New and old aspects of immunoglobulin application. The use of intravenous IgG as prophylaxis and for treatment of infections

Immunoglobulin G in Platelet-Derived Wound Healing Factors

We intended to reformulate an existing platelet-derived wound healing formula to target each phase of the healing wound with the appropriate phase-specific molecules. A decreased perfusion of the skin, often associated with conditions such as thalassemia, sickle cell disease, diabetes mellitus, and chronic vascular disease, is the most common etiology of cutaneous ulcers and chronic wounds. We had previously shown that a PDWHF topically applied to a chronic nonhealing ulcer of a β-thalassemia homozygote stimulated and accelerated closure of the wound. The PDWHF was prepared from a pooled platelet concentrate of a matching blood group, consisting of a combination of platelet α-granule-derived factors. Processing of the apheresis-pooled platelets yielded various amounts of proteins (3.36 g/mL ± 0.25 (SD) (N = 10)) by the better lysis buffer method. Immunoglobulin G was found to be the most abundant α-granule-secreted protein. Equally broad quantities of the IgG (10.76 ± 12.66% (SD) (N = 10)) and IgG/albumin ratios (0.6 ± 0.4 (SD) (N = 10)) were quantified. We have developed a method using a reformulated lysis buffer followed by size exclusion chromatography and affinity chromatography to extract, identify, quantify, and purify IgG from activated platelets. IgG purification was confirmed by Western blot and flow cytometry. It was thought unlikely that the platelet IgG could be accounted for by adsorption of plasma protein, though the variable quantities could account for diversity in wound healing rates. The IgG could protect the wound even from subclinical infections and functionally advance healing. It may be useful in the management of skin ulcers in the early phase of wound healing.

Intravenous immunoglobulin for preventing infection in preterm and/or low birth weight infants

BACKGROUND

Nosocomial infections continue to be a significant cause of morbidity and mortality among preterm and/or low birth weight (LBW) infants. Preterm infants are deficient in immunoglobulin G (IgG); therefore, administration of intravenous immunoglobulin (IVIG) may have the potential of preventing or altering the course of nosocomial infections.

OBJECTIVES

To use systematic review/meta-analytical techniques to determine whether IVIG administration (compared with placebo or no intervention) to preterm (< 37 weeks' postmenstrual age (PMA) at birth) or LBW (< 2500 g birth weight) infants or both is effective/safe in preventing nosocomial infection.

SEARCH METHODS

For this update, MEDLINE, EMBASE, CINAHL, The Cochrane Library, Controlled Trials, ClinicalTrials.gov and PAS Abstracts2view were searched in May 2013.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) in which a group of participants to whom IVIG was given was compared with a control group that received a placebo or no intervention for preterm (< 37 weeks' gestational age) and/or LBW (< 2500 g) infants. Studies that were primarily designed to assess the effect of IVIG on humoral immune markers were excluded, as were studies in which the follow-up period was one week or less.

DATA COLLECTION AND ANALYSIS

Data collection and analysis was performed in accordance with the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Nineteen studies enrolling approximately 5000 preterm and/or LBW infants met inclusion criteria. No new trials were identified in May 2013. When all studies were combined, a significant reduction in sepsis was noted (typical risk ratio (RR) 0.85, 95% confidence interval (CI) 0.74 to 0.98; typical risk difference (RD) -0.03, 95% CI 0.00 to -0.05; number needed to treat for an additional beneficial outcome (NNTB) 33, 95% CI 20 to infinity), and moderate between-study heterogeneity was reported (I2 54% for RR, 55% for RD). A significant reduction of one or more episodes was found for any serious infection when all studies were combined (typical RR 0.82, 95% CI 0.74 to 0.92; typical RD -0.04, 95% CI -0.02 to -0.06; NNTB 25, 95% CI 17 to 50), and moderate between-study heterogeneity was observed (I2 50% for RR, 62% for RD). No statistically significant differences in mortality from all causes were noted (typical RR 0.89, 95% CI 0.75 to 1.05; typical RD -0.01, 95% CI -0.03 to 0.01), and no heterogeneity for RR (I2 = 21%) or low heterogeneity for RD was documented (I2 = 28%). No statistically significant difference was seen in mortality from infection; in incidence of necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD) or intraventricular haemorrhage (IVH) or in length of hospital stay. No major adverse effects of IVIG were reported in any of these studies.

