Hemodynamic Effect of IgM-Enriched Immunoglobulin in the Early Stage of E. coli-Induced Experimental Sepsis

<b>Background:</b> Current sepsis guidelines recommend the best supportive treatment for severe sepsis, but they are limited on the effectiveness of immunomodulatory therapies. Recent data suggest that IgM-enriched immunoglobulin preparations may decrease mortality, but the exact pathomechanism remains unknown. The present experimental study aims to test the hypothesis that IgM-enriched immunoglobulin may improve hemodynamics in E-coli-induced severe sepsis. <b>Subjects and methods:</b> Sepsis was induced in the <i>E. coli</i> bacteriemia (<i>n</i> = 8), <i>E. coli</i>-parallel Pentaglobin treatment (PR-PG; <i>n</i> = 8), and <i>E. coli</i>-delayed Pentaglobin treatment (D-PG; <i>n</i> = 8). Sepsis was induced in the sepsis, PR-PG, and D-PG groups by infusing 38 mL of an <i>E. coli</i> suspension (2.5 × 10⁵/mL) over 3 h. The PR-PG group received a 0.75 g/kg Pentaglobin bolus over 20 min concurrently with the start of <i>E. coli</i> infusion. The D-PG group was given a 0.67 g/kg Pentaglobin bolus one hour after starting <i>E. coli</i>, followed by a continuous infusion at 0.02 g/kg/h for 240 min. Hemodynamic parameters were monitored every 2 h using a pulse contour cardiac output monitoring technique (PiCCo™). <b>Results:</b> Heart rate increased in all groups to varying extents. Mean arterial pressure (MAP) remained stable in controls but declined in untreated sepsis. Both Pentaglobin-treated groups showed higher MAP than untreated septic animals. Mild cardiac index increases occurred in controls and untreated sepsis, whereas the treated groups maintained a consistently elevated CI after Pentaglobin administration. Systemic vascular resistance index (SVRI) transiently increased in controls before normalizing, while untreated septic animals experienced continuous SVRI decline. Treated animals showed an initial transient SVRI rise followed by a decline; yet, SVRI remained higher than in untreated sepsis. <b>Conclusions:</b> IgM-enriched immunoglobulin led to a slight stabilization of some hemodynamic parameters, probably due to the reduced extpnfiravasation of fluids into the interstitium and, hence, had an effect on preload.