenous immunoglobulins (IVIg) are therapeutic preparations of normal human IgG obtained from pools of more than 1000 healthy blood donors. They are currently used in the treatment of a wide range of auto-immune diseases, whether associated with auto-antibodies or auto-reactive T lymphocytes, as well as in the treatment of systemic inflammatory diseases. Several mechanisms of action have been identified during the last 20 years, including: (i) modulation of Fc receptors expression on leukocytes and endothelial cells; (ii) interaction with complement proteins; (iii) modulation of cytokines and chemokines synthesis and release; (iv) modulation of cell proliferation and apoptosis; (v) remyelinisation; (vi) neutralisation of circulating autoantibodies; (vii) selection of repertoires of B and T lymphocytes; (viii) interaction with other cell-surface molecules on lymphocytes and monocytes; (ix) corticosteroid sparing. These mechanisms of action are multiple and often intricate. However, they are still little known and further investigations are warranted.

Increased risk of adverse events when changing intravenous immunoglobulin preparations

Intravenous immunoglobulin (IVIG) therapy has represented a major advance in the treatment of patients with primary immune deficiency disorders. In September 2000 a new IVIG formulation, Intragam P, was introduced into clinical use. Intragam P is prepared by delipidation of pooled plasma followed by an ion exchange chromatography step to eliminate immunoglobulin aggregates. It is then pasteurized for 10 h at 60 degrees C for viral inactivation before storage at pH 4.25 in 10% maltose. We report initial clinical experience with this new preparation. The details of adverse reactions of patients who received the new preparation were gathered shortly after it became apparent there was a change in IVIG formulation. Seven of 49 patients receiving Intragam P spontaneously reported adverse effects, which were temporally related to infusions. Subsequently, all seven patients have been able to tolerate the product with prophylactic use of antihistamines and paracetamol. This case series indicates that long-term tolerance of an older IVIG product does not necessarily equate to tolerance to a newer product, even if technically superior. Caution should be exercised when changing IVIG products, as they are not biologically equivalent.

Adverse reactions of prophylactic intravenous immunoglobulin infusions in Iranian patients with primary immunodeficiency

BACKGROUND

Although long-term intravenous immunoglobulin infusion is an effective treatment for children with antibody deficiencies, it can be complicated by systemic adverse reactions.

OBJECTIVE

To evaluate the adverse reactions of intravenous immunoglobulin therapy in patients with primary immunodeficiency.

METHODS

Seventy-one immunodeficient patients receiving intravenous immunoglobulin were evaluated during a 7-year period (1995-2002) at Children's Medical Center in Tehran, Iran. Immunological diagnoses were as follows: common variable immunodeficiency (31 patients), X-linked agammaglobulinemia (25 patients), IgG subclass deficiency (5 patients), hyper-IgM syndrome (2 patients), and ataxia-telangiectasia (8 patients).

RESULTS

One hundred fifty-two cases (12.35%) of adverse reactions occurred following 1,231 infusions in 35 patients. The most frequent immediate adverse reactions were mild reactions (131 infusions), including chills, fever, flushing, muscle pains, nausea, headache, and anxiety. Moderate reactions, such as vomiting, chest pain, and wheezing, occurred in 19 infusions. Two patients experienced severe adverse reactions. The highest proportion (23.06%) of reaction to injection was in patients with common variable immunodeficiency.

CONCLUSIONS

Intravenous immunoglobulin is a well tolerated medical agent for patients with antibody deficiency. However, to prevent occurrence of immediate adverse reactions during infusion in these patients, physicians should perform a detailed history and proper physical examination and check the titer of anti-IgA.

[Intravenous immunoglobulin (Endobulin) clinical tolerance: prospective therapeutic follow-up of 142 adults and children]

PURPOSE

Prospective report of Endobulin clinical tolerance experience for 19 months over a large number of patients.

METHOD

Collect diagnosis, age, gender, weight, dose regimen, infusion duration, and clinical tolerance of Endobulin. Treatment with this product was the only inclusion criteria in this follow-up.

RESULTS

A hundred and forty-two patients, 85 children and 57 adults, mean age 23 (1-85 years) received 70 substitutive treatments for primary immunodeficiency, 36 substitutive treatments for secondary immunodeficiency and 36 immunomodulatory treatments. A thousand six hundred and sixty Endobulin infusions that led to 14, 061.5 g, from 52 different batches. Tolerance was judged as good for 135 patients even though side effects occurred in 2 of them. Thus, 133 out of 142 patients, that is 93.7% did not present any side effect and their tolerance to Endobulin infusions was defined as good. Tolerance was bad for 7 patients because of side effects occurrence. For a mean number of 11.7 infusions per patient (1-31), the 9 side effects observed led to a rate of 0.54% of collected infusions and 6.3% of patients included.

CONCLUSION

This therapeutic follow-up of 142 patients confirms Endobulin clinical tolerance judged as good in 93.7% of patients (133/142) with a very low rate of side effects of 0.54% of infusions (9 side effects for 1660 infusions) for a mean number of 11.7 infusions per patient for an average of 10.9 months follow-up.