AUTHORS' CONCLUSIONS

IVIG administration results in a 3% reduction in sepsis and a 4% reduction in one or more episodes of any serious infection but is not associated with reductions in other clinically important outcomes, including mortality. Prophylactic use of IVIG is not associated with any short-term serious side effects. The decision to use prophylactic IVIG will depend on the costs and the values assigned to the clinical outcomes. There is no justification for conducting additional RCTs to test the efficacy of previously studied IVIG preparations in reducing nosocomial infections in preterm and/or LBW infants.

Dynamic Alterations in the Gut Microbiota of Collagen-Induced Arthritis Rats Following the Prolonged Administration of Total Glucosides of Paeony

Rheumatoid arthritis (RA) is a common autoimmune disease linked to chronic inflammation. Dysbiosis of the gut microbiota has been proposed to contribute to the risk of RA, and a large number of researchers have investigated the gut-joint axis hypothesis using the collagen-induced arthritis (CIA) rats. However, previous studies mainly involved short-term experiments; very few used the CIA model to investigate changes in gut microbiota over time. Moreover, previous research failed to use the CIA model to carry out detailed investigations of the effects of drug treatments upon inflammation in the joints, hyperplasia of the synovium, imbalance in the ratios of Th1/Th2 and Th17/Treg cells, intestinal cytokines and the gut microbiota following long-term intervention. In the present study, we carried out a 16-week experiment to investigate changes in the gut microbiota of CIA rats, and evaluated the modulatory effect of total glucosides of paeony (TGP), an immunomodulatory agent widely used in the treatment of RA, after 12 weeks of administration. We found that taxonomic differences developed in the microbial structure between the CIA group and the Control group. Furthermore, the administration of TGP was able to correct 78% of these taxonomic differences, while also increase the relative abundance of certain forms of beneficial symbiotic bacteria. By the end of the experiment, TGP had reduced body weight, thymus index and inflammatory cell infiltration in the ankle joint of CIA rats. Furthermore, the administration of TGP had down-regulated the synovial content of VEGF and the levels of Th1 cells and Th17 cells in CIA rats, and up-regulated the levels of Th2 cells and Treg cells. The administration of TGP also inhibited the levels of intestinal cytokines, secretory immunoglobulin A (SIgA) and Interferon-γ (IFN-γ). In conclusion, the influence of TGP on dynamic changes in gut microbiota, along with the observed improvement of indicators related to CIA symptoms during 12 weeks of administration, supported the hypothesis that the microbiome may play a role in TGP-mediated therapeutic effects in CIA rats. The present study also indicated that the mechanism underlying these effects may be related to the regulation of intestinal mucosal immunity remains unknown and deserves further research attention.

Infections associated with mesh repairs of abdominal wall hernias: Are antimicrobial biomaterials the longed-for solution?

The incidence of mesh-related infection after abdominal wall hernia repair is low, generally between 1 and 4%; however, worldwide, this corresponds to tens of thousands of difficult cases to treat annually. Adopting best practices in prevention is one of the keys to reduce the incidence of mesh-related infection. Once the infection is established, however, only a limited number of options are available that provides an efficient and successful treatment outcome. Over the past few years, there has been a tremendous amount of research dedicated to the functionalization of prosthetic meshes with antimicrobial properties, with some receiving regulatory approval and are currently available for clinical use. In this context, it is important to review the clinical importance of mesh infection, its risk factors, prophylaxis and pathogenicity. In addition, we give an overview of the main functionalization approaches that have been applied on meshes to confer anti-bacterial protection, the respective benefits and limitations, and finally some relevant future directions.

Intravenous immunoglobulin for preventing infection in preterm and/or low birth weight infants

BACKGROUND

Nosocomial infections continue to be a significant cause of morbidity and mortality among preterm and/or low birth weight (LBW) infants. Preterm infants are deficient in immunoglobulin G (IgG); therefore, administration of intravenous immunoglobulin (IVIG) may have the potential of preventing or altering the course of nosocomial infections.

OBJECTIVES

To use systematic review/meta-analytical techniques to determine whether IVIG administration (compared with placebo or no intervention) to preterm (< 37 weeks' postmenstrual age (PMA) at birth) or LBW (< 2500 g birth weight) infants or both is effective/safe in preventing nosocomial infection.

