Immune complex-like moieties in immunoglobulin for intravenous use (i.v.Ig) bind complement and enhance phagocytosis of human erythrocytes

Immunoglobulin-induced hemolysis, splenomegaly and inflammation in patients with antibody deficiencies

IgG replacement for primary antibody deficiencies is a safe treatment administered to prevent recurrent infections and reduce mortality. Recently, several reports described acute hemolytic episodes following IgG administration due to a passive transfer of blood group alloantibodies, including anti-A, anti-B, as well as anti-Rh antibodies. Here, we reviewed and discussed the consequences of passively transferred RBCs antibodies. The chronic passive transfer of alloantibodies might also cause a subclinical condition due to a compensated extravascular chronic hemolysis with poorly understood consequences. This phenomenon might possibly represent an unrecognized cause of splenomegaly and might contribute to inflammation in patients with primary antibody deficiencies.

Do immune complexes play a role in hemolytic sequelae of intravenous immune globulin?

Intravenous immune globulin (IVIG) was developed initially as an immunoglobulin replacement therapy for primary humoral immunodeficiency, but is now widely used in the treatment of autoinflammatory and autoimmune pathologies. In a small number of patients, hemolytic sequelae have been observed after IVIG administration. The lack of a simple one-to-one correlation between measurable hemagglutinins and hemolysis has led to complicated hypotheses involving coincident necessary variables (e.g., a two-hit hypothesis) and also to the positing of causal factors other than hemagglutinins. One such hypothesis is that immune complexes (ICs) contained within IVIG lead to hemolysis. IVIG-mediated hemolysis was addressed at a recent meeting sponsored by the Food and Drug Administration; the Plasma Protein Therapeutics Association; and the National Heart, Lung, and Blood Institute. The primary literature was reviewed at this meeting followed by detailed discussion. Participants concluded that there is both a theoretical basis by which ICs could contribute to hemolysis after IVIG administration and some published data in support of such a possibility. However, the reported data contain substantial caveats, and the existing evidence does not rise to a level sufficient to either confirm or reject a role for ICs. More detailed and focused human studies will be required to further assess the potential role of ICs in IVIG induced hemolysis. This paper summarizes the relevant literature and expands upon the conclusions of this workshop.

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.

Hemolysis in patients with antibody deficiencies on immunoglobulin replacement treatment

BACKGROUND

Immunoglobulin (Ig)G replacement with intravenous or subcutaneous immunoglobulins is a lifelong substitutive therapy in patients with primary antibody deficiencies (PADs). Hemolysis after immunoglobulin therapy was described in patients receiving high immunoglobulin dosages. The issue of hemolysis after immunoglobulin administration at replacement doses has been considered of little clinical significance.

STUDY DESIGN AND METHODS

This was a single-center observational study over a 2-year period on immunoglobulin-induced hemolysis in a cohort of 162 patients with PADs treated with immunoglobulin administered at replacement dosages.

RESULTS

Six patients had signs and symptoms of immunoglobulin-induced hemolysis. Two additional asymptomatic patients were identified by a short-term study run on 16 randomly selected asymptomatic patients. Alloantibodies eluted from patients' red blood cells (RBCs) had anti-A and Rh specificities (anti-D and anti-C). The immunoglobulins contained alloantibodies with the same specificities of the antibodies eluted from patients' RBCs.

CONCLUSION

Hemolysis occurred in patients receiving immunoglobulin at replacement dosages. Polyvalent immunoglobulin preparations contained multiple clinically significant antibodies that could have unexpected hemolytic consequences, as anti-C whose research and titration are not required by the European Pharmacopoeia. The issue of hemolysis in long-term recipients of immunoglobulin treatment administered at replacement dosages should be more widely recognized.

Formation, Clearance, Deposition, Pathogenicity, and Identification of Biopharmaceutical-related Immune Complexes

Vascular inflammation, infusion reactions, glomerulopathies, and other potentially adverse effects may be observed in laboratory animals, including monkeys, on toxicity studies of therapeutic monoclonal antibodies and recombinant human protein drugs. Histopathologic and immunohistochemical (IHC) evaluation suggests these effects may be mediated by deposition of immune complexes (ICs) containing the drug, endogenous immunoglobulin, and/or complement components in the affected tissues. ICs may be observed in glomerulus, blood vessels, synovium, lung, liver, skin, eye, choroid plexus, or other tissues or bound to neutrophils, monocytes/macrophages, or platelets. IC deposition may activate complement, kinin, and/or coagulation/fibrinolytic pathways and result in a systemic proinflammatory response. IC clearance is biphasic in humans and monkeys (first from plasma to liver and/or spleen, second from liver or spleen). IC deposition/clearance is affected by IC composition, immunomodulation, and/or complement activation. Case studies are presented from toxicity study monkeys or rats and indicate IHC-IC deposition patterns similar to those predicted by experimental studies of IC-mediated reactions to heterologous protein administration to monkeys and other species. The IHC-staining patterns are consistent with findings associated with generalized and localized IC-associated pathology in humans. However, manifestations of immunogenicity in preclinical species are generally not considered predictive to humans.

