Tumor necrosis factor and intravenous gammaglobulins in common variable immunodeficiency

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.

Inhibitory effect of pooled human immunoglobulin on cytokine production in peripheral blood mononuclear cells

Human intravenous immunoglobulins (IVIG) are widely used as immunomodulators because of their ability to modify the course of various immune-mediated diseases. We investigated the mechanisms responsible for the regulatory effects of IVIG on in vitro human peripheral blood mononuclear cell (PBMC) cytokine production. Pre-incubation of PBMCs with IVIG inhibited lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA)/ionomycin stimulated cytokine secretion. Pre-incubation of PBMCs with IVIG induced a significant inhibition of LPS-stimulated (IL-6) secretion (p = 0.045); the effect on tumor necrosis factor-alpha (TNF-alpha) secretion was not significant (p = 0.234). Pre-incubation of PBMCs with IVIG inhibited IL-6 secretion (p = 0.033) stimulated with anti-CD14 antibody cross-linking but had no significant effect on TNF-alpha secretion (p = 0.125). PBMC pre-incubation with anti-CD14-blocking antibody induced a significant reduction (p = 0.042) in LPS-stimulated TNF-alpha secretion in comparison with a non-significant reduction (p =0.256) noted with IVIG pre-treatment. In contrast, pre-incubation of PBMCs with anti-CD14 antibody did not induce a significant reduction in LPS-stimulated IL-6 secretion (p = 0.166) in comparison with a significant reduction (p = 0.001) induced with IVIG pre-treatment. Our data suggest that the immunoregulatory properties of IVIG may rely on several mechanisms, some of which may be independent of CD14. Our data also showed that cross-linking cell membrane-bound IVIG with anti-human kappa- and lambda-chain antibodies resulted in cytokine secretion levels similar to those elicited by LPS. In addition, intracellular DNA staining results did not support the involvement of apoptosis in the regulatory mechanisms of IVIG. This data may further our understanding of the immunoregulatory effects exerted by IVIG on the production of inflammatory-response mediators.

High dose intravenous immunoglobulin treatment: mechanisms of action

Intravenous immunoglobulin (IVIg) treatment was introduced as replacement therapy for patients with antibody deficiencies, but evidence suggests that a wide range of immune-mediated conditions could benefit from IVIg. The immunoglobulins are precipitated from human plasma by fractionation methods. In conclusion, the differences in basic fractionation methods and the addition of various modifications for purification, stabilization, and virus inactivation result in products significantly different from each other.

Intravenous (IV) anti-D and IV immunoglobulin achieve acute platelet increases by different mechanisms: modulation of cytokine and platelet responses to IV anti-D by FcgammaRIIa and FcgammaRIIIa polymorphisms

Intravenous (IV) anti-D and IV immunoglobulin (IVIG) slow the Fcgamma receptor (FcgammaR)-mediated destruction of antibody-coated platelets in patients with immune thrombocytopenic purpura (ITP). This pilot study explored the mechanism of these immunoglobulin preparations by measuring interleukin-10 (IL-10), monocyte chemoattractant protein-1 (MCP-1), IL-6 and tumour necrosis factor alpha (TNFalpha), before and after infusion and by assessing the effect of FcgammaRIIa and FcgammaRIIIa polymorphisms on both cytokine and haematologic responses to anti-D. Following IVIG, only IL-10 was increased at 2 h and MCP-1 on day 7 (P < 0.05). In contrast, 2 h after anti-D infusion, plasma levels of all four cytokines were increased (P < 0.01); five of six patients with the highest MCP-1, IL-6 and TNFalpha levels had chills. Higher IL-10 levels correlated with platelet increases at 24 h and haemoglobin decreases at day 7 (P < 0.025). Patients with the FcgammaRIIa-131HH genotype had significantly higher MCP-1, IL-6 and TNFalpha levels. Patients with the FcgammaRIIIa-158VF genotype had higher platelet increments at day 7 (P < 0.05). Soluble CD16 (sCD16) was increased 2 h after IV anti-D; day 7 levels correlated with day 7 haemoglobin decreases (P < 0.01). In conclusion, the relationship of FcgammaRIIa and FcgammaRIIIa polymorphisms with both cytokine levels and platelet increments implicated these receptors in responses to anti-D and supported different mechanisms of FcgammaR interaction to those seen with IVIG.

