Generation of anaphylatoxin C3a in plasma and bronchoalveolar lavage fluid in trauma patients at risk for the adult respiratory distress syndrome.

Abstract

OBJECTIVE:

To determine the generation of anaphylatoxin C3a in plasma and bronchoalveolar lavage fluid in trauma patients at risk for the adult respiratory distress syndrome (ARDS).

DESIGN:

Prospective study.

SETTING:

ICU in a university hospital.

PATIENTS:

Severely traumatized patients at risk for the ARDS (n = 25).

INTERVENTION:

EDTA plasma samples and bronchoalveolar lavage fluid were obtained.

MEASUREMENTS AND MAIN RESULTS:

Complement proteins C3, C4, C5, and the inhibitors C1-inhibitor, Factor H, and Factor I were quantitated in EDTA-plasma samples obtained every 6 hrs during the first 48 hrs after ICU admission and every morning from days 4 to 14 after injury. In bronchoalveolar lavage fluid, the complement activation production of C3a-desArg was quantitated and the volume of epithelial lining fluid was calculated. All patients showed a decrease of the complement proteins C3, C4, C5 and of the inhibitors C1-inhibitor, Factor H, and Factor I during the first 24 hrs, indicating complement consumption. Patients developing ARDS (n = 11) showed significantly higher C3 concentrations and a higher C3a/C3 ratio in the first few hours after multitrauma. Follow-up bronchoalveolar lavages demonstrated highly increased amounts of C3a in epithelial lining fluid during the first 24 hrs, mainly in ARDS patients and, to a lesser degree, in non-ARDS patients. To determine the origin of C3a in bronchoalveolar lavages, the ratio of C3a in epithelial lining fluid and plasma was calculated.

CONCLUSION:

The C3a of epithelial lining fluid to plasma ratio was extremely high in patients developing ARDS, but even the non-ARDS group had a ratio greater than 1, indicating that a substantial local complement activation occurs in the lung.

• Authors: G Zilow, T Joka, U Obertacke, U Rother, M Kirschfink
• Journal: Critical care medicine (Crit Care Med) Vol. 20 Issue 4 Pg. 468-73 (Apr 1992) ISSN: 0090-3493 [Print] United States
• PMID: 1559358 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Complement C3a
• Complement System Proteins

Topics

• Adult
• Bronchoalveolar Lavage Fluid (immunology)
• Complement Activation (physiology)
• Complement C3a (metabolism)
• Complement System Proteins (metabolism)
• Humans
• Lung (immunology)
• Multiple Trauma (complications, immunology)
• Predictive Value of Tests
• Respiratory Distress Syndrome (etiology, immunology)
• Risk
• Time Factors