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Properdin deficiency in a family with fulminant meningococcal infections

A G Sjöholm, J H Braconier, C Söderström

    Clinical and Experimental Immunology
    |November 1, 1982
    PubMed

    Insights

    A rare properdin (P) deficiency in three males led to fatal Neisseria meningitidis infections. This suggests P is crucial for immunity against such bacteria, with potential X-linked inheritance.

    Area of Science:

    • Immunology
    • Genetics

    Background:

    • Properdin (P) is a key component of the complement system's alternative pathway.
    • Deficiencies in complement proteins can lead to increased susceptibility to infections.

    Observation:

    • Three males from a large family presented with a selective deficiency of properdin (P).
    • One affected individual died from a severe Neisseria meningitidis group C infection.
    • Family history indicated three prior similar fatal infections.

    Findings:

    • The properdin deficiency was not linked to recurrent bacterial infections.
    • The inheritance pattern suggested an X-linked mode of transmission.
    • Properdin-deficient serum showed impaired alternative pathway functions (C3 activation, erythrocyte lysis, opsonization) but normal classical pathway function.

    Implications:

    • Properdin deficiency significantly increases the risk of severe meningococcal disease.
    • Understanding the genetic basis (potentially X-linked) is crucial for genetic counseling.
    • This highlights the critical role of the complement alternative pathway in host defense against Neisseria infections.

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