Hemolysis upon intravenous immunoglobulin transfusion

Intravenous immunoglobulin (IVIG) is a mainstay of therapy in many disorders. An uncommon adverse side effect is IVIG-related hemolysis. Risk factors for IVIG-related hemolysis have been identified, including high dose IVIG given to non-O blood group recipients with an underlying inflammatory state. IVIG-related hemolysis has been linked to anti-A and anti-B hemagglutinins in the IVIG preparations and may involve both IgG and complement mediated hemolysis. A two-hit mechanism with threshold effect is proposed for IVIG-related hemolysis. Strategies exist to minimize or avoid IVIG-related hemolysis.

Liver allograft antibody-mediated rejection with demonstration of sinusoidal C4d staining and circulating donor-specific antibodies

The importance of antibody-mediated rejection (AMR) in ABO-compatible liver transplantation is controversial. Here we report a prospective series of liver recipients with a preoperative positive crossmatch. To establish the diagnosis of AMR in liver recipients, the criteria described for kidney allografts were adopted. In approximately 10% of 197 liver transplants, we observed a positive T and B cell flow crossmatch before transplantation. Fifteen of 19 patients converted to negative crossmatches early after transplantation and displayed normal liver function while they were on routine immunosuppression. Four patients maintained positive crossmatches. Three of the 4 met the criteria for AMR and showed evidence of graft dysfunction, the presence of donor-specific antibodies (DSAs), morphological tissue destruction with positive C4d linear staining on the graft sinusoidal endothelium, and improved function with attempts to eliminate DSAs. A persistently positive crossmatch after liver transplantation may lead to early, severe AMR and liver failure. C4d staining in the liver sinusoidal endothelium should alert one to the possibility of AMR. In our experience, patients with a positive crossmatch should have it repeated at 2 weeks and, if it is positive, again at 3 to 5 weeks. Recipients with an unknown preoperative crossmatch who develop early cholestasis of unclear etiology should be crossmatched or tested for the presence of DSAs to evaluate for AMR.

Acute hemolysis after high-dose intravenous immunoglobulin therapy in highly HLA sensitized patients

BACKGROUND AND OBJECTIVES

Intravenous Ig (IVIG) is used in renal transplantation for desensitization and treatment of antibody-mediated rejection (AMR). The infusion of high-dose IVIG is generally well tolerated, but there are reports of hemolytic anemia induced by anti-blood group antibodies present in IVIG. Here, we report our experience with IVIG-induced hemolytic anemia (IH) in ESRD patients receiving IVIG for desensitization or treatment of AMR.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

All patients receiving IVIG for desensitization or for treatment of AMR were monitored for evidence of acute anemia and hemolysis. Markers of hemolysis, including direct antiglobulin tests, were recorded. Five different IVIG products were tested for isohemagglutinin titers.

RESULTS

There were 18 cases of IH in 16 patients. All identified cases received the IVIG product Gamunex, Gammagard liquid, or Privigen. All patients developing hemolysis were non-O blood types. Isohemagglutinin titers ranged from 1:2 to 1:64 in the various IVIG products, with higher titers noted in the liquid, nonlyophilized products.

CONCLUSIONS

Acute IH is a significant complication of high-dose IVIG infusion. Identified risk factors include non-O blood type of the recipient and administration of liquid IVIG preparations with high titer anti-A/B IgG antibodies. We recommend monitoring hemoglobin 48 to 72 h after IVIG infusion. If the hemoglobin decreases, a hemolytic work-up is recommended. Hemolysis could be avoided in at risk patients by choosing a low titer product. However, other complications such as acute renal failure or thrombosis may be seen because the low titer products are usually hyperosmotic.

Hemolytic transfusion reactions after administration of intravenous immune (gamma) globulin: a case series analysis

BACKGROUND

This case series summarizes our observations of hemolytic reactions after the administration of large amounts of intravenous immune (gamma) globulin (IVIG).

STUDY DESIGN AND METHODS

Cases of hemolysis were identified by a decrease in hemoglobin not otherwise explained following IVIG administration.