SEARCH METHODS

For this update, MEDLINE, EMBASE, CINAHL, The Cochrane Library, Controlled Trials, ClinicalTrials.gov and PAS Abstracts2view were searched in May 2013.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) in which a group of participants to whom IVIG was given was compared with a control group that received a placebo or no intervention for preterm (< 37 weeks' gestational age) and/or LBW (< 2500 g) infants. Studies that were primarily designed to assess the effect of IVIG on humoral immune markers were excluded, as were studies in which the follow-up period was one week or less.

DATA COLLECTION AND ANALYSIS

Data collection and analysis was performed in accordance with the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Nineteen studies enrolling approximately 5000 preterm and/or LBW infants met inclusion criteria. No new trials were identified in May 2013.When all studies were combined, a significant reduction in sepsis was noted (typical risk ratio (RR) 0.85, 95% confidence interval (CI) 0.74 to 0.98; typical risk difference (RD) -0.03, 95% CI 0.00 to -0.05; number needed to treat for an additional beneficial outcome (NNTB) 33, 95% CI 20 to infinity), and moderate between-study heterogeneity was reported (I(2) 54% for RR, 55% for RD). A significant reduction of one or more episodes was found for any serious infection when all studies were combined (typical RR 0.82, 95% CI 0.74 to 0.92; typical RD -0.04, 95% CI -0.02 to -0.06; NNTB 25, 95% CI 17 to 50), and moderate between-study heterogeneity was observed (I(2) 50% for RR, 62% for RD). No statistically significant differences in mortality from all causes were noted (typical RR 0.89, 95% CI 0.75 to 1.05; typical RD -0.01, 95% CI -0.03 to 0.01), and no heterogeneity for RR (I(2) = 21%) or low heterogeneity for RD was documented (I(2) = 28%). No statistically significant difference was seen in mortality from infection; in incidence of necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD) or intraventricular haemorrhage (IVH) or in length of hospital stay. No major adverse effects of IVIG were reported in any of these studies.

AUTHORS' CONCLUSIONS

IVIG administration results in a 3% reduction in sepsis and a 4% reduction in one or more episodes of any serious infection but is not associated with reductions in other clinically important outcomes, including mortality. Prophylactic use of IVIG is not associated with any short-term serious side effects.The decision to use prophylactic IVIG will depend on the costs and the values assigned to the clinical outcomes. There is no justification for conducting additional RCTs to test the efficacy of previously studied IVIG preparations in reducing nosocomial infections in preterm and/or LBW infants.

Intravenous immunoglobulin for preventing infection in preterm and/or low-birth-weight infants

BACKGROUND

Nosocomial infections continue to be a significant cause of morbidity and mortality among preterm and/or low birth weight infants. Maternal transport of immunoglobulins to the fetus mainly occurs after 32 weeks gestation and endogenous synthesis does not begin until several months after birth. Administration of intravenous immunoglobulin provides IgG that can bind to cell surface receptors, provide opsonic activity, activate complement, promote antibody dependent cytotoxicity, and improve neutrophilic chemo luminescence. Intravenous immunoglobulin thus has the potential of preventing or altering the course of nosocomial infections.

OBJECTIVES

To assess the effectiveness/safety of intravenous immunoglobulin (IVIG) administration (compared to placebo or no intervention) to preterm (< 37 weeks gestational age at birth) and/or low birth weight (LBW) (< 2500 g BW) infants in preventing nosocomial infections.

SEARCH STRATEGY

MEDLINE, EMBASE, and The Cochrane Library Databases were searched in September 2003 using the keywords: immunoglobulin and infant-newborn and random allocation or controlled trial or randomized controlled trial (RCT). The reference lists of identified RCTs and personal files were searched. No language restrictions were applied.

SELECTION CRITERIA

The criteria used to select studies for inclusion in this overview were: 1) DESIGN: RCTs in which administration of IVIG was compared to a control group that received a placebo or no intervention. 2) POPULATION: preterm (< 37 weeks gestational age) and/or LBW (<2500 g) infants. 3) INTERVENTION: IVIG for the prevention of bacterial/fungal infection during initial hospital stay (8 days or longer). (Studies that were primarily designed to assess the effect of IVIG on humoral immune markers were excluded as were studies in which the follow-up period was one week or less).4) At least one of the following outcomes was reported: sepsis, any serious infection, death from all causes, death from infection, length of hospital stay, intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD).

