Comparison of early IgM-enriched immunoglobulin vs polyvalent IgG administration in score-identified postcardiac surgical patients at high risk for sepsis

Role of Immunoglobulin Therapy to Prevent and Treat Infections

Immunoglobulins have been used widely in medicine for a variety of diseases including infectious diseases. While the main clinical applications of immunoglobulin therapy concern their use as replacement for patients with primary immunodeficiencies, or as treatment for autoimmune and inflammatory disorders, their role in infectious disease is limited largely to viral and toxin neutralization and replacement therapy in patients with immunoglobulin deficiencies. Many aspects of the therapeutic regimen of immunoglobulins even in the established indications remain open. Recently, due to the worldwide surge of immunosuppression caused by AIDS, organ transplantation, cancer, and autoimmune therapies, as well as the emergence of multidrug-resistant bacteria, there has been renewed interest in the use of antibody preparation to prevent infections in high-risk groups.

Knowing the limitations of the current anti-infective armamentarium, approaches that target the host through manipulations to augment the host immune response provide a helpful aid to conventional treatment options. A substantial body of evidence has demonstrated that strategies aiming to support or stimulate immune response could be feasible approaches that would benefit immunocompromised patients. In the present chapter, we present contemporary indications of immunoglobulin administration for therapy and prophylaxis of infections in the immunocompromised population.

Intravenous immunoglobulin for treating sepsis, severe sepsis and septic shock

BACKGROUND

Mortality from sepsis and septic shock remains high. Results of trials on intravenous immunoglobulins (IVIG) as adjunctive therapy for sepsis have been conflicting. This is an update of a Cochrane review that was originally published in 1999 and updated in 2002 and 2010.

OBJECTIVES

To estimate the effects of IVIG as adjunctive therapy in patients with bacterial sepsis or septic shock on mortality, bacteriological failure rates, and duration of stay in hospital.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 6), MEDLINE (1966 to December 2012), and EMBASE (1988 to December 2012). We contacted investigators in the field for unpublished data. The original search was performed in 1999 and updated in 2002 and 2008.

SELECTION CRITERIA

We included randomized controlled trials comparing IVIG (monoclonal or polyclonal) with placebo or no intervention in patients of any age with bacterial sepsis or septic shock.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the studies for inclusion and undertook methodologic quality assessment and data abstraction. We conducted pre-specified subgroup analyses by type of immunoglobulin preparation.

MAIN RESULTS

We included 43 studies that met our inclusion criteria in this updated review out of 88 potentially eligible studies. The studies included a large polyclonal IVIG trial in neonates that was concluded in 2011 and classified as ongoing in the 2010 version of this review. Pooled analysis of polyclonal and monoclonal IVIG was not done due to clinical heterogeneity. Subgroup analysis of 10 polyclonal IVIG trials (n = 1430) and seven trials on IgM-enriched polyclonal IVIG (n = 528) showed significant reductions in mortality in adults with sepsis compared to placebo or no intervention (relative risk (RR) 0.81; 95% confidence interval (CI) 0.70 to 0.93 and RR 0.66; 95% CI 0.51 to 0.85, respectively). Subgroup analysis of polyclonal IVIG in neonates, which now includes the recently concluded large polyclonal IVIG trial, showed no significant reduction in mortality for standard IVIG (RR 1.00; 95% CI 0.92 to 1.08; five trials, n = 3667) and IgM-enriched polyclonal IVIG (RR 0.57; 95% CI 0.31 to 1.04; three trials, n = 164). Sensitivity analysis of trials with low risk of bias showed no reduction in mortality with polyclonal IVIG in adults (RR 0.97; 95% CI 0.81 to 1.15; five trials, n = 945) and neonates (RR 1.01; 95% CI 0.93 to 1.09; three trials, n = 3561). Mortality was not reduced among patients (eight trials, n = 4671) who received anti-endotoxin antibodies (RR 0.99; 95% CI 0.91 to1.06) while anti-cytokines (nine trials, n = 7893) demonstrated a marginal reduction in mortality (RR 0.92; 95% CI 0.86 to 0.97).

AUTHORS' CONCLUSIONS

Polyclonal IVIG reduced mortality among adults with sepsis but this benefit was not seen in trials with low risk of bias. Among neonates with sepsis, there is sufficient evidence that standard polyclonal IVIG, as adjunctive therapy, does not reduce mortality based on the inclusion of the large polyclonal IVIG trial on neonates. For Ig-M enriched IVIG, the trials on neonates and adults were small and the totality of the evidence is still insufficient to support a robust conclusion of benefit. Adjunctive therapy with monoclonal IVIGs remains experimental.