RESULTS

Sixteen cases were identified over a 2 1/2-year period at the Ottawa Hospital of approximately 1000 patients receiving IVIG (1.6%). Characteristics of these patients include a large dose of IVIG, female sex, non-O blood group, and underlying inflammatory state.

CONCLUSIONS

Significant hemolysis may occur after the administration of large doses of IVIG. A two-step mechanism of hemolysis is proposed, sensitization by ABO isohemagglutinins followed by phagocytosis by activated macrophages. A simple protocol to facilitate the early detection of such cases is presented.

Variations in serum hemoglobin, albumin, and electrolytes in patients receiving intravenous immunoglobulin therapy: a real clinical threat?

BACKGROUND AND OBJECTIVE

Intravenous immunoglobulin (IVIg) is a solution of globulins containing antibodies derived from pooled human plasma of donors and used in the treatment of a number of immune deficiencies and autoimmune diseases. However, several investigators have reported biochemical alterations with use of IVIg. The objective of this study was to evaluate the effects of IVIg therapy on selected biochemical and hematologic parameters in patients with autoimmune mucocutaneous blistering diseases (AMBDs).

METHODS

In this preliminary clinical study, ten patients with AMBDs (seven with pemphigus vulgaris and three with mucous membrane pemphigoid) received 133 cycles of IVIg for a total of 399 infusions. We evaluated the effects of IVIg therapy on serum hemoglobin (Hb), albumin, and electrolyte levels, including sodium (Na+), potassium (K+), chloride (Cl-) and calcium (Ca2+). Values of these parameters were measured 24 hours before, during, and 24 hours and 4 weeks after the 3-day infusion period.

RESULTS

The observed variations in serum electrolyte levels were physiologically and clinically negligible. Furthermore, 24 hours after the last infusion, mean electrolyte values had spontaneously returned to normal levels without the need for additional supplementation: Na+ 137.59+/-1.42 mmol/L (p=0.6091 vs baseline); K+ 3.97+/-0.5 mmol/L (p=0.2689); Cl- 103.4+/-2.69 mmol/L (p=0.0388); and Ca2+ 9.07+/-0.44 mg/dL (p=0.5332). Conversely, significant variations in mean Hb and albumin levels were observed. When measured 24 hours after the last infusion, mild/moderate decreases in Hb (11.62+/-2.12 g/dL; p=0.009 vs baseline) and/or albumin (mean 3.14+/-0.24 g/dL; p=0.0016 vs baseline) were evident. Such changes may, albeit very rarely, be of sufficient clinical significance in individual patients as to necessitate additional treatment.

CONCLUSION

In patients receiving intravenous IVIg for AMBDs, electrolyte values should be monitored but do not represent a real clinical threat. Hemoglobin and albumin values may be altered sufficiently to require additional treatment but this is a very rare occurrence. These findings confirm and extend previous reports of the safety of IVIg therapy.

The increased flexibility of CDR loops generated in antibodies by Congo red complexation favors antigen binding

The dye Congo red and related self-assembling compounds were found to stabilize immune complexes by binding to antibodies currently engaged in complexation to antigen. In our simulations, it was shown that the site that becomes accessible for binding the supramolecular dye ligand is located in the V domain, and is normally occupied by the N-terminal polypeptide chain fragment. The binding of the ligand disrupts the beta-structure in the domain, increasing the plasticity of the antigen-binding site. The higher fluctuation of CDR-bearing loops enhances antigen binding, and allows even low-affinity antibodies to be engaged in immune complexes. Experimental observations of the enhancement effect were supported by theoretical studies using L lambda chain (4BJL-PDB identification) and the L chain from the complex of IgM-rheumatoid factor bound to the CH3 domain of the Fc fragment (1ADQ-PDB identification) as the initial structures for theoretical studies of dye-induced changes. Commercial IgM-type rheumatoid factor (human) and sheep red blood cells with coupled IgG (human) were used for experimental tests aimed to reveal the dye-enhancement effect in this system. The specificity of antigen-antibody interaction enhanced by dye binding was studied using rabbit anti-sheep red cell antibodies to agglutinate red cells of different species. Red blood cells of hoofed mammals (horse, goat) showed weak enhancement of agglutination in the presence of Congo red. Neither agglutination nor enhancement were observed in the case of human red cells. The dye-enhancement capability in the SRBC-antiSRBC system was lost after pepsin-digestion of antibodies producing (Fab)2 fragments still agglutinating red cells. Monoclonal (myeloma) IgG, L lambda chain and ovoalbumin failed to agglutinate red cells, as expected, and showed no enhancement effect. This indicates that the enhancement effect is specific.