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted information for each outcome reported in each study, and one researcher (AO) checked for any discrepancies and pooled the results. Relative risk (RR) and Risk Difference (RD) with 95% confidence intervals (CI) using the fixed effects model are reported. When a statistically significant RD was found the number needed to treat (NNT) was also calculated with 95% CIs. The results include all accepted studies in which the outcome of interest was reported. Statistically significant between study heterogeneity was reported. The results of the inconsistency test (I squared) are also reported when statistically significant heterogeneity was found.

MAIN RESULTS

No new trials were identified in September 2003. Nineteen studies met inclusion criteria. These included approximately 5,000 preterm and/or LBW infants and reported on at least one of the outcomes of interest for this systematic review. When all studies were combined there was a statistically significant reduction (p = 0.02) in sepsis, RR [0.85 (95% CI 0.74, 0.98)] and RD [-0.03 (95% CI 0.00, -0.05)], NNT 33. There was statistically significant between-study heterogeneity (p = 0.02); I squared 54%. A statistically significant reduction was found for any serious infection, one or more episodes, when all studies were combined [RR 0.82 (95% CI 0.74, 0.92); RD -0.04 (95% CI -0.02, -0.06,); NNT 25 (95% CI, 16.7, 50). There was statistically significant between-study heterogeneity (p = 0.0006); I squared 50%. There were no statistically significant differences for mortality from all causes, mortality from infection, incidence of NEC, BPD and IVH or length of hospital stay. No major adverse effects of IVIG were reported in any of the studies.

REVIEWER'S CONCLUSIONS

IVIG administration results in a 3% reduction in sepsis and a 4% reduction in any serious infection, one or more episodes, but is not associated with reductions in other important outcomes: sepsis, NEC, IVH, or length of hospital stay. Most importantly, IVIG administration does not have any significant effect on mortality from any cause or from infections. Prophylactic use of IVIG is not associated with any short term serious side effects. From a clinical perspective a 3-4% reduction in nosocomial infections without a reduction in mortality or other important clinical outcomes is of marginal importance.The decision to use prophylactic IVIG will depend on the costs and the values assigned to the clinical outcomes. There is no justification for further RCTs testing the efficacy of previously studied IVIG preparations to reduce nosocomial infections in preterm and/or LBW infants. The results of these meta-analyses should encourage basic scientists and clinicians to pursue other avenues to prevent nosocomial infections.

Polyclonal human antibodies reduce bacterial attachment to soft contact lens and corneal cell surfaces

Bacterial keratitis due to Pseudomonas aeruginosa is a potentially serious complication of extended-wear contact lens use. Adhesion of P. aeruginosa to soft contact lens materials or corneal endothelial cells in the presence of pooled human immunoglobulins and/or neutrophils in artificial tear fluid was studied in vitro as a potential method to treat contact lens-associated infection. Soft hydrophilic contact lens materials equilibrated in sterile saline were soaked in artificial tear fluid for 18 h prior to use. P. aeruginosa IFO 3455 was added to groups of lenses or confluent cultured bovine corneal endothelial cells with varying amounts of human polyclonal immunoglobulin (IgG) and human blood neutrophils or serum albumin as a control. After 2 or 4 h incubation, adherent viable bacteria on lenses were quantified. Fluorescence microscopy was used to assess bacterial adherence to bovine corneal endothelial cells in the presence and absence of IgG and neutrophils. Various concentrations of albumin had no effect on adhesion. Human immunoglobulin solutions (25 mg/ml) reduced P. aeruginosa adhesion by nearly 1 log and 2 logs after 2 and 4 h incubations, respectively. Neutrophils in combination with 25 mg/ml IgG reduced bacterial adhesion approximately 1 log over reduction in adhesion by neutrophils alone. Diluted human IgG (10 mg/ml) did not significantly decrease bacterial adhesion after 2 or 4 h, but did reduce adhesion in combination with human neutrophils at both time points. Similar reductions in amounts of fluorescently labeled bacteria adhered to cultured monolayers of corneal endothelial cells under these conditions were qualitatively observed.