Utility of intravenous immune globulin in kidney transplantation: efficacy, safety, and cost implications

Intravenous immunoglobulin preparations (IVIG) are known to be effective in the treatment of various autoimmune and inflammatory disorders into their immunomodulatory, immunoregulatory, and anti-inflammatory properties. Recently, IVIG has been utilized in the management of highly sensitized patients awaiting renal transplantation. The mechanisms of suppression of panel reactive antibodies (PRA) in patients awaiting transplantation are currently under investigation and appear to be related to anti-idiotypic antibodies present in IVIG preparations. In this review, the various immunomodulatory mechanisms attributable to IVIG and their efficacy in reducing PRAs will be described. In addition, the use of IVIG in solid organ transplant recipients will be reviewed. The adverse events, safety considerations, and economic impact of IVIG protocols for patients awaiting solid organ transplantation will be discussed.

Mechanisms of intravenous immunoglobulin action in the treatment of autoimmune disorders

Intravenous immunoglobulins (IVIg) are therapeutic preparations of normal human immunoglobulin (Ig) G obtained from pools of blood from more than 1000 healthy donors, and exert immunomodulatory effects in autoantibody-mediated and T-cell-mediated autoimmune disorders and systemic inflammatory diseases. IVIg mechanisms of action in autoimmune diseases have been extensively analysed during the last 15 years and include the following: (i) interaction of the IgG Fc fragment with Fc receptors on leucocytes and endothelial cells; (ii) interaction of infused IgG with complement proteins; (iii) monocyte and lymphocyte modulation of synthesis and release of cytokines and cytokine antagonists; (iv) modulation of cell proliferation and reparation; (v) neutralisation of circulating autoantibodies; (vi) selection of immune repertoires; and (vii) interaction with other cell-surface molecules on T and B lymphocytes.

IVIG in autoimmunity and cancer--efficacy versus safety

Intravenous immunoglobulin (IVIG) is an accepted treatment for certain immunodeficiency states, but also for some autoimmune diseases. In other autoimmune conditions (i.e., systemic lupus erythematosus), it is still empirical although very efficacious. Based mainly on animal studies, IVIG has been shown to exert different antitumour mechanisms that result in metastases suppression. This effective therapy is associated with frequent occurrence of either immediate, delayed or late adverse effects, most of which are mild and transient. Efforts are taken in order to minimise these adverse effects both by pharmaceutical companies that attempt to decrease the risk of infectious agents transmission, and by physicians who monitor closely patients and choose the appropriate mode of administration of IVIG with respect to dose, duration of treatment and preparations used. Overall, IVIG is used in severe medical conditions and it is quite safe. Future research would help to further minimise its associated risks.

Intravenous immunoglobulins: clinical experience and viral safety

OBJECTIVES

To discuss the current procedures and processes by which viral safety is ensured for intravenous immunoglobulins (IVIGs), to place in context the current increase in clinical indications for IVIGs, and to describe the safety issues that have led to product shortages.

DATA SOURCES

Articles on viral safety retrieved from MEDLINE using the search terms gamma globulin, intravenous, adverse reaction, and infection and information from the manufacturers' literature and Food and Drug Administration package inserts.

STUDY SELECTION AND DATA EXTRACTION

Studies that specifically addressed the areas of major concern or advancement in viral safety of IVIGs, including donor selection, plasma screening, and other quality control procedures to ensure safety of source plasma; detection of viruses that may have escaped antibody screening tests through the use of polymerase chain reaction-based assays, which are capable of detecting small amounts of viral genomic material (e.g., hepatitis C virus, hepatitis B virus, and human immunodeficiency virus [HIV]) in small plasma pools; and industrial-scale, validated viral inactivation methods, such as pasteurization and solvent/detergent treatment, that have been incorporated into the manufacturing processes of immunoglobulins to further minimize the risk of viral transmission.

DATA SYNTHESIS

In addition to the treatment of primary immunodeficiency disorders, the clinical uses of IVIGs have expanded to include treatment of Kawasaki's syndrome, idiopathic thrombocytopenic purpura, infection following bone marrow transplantation, secondary immunologic disorders (e.g., pediatric HIV infection), hematologic disorders (e.g., chronic lymphocytic leukemia), and neurologic indications (e.g., Guillain-Barré syndrome). Although IVIG preparations are derived from human plasma, they have a long safety record and a low risk for transmitting viral infections.

CONCLUSION

Viral validation studies demonstrated that the processes discussed herein differ in their capabilities to inactivate lipid-enveloped and nonlipid-enveloped viruses.

IVIG-pools: regulatory gifts--transiting from harmony toward harmonious immunoglobulins: why? and why not?

