Increased apolipoprotein-E concentrations in individuals suffering chronic low back syndrome identified by two-dimensional gel electrophoresis.

Non-biased screening of plasma proteins by two-dimensional gel electrophoresis from individuals suffering low back syndrome revealed a polypeptide spot that was increased 2-5-fold over the concentration found in normal control individuals. The apparent molecular weight (34-36 kDa) and pI (5.7) of this spot suggested that it might be apolipoprotein-E. Immunoblot analysis showed that the polypeptide was reactive with anti-apolipoprotein-E antibodies. N-terminal amino acid microsequence confirmed the identify of this polypeptide as apolipoprotein-E. We have determined that elevated plasma levels of apolipoprotein-E is associated with inflammation and nerve damage.