[Assessment of elderly intensive care patients]

The standard geriatric basic assessment validly presents the functional limitations of elderly patients. The prognosis estimation of elderly people is less precise using the instruments for cardiovascular and preoperative risk evaluation or by the intensive care medicine scores on organ failure. An adaptation and further development of score systems could clarify these vague areas.

Reducing elevated heart rate in patients with multiple organ dysfunction syndrome by the I (f) (funny channel current) inhibitor ivabradine : MODI (f)Y trial

BACKGROUND

Heart rate (HR) is of relevant prognostic value not only in the general population and patients with cardiovascular disease, but also in critically ill patients with multiple organ dysfunction syndrome (MODS). An elevated HR in MODS patients is associated with a worse prognosis. Beta-blocker (BB) administration has been shown to reduce mortality in MODS. In most cases, negative inotropic effects prevent administration of BBs in MODS patients. In this trial we investigate, whether the "funny current" (I (f)) channel inhibitor ivabradine is able and apt to reduce pathologically elevated HR in MODS patients. We hypothesize that critically ill patients could derive particular benefit from the specific HR-lowering agent ivabradine.

METHODS

MODI (f)Y is a prospective, single centre, open label, randomized, controlled two arms, phase II-trial to evaluate the potential of ivabradine to reduce an elevated HR in MODS patients. The primary end point is the proportion of patients with a reduction of HR by at least 10 beats per minute (bpm) within 4 days. This trial will randomize 70 patients (men and women, aged ≥18 years) with newly diagnosed MODS, with an elevated HR (sinus rhythm with HR ≥90 bpm) and contraindications to BB therapy. Treatment period will last for 4 days. All patients will be followed for 6 months.

RESULTS

The first patient was randomized on May 21, 2010.

CONCLUSIONS

The MODI (f)Y trial is the first application of ivabradine as a pure heart rate reducing agent in MODS patients.

Clinical applications of intravenous immunoglobulins (IVIg)--beyond immunodeficiencies and neurology

The clinical use of intravenous immunoglobulin (IVIg) has expanded beyond its traditional place in the treatment of patients with primary immunodeficiencies. Due to its multiple anti-inflammatory and immunomodulatory properties, IVIg is used successfully in a wide range of autoimmune and inflammatory conditions. Recognized autoimmune indications include idiopathic thrombocytopenic purpura (ITP), Kawasaki disease, Guillain-Barré syndrome and other autoimmune neuropathies, myasthenia gravis, dermatomyositis and several rare diseases. Several other indications are currently under investigation and require additional studies to establish firmly the benefit of IVIg treatment. Increasing attention is being turned to the use of IVIg in combination with other agents, such as immunosuppressive agents or monoclonal antibodies. For example, recent studies suggest that combination therapy with IVIg and rituximab (an anti-CD20 monoclonal antibody) may be effective for treatment of autoimmune mucocutaneous blistering diseases (AMBDs), with sustained clinical remission. The combination of IVIg and rituximab has also been used in the setting of organ transplantation. Firstly, IVIg +/- rituximab has been administered to highly human leucocyte antigen (HLA)-sensitized patients to reduce anti-HLA antibody levels, thereby allowing transplantation in these patients. Secondly, IVIg in combination with rituximab is effective in the treatment of antibody-mediated rejection following transplantation. Treatment with polyclonal IVIg is a promising adjunctive therapy for severe sepsis and septic shock, but its use remains controversial and further study is needed before it can be recommended routinely. This review covers new developments in these fields and highlights the broad range of potential therapeutic areas in which IVIg may have a clinical impact.

Immunoglobulin M-enriched human intravenous immunoglobulins reduce leukocyte-endothelial cell interactions and attenuate microvascular perfusion failure in normotensive endotoxemia

