Abstract

The serum concentration of 19 serum proteins was determined by electrophoresis in 42 patients with Crohn's disease and 36 patients with ulcerative colitis. The results were compared with 78 healthy persons as matched controls. Distinctive, but similar, changes were present in the two diseases. An increased serum concentration of orosomucoid, α₁-antitrypsin, easily precipitable glycoprotein, α₁-antichymotrypsin, haptoglobin, and haemopexin was present. The serum concentration was decreased for prealbumin, albumin, α₂-HS glycoprotein, caeruloplasmin, α₂-macro-globulin, and transferrin. No significant difference between the two diseases existed as far as the serum protein pattern was concerned.

Certain proteins, `the acute phase reactants' (orosomucoid, α<sub>1</sub>-antitrypsin, α<sub>1</sub>-antichymotrypsin, and haptoglobin) and the immunoglobulins were clinically useful, since their serum concentration reflected the grade of activity of the disease. A pronounced elevation of haptoglobin compared with that of the other `acute phase reactants' was present in patients with Crohn's disease complicated by suppurative fistulas or abscesses. Patients with active Crohn's disease who responded favourably to medical treatment had significantly higher immunoglobulin levels than patients not responding. A similar observation, though not statistically significant, was made in patients with ulcerative colitis.