Adverse effect of polyvalent immunoglobulin in the treatment of Guillain-Barre syndrome

BACKGROUND

Acute polyradiculoneuropathy or Guillain-Barre syndrome is a neurological disease which may present with severe forms which have a poor prognosis. The patient's management requires multidisciplinary specialised care. Morbidity has been reported to be significantly improved with initial therapy using high-dose intravenous immunoglobulin (IVIG). However, this therapy represent an immunological risk which has remained overlooked by clinicians in the majority of cases and is not clearly stated by the pharmaceutical companies. Therefore, the use of IVIG in the intensive care unit can cause some problems.

CASE REPORT

A 32-year-old woman presented with clinical signs of Guillain-Barre syndrome. The patient received high-dose intravenous immunoglobulin (TEGELINE). Nine days after beginning therapy, she presented with severe immunological hemolytic anaemia; the IVIG was suspected as the cause. The blood cell count returned to normal approximately two months after the onset of the hemolytic syndrome.

CONCLUSION

Despite the effectiveness of IVIG therapy in the management of various diseases, intensive care clinicians should be aware of possible major adverse effects which make a careful assessment of the patient necessary before treatment. It may also be important to consider the patient's ABO blood group before initiating IVIG treatment, particularly in patients bearing A and/or B blood group antigens.

[Insisting on intravenous polyvalent immunoglobulin therapy in polymyositis in spite of the occurrence of sever hemolytic anemia]

A 23-year-old female with polymyositis received high dose intravenous immunoglobulin (IVIg) therapy. The patient suffered severe hemolytic anemia after receiving first course of IVIg infusion. This adverse reaction was likely due to allohemaglutinin A and B and from or high molecular weight IgG complexes contained in the preparation. Though this effect was observed, the treatment was repeated six times. A mild hemolysis occurred following each IVIg, with no clinical consequence. Involvement of the saturation of macrophagic receptors might explain this partial destruction of erythrocytes.

Normal polyclonal immunoglobulins ('IVIg') inhibit microglial phagocytosis in vitro

Phagocytosis removes pathogens and tissue debris during inflammatory reactions, but also plays an important role in autoimmune reactions. The main phagocytes in the central nervous system (CNS) are microglial cells that are activated during CNS inflammation. In the treatment of inflammatory demyelinating diseases like multiple sclerosis (MS), administration of intravenous immunoglobulins (IVIg) has become a promising immunomodulatory therapy. Although a large number of potential mechanisms for the effects of IVIg has been suggested, the precise mode of action in CNS inflammation is unknown. We assessed the influence of IVIg on phagocytosis and endocytosis in microglia in vitro. IVIg had little effect on non-specific phagocytosis of latex particles in untreated microglia, while there was a dose-dependent inhibition in microglia activated with LPS and IFNgamma. Endocytosis of soluble myelin basic protein (MBP) was downregulated by IVIg in both untreated and activated microglia. The effect was mediated by an F(ab')(2) preparation of immunoglobulins, suggesting that Fc receptor-mediated phagocytosis is not involved. Intact IVIg, but not F(ab')(2) fragments also suppressed Fc receptor-mediated phagocytosis of opsonised erythrocytes in both untreated and activated microglia. These results show that IVIg can inhibit the phagocytic activity of microglia via different mechanisms. Such an effect could contribute to the immunomodulatory capacity of IVIg in inflammatory CNS diseases.

In vivo administration of intravenous immunoglobulin (IVIg) can lead to enhanced erythrocyte sequestration

Enhanced erythrocyte sequestration is one of the very few major adverse effects of intravenous immunoglobulin (IVIg). IVIg contains high molecular weight IgG complexes ( approximately 300 kDa) which, in the presence of serum, mimic immune complexes by activating complement, binding to CR1 of red blood cells (RBC) (CD35) and mediating erythrophagocytosis. Four of seven patients undergoing IVIg therapy showed significant drops in haematocrit and haemoglobin that were not due to isoantibodies in the IVIg. Prior to treatment, patients' RBC carried IgG and complement (C') 3d that were not bound as immune complexes via CR1 (CD35). The patients whose RBC bound immune complex-like moieties and showed drops in haematocrit and haemoglobin subsequent to IVIg were young adults (22-35 years); older patients (50-69 years) showed no ill effects. In the presence of complement, RBC of young patients bound IVIg complexes in vitro while those of older patients did not. It is not the absolute levels of erythrocyte-associated IgG or C'3 fragments, neither pre- nor post-therapy, which are predictive of IVIg associated decreases in haematocrit and haemoglobin levels. Patient age and RBC inability to bind the IVIg immune complex-like moieties in vitro both appear to be predictors of resistance to sequestration after in vivo treatment with IVIg.