Clinical studies indicate potential differences in the efficacy of immunoglobulin (Ig) preparations in patients with sepsis. A recent meta-analysis showed improved survival rates with IgM-enriched Igs. It was the objective of the present study to characterize microcirculatory actions of different clinically used Ig preparations in a rodent endotoxin model by intravital microscopy. Male Syrian golden hamsters 6 to 8 weeks old with a body weight of 60 to 80 g were investigated by intravital fluorescence microscopy. Endotoxemia was induced by administration of 2 mg/kg (i.v.) endotoxin (LPS, Escherichia coli). Two different Ig preparations containing IgM, IgA, and IgG (intravenous IgM group; n = 6; 5 mL Pentaglobin/kg body weight, i.v.) or exclusively IgG (intravenous IgG group; n = 5; 5 mL Flebogamma/kg body weight, i.v.) were applied 5 min before LPS. Saline-treated endotoxemic animals served as controls (control; n = 8). In controls, LPS induced massive leukocyte-endothelial cell interactions, pronounced microvascular leakage, a decrease of systemic platelet count, and distinct capillary perfusion failure (P < 0.05). Both intravenous IgM and IgG reduced venular leakage (P< 0.05) and ameliorated the decrease in platelet count (P < 0.05). Of interest, intravenous IgM was capable of significantly (P< 0.05) reducing leukocyte adhesion in venules. This was associated with normalization of capillary perfusion at 24 h of endotoxemia, whereas intravenous IgG could not prevent LPS-mediated microvascular perfusion failure. We demonstrate that IgM-enriched Igs are superior to IgG alone in attenuating LPS-induced leukocytic inflammation and microcirculatory dysfunction. Our findings can explain better efficacy of IgM-enriched Igs in patients with severe sepsis.

Role of endotoxin in the pathogenesis of critical illness polyneuropathy

Critical illness polyneuropathy (CIP) occurs in association with sepsis and multiple organ failure; however, little is known about the pathomechanisms of CIP and its therapy. In order to determine the parameters which interfere with development of CIP, electrophysiological investigations of peripheral nerves and biochemical measures were correlated to each other. The present study includes 20 consecutive patients in an intensive care unit developing severe sepsis or septic shock. Nerve conduction studies and electromyography were performed with occurring sepsis (day 1, 7, 14) and neurophysiological parameters were correlated with biochemical measures, especially indicators of infection and inflammation. It was found that all patients developed neurophysiological signs of axonal motor polyneuropathy. There was a significant correlation between serum concentrations of endotoxin and interleukin-2 receptors (IL2-R) and reduction of the amplitude of the compound motor action potentials. Other clinical and biochemical parameters showed no significant correlations with neurophysiological data. This finding apparently indicates that endotoxin damages nerve axons directly or indirectly, e.g. by activation of inflammatory cascades (IL2-R). Endotoxin appears to be an essential factor in the pathogenesis of CIP in sepsis, and therapeutic options neutralizing endotoxin may prevent development of CIP.

Intravenous polyclonal IgM-enriched immunoglobulin therapy in sepsis: a review of clinical efficacy in relation to microbiological aetiology and severity of sepsis

The efficacy of intravenous polyclonal immunoglobulin (IVIG) as adjunct therapy in sepsis has long been debated. Clinical trials have yielded contradicting results, in part due to the varying study design and varying microbiological aetiologies. In most trials, the study drug has been IVIG containing polyclonal IgG. However, in recent reports, the efficacy of IgM-enriched IVIG as adjunct therapy in sepsis has been highlighted. Here we review studies on IgM-enriched IVIG therapy in sepsis and we discuss the clinical efficacy in relation to microbiological aetiology and severity of sepsis. The results suggest that patients most likely to benefit from IgM-enriched IVIG therapy are those with Gram-negative septic shock.

Restoration of Natural IgM Production from Liver B Cells by Exogenous IL-18 Improves the Survival of Burn-Injured Mice Infected withPseudomonas aeruginosa

Pseudomonas aeruginosa is the most common bacterium of postburn infection. In the present study we investigated the immune mechanism of susceptibility to this type of postburn infection and also examined the efficacy of IL-18 treatment. C57BL/6 mice were challenged with P. aeruginosa on day 7 after burn injury. Although the burn-injured mice showed a poor survival rate after bacterial challenge, they retained their IFN-gamma production. The burned mice showed lower serum IgM levels and a poor IgM response following P. aeruginosa challenge in comparison with the sham mice, whereas IL-18 treatment after burn injury (alternate day injections for 1 wk) greatly improved the serum IgM levels, which are P. aeruginosa-independent natural IgM before bacterial challenge, thereby increasing the survival rate after the challenge. IL-18 treatment also induced specific IgM to P. aeruginosa in the sera 5 days after bacterial challenge in the burned mice. Interestingly, CD43(+)CD5(-)CD23(-)B220(dim) cells, namely B-1b cells, increased in the liver after the IL-18 treatment and were found to actively produce IgM in vitro without any additional stimulation. Furthermore, the IL-18 treatment up-regulated the neutrophil count and the C3a levels in the blood as a result of the increased IgM level, which may thus play a critical role in the opsonization and elimination of any invading bacteria. IL-18 treatment for the burned mice and their resultant natural IgM production were thus found to strengthen the host defense against P. aeruginosa infection.

