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Mannan binding lectin in febrile adults: no correlation with microbial infection and complement activation

A N Tacx1, A B J Groeneveld, M H Hart

  • 1Department of Intensive Care, Vrije Universiteit Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.

Journal of Clinical Pathology
|December 4, 2003
PubMed
Abstract

Insights

Mannan-binding lectin (MBL) pathway activation occurs during microbial infections, but MBL deficiency does not appear to increase the risk of serious infections in hospitalized adults. Complement activation is independent of MBL levels in these patients.

Area of Science:

  • Immunology
  • Complement System Biology

Background:

  • The mannan-binding lectin (MBL) pathway is a key component of the innate immune system, crucial for host defense against microbial pathogens.
  • Understanding the role of MBL in vivo is essential for comprehending host-pathogen interactions and infectious disease outcomes.

Purpose of the Study:

  • To investigate the role of the MBL pathway in host defense against microbial infections.
  • To determine the association between MBL levels and infectious mortality in a general hospital patient population.

Main Methods:

  • A prospective observational study involving 177 hospitalized medical patients presenting with new-onset fever.
  • Assessment of infection presence, origin, and microbial cause, alongside measurements of MBL and complement activation product C3a.
  • Monitoring of patient outcomes over a 28-day hospital course.

Main Results:

  • Patients exhibited MBL levels comparable to healthy individuals, with MBL deficiency observed in 18% of patients and 14% of blood donors.
  • Microbiologically confirmed infections correlated with higher C3a levels, but MBL levels or deficiency frequency did not differ significantly across infection groups.
  • Overall mortality was 8%, with no significant differences in MBL levels between outcome groups.

Conclusions:

  • The findings suggest that the MBL pathway does not play a predominant role in the host defense against serious microbial infections in non-selected adult patients.
  • MBL deficiency does not appear to be a significant predisposing factor for severe or invasive microbial infections in this population.
  • Microbial infection in hospitalized febrile adults activates the complement system independently of MBL levels.

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