Prophylactic treatment of gram-positive and gram-negative abdominal implant infections using locally delivered polyclonal antibodies

The increasing clinical incidence and host risk of biomaterial-centered infections, as well as the reduced effectiveness of clinically relevant antibiotics to treat such infections, provide compelling reasons to develop new approaches for treating implanted biomaterials in a surgical context. We describe the direct local delivery of polyclonal human antibodies to abdominal surgical implant sites to reduce infection severity and mortality in a lethal murine model of surgical implant-centered peritoneal infection. Surgical implant-centered peritonitis was produced in 180 female CF-1 mice by the direct inoculation of surgical-grade polypropylene mesh disks placed in the peritoneal cavity with lethal doses of either methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa. Mice randomly received a resorbable antibody delivery vehicle at the implant site: either a blank carboxymethylcellulose (CMC) aqueous gel or the same CMC gel containing 10 mg of pooled polyclonal human immunoglobulin G locally on the implant after infection, either alone or in combination with systemic doses of cefazolin or vancomycin antibiotics. Human antibodies were rapidly released (first-order kinetics) from the gel carrier to both peritoneal fluids and serum in both infection scenarios. Inocula required for lethal infection were substantially reduced by surgery and the presence of the implant versus a closed lethal peritonitis model. Survival to 10 days with two different gram-negative P. aeruginosa strains was significantly enhanced (p < 0.01) by the direct application of CMC gel containing antibodies alone to the surgical implant site. Human-equivalent doses of systemic vancomycin provided a significantly improved benefit (p < 0.01) against lethal, implant-centered, gram-positive MRSA infection. However, locally delivered polyclonal human antibodies in combination with a range of systemic vancomycin doses against MRSA failed to improve host survival. Successful antibody therapy against gram-negative, implant-centered infections complements the clinically routine use of systemic antibiotics, providing a mechanism of protection independent of antibiotic resistance.

Locally delivered antibodies combined with systemic antibiotics confer synergistic protection against antibiotic-resistant burn wound infection

BACKGROUND

Nosocomially derived gram-negative infections, particularly from antibiotic-resistant pathogens, are a cause of morbidity in patients with severe burn wounds.

METHODS

Locally delivered polyclonal antibodies and systemically infused ceftazidime were combined in a lethal murine burn wound model against a virulent Pseudomonas aeruginosa strain that exhibits intermediate resistance to ceftazidime.

RESULTS

Survival was synergistically enhanced in cohorts of burned mice treated both locally (subeschar) with pooled polyclonal human immunoglobulin G (1-mg dose) and intravenously with infused ceftazidime (0.44 mg dose). Enhancement of survival correlated with reduced bacterial quantitation in local and systemic tissue observed in separate burned cohorts. Burned, infected mice treated prophylactically with either individual treatment at the same dose or a combination of both treatments administered systemically showed no survival enhancement as compared with the untreated control group.

CONCLUSION

Treatment of antibiotic-resistant burn wound infections with antibiotics together with locally delivered immunoglobulins may improve antibiotic protective effects against antibiotic-resistant pathogens.

Polyurethane coatings release bioactive antibodies to reduce bacterial adhesion

This study describes the formulation of a biomedical grade polyurethane hydrogel coating containing solid dispersed bioactive antibodies cast from an organic solvent onto a model polymer biomaterial substrate. A prepolymer dispersion in anhydrous isopropanol containing a uniformly distributed slurry of 22 microm sieved commercial lyophilized polyclonal pooled human immunoglobulin G (IgG) solids was coated onto polymer substrates by simple immersion. Maximum antibody release was approximately 50 microg/cm(2) from a 15% w/w IgG polymer coating. In vitro antimicrobial studies utilized Escherichia coli to compare performance of bare uncoated tubing, hydrogel-coated tubing with added aqueous phase antibodies, and antibody-dispersed hydrogel-coated tubing. Bacterial adhesion was reduced significantly (p<0.05) in the presence of antibodies with the greatest reduction seen with the antibody releasing coating. The presence of antibody also significantly enhanced the killing of the bacteria in an in vitro opsonophagocytic assay using freshly isolated blood neutrophils over 2 h indicating that antibody bioactivity is maintained. This controlled release polyurethane hydrogel coating imparts infection resistance by exploiting the low adhesive properties of the biomedical grade hydrogel and the intrinsic bioactive role of the antibodies to reduce bacterial adhesion and promote clearance via natural immune mechanisms.

