Elizabeth J. Ziegler

Treatment of gram-negative bacteremia and septic shock with ha-1a human monoclonal antibody against endotoxin: A randomized, double-blind, placebo-controlled trial

BACKGROUND HA-1A is a human monoclonal IgM antibody that binds specifically to the lipid A domain of endotoxin and prevents death in laboratory animals with gram-negative bacteremia and endotoxemia. METHODS To evaluate the efficacy and safety of HA-1A, we conducted a randomized, double-blind trial in patients with sepsis and a presumed diagnosis of gram-negative infection. The patients received either a single 100-mg intravenous dose of HA-1A (in 3.5 g of albumin) or placebo (3.5 g of albumin). Other interventions, including the administration of antibiotics and fluids, were not affected by the study protocol. RESULTS Of 543 patients with sepsis who were treated, 200 (37 percent) had gram-negative bacteremia as proved by blood culture. For the patients with gram-negative bacteremia followed to death or day 28, there were 45 deaths among the 92 recipients of placebo (49 percent) and 32 deaths among the 105 recipients of HA-1A (30 percent; P = 0.014). For the patients with gram-negative bacteremia and shock at entry, there were 27 deaths among the 47 recipients of placebo (57 percent) and 18 deaths among the 54 recipients of HA-1A (33 percent; P = 0.017). Analyses that stratified according to the severity of illness at entry showed improved survival with HA-1A treatment in both severely ill and less severely ill patients. Of the 196 patients with gram-negative bacteremia who were followed to hospital discharge or death, 45 of the 93 given placebo (48 percent) were discharged alive, as compared with 65 of the 103 treated with HA-1A (63 percent; P = 0.038). No benefit of treatment with HA-1A was demonstrated in the 343 patients with sepsis who did not prove to have gram-negative bacteremia. For all 543 patients with sepsis who were treated, the mortality rate was 43 percent among the recipients of placebo and 39 percent among those given HA-1A (P = 0.24). All patients tolerated HA-1A well, and no anti-HA-1A antibodies were detected. CONCLUSIONS HA-1A is safe and effective for the treatment of patients with sepsis and gram-negative bacteremia.

Treatment of Gram-Negative Bacteremia and Shock with Human Antiserum to a Mutant Escherichia coli

Abstract In an effort to decrease deaths from gram-negative bacteremia and endotoxin shock, we treated bacteremic patients with human antiserum to endotoxin (lipopolysaccharide) core. Antiserum was prepared by vaccinating healthy men with heat-killed Escherichia coli J5; this mutant lacks lipopolysaccharide oligosaccharide side chains, so that the core, which is nearly identical to that of most other gram-negative bacteria, is exposed for antibody formation. In a randomized controlled trial, patients were given either J5 antiserum or preimmune control serum intravenously, near the onset of illness. The number of deaths in the bacteremic patients was 42 of 109 (39 per cent) in controls and 23 of 103 (22 per cent) in recipients of J5 antiserum (P = 0.011). In those with profound shock, mortality was 30 of 39 (77 per cent) in controls and 18 of 41 (44 per cent) in recipients of J5 antiserum (P = 0.003). We conclude that human antiserum to the lipopolysaccharide core can substantially reduce deaths from gram-...

Treatment of Gram-Negative Bacteremia and Septic Shock with HA-1A Human Monoclonal Antibody against Endotoxin

BACKGROUND HA-1A is a human monoclonal IgM antibody that binds specifically to the lipid A domain of endotoxin and prevents death in laboratory animals with gram-negative bacteremia and endotoxemia. METHODS To evaluate the efficacy and safety of HA-1A, we conducted a randomized, double-blind trial in patients with sepsis and a presumed diagnosis of gram-negative infection. The patients received either a single 100-mg intravenous dose of HA-1A (in 3.5 g of albumin) or placebo (3.5 g of albumin). Other interventions, including the administration of antibiotics and fluids, were not affected by the study protocol. RESULTS Of 543 patients with sepsis who were treated, 200 (37 percent) had gram-negative bacteremia as proved by blood culture. For the patients with gram-negative bacteremia followed to death or day 28, there were 45 deaths among the 92 recipients of placebo (49 percent) and 32 deaths among the 105 recipients of HA-1A (30 percent; P = 0.014). For the patients with gram-negative bacteremia and shock at entry, there were 27 deaths among the 47 recipients of placebo (57 percent) and 18 deaths among the 54 recipients of HA-1A (33 percent; P = 0.017). Analyses that stratified according to the severity of illness at entry showed improved survival with HA-1A treatment in both severely ill and less severely ill patients. Of the 196 patients with gram-negative bacteremia who were followed to hospital discharge or death, 45 of the 93 given placebo (48 percent) were discharged alive, as compared with 65 of the 103 treated with HA-1A (63 percent; P = 0.038). No benefit of treatment with HA-1A was demonstrated in the 343 patients with sepsis who did not prove to have gram-negative bacteremia. For all 543 patients with sepsis who were treated, the mortality rate was 43 percent among the recipients of placebo and 39 percent among those given HA-1A (P = 0.24). All patients tolerated HA-1A well, and no anti-HA-1A antibodies were detected. CONCLUSIONS HA-1A is safe and effective for the treatment of patients with sepsis and gram-negative bacteremia.

