In vitro and in vivo effect of immunoglobulin G on the integrity of bacterial membranes

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.

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

STUDY OBJECTIVE

To address the relevance of the IgM component in polyvalent immunoglobulins in sepsis treatment by comparison of the clinical course under polyvalent IgG vs IgGMA therapy in postcardiac surgical patients at high risk for sepsis and to reassess the prognostic validity of sequential changes in acute physiology and chronic health evaluation (APACHE II) scores during treatment.

DESIGN

Prospective, randomized clinical trial.

SETTING

Cardiac surgical ICU in a university hospital.

PATIENTS

Among 870 consecutive patients after elective open-heart surgery, 29 (3.3%) met the previously validated high-risk criterion (APACHE II score > or = 24 on the first postoperative day) with a mean APACHE II score-predicted mortality risk of 63%.

INTERVENTIONS

In addition to standard therapy, 27 of these patients were randomized to receive commercially available IV IgG (Polyglobin N, n = 14, total dosage: 18 mL/kg) or IgGMA (Pentaglobin, n = 13, total dosage: 15 mL/kg).

MEASUREMENTS AND RESULTS

The two groups were comparable in baseline disease severity and concurrent therapy. The extent of score-quantified improvement in disease severity during treatment was similar in both groups (mean fall in APACHE II scores within 4 days; IgG, -6.9; IgGMA, -5.2), as were score-defined improvement rates (rate of patients with score decrease > or = 7 within 4 days: IgG, 57%; IgGMA, 54%) and in-hospital mortality (IgG, 29%; IgGMA, 31%) (all p = NS). There was a strong association between the decrease over time in APACHE II scores during therapy and prognosis (mortality rates in patients with vs without score-assessed improvement: 0% vs 67%, p = 0.0002).

CONCLUSIONS

IgG and IgGMA were associated with a comparable improvement in disease severity in score-identified postcardiac surgical patients at high risk for sepsis. Given the design as an efficacy rather than an equivalence study, this hypothesis derived from our results needs independent validation in larger trials. Sequential APACHE II score changes were reconfirmed as a prognostically valid quantitative measure of disease progress during sepsis therapy.

Early sepsis treatment with immunoglobulins after cardiac surgery in score-identified high-risk patients

In patients at risk for sepsis after cardiac surgery, the efficacy of intravenous immunoglobulin (Ig) treatment was compared with a historical control population, equivalent in patient characteristics and disease severity. Using APACHE II scores, especially in the high-risk group (IgG), we could discriminate between low-risk patients (score < 19; mortality 1 percent) and the small groups at risk (score 19 to 23) and high risk (score > or = 24) with a significantly higher mortality (14 percent and 76 percent, respectively) [corrected]. Subsequently, among 1,341 consecutive patients we prospectively identified and treated (IgG n = 41 IgGMA: n = 25) these at-risk groups. In contrast to controls (risk: n = 21; high-risk; n = 21), we found a marked fall in APACHE II scores, especially in the high-risk group (IgG, n = 26: p < 0.05; IgGMA, n = 13: p = 0.08) [corrected]. In this group, Ig therapy produced higher (p < 0.05) response rates (score decrease 7 within 4 days: IgG: 54 percent, IgGMA: 62 percent; controls: 19 percent) and reduced mortality (IgG: 46 percent, IgGMA: 46 percent; controls: 76 percent), statistically significant (p < 0.05) for Ig treatment overall. Thus, early Ig treatment improves disease severity and may improve prognosis in prospectively score-identified high-risk postcardiac surgical patients.

Supplemental immunoglobulin (ivIgG) treatment in 163 patients with sepsis and septic shock--an observational study as a prerequisite for placebo-controlled clinical trials

In a multicenter observational study of 163 medical and surgical patients with a total of 173 episodes of sepsis or septic shock (Elebute sepsis score: 19.0 +/- 0.5), the effects of supplemental i.v. immunoglobulin (i.v. IG) treatment (unmodified polyvalent IgG pH 4.25, n = 123; for Pseudomonas sepsis, n = 50, Pseudomonas IgG) on multiple organ failure (MOF) were investigated by means of APACHE II score changes (pretreatment: 23.7 +/- 0.6). In 44% of the cases ("responders"), a prompt improvement in APACHE II score (defined as decrease greater than or equal to 4) was evident from day 0 to day 4 after onset of therapy, thus being in close time relationship to the i.v. IG administration. This improvement, associated with a better prognosis (mortality 24% vs. 55%), was found in all subgroups, most importantly the following: polyvalent IgG vs. Pseudomonas IgG treatment; medical vs. surgical patients; moderate vs. severe MOF; and gram-positive vs. gram-negative septicemia. In a small-sized second comparative nonrandomized control group (n = 27, antibiotic treatment alone) of septic patients (Elebute: 14.7 +/- 1.0) with similar MOF severity (APACHE II: 23.6 +/- 1.4), the response rate (30%) was, though not statistically significant, lower by one-third. The optimal baseline score ranges for patient inclusion into future placebo-controlled randomized i.v. IG trials were found to be 20-35 for the APACHE II score and 12-27 for the Elebute score.