Complement-3 deficiency

From Dog

Complement-3 deficiency is an autosomal-recessive genetic immune deficiency of Brittany Spaniels[2] clinically characterized by an increased susceptibility to infection and renal disease.

Despite having no detectable antigenic C3, C3-deficient dog serum has approximately 10% of normal serum C3 hemolytic activity[3].

The third component of complement (C3) plays a critical role in the generation of the inflammatory and protective functions of the complement system[4][5][6].

This condition in dogs appear to mirror genetically the same condition observed in humans[7].

Affected dogs are also predisposed to developing hereditary canine spinal muscular atrophy[8] and familial juvenile glomerulonephropathy[9][10].

Dogs that are homozygous for the trait have no detectable C3, while heterozygous dogs have serum C3 concentrations approximately 30 to 50% of normal. Only homozygous dogs are clinically affected, but heterozygotes (carriers) can pass on the trait to their offspring.

Affected animals have markedly reduced levels of serum opsonic and chemotactic activities[11], leading to increased susceptibility to bacterial infections. There appears to be no correlation between this condition and a predisposition to demodicosis.

Although there is no specific treatment for this condition, antimicrobial therapy is remedial when acute bacterial infections are evident clinically.

References

  1. Baby Dog Names
  2. Winkelstein, JA et al (1981) Genetically determined deficiency of the third component of complement in the dog. Science 212:1169
  3. Johnson JP (1987) C3-like activity in C3-deficient dog serum. Complement 4(1):53-60
  4. Lambris, JD (1993) The chemistry, biology and phylogeny of C3. In Complement Profiles. J. M. Cruse and F. R. Lewis. eds. Karger, Basel, p. 16.
  5. Winkelstein, JA et al (1995) Genetically determined disorders of the complement system. In The Metabolic and molecular Basis of Inherited Disease. C. R. Scriver, A. L. Beaudet, W. S. Sly, and D. Valle. eds. McGraw-Hill, New York, p:3911
  6. Ameratunga R et al (1998) Molecular analysis of the third component of canine complement (C3) and identification of the mutation responsible for hereditary canine C3 deficiency. J Immunol 160(6):2824-2830
  7. Johnson JP et al (1986) Genetic analysis of an inherited deficiency of the third component of complement in Brittany spaniel dogs. Am J Med Genet 25(3):557-562
  8. Lorenz MD et al (1979) Hereditary spinal muscular atrophy in Brittany Spaniels: clinical manifestations. J Am Vet Med Assoc 175(8):833-839
  9. Cork, LC et al (1991) Membranoproliferative glomerulonephritis in dogs with a genetically determined deficiency of the third component of complement. Clin Immunol Immunopathol 60:455
  10. Blum, JR et al (1985) The clinical manifestations of a genetically determined deficiency of the third component of complement in the dog. Clin Immunol Immunopathol 34:304
  11. Winkelstein, JA et al (1982) Genetically determined deficiency of the third component of complement in the dog: in vitro studies on the complement system and complement-mediated serum activities. J Immunol 129:2598