IVIG--mechanisms of action

Intravenous immunoglobulin (IVIG) preparations are fractionated from a plasma pool of several thousand donors. IVIG contain immune antibodies and physiologic autoantibodies. Immune antibodies reflect the immunologic experience of the donor population. This fraction of IVIG preparations is useful for replacement therapy and passive immunisation. Natural autoantibodies are able to react with the immune system of the recipient of IVIG and are suggested to help to correct immune deregulation. Immunomodulatory and anti-inflammatory properties are based on multiple mechanisms of action which are described. These mechanisms are effective concomitantly and synergistically at every occasion of use of IVIG in inflammatory and autoimmune disorders.

Efficacy, tolerability, safety and pharmacokinetics of a nanofiltered intravenous immunoglobulin: studies in patients with immune thrombocytopenic purpura and primary immunodeficiencies

BACKGROUND AND OBJECTIVES

A nanofiltration step with the capacity to reduce blood-borne pathogens was introduced into the manufacturing process of intravenous immunoglobulin (IVIG). In order to demonstrate the efficacy, safety and pharmacokinetics of the modified product, we conducted Phase II/III studies comparing the nanofiltered IVIG (IVIG-N) with its parent product, Sandoglobulin, in patients with chronic immune thrombocytopenic purpura (ITP) and primary immunodeficiencies (PID).

MATERIALS AND METHODS

Patients with ITP (n = 27) with platelet counts of < 20 x 10(9)/l were treated with Sandoglobulin or IVIG-N infusions at a dose of 0.4 g/kg body weight on five consecutive days. The primary efficacy end-point was the number of patients with an increase in platelet counts to > 50 x 10(9)/l. Secondary end-points were time to and duration of response, and regression of bleeding. Patients with PID (n = 36) were treated for 6 months with Sandoglobulin or IVIG-N at doses of 0.2-0.8 g/kg, infused at 3- or 4-week intervals. The primary end-point was the number of days absent from school/work. Secondary end-points were hospitalization, use of antibiotics and feeling of well-being. In both studies, tolerability was assessed by recording of adverse events and laboratory determinations. Viral safety was ascertained by serology supplemented with nucleic acid detection methods. Pharmacokinetics were analysed in patients with PID using serum concentration-time data for immunoglobulin G (IgG), and IgG antibodies to hepatitis B surface antigen (anti-HBsAg).

RESULTS

In the ITP study, the primary end-point was met by 12/16 patients on IVIG-N and by 10/10 patients on Sandoglobulin (P = 0.123). A shift towards lesser bleeding intensity was seen in both groups. In the PID study, seven of 18 patients on IVIG-N and six of 16 patients on Sandoglobulin missed days at work/school, with monthly mean absences of 0.4 and 0.5 days (P = 0.805). The feeling of well-being was comparable in both groups. In the ITP study, adverse events with a causal relationship to medication were suspected in six patients on IVIG-N and in seven on Sandoglobulin. In the PID study, three patients on IVIG-N and two on Sandoglobulin experienced possible drug-related adverse events. In both studies, serological and polymerase chain reaction (PCR) tests gave evidence for virus safety. Pharmacokinetics showed constant peak and trough serum IgG levels in all patients, indicating almost steady-state conditions for both formulations. The overall half-life (t1/2) for total IgG was 33 +/- 17 days in the IVIG-N arm and 25 +/- 16 days in the Sandoglobulin arm; for anti-HBsAg t1/2, values were 17 +/- 7 and 17 +/- 9 days, respectively.

CONCLUSIONS

IVIG-N is efficacious, well tolerated and safe in patients with ITP and PID. Its pharmacokinetic properties were comparable to those of Sandoglobulin.

