The Fibrinogen Concentration in Blood of Dairy Cows and its Influence on the Interpretation of the Glutaraldehyde and Formol-Gel Test Reactions

Abstract

It has earlier been shown that the formol-gel test on serum and glutaraldehyde test on whole blood are simple and rapid methods for evaluation or the immunoglobulin status in the cow. Both tests function as coagulation tests in which aldehyde groups oross-link basic blood globulins at their NH₂-groups, forming polymerisates. The glutaraldehyde has in whole blood the capacity to polymerize not only immunoglobulins but also fibrinogen.

This investigation was made in order to study whether the fibrinogen level may influence the result of the glutaraldehyde test, so revealing any differences between the results of that and the formol-gel test carried out on serum. In 92 cows with a variety of clinical disorders (most of them with inflammatory processes) the total protein, albumin, total globulin concentration and albumin/globulin ratio in serum and fibrinogen concentration in plasma were recorded. The material was grouped according to glutaraldehyde and formol-gel test reactions.

It is shown that increases in the fibrinogen level have an effect on the results of the glutaraldehyde test. A positive glutaraldehyde test in more acute processes is ascribed to a heavy rise of plasma fibrinogen in its capacity of acute-phase protein. A positive glutaraldehyde test in chronic diseases may be viewed as a result of interaction between high immunoglobulin concentrations and elevated fibrinogen concentration.

In conclusion the fibrinogen and immunoglobulin status of blood is important to assess in many diseases of cattle. The semiquantitative tests described for field use can separately, or especially in parallel use, provide valuable information about the character and development of a disease and may be regarded as good substitutes for the sedimentation rate (SR), which is not demonstrable in cattle. kw|Keywords|k]bovine fibrinogen; k]bovine serum proteins; k]formol-gel reaction; k]glutaraldehyde test; k]acute and chronic inflammations

Sammanfattning

Det har tidigare visats att formol-geltestet på serum och glutaral-dehydtestet på helblod är enkla snabbmetoder för bedomning av immunoglobulinstatus hos ko. Båda testerna fungerar som koagulationstester i vilka aldehydgrupper kopplar basiska blodglobuliners NH₂-grupper. Därvid bildas polymerisat. Glutaraldehyden har i helblod förmåga att polymerisera inte bara immunoglobulinerna utan även fibrinogen. Hos 92 kor med olika kliniska sjukdomstillstånd (flertalet av inflammatorisk karaktär) bestämdes totalprotein-, albumin-, total-globulinkoncentration och A/G-kvoten i serum samt fibrinogenkon-centrationen i plasma. Materialet grupperades efter glutaraldehyd- och formol-geltestutslagen. Av resultaten framgår tydligt att ökningen av fibrinogenhalten har betydelse för utslagen i glutaraldehydtestet. En positiv glutaraldehydtest vid mer akuta processer kan tillskrivas en kraftig ökning av plasmafibrinogen i egenskap av akut-fas-protein. Positiv glutaraldehydtest vid kroniska sjukdomsprocesser bör ses som ett resultat av samverkan mellan höga immunoglobulinkoncentrationer och förhöjd fibrinogenkoncentration i blodet.