Based on 'initial conditions' which depend on each donors' exposure to a unique environment, a pooled intravenous immunoglobulin (IVIG) product transfers its immunoglobulin molecule repertoire, unchanged, to the altered host. The relay function of the cell-bound receptors, especially that of the inhibitory Fc(gamma)RIIB, may then allow sufficient amplification to make regulatory activity possible. To the clinician, IVIG may be considered a tool to promote reversal of the dysregulation causing autoimmune disease. Generically, IVIG may be seen as a promoter allowing a progression from harm by an inflammatory/fibrotic reaction, then down-regulating toward restitutio ad integrum. By modifying natural processes, IVIG may play minor roles in promoting defense against spontaneous bleeding and, perhaps, stimulating remyelination. The wide spectrum of IVIG specificities, by reflecting evolutionary epitope selection, may not further destabilize cell/molecule disarray in the affected host. Benefit to the patient by IVIG treatment cannot be predicted nor can potentially severe or even fatal accidents entirely be excluded. Important aspects of IVIG treatment still await clarification including dosage, timing and the isotype form. In the foreseeable future it does not seem that biotechnological advances will match the physiologic harmony of IVIG, leaving antibody characteristics aside.

Intravenous immunoglobulin application following immunoadsorption: benefit or risk in patients with autoimmune diseases?

OBJECTIVE

To evaluate infection rates, side-effects and autoantibody resynthesis after immunoadsorption with and without intravenous immunoglobulin substitution.

METHODS

Thirty-five patients with autoimmune diseases who were on long-term immunoadsorption therapy participated in a prospective, randomized study. Results and conclusions. Infections were rare but similar in frequency in patients receiving combined immunoadsorption and intravenous immunoglobulins (intervention group, n=17, 1.3 infections per patient-year) and in a control group (n=18, 0.9 infections per patient-year) treated by immunoadsorption alone. The reduction in IgG achieved with two immunoadsorptions within 3 days was 95.0+/-2.5%. The extent of removal of pathogenic autoantibodies was similar to the removal of IGG: Substitution of immunoglobulins was not associated with an increased circulating IgG level before the following immunoadsorption. Infusion of immunoglobulins at a dose of 0.14 g/kg (interquartile range 0.12-0.16) body weight in patients in whom circulating immunoglobulins had been depleted was associated with a high incidence of serious side-effects; these necessitated the termination of treatment in 24% of the patients. No evidence was found that immunoglobulin administration had any beneficial effect with respect to autoantibody resynthesis after immunoadsorption.

Intravenous immunoglobulin preparations induce mild activation of neutrophils in vivo via triggering of macrophages--studies in a rat model

Despite widespread use in various immune disorders, the in vivo mechanisms of action of intravenous immunoglobulin (IVIG) preparations are not well known. We previously reported that human neutrophils degranulate after incubation with IVIG in vitro as a result of interaction with FcgammaRII. The purpose of this study was to determine whether IVIG might stimulate neutrophils in vivo. Anaesthetized rats received a bolus intravenous injection of IVIG preparations, containing either high (aged IVIG) or low (fresh IVIG) amounts or IgG dimers at a dose of 250 mg/kg. Administration of aged IVIG induced neutrophil activation in vivo, whereas no effect was observed after infusion of fresh IVIG. Histological examination of lung tissue demonstrated mild influx of neutrophils into the pulmonary tissue after aged IVIG administration, though gross damage did not occur. Macrophage-depleted rats no longer showed activation of neutrophils after infusion of aged IVIG, suggesting that neutrophils become activated via an indirect macrophage dependent way. We conclude that IVIG induces a mild activation of neutrophils in vivo via triggering of macrophages depending on the amount of IgG dimers. For this reason, IVIG preparations with a high content of dimers may not always be as harmless as generally believed and may be responsible for some of the side-effects observed during IVIG infusions.

Monocyte-macrophage system as targets for immunomodulation by intravenous immunoglobulin

Pooled human intravenous immunoglobulin (IVIg) has been used successfully to treat or ameliorate the clinical manifestations of humoral immune deficiencies, haematological disorders, HIV infection and many other diseases states. However, the mechanism of action of IVIg remains unclear. Several mechanisms of action of IVIg have been proposed. These include Fcy receptor blockade, accelerated clearance of endogenous pathogenic auto-antibodies, inhibition of components of the complement cascade, neutralization of super-antigens and bacterial toxins as well as anti-cytokine and anti-idiotype effects. A major contributor to host immunity and immune surveillance against infection, tissue or cell damage and malignancy is the monocyte/macrophage system. Monocyte-directed inflammation is a desirable consequence of microbiological or malignant challenge. However, monocyte hyperactivity may contribute to certain pathological conditions. These include the systemic inflammatory response syndrome (SIRS), septic shock, other dysregulated inflammatory disorders and auto-immunity. Novel therapies that can suppress the hyperactive state or correct monocyte/macrophage dysfunction without compromising normal host cell-mediated immunity are desirable. In this review, we discuss the immunomodulatory effects of IVIg focussing particularly upon the monocyte/macrophage system in pertinent disease states.