IgM-enriched human intravenous immunoglobulin suppresses T lymphocyte functions in vitro and delays the activation of T lymphocytes in hu-SCID mice

Previous studies of an experimental human immunoglobulin preparation for intravenous use, containing normal pooled IgM (IVIgM), have shown its beneficial therapeutic effect in experimental autoimmune diseases. The mechanisms of its immunomodulatory activity remain however, poorly understood. In the experiments reported here, IVIgM inhibited the proliferation of various autonomously growing human lymphoid cell lines in vitro, as well as of MLR- and of PHA-stimulated human T-lymphocytes. These effects of IVIgM were observed at non-apoptotic concentrations and were stronger on a molar basis than those of normal pooled IgG for intravenous use (IVIg). Both preparations, when administered to SCID mice, repopulated with human peripheral blood mononuclear cells, delayed the expression of the early activation marker CD69 on both human CD4+ and CD8+ T-lymphocytes, activated by the mouse antigenic environment. The data obtained show that normal pooled human IgM exerts a powerful antiproliferative effect on T-cells that is qualitatively similar but quantitatively superior to that of therapeutic IVIg. Our results suggest that infusions with IVIgM might have a significant beneficial immunomodulating activity in patients with selected autoimmune diseases.

IgMA-enriched immunoglobulin in neutropenic patients with sepsis syndrome and septic shock: A randomized, controlled, multiple-center trial*

OBJECTIVE

To evaluate the effect of intravenous IgMA-enriched immunoglobulin (ivIGMA) therapy on mortality in neutropenic patients with hematologic malignancies and sepsis syndrome or septic shock.

DESIGN

Multiple-center, prospective randomized, controlled study.

SETTING

Six university hospitals in Germany.

PATIENTS

Patients were 211 neutropenic patients with sepsis syndrome or septic shock after chemotherapy for severe hematologic disorders between 1992 and 1999.

INTERVENTIONS

Patients received 1300 mL of ivIGMA (7.8 g IgM, 7.8 g IgA, and 49.4 g IgG) infused intravenously within a period of 72 hrs or human albumin according to the same schedule as ivIGMA.

MEASUREMENTS AND MAIN RESULTS

All-cause mortality at 28 days, sepsis-related mortality at 28 days, all-cause mortality at 60 days, mortality from septic shock, and mortality from microbiologically proven Gram-negative sepsis and septic shock were recorded. Immunoglobulin had no benefit over human albumin. The 28-day mortality rate was 26.2% and 28.2% in the ivIGMA and control patients, respectively (difference, 2.0% [95% confidence interval, -10.2 to 14.2 percentage points]). Likewise, the 60-day mortality rate did not differ between both arms (29.6% vs. 34.7% in the ivIGMA and control patients, respectively). Mortality rates in patients with sepsis syndrome (17.1% vs. 16.7%) and septic shock (51.9% vs. 54.8%) were also found to be similar between both groups.

CONCLUSIONS

Intravenous ivIGMA had no beneficial effects in neutropenic patients with hematologic malignancies and sepsis syndrome and septic shock.

Clinical Experience With Polyclonal IgM-Enriched Immunoglobulins in a Group of Patients Affected by Sepsis After Cardiac Surgery

OBJECTIVE

The purpose of this study was to evaluate the efficiency, in terms of decreasing overall mortality (primary endpoint), of an immunoglobulin M (IgM)-enriched, polyclonal intravenous immunoglobulin preparation (IVIg) (Pentaglobin; Biotest AG, Dreieich, Germany) in the treatment of a group of patients affected by sepsis after cardiac surgery. A secondary endpoint was to evaluate which subgroup, on the basis of the infectious state when the patient enrolled, could benefit the most from the treatment. Another secondary endpoint was the evaluation of an improvement in the severity score or in other variables such as Glasgow Coma Scale; arterial pressure (systolic, average, and diastolic); heart rate; central venous pressure; cardiac index; respiratory rate; PaO(2), F(I)O(2), and the ratio of PaO(2) to F(I)O(2); pH, base excess, and bicarbonate; C reactive protein and leukocytes; platelets, prothrombin time, partial thromboplastin time, fibrinogen, and anti-thrombin III; creatinine; and bilirubin.

DESIGN

Retrospective case-controlled study.

SETTING

Cardiovascular intensive care unit of a university hospital.