Induction of immunity against lethal Haemophilus influenzae type b infection by Escherichia coli core lipopolysaccharide.

Efforts to prevent Haemophilus influenzae type b (HIB) infections in infancy have been hampered by the low immunogenicity of capsular polysaccharide vaccines in children younger than 18 mos. In searching for alternate immunogens, we have studied the protective potential of polysaccharide-poor, lipid-rich endotoxin (LPS) core in experimental HIB infections. Because all gram-negative bacteria have similar LPS core structures, we were able to use as vaccine the J5 mutant of Escherichia coli 0111, the LPS of which consists only of core components, and thus to avoid problems in interpretation arising from vaccine contamination with non-LPS HIB immunogens. Mice were given graded inocula of HIB and developed lethal infection analogous to human HIB disease when virulence was enhanced with mucin and hemoglobin. After active immunization with heat-killed E. coli J5, 40/50 (80%) of infected mice survived, compared with 14/50 (28%) of saline-immunized controls (P less than 0.005). Passive immunization with rabbit antiserum against E. coli J5 prevented lethal HIB infection when administered 24 or 72 h before or 3 h after infection. This protection was abolished by adsorption of antiserum with purified J5 LPS, with survival reduced from 14/24 to 0/24 (P less than 0.005). Furthermore, rabbit antiserum to purified J5 LPS gave just as potent protection against death as antiserum to whole J5 cells. These studies demonstrate that immunity to core LPS confers protection against experimental murine HIB infection and provide the framework for a new approach to prevention of human disease from HIB.

Tumor Necrosis Factor in Humans

When immune cells are stimulated in a variety of ways, they release soluble proteins called cytokines. Because of their far-reaching effects on many different types of cells and tissues, cytokines ...

Fibrin-enmeshed Tobramycin Liposomes: Single Application Topical Therapy of Pseudomonas Keratitis

Treatment of bacterial keratitis requires frequent application of topical antibiotics. We studied the efficacy of a single topical administration of tobramycin incorporated in large multivesicular liposomes and enmeshed in a fibrin sealant on rabbit corneas infected with Pseudomonas aeruginosa. One cornea each of 25 New Zealand albino rabbits was infected with P. aeruginosa. Twenty-four hours later, the animals were randomly divided into five groups of five. Group A received single hourly drops (50 μl) of fortified tobramycin (14.5 mg/ml, total of 17.4 mg). Group B received a single topical application of 3.5 mg tobramycin, in 0.1 ml multivesicular liposomes, enmeshed in a fibrin sealant with an overlaying bandage contact lens. Group C was treated in the same manner as group B without the addition of fibrin sealant. Groups D and E served as nondrug-treated controls, with group D receiving topical fibrin-enmeshed liposomes devoid of tobramycin and group E receiving hourly topical balanced salt solution (BSS) drops. All animals were killed 24 h after initiation of therapy. Significantly fewer colonies of Pseudomonas were present in corneas of all three treated groups, as compared with the two nondrug-treated control groups (p < 0.02). There were significantly fewer colonies of Pseudomonas in groups A and B as compared with group C (p < 0.02). No significant difference was noted between a single administration of topical fibrinenmeshed tobramycin-encapsulated liposomes (group B) and 24 doses of hourly fortified topical tobramycin (group A, p > 0.05). Tobramycin-encapsulated megaliposomes may serve as a useful adjunct in treatment of Pseudomonas keratitis.

Human Antiserum for Prevention of the Local Shwartzman Reaction and Death from Bacterial Lipopolysaccharides

Bacterial lipopolysaccharides from dead bacteria have been blamed for the continuing high mortality from gram-negative infections despite antibiotic treatment. Because animal antiserum against these lipopolysaccharides has been shown to protect against several of the effects of endotoxin, we undertook the development of antiserum in human subjects. 21 men were immunized with a single injection of Salmonclla typhimurium or Escherichia coli 0:111 heat-killed cells and immune serum was collected at 2 wk. Preimmune serum was obtained as a control in all animal experiments. 1 ml antiserum given intravenously protected mice against a lethal intravenous dose of homologous endotoxin (P < 0.005 for both antisera). E. coli antiserum reduced the incidence of positive local Shwartzman reactions with E. coli endotoxin from 100 to 38%; S. typhimurium antiserum reduced the incidence from 92 to 35%. (P < 0.0005 for both antisera). There was no protection against heterologous endotoxin in either animal model. These experiments demonstrate for the first time that human antiserum confers exceedingly potent passive immunity to the effects of endotoxin.