Intravenous immunoglobulin for preventing infection in preterm and/or low-birth-weight infants

BACKGROUND

Nosocomial infections continue to be a significant cause of morbidity and mortality among preterm and/or low birth weight infants. Maternal transport of immunoglobulins to the fetus mainly occurs after 32 weeks gestation and endogenous synthesis does not begin until several months after birth. Administration of intravenous immunoglobulin provides IgG that can bind to cell surface receptors, provide opsonic activity, activate complement, promote antibody dependent cytotoxicity, and improve neutrophilic chemoluminescence. Intravenous immunoglobulin thus has the potential of preventing or altering the course of nosocomial infections.

OBJECTIVES

To assess the effectiveness/safety of intravenous immunoglobulin (IVIG) administration (compared to placebo or no intervention) to preterm (< 37 weeks gestational age at birth) and/or low birth weight (LBW) (< 2500 g BW) infants in preventing nosocomial infections.

SEARCH STRATEGY

Medline, Embase, Cochrane Library and Reference Update Databases were searched in November 1997 using keywords: immunoglobulin and infant-newborn and random allocation or controlled trial or randomized controlled trial (RCT). The reference lists of identified RCTs, personal files and Science Citation Index were searched. No language restrictions were applied.

SELECTION CRITERIA

The criteria used to select studies for inclusion in this overview were: 1) DESIGN: RCTs in which administration of IVIG was compared to a control group that received a placebo or no intervention. 2) POPULATION: preterm (< 37 weeks gestational age) and/or LBW (<2500 g) infants. 3) INTERVENTION: IVIG for the prevention of bacterial/fungal infection during initial hospital stay (8 days or longer). (Studies that were primarily designed to assess the effect of IVIG on humoral immune markers were excluded as were studies in which the follow-up period was one week or less). 4) At least one of the following outcomes was reported: sepsis, any serious infection, death from all causes, death from infection, length of hospital stay, intraventricular haemorrhage (IVH), necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD).

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted information for each outcome reported in each study, and one researcher (AO) checked for any discrepancies and pooled the results. Relative risk (RR) and Risk Difference (RD) with 95% confidence intervals (CI) using the fixed effects model are reported. When a statistically significant RD was found the number needed to treat (NNT) was also calculated with 95% CIs. The results include all accepted studies in which the outcome of interest was reported. When statistically significant heterogeneity was found for an outcome, secondary (sensitivity) analyses were performed including only studies of the highest quality.

MAIN RESULTS

Fifteen studies met inclusion criteria. These included 5,054 preterm and/or LBW infants and reported on at least one of the outcomes of interest for this systematic review. When all studies were combined there was a statistically significant reduction in sepsis, one or more episodes [RR 0.83 (95% CI 0.72, 0.97); RD -0.028 (95% CI -0.006, -0.051); NNT 36 (95% CI 20, 167)]. There was significant between-study heterogeneity. When, in a sensitivity analysis, the high quality studies were combined, the results remained significant [RR 0.78 (95% CI 0.62, 0.98); RD -0.031(95% CI -0.003, -0.059); NNT 32 (95% CI 17, 333]. For this analysis there was no statistically significant between-study heterogeneity. A statistically significant reduction was also found for any serious infection, one or more episodes, when all studies were combined [RR 0.85 (95% CI 0.75, 0. 95); RD -0.032 (95% CI -0.010, -0.054,); NNT 31 (95% CI 19, 100). There was statistically significant between-study heterogeneity. When, in a sensitivity analysis, the high quality studies were combined the results remained statistically significant [RR 0.80 (95% CI

Efficacy of locally delivered polyclonal immunoglobulin against Pseudomonas aeruginosa infection in a murine burn wound model