PARTICIPANTS

Sixty-six patients who developed sepsis in the postoperative period after cardiac surgery were admitted to the cardiovascular intensive care unit from June 1, 2001, to June 30, 2003: 30 patients (45.5%) had valvular surgery, 18 (27.5%) had myocardial revascularization, 14 (21%) had thoracic aorta surgery, and 4 (6%) had other surgery.

INTERVENTIONS

From the 66 patients diagnosed with sepsis, 22 patients (IVIg group) received IgM-enriched immunoglobulins in addition to the conventional therapy, whereas the other 44 patients (control group) were treated only with conventional therapy. The decision as to whether or not to administer the immunoglobulins was made by physicians in the intensive care unit.

MEASUREMENTS AND MAIN RESULTS

Of the 66 patients, 8 patients (3 from the IVIg group and 5 from the control group) had sepsis, 47 patients (15 from the IVIg group and 32 from the control group) had severe sepsis, and 11 patients had septic shock (4 from the IVIg group and 7 from the control group). The overall mortality rate was 31.8% without significant differences between groups (22.7% IVIg group v 36.4% control group, p = not significant). Among the 47 patients affected by severe sepsis, those from the control group had a mortality rate significantly higher than that of the IVIg group (12/32 [37.5%] v 1/15 [6.6%], p = 0.036 [2-sided Fisher exact test]). The 70-day survival rate was significantly higher in the IVIg group than in the control group (log-rank test, p < 0.04). No significant differences were found between study groups in Acute Physiology and Chronic Health Evaluation II or SOFA scores.

CONCLUSIONS

The polyclonal IgM-enriched immunoglobulins did not significantly reduce the mortality rate in the overall study population. However, in the subgroup of patients with severe sepsis, they improved the survival rate significantly.

Surgical trauma affects the proinflammatory status after cardiac surgery to a higher degree than cardiopulmonary bypass

OBJECTIVES

Cytokines contribute to the development of the systemic inflammatory response syndrome or multiple-organ failure frequently observed after cardiopulmonary bypass-supported cardiac surgery. To quantify the contribution of bypass-induced versus trauma-induced inflammatory response after coronary artery bypass grafting, we examined plasma cytokine levels in 120 patients with coronary artery disease who were treated with or without cardiopulmonary bypass-assisted procedures.

METHODS

Patients were treated in accordance with one of the following protocols: (1) elective percutaneous coronary intervention without cardiopulmonary bypass (n = 69), (2) cardiopulmonary bypass-supported percutaneous coronary intervention (cardiopulmonary bypass-percutaneous coronary intervention; n = 10), and (3) cardiopulmonary bypass-supported coronary artery bypass grafting (cardiopulmonary bypass-coronary artery bypass grafting; n = 41). Cytokine levels (picograms/milliliter) were measured by enzyme-linked immunosorbent assay from plasma samples obtained at various time points.

RESULTS

Interleukin-6 was measured in blood samples from all 3 patient populations. The maximum interleukin-6 level was 13.6 +/- 22.3 pg/mL in the percutaneous coronary intervention group, 170.4 +/- 165.4 pg/mL in the cardiopulmonary bypass-percutaneous coronary intervention group, and 640.3 +/- 285.7 pg/mL in the cardiopulmonary bypass-coronary artery bypass grafting group. Interleukin-6 levels were significantly different, and the 95% confidence intervals did not overlap. In the cardiopulmonary bypass-percutaneous coronary intervention group, bypass duration correlated well with interleukin-6 production ( r = 0.915; P < .001), whereas these parameters did not correlate in patients who underwent cardiopulmonary bypass-coronary artery bypass grafting ( r = 0.307; P = .054).

CONCLUSIONS

These findings support the suggestion that surgical trauma and cardiopulmonary bypass contribute to the inflammatory response after cardiac surgery, although trauma may contribute to a higher degree.

[End-organ damage in inflammation and sepsis]

Inflammatory components form part of the pathogenesis of infectious, but also non-infectious diseases. One of the most important revelations of the last decades was the finding of an activation of the natural immune response in numerous physiological and pathophysiological processes despite the absence of an infectious agent. Even physical exercise or psychical stress may evoke an inflammatory response. Substantial insight has been gained in the recent decades into the molecular mechanisms of cellular and organ dysfunction by the impact of mediators with inflammatory potential. Validated score systems allow a precise detection and quantification of organ dysfunctions in inflammation and sepsis. In contrast therapy of organ damage in severe septic and non-septic inflammatory processes presently is mainly still based on supportive therapeutic measures.

