Endotoxin concentration in neutropenic patients with suspected gram-negative sepsis: correlation with clinical outcome and determination of anti-endotoxin core antibodies during therapy with polyclonal immunoglobulin M-enriched immunoglobulins

Abstract

We carried out a study in patients with severe neutropenia from hematologic malignancy and suspected gram-negative sepsis to evaluate the clinical significance of endotoxin concentrations in plasma before and during a therapeutic intervention with a human polyclonal immunoglobulin M (IgM)-enriched immunoglobulin preparation (Pentaglobin; Biotest, Dreieich, Germany). Twenty-one patients with acute leukemia or nonHodgkin's lymphoma entered the study upon the development of clinical signs of gram-negative sepsis and received the IgM-enriched immunoglobulin preparation every 6 h for 3 days (total dose, 1.3 liter with 7.8 g of IgM, 7.8 g of IgA, and 49.4 g of IgG), in addition to standardized antibiotic treatment. Concentrations of endotoxin and IgM and IgG antibodies against lipid A and Re lipopolysaccharide (LPS) in plasma were determined by a modified chromogenic Limulus amebocyte lysate test and semiquantitative enzyme linked immunosorbent assay, respectively, before each immunoglobulin infusion and during the following 25 days. Seventeen patients were endotoxin positive; in five of these patients, gram-negative infection was confirmed by microbiologic findings. Prior to therapy, endotoxemia correlated significantly with the occurrence of fever, and a quantitative correlation between the endotoxin concentration and body temperature was found during the individual course of infection in 8 of the 17 patients. Overall mortality from endotoxin-positive sepsis was 41% (7 of 17) and 64% (7 of 11) in patients with symptoms of septic shock. Nonsurvivors had significantly higher maximum concentrations of endotoxin in plasma compared with those of survivors at the first study day (median of 126 versus 34 pg/ml; P < 0.05) and during the whole septic episode (median of 126 versus 61 pglml; P < 0.05). In survivors, immunoglobulin therapy resulted in a significant decrease in endotoxin levels in plasma within the initial 18-h treatment period, from a pretreatment median value of 28 pg/ml to a value of 8 pg/ml (P < 0.05). In the seven patients who died from uncontrollable infection, no effect of therapy on endotoxin levels in plasma was observed. IgM and IgG antibodies against Upid A and Re LPS increased significantly under immunoglobulin treatment, with significant correlations between antibodies against lipid A and Re LPS. These data strongly suggest a prognostic significance of the endotoxin levels in plasma and a potential effect of treatment with a polyclonal IgM-enriched immunoglobulin preparation. Further studies are needed to substantiate these findings and to assess the impact on the clinical course by way of a prospective placebo-controlled clinical trial.Despite the development of new and effective antimicrobial agents and their early application in combination regimens, gram-negative sepsis is still associated with an overall mortality of 20 to 40% (22,39,40) or even 40 to 75% in patients who develop clinical signs of septic shock (3,16,39,40). This high death rate is at least partly attributed to endotoxin, the lip...

Automation and validation of a rapid method to assess neutrophil and monocyte activation by routine fluorescence flow cytometry in vitro

“…In agreement with the ex-vivo TNFa stimulation assay and the endotoxin levels in sepsis patients (36,37) we identified an almost identical optimum LPS concentration of 500 pg/mL for cytokine production (TNF-a and IL-8) and for morphological shape change and granularity after 3 h incubation in healthy volunteers-except for MPXI. The optimum for fMLP was determined at 44 ng/ mL (10 27 M).…”

Reconstituted Human Polyclonal Plasma-derived Secretory-like IgM and IgA Maintain the Barrier Function of Epithelial Cells Infected with an Enteropathogen

“…Stehr et al (26) emphasized the benefits of polyclonal IgM-enriched solution by using a rabbit model of bacteremia. Clinical trials showed that IgM-enriched preparations were able to significantly decrease endotoxin levels in plasma (23) and even reduce mortality (22) during the early phase of septic shock. Norrby-Teglund et al (47) showed that IgM-enriched Immune complexes between bacteria and human plasma-derived pIgA, SIgA, mIgA, IgG, IgM, SigM, or anti-Shigella LPS-specific SIgAC5 monoclonal Ab were formed for 1 h as described under "Experimental procedures," and the expression of virulence factors was induced by Congo red.…”

“…Preclinical and clinical studies have underscored the efficacy against various infectious agents of polyclonal IgM-enriched preparations administered by the systemic route (22)(23)(24)(25)(26). Similar to SIgA, SIgM can be seen as a valid candidate immunoglobulin for mucosal application, given its ability to bind antigens with strong avidity, its potential to ensure long term protection (27), its capacity to survive low pH conditions (28), as well as its resistance to proteases (29).…”

Endotoxin-induced activation of equine platelets: evidence for direct activation of p38 MAPK pathways and vasoactive mediator production

“…Human and equine patients are exquisitely sensitive to the acute effects of endotoxaemia. In both of these species, plasma concentrations of LPS in the picomolar range are associated with severe clinical signs of endotoxaemia, including haematological and metabolic alterations and haemodynamic disturbances leading to multiple organ failure [2][3][4]. It is therefore appropriate to evaluate the effects of LPS experimentally in these species using concentrations of LPS that are likely to be present in endotoxaemic patients.…”