Opsonic activity of human ascitic fluid: A potentially important protective mechanism against spontaneous bacterial peritonitis

Authors

  • Bruce A. Runyon M. D.,

    Corresponding author
    1. Departments of Medicíne, University of New Mexico, Albuquerque, New Mexico 87131; Long Beach Veteran's Administration Medical Center, Long Beach, California 90822; and University of California, Irvine, California 92717
    • Gastroenterology Division, Department of Medicine, University of New Mexico, School of Medicine, Albuquerque, New Mexico 87131
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  • Richard L. Morrissey,

    1. Departments of Medicíne, University of New Mexico, Albuquerque, New Mexico 87131; Long Beach Veteran's Administration Medical Center, Long Beach, California 90822; and University of California, Irvine, California 92717
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  • John C. Hoefs,

    1. Departments of Medicíne, University of New Mexico, Albuquerque, New Mexico 87131; Long Beach Veteran's Administration Medical Center, Long Beach, California 90822; and University of California, Irvine, California 92717
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  • Frederic A. Wyle

    1. Departments of Medicíne, University of New Mexico, Albuquerque, New Mexico 87131; Long Beach Veteran's Administration Medical Center, Long Beach, California 90822; and University of California, Irvine, California 92717
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Abstract

The opsonic activity of 60 ascitic fluids from 47 patients was measured using a standard opsonophagocytic assay. Curve analysis of the opsonic activity compared to the ascitic fluid concentration of total protein, total hemolytic complement, C3 and C4 yielded correlation coefficients of 0.84 (p < 0.001), 0.84 (p < 0.001), 0.94 (p < 0.001) and 0.92 (p < 0.001), respectively. There appeared to be a threshold of concentration for each protein below which there was no killing of bacteria. Cirrhotic ascites had significantly (all p < 0.001) lower concentrations of total protein and complement and less opsonic activity than noncirrhotic ascites (including malignant, cardiac and miscellaneous types). Perhaps it is the dilution of crucial antimicrobial proteins below a threshold which predisposes to spontaneous bacterial peritonitis.

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