The effects of IgM-enriched immunoglobulin preparations in patients with severe sepsis [ISRCTN28863830]

INTRODUCTION

In this prospective, randomized controlled study, we aimed to evaluate the effect of IgM-enriched immunoglobulin treatment on progression of organ failure and septic shock in patients with severe sepsis.

MATERIALS AND METHODS

Forty-two patients with severe sepsis were enrolled in the study. Patients in the study group (n = 21) received an intravenous immunoglobulin preparation (Pentaglobin in addition to standard therapy. Pentaglobin therapy was commenced on the day of diagnosis of severe sepsis: 5 ml/kg per day Pentaglobin (38 g/l IgG, 6 g/l IgM, and 6 g/l IgA) was infused over 6 hours and repeated for 3 consecutive days. Patients in the control group (n = 18) received standard sepsis therapy, but no immunoglobulin administration. Blood samples for procalcitonin (PCT) measurements were taken daily for 8 days. Severity of critical illness and development of organ failure were assessed by obtaining daily acute physiological and chronic health evaluation (APACHE) II and sequential organ failure assessment (SOFA) scores.

RESULTS AND DISCUSSION

Procalcitonin levels showed a statistically significant decrease in the Pentaglobin group (P < 0.001); however, an improvement in SOFA scores could not be demonstrated. Procalcitonin levels and SOFA scores did not change significantly in the control group. Septic shock incidence (38% versus 57%) and 28-day mortality rate (23.8% versus 33.3%) were found to be similar between the Pentaglobin and control groups. The evaluation of serial APACHE II scores did not demonstrate a difference between Pentaglobin and control groups either.

CONCLUSION

Present data could not demonstrate any beneficial effects of polyclonal immunoglobulin preparation Pentaglobin on organ morbidity, septic shock incidence and mortality rate in patients with severe sepsis.

Intravenous immunoglobulin for treating sepsis and septic shock

BACKGROUND

Death from severe sepsis and septic shock is common, and researchers have explored whether antibodies to the endotoxins in some bacteria reduces mortality.

OBJECTIVES

To estimate the effects of intravenous immunoglobulin (IVIG) in patients with bacterial sepsis or septic shock on mortality, bacteriological failure rates, and duration of stay in hospital.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group specialized register up to November 2001; the Cochrane Controlled Trials Register, The Cochrane Library issue 4, 2001; MEDLINE 1966 to November 2001; and EMBASE 1988 to September 2001. We contacted investigators active in the field for unpublished data.

SELECTION CRITERIA

Randomised trials comparing intravenous immunoglobulin (monoclonal or polyclonal) with placebo or no intervention, in patients with bacterial sepsis or septic shock.

DATA COLLECTION AND ANALYSIS

Inclusion criteria, trial quality assessment, and data abstraction were done in duplicate. We conducted pre-specified subgroup analyses by type of immunoglobulin preparation.

MAIN RESULTS

Twenty-seven out of 55 studies met our inclusion criteria. Pooled analysis of all types of IVIG preparations revealed a significant trend toward reduction of mortality (n= 8,856; RR=0.91; 95%CI 0.86-0.96). Overall mortality was reduced in patients who received polyclonal IVIG (n=492; RR=0.64; 95% CI 0.51 to 0.80). For the two high-quality trials on polyclonal IVIG, the RR for overall mortality was 0.30, but the confidence interval was wide (95% CI 0.09 to 0.99, n=91). Mortality was not reduced among patients who received monoclonal antibodies such as anti-endotoxins (n=2,826 in 5 good-quality studies; RR=0.97; 95% CI 0.88 to 1.07) or anti-cytokines (n=4,318; RR=0.93; 95% CI 0.86 to 1.01). A few studies measured secondary outcomes (deaths from sepsis or length of hospitalisation) but no differences in the intervention and control groups were identified except among those who received polyclonal IVIG, where sepsis-related mortality was significantly reduced (n=161; RR=0.35; 95% CI 0.18 to 0.69).

REVIEWER'S CONCLUSIONS

Polyclonal IVIG significantly reduced mortality and and is a promising adjuvant in the treatment of sepsis and septic shock. However, all the trials were small and the totality of the evidence is insufficient to support a robust conclusion of benefit. Adjunctive therapy with monoclonal IVIGs remains experimental.