Influence of alterations in forgoing life-sustaining treatment practices on a clinical sepsis trial

Objectives: To evaluate the timing of forgoing life-sustaining treatments in patients enrolled in a sepsis trial and to determine their influence on patient outcome and trial results. Design: Subset of patients in a prospective, randomized, double-blind, placebo-controlled study. Setting: Twenty-three academic medical centers. Patients. Enrolled patients who had life-sustaining therapies withheld or withdrawn. Measurements and Main Results: The number of patients, types of disorders and interventions, reasons, and timing of withholding and withdrawing life-sustaining treatments and their effect on mortality and trial results were assessed. Forgoing of life-sustaining therapies took place in 117 (22%) of 543 patients and occurred within 72 hrs of study drug administration in 38 (32%) patients. Withholding treatment (60%) was more common than withdrawing treatment (40%), but withdrawing treatment was more frequent (51%) than withholding treatment (20%) in the first 72 hrs of the trial (p <.01). Sixty-one (52%) patients had severe underlying disorders with a poor prognosis. The hospital mortality rate was 94% (of the 117 patients). The mean time (SEM) from withholding or withdrawing of treatment until death was 2.83 ± 0.57 and 0.32 ± 0.13 days, respectively (p <.001). Patients who had therapies forgone in the first 24, 48, and 72 hrs after receiving the study drug had higher mortality rates in the first 72 hrs (p <.01). Conclusions: A substantial number of patients enrolled in a sepsis trial had severe underlying diseases and had forgoing of therapies early in the course of the trial, which led to a higher early mortality rate. Enrollment of patients in clinical trials with severe underlying disorders with a high likelihood of having therapies forgone may bias the potential for showing the efficacy of new therapeutic modalities. (Crit Care Med 1997; 25:383-387).

Antiserum to endotoxin in hemorrhagic shock

Antiserum to Escherichia coli J5, a mutant endotoxin (LPS) which contains only core determinants, has proven effective in reducing mortality from endotoxic shock due to a wide variety of gram-negative bacteria. Twenty New Zealand white rabbits with coliforms in the gut were subjected to hemorrhagic shock of 36 mm Hg for 3 hr. Treated rabbits were resuscitated with 15 cc of rabbit J5 antiserum (hemagglutinating antibody titer against J5 lipopolysaccharide of 1:1024), remaining shed blood, and lactated Ringers to achieve a mean arterial blood pressure (MABP) within 20% of baseline. The control group was similarly resuscitated but received 15 cc normal rabbit serum (titer 1:2). Catheters were removed and rabbits were returned to their cages until death or 5 days of survival. Hemodynamic parameters (heart rate, MABP, cardiac output, and total peripheral resistance) did not differ significantly between groups. However, six treated rabbits survived 5 days (60%) and no control rabbit lived past the third postexperimental day (P less than 0.019). Our data suggest that systemic endotoxemia may contribute to morbidity and mortality in severe hemorrhagic shock.

Lethal Haemophilus influenzae type b infection in mice

SummaryPrevious animal models of invasiveHaemophilus influenzae type b (HITB) infection are characterized by a low mortality rate. We produced a highly lethal infection in CF1 mice using mouse passage, mucin, and hemoglobin to enhance infectivity. Infection by the intraperitoneal route was followed by progressive peritonitis and bacteremia with subsequent HITB infection of the brain and meninges, and death. Death occurred between eight and 72 hours after infection and was associated with 106 to 109 HITB per ml of blood and with 102 to 105 HITB per g of brain. Mucin-hemoglobin did not augment HITB growth, but impaired macrophage adherence to glassin vitro, without decreasing cellular viability.In vivo, mucin-hemoglobin decreased the rate of disappearance of51Cr-labelled HITB from the blood by impairment of hepatic clearance. This technically simple and inexpensive model is useful for the study of HITB infections in which bacterial multiplication, invasion and host lethality are desired features.ZusammenfassungHerkömmliche Tiermodelle für die invasiveHaemophilus influenzae Typ b-(HITB-)Infektion haben nur eine geringe Letalität. Durch erhöhte Infektiosität des Erregers über Mäuse-Passage sowie mit Mucin und Hämoglobin konnten wir bei CF1-Mäusen eine Infektion mit hoher Letalität hervorrufen. Nach intraperitonealer Infektion entwickelte sich eine progressiv verlaufende Peritonitis und Bakteriämie, der eine HITB-Infektion des Gehirns und der Meningen mit letalem Ausgang folgte. Der Tod trat zwischen acht und 72 Stunden nach der Infektion ein, die Keimzahlen im Blut lagen zwischen 106 und 109 HITB pro ml, im Gehirn fanden sich 102 bis 105 HITB pro g. Mucin-Hämoglobin führte nicht zu einer Steigerung des HITB-Wachstums, doch hemmte esin vitro die Makrophagenadhäsion an Glas, ohne die Überlebenszeit der Zellen zu verändern.In vivo führte Mucin-Hämoglobin durch Störung der hepatischen Clearance zu einer Verminderung der Eliminationsrate von51Cr-markierten HITB aus dem Blut. Dieses technisch einfache und wenig aufwendige Model eignet sich zum Studium von Infektionen durch HITB, die die Charakteristika Bakterienvermehrung, Invasion und tödlicher Ausgang haben sollen.