In vivo modulation of cytokine synthesis by intravenous immunoglobulin

We examined the effects of intravenous immunoglobulin (IVIG) on cytokine regulation in vivo using samples taken before and after replacement-dose (200-400 mg/kg) IVIG in a group of patients with common variable immunodeficiency (CVID) and X-linked agammaglobulinaemia (XLA). The intracellular cytokine content of CD4+ and CD8+ lymphocytes, and their CD28+/- subsets, were measured following in vitro activation with phorbol myristate acetate (PMA) and ionomycin. The cytokines IL-2, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha), and the early activation marker CD69, were assessed by four-colour flow cytometry of whole blood cultures taken before and after IVIG infusion. There was a significant increase in IL-2 expression in CD4+ (and CD4+28-) cells and an increase in TNF-alpha expression in CD8+28- cells following IVIG in CVID, but not in XLA patients. IFN-gamma and CD69 expression were not affected by IVIG infusion. This increase in TNF-alpha and IL-2, combined with unchanged IFN-gamma expression, is evidence against the putative 'anti-inflammatory' role of IVIG, and may explain the failure of resolution of granulomata in CVID patients treated with IVIG alone.

Selective induction of interleukin-1 receptor antagonist and interleukin-8 in human monocytes by normal polyspecific IgG (intravenous immunoglobulin)

We have investigated the effects of intravenous immunoglobulin (IVIg), a therapeutic preparation of normal human polyspecific IgG, on the synthesis and release of cytokines by peripheral blood monocytes. IVIg was found to selectively induce gene transcription and secretion of interleukin-1 receptor antagonist (IL-1ra) and IL-8 in cultures of normal human monocytes. The addition of IVIg to cultures of purified monocytes induced a dose-dependent secretion of IL-1ra and IL-8 without stimulating the production of IL-1 alpha, IL-1 beta, tumor necrosis factor-alpha or IL-6. The effects of IVIg required both the Fc and F(ab')2 portions of IgG. IVIg-induced production of IL-8 by monocytes was enhanced by lipopolysaccharide (LPS), although LPS inhibited the secretion of IL-1ra, suggesting that IVIg and LPS stimulate distinct intracellular pathways in monocytes. Induction of IL-1ra and IL-8 by IVIg was enhanced in the presence of autologous T lymphocytes. Our observations document the selectivity of the effects of IVIg on the synthesis of cytokines and cytokine antagonists by human monocytes. Induction of IL-1ra and IL-8 by IVIg may contribute to the anti-inflammatory effects of immunoglobulin therapy in patients with autoimmune and systemic inflammatory disorders.

In vitro inhibition of tumour necrosis factor-alpha and interleukin-6 production by intravenous immunoglobulins

In vitro data about the action of pooled immunoglobulins (Ig) on cytokine (CK) production are controversial. The recent finding of natural antibodies against staphylococcal toxins neutralizing superantigen-induced activation prompted us to design an assay determining their ability to modulate staphylococcal enterotoxin B (SEB) induced CK production (IL-6 and TNF-alpha). Presence of anti-SEB antibodies was demonstrated by a dot-blot assay in the three preparations tested. Preincubation of SEB with pooled Ig prior to addition into the test tube containing PBMCs (neutralizing condition) resulted in a strong inhibition of both TNF-alpha and IL-6 release (TNF alpha: 59 +/- 5% inhibition, P < 0.0001; IL-6: 71 +/- 7% inhibition, P < 0.0001, n = 15). Anti-CD3 MoAb-induced CK production was not modified. During our study it was found that experimental conditions were critical to observe this inhibitory effect. Reversing the previous procedure by adding PBMCs into the test tube containing pooled Ig mixed with SEB resulted in a marked induction of TNF-alpha and IL-6 production. The same observation was made when pooled Ig solely was added (coating condition). F(ab')2 fragments of pooled Ig displayed similar inhibitory capacity when added in neutralizing condition, indicating that the mechanism involved was not Fc dependent. The fragments lost the activating properties of intact Ig when incubated in coating condition, showing that Fc receptor activation occurs in this setting. The present work demonstrates that inhibition of SEB-induced CKs release by pooled Ig can be achieved by SEB neutralization, provided that the experimental conditions avoid activation through the Fc receptor. It can be assumed that similar mechanisms take place in some clinical conditions during which pooled Ig are infused.