Pathophysiology of septic shock and multiple organ dysfunction syndrome and various therapeutic approaches with special emphasis on immunoglobulins

The pathophysiology of sepsis and septic shock is dominated by an imbalance of pro- and antiinflammatory mediators produced by toxin-activated inflammatory cells. Both the overshooting of proinflammatory mediators as well as the development of immune paralysis are deleterious to the patient. Available therapeutic approaches with monoclonal antibodies and antagonists targeted against toxins and mediators have focused mainly on inhibition of overshooting proinflammation: the results, however, have been disappointing. Due to these disappointing results of specific antiinflammatory regimens, adjuvant treatment of sepsis and septic shock with intravenous immunoglobulins (IVIgs) has regained interest although this indication has at best been validated in part. Likely beneficial mechanisms of action may include the improvement of serum bactericidal activity due to neutralizing and opsonizing IgG and IgM antibodies as well as stimulation of phagocytosis and neutralization of bacterial endo- and exotoxins; another attractive mode of action may represent Ig-mediated modification and specific suppression of proinflammatory cytokine release from endotoxin- and superantigen-activated blood cells. For the total group of patients with sepsis and septic shock, a reduction in mortality by IVIg could not be documented; however, in the SBITS study with 653 patients included, a moderate improvement in sepsis morbidity and multiple organ dysfunction syndrome was demonstrated. In defined sepsis sub-groups, a reduction in mortality by IVIg has been seen in each small, not yet confirmed trial. Thus, IVIg is not a magic bullet of sepsis treatment, but it may reduce morbidity and thereby may be useful in the therapeutic mosaic of sepsis treatment.

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.

Neutralization of disease associated autoantibodies by an immunoglobulin M- and immunoglobulin A-enriched human intravenous immunoglobulin preparation

Immunoglobulin preparations enriched with IgM and IgA are used in the therapy of severe bacterial infections and for the treatment of acute graft-versus-host disease, but not as yet, in the treatment of autoimmune diseases. We investigated the potential of an IgM- and IgA-enriched immunoglobulin preparation to neutralize activity autoantibodies from patients with autoimmune diseases. We demonstrate that Pentaglobin(R) was at least as effective as intravenous immunoglobulin (Sandoglobulin(R)) in inhibiting autoantibody activity. Each of the immunoglobulin isotypes present in Pentaglobin(R) may be responsible for the inhibitory effect. Pentaglobin(R) immobilized on an affinity matrix retained the disease associated autoantibodies and interacted with F(ab')2 fragments of IgG autoantibodies. Suppression of autoantibody activity is dependent, at least in part, on idiotypic interactions. The present findings provide a rationale for considering these preparations for the immunomodulation of autoimmune disease.

Clinical trials for severe sepsis. Past failures, and future hopes

Recent clinical trials with experimental immunotherapeutic agents for severe sepsis and septic shock have been largely unsuccessful despite seemingly convincing preclinical evidence of significant benefit of these antisepsis therapies. This article reviews basic therapeutic rationale, preclinical evaluation, and clinical trial design of past clinical trials of innovative sepsis treatments. Lessons learned from past failures should provide insights into the design and implementation of successful clinical trials for new anti-sepsis agents in the future.

Effect of polyclonal immunoglobulins on neutrophil phagocytic capacity and reactive oxygen production in patients with gram-negative septicemia

The effect of immunoglobulin (Ig) preparations on neutrophil phagocytic ability and oxidative burst in response to Escherichia coli stimulation was analyzed in 14 patients with gram-negative septicemia by an ex vivo whole blood assay using flow cytometry. In patients, neutrophils exhibited a decreased capacity to phagocytize E. coli and generate reactive oxygen products compared to healthy controls (median -68%, P < 0.01). The addition of both 7S-Ig and 19S-Ig enriched preparations in vitro resulted in a dose-dependent increase in neutrophil reactive oxygen production at concentrations of 10 g/l (median +153% and +211%, P < 0.01, respectively) and 20 g/l (median +205% and +282%, P < 0.01, respectively). A decreased neutrophil phagocytic ability was seen in patients with septicemia (median -58%) compared to healthy controls (P < 0.01). Again, the addition of 7S and 19S-Igs enhanced the phagocytic ability in a dose-dependent manner (10 g/l: median +56 and +126%; 20 g/l: median +126% and +165%, P < 0.01 for all). It can be concluded that both polyclonal Igs can increase depressed neutrophil reactive oxygen production and neutrophil phagocytosis in patients with gram-negative septicemia.

