Effect of a human immunoglobulin preparation for intravenous use in a rabbit model of meningococcal endotoxin-induced shock

Standing on the shoulders of giants: two centuries of struggle against meningococcal disease

Meningococcal disease was first clinically characterised by Gaspard Vieusseux in 1805, and its causative agent was identified by Anton Weichselbaum in 1887, who named it Diplococcus intracellularis menigitidis. From the beginning, the disease was dreaded because of its epidemic nature, predilection for previously healthy children and adolescents, and high mortality. In the last decade of the 19th century, the concept of serum therapy for toxin-related bacterial diseases was identified. This concept was applied to meningococcal disease therapy, in an independent way, by Wilhelm Kolle, August von Wasserman, and Georg Jochmann in Germany, and Simon Flexner in the USA, resulting in the first successful approach for the treatment of meningococcal disease. During the first three decades of the 20th century, serum therapy was the standard treatment for meningococcal disease. With the advent of sulphamides first and then antibiotics, serum therapy was abandoned. The great challenges that infectious diseases medicine is facing and the awaiting menaces in the future in terms of increasing antibiotic resistance, emergence of new pathogens, and re-emergence of old ones without effective therapy, make passive immunotherapy a promising tool. Acknowledging the achievements of our predecessors might teach us some lessons to bring light to our future.

Protective capacity of a IgM/IgA-enriched polyclonal immunoglobulin-G preparation in endotoxemia

Animal experiments were carried out to investigate whether a protective effect can be achieved in endotoxemia by intravenous (i.v.) application of a polyclonal immunoglobulin preparation (IVIG-IgG/A/M) enriched with 12% IgM and 12% IgA. Following administration of IVIG-IgG/A/M (500 mg/kg), endotoxemia was induced by intraperitoneal inoculation of a sublethal dose (5x10(8) CFU/kg) of Escherichia coli (E. coli) and subsequent i.v. administration of an antimicrobial agent (Imipenem). Plasma endotoxin activity, IL-6 activity, mean arterial pressure, and skeletal muscle oxygen pressure (tpO2) were measured at regular intervals over a total observation period of 7 h. Prophylactic administration of IVIG-IgG/A/M was found to significantly attenuate (P<0.01) the antibiotic-induced increase in endotoxin activity as compared to the albumin control group. Limited endotoxemia in the IgG/A/M group was associated with reduced levels of circulating IL-6 (P<0.01). Both lipopolysaccharide-induced hypotension and depression of tissue oxygenation were attenuated (P<0.01) by pre-treatment with IVIG-IgG/A/M. The experimental results suggest that in endotoxemia the polyclonal immunoglobulin preparation has a prophylactic protective effect on the acute phase responses and reduces the cardiodepressant effects of E. coli septicaemia.

Increased In Vivo Antibody Activity Against Interferon α, Interleukin-1α, and Interleukin-6 After High-Dose Ig Therapy

High-avidity antibodies against interferon α (IFNα), interleukin-1α (IL-1α), and IL-6 have been demonstrated in preparations of normal human IgG, and in vivo modulation of these cytokines may therefore account for immunomodulatory and anti-inflammatory effects of high-dose intravenous IgG therapy. We have investigated the in vivo recovery and the effect on serum cytokine levels of antibodies to IFNα, IL-1α, and IL-6 infused with IgG preparations. Fifteen treatment series of 0.4 g IgG/kg/d were administered over 3 days to eight patients with autoimmune diseases. All IgG preparations contained variable amounts of antibodies binding to 125I-labeled human IFNα2A, -IL-1α, and -IL-6, and the contents of these molecules correlated with increased levels in serum anticytokine activities after IgG infusion. The infused anti–IL-1α antibody activity was fully recovered, whereas the recovery of anti-IFNα2A antibodies was significantly reduced. Serum antiviral activities were significantly reduced after IgG therapy (before, 0 to 5.6 IU/mL; after, 0 to 0.6 IU/mL). In contrast, enzyme-linked immunosorbent assay (ELISA) showed no significant reduction in the serum levels of IL-6 (before, 1 to 70 pg/mL; after, 2 to 55 pg/mL), and the levels of IL-1α were consistently below the detection limit (<30 pg/mL). In conclusion, increased levels of antibodies to IFNα2A, IL-1α, and IL-6 occurred in patients receiving IgG and this reduced the serum antiviral activity.

Increased In Vivo Antibody Activity Against Interferon α, Interleukin-1α, and Interleukin-6 After High-Dose Ig Therapy

High-avidity antibodies against interferon α (IFNα), interleukin-1α (IL-1α), and IL-6 have been demonstrated in preparations of normal human IgG, and in vivo modulation of these cytokines may therefore account for immunomodulatory and anti-inflammatory effects of high-dose intravenous IgG therapy. We have investigated the in vivo recovery and the effect on serum cytokine levels of antibodies to IFNα, IL-1α, and IL-6 infused with IgG preparations. Fifteen treatment series of 0.4 g IgG/kg/d were administered over 3 days to eight patients with autoimmune diseases. All IgG preparations contained variable amounts of antibodies binding to 125I-labeled human IFNα2A, -IL-1α, and -IL-6, and the contents of these molecules correlated with increased levels in serum anticytokine activities after IgG infusion. The infused anti–IL-1α antibody activity was fully recovered, whereas the recovery of anti-IFNα2A antibodies was significantly reduced. Serum antiviral activities were significantly reduced after IgG therapy (before, 0 to 5.6 IU/mL; after, 0 to 0.6 IU/mL). In contrast, enzyme-linked immunosorbent assay (ELISA) showed no significant reduction in the serum levels of IL-6 (before, 1 to 70 pg/mL; after, 2 to 55 pg/mL), and the levels of IL-1α were consistently below the detection limit (<30 pg/mL). In conclusion, increased levels of antibodies to IFNα2A, IL-1α, and IL-6 occurred in patients receiving IgG and this reduced the serum antiviral activity.

Reduced tumorigenicity of threshold syngeneic tumor inocula in xid-bearing mice treated with natural antibodies

Several correlative experimental approaches have provided evidence that polyclonal serum natural antibodies (NAb) participate in the defense against small syngeneic tumor foci in vivo. The threshold subcutaneous tumor inoculum model of incipient neoplasia has consistently revealed an inverse relationship between tumorigenicity in vivo and the NAb binding capacity of the tumor injected or the anti-tumor NAb levels of the recipient animals, including B cell-deficient mice bearing the xid mutation of the CBA/N mouse strain. Now passive i.v. administration of whole normal syngeneic serum NAb in bolus injections, given I each day beginning on day -2, -1 or 0 prior to the threshold s.c. challenge of xid-bearing CBA/N or male (CBA/N x CBA/J)F1 mice with syngeneic RI-28 lymphoma cells, consistently and significantly reduced their tumorigenicity assayed as tumor appearance and latency. Three similar injections of an ammonium sulfate-precipitated fraction of whole serum NAb also reduced tumor frequency and latency, while a combination of purified IgG and IgM NAb reduced the appearance of tumors slightly and increased the survival of recipients. The reconstitution of the xid-defect in anti-tumor NAb provides more direct evidence to substantiate a role for NAb in the defense against early tumor development in vivo and establishes a model for the dissection of the in vivo mechanisms of the NAb anti-tumor activity.