The leading cause of morbidity and mortality in severe burn wound patients is infection. Treatment of burn wound infection is complicated by the emergence of antibiotic resistant organisms. A potential therapeutic alternative to antibiotic drugs is the local administration of polyclonal antibodies, termed passive local immunotherapy (PLI), directly to the burned tissue. A mouse burn wound infection model to simulate full thickness burn wound infection was used to evaluate the efficacy of passive local immunotherapy as a viable prophylactic or therapeutic agent. Pooled human immunoglobulins (IgG), delivered locally to the site of infection, are shown to be more effective at preventing fatal burn wound sepsis than treatment by intravenous infusion of IgG. A single 10 mg dose of human IgG administered locally to the burned, infected tissue site, either 24 hours prior to bacterial challenge, or within 3 hours after bacterial challenge, enhanced animal survival significantly (P < 0.001 and P < 0.05 respectively) compared to control animals. In addition, reduced levels of bacteria were found in local and systemic tissues of IgG-treated mice compared to control mice (P < 0.05). These data support the local use of polyclonal immunoglobulin preparations as an efficacious and cost effective means to prevent and treat burn wound infections.

Intranasal antibody prophylaxis for protection against viral disease

For more than a century, antibody has been used for passive parenteral immunization against viral and bacterial pathogens. This approach has been successful for prevention of viral respiratory infection and has led to testing of intranasal or aerosol delivery of antibody to passively immunize the respiratory tract mucosal surface. Mucosal delivery may be advantageous because it allows the antibody to neutralize the virus particles before they initiate infection and because it concentrates the antibody where viral replication takes place. Animal studies have shown the feasibility of passive intranasal immunization against a number of respiratory tract viruses. Development of nasal antibody treatments for humans is under way, and early clinical studies have confirmed that this approach is safe and can be used to prevent respiratory tract disease. Polyclonal human immunoglobulin from pooled plasma preparations can be used to provide broad protection against a number of different pathogens, while monoclonal antibodies or their fragments can be used to target specific viruses.

Efficacy of locally delivered polyclonal immunoglobulin against Pseudomonas aeruginosa peritonitis in a murine model

Infectious peritonitis results from bacterial contamination of the abdominal cavity. Conventional antibiotic treatment is complicated both by the emergence of antibiotic-resistant bacteria and by increased patient populations intrinsically at risk for nosocomial infections. To complement antibiotic therapies, the efficacy of direct, locally applied pooled human immunoglobulin G (IgG) was assessed in a murine model (strains CF-1, CD-1, and CFW) of peritonitis caused by intraperitoneal inoculations of 10(6) or 10(7) CFU of Pseudomonas aeruginosa (strains IFO-3455, M-2, and MSRI-7072). Various doses of IgG (0.005 to 10 mg/mouse) administered intraperitoneally simultaneously with local bacterial challenge significantly increased survival in a dose-dependent manner. Local intraperitoneal application of 10 mg of IgG increased animal survival independent of either the P. aeruginosa or the murine strains used. A local dose of 10 mg of IgG administered up to 6 h prophylactically or at the time of bacterial challenge resulted in 100% survival. Therapeutic 10-mg IgG treatment given up to 12 h postinfection also significantly increased survival. Human IgG administered to the mouse peritoneal cavity was rapidly detected systemically in serum. Additionally, administered IgG in peritoneal lavage fluid samples actively opsonized and decreased the bacterial burden via phagocytosis at 2 and 4 h post-bacterial challenge. Tissue microbial quantification studies showed that 1.0 mg of locally applied IgG significantly reduced the bacterial burden in the liver, peritoneal cavity, and blood and correlated with reduced levels of interleukin-6 in serum.

Polyclonal preparations of anti-tetanus toxoid antibodies derived from a combinatorial library confer protection

We have compared the in vivo therapeutic potential of anti-tetanus toxin (TT) human Fab antibodies derived from a combinatorial phage display library to established polyclonal and monoclonal reagents. The oligoclonality and fine specificity distribution of the synthetic anti-TT Fab preparations was comparable to the antibody spectrum present in the donor serum and the affinities determined for the synthetic phage-bound Fab (Phab) and soluble Fab were in the same range as their monoclonal and polyclonal counterparts. On a weight basis, the protective capacity of the new oligoclonal preparations in vivo (16.4 IU/100 micrograms Fab) was comparable to those of the best combinations of hybridoma derived human monoclonal antibodies, and far better than those exhibited by the polyclonal serum antibodies of the donor (0.29 IU/100 micrograms IgG) or by a standard commercial human tetanus immunoglobulin preparation. These data suggest that recombinant antibodies may become a safe and effective alternative to human plasma-derived immunoglobulins for passive immunization.