Supplemental immune globulins in sepsis

Intravenous immune globulins are widely used as supplemental treatment of sepsis, septic shock and systemic inflammation in the critically ill, although this indication has at best been validated in part. Likely beneficial mechanisms of action may include the improvement of serum bactericidal activity due to neutralizing and opsonizing immunoglobulin (Ig)G- and IgM-antibodies, as well as stimulation of phagocytosis and neutralization of bacterial endo- and exotoxins; another attractive mode of action may represent immune globulin-mediated modification and specific suppression of proinflammatory cytokine release from endotoxin- and superantigen-activated blood cells. For the "entire group of patients with sepsis and septic shock" a reduction in mortality by intravenous immune globulin could not be documented; however, in the score-based immunoglobulin in sepsis (SBITS)-study with 653 patients included, a moderate improvement in sepsis morbidity and multiple organ dysfunction syndrome was demonstrated. In defined sepsis subgroups, a reduction in mortality by intravenous immune globulin has been seen in individual small, not yet confirmed trials. Finally, the incidence of some severe infections in well characterized "patients at risk" and "operations at risk" is reduced by intravenous immune globulin prophylaxis. Thus, intravenous immune globulin is not a "magic bullet"of sepsis treatment, but it may reduce morbidity and thereby represent a useful piece of stone in the therapeutic mosaic of sepsis treatment.

Expansion of CD14+CD16+ monocytes in critically ill cardiac surgery patients

We have asked whether critically ill cardiac valve surgery patients identified by a high APACHE II score exhibit an increase in the number of proinflammatory CD14+CD16+ monocytes. A group of 12 patients was studied over a period of 5 days post cardiac valve surgery for changes in blood monocyte populations. Patients were selected on day 1 post surgery to either be in good clinical condition (APACHE II Score of < or = 14; N = 9) or to be critically ill (APACHE II score of > or = 24; N = 3). The < or = 14 patients had an uneventful course and could leave the ICU after 2-3 days. Among the > or = 24 patients two showed a decrease of the score to < or = 14 within the 5 days of observation and they could leave the ICU thereafter. One > or = 24 patient (patient #2) had a persistently high score and finally died on day 28. Analysis of blood monocytes on day 1 post surgery revealed that the < or = 14 patients had normal values of CD14+CD16+ monocytes (44 +/- 9/microliter). By contrast the > or = 24 patients had increased values of these cells with 243 +/- 106 cells per microliter on day 1. The numbers of CD14+CD16+ monocytes returned to the control range over the 5 days of observation in 2 of the > or = 24 patients concomitant with the improvement of the APACHE II score. CD14+CD16+ monocytes remained, however, at a high level in patient #2, the patient with persistently high APACHE II score.

Effects of early treatment with immunoglobulin on critical illness polyneuropathy following multiple organ failure and gram-negative sepsis

OBJECTIVE

The evaluation of incidences and relating factors of severe persisting critical illness polyneuropathy (CIP) in survivors of multiple organ failure (MOF).

DESIGN

Prospective study with an entry period of 24 months. Electrophysiological studies for the diagnosis of CIP were performed 1 or 2 days before the patients were discharged from the intensive care unit (ICU). Factors which might have been related to the development of CIP were identified by a retrospective chart analysis.

SETTING

The interdisciplinary ICU of a university hospital.

PATIENTS

Thirty-three patients who survived MOF. Sixteen of these critically ill patients developed severe sepsis due to nosocomial infections with gram-negative bacteria.

RESULTS

In seven survivors of MOF and sepsis typical electrophysiological features of CIP, like spontaneous fibrillations and low compound muscle action potentials, were detectable at the time of discharge from the ICU. Seventeen patients with MOF following multiple trauma who developed no sepsis, and nine survivors of MOF with sepsis showed no signs of persisting CIP at the end of their ICU stay. Chart analysis revealed that eight survivors of MOF with sepsis and without the development of CIP had been treated with intravenous immunoglobulin (IVIG) with a dosage of 0.3 g/kg per day for 3 days immediately (within 24 h) after the diagnosis of sepsis. Four out of seven patients with MOF and sepsis who developed CIP were transferred to our ICU after the onset of sepsis and had not received IVIG treatment. The IVIG treatment in three patients was delayed for more than 24 h after the diagnosis of sepsis and was then omitted. Obviously not related to the development of CIP were aminoglycoside antibiotics, steroids, nutritional disturbances and episodes of hypotension or hypoxia. Neuromuscular blocking agents were not used during intensive care treatment.

CONCLUSIONS

A high incidence of severe CIP persisting until the day of discharge from the ICU was related to gram-negative sepsis but not to MOF alone. Retrospective chart analysis suggested that early application of IVIG may prevent or mitigate this severe complication. However, these results have to be confirmed in a prospective, placebo-controlled study.