Comparison of the Erythrocyte Sedimentation Rate, C-Reactive Protein, Serum Diphenylamine, and Tetrammonium Tests in Rheumatic Fever and Rheumatic Heart Disease
Authors: R.D. Eastham, P. Szekely, K. Davison
Journal: Annals of the Rheumatic Diseases (1958)

The difficulty in assessing the activity of the disease process in rheumatic fever and rheumatic heart disease is apparent from the large number of laboratory tests which have been used from time to time.In a previous study (Eastham, Szekely, and Davison, 1958) we have attempted to assess the value and limitations of the C-reactive protein test as a measure of rheumatic activity in a group of unselected cases of rheumatic fever and rheumatic heart disease.In the present study, using the same clinical material, we have correlated four laboratory tests in the hope that it might be possible to demon- strate a distinct advantage of one test over the others.In acute rheumatic fever, serum electrophoresis shows that the albumin content falls, while alpha-1, alpha-2 and gamma globulin concentrations rise (Dole, Watson, and Rothbard, 1945).Ernstene (1930) showed that plasma fibrinogen concentration rose and the haematocrit level fell.According to Jackson, Kelly, Smith, Wang, and Routh (1953), these changes are reflected in the rise in the erythro- cyte sedimentation rate.Roantree and Rantz (1955) showed that C-reactive protein occurred in the serum early in the course of acute inflammation.Coburn, Moore, and Haninger (1953) demonstrated that the serum diphenylamine reaction paralleled the erythrocyte sedimenta- tion rate, and Jacox (1951) showed a similar correlation between the serum tetrammonium turbidity and the erythrocyte sedimentation rate in cases of rheumatic fever.The last two tests were, therefore, selected for comparison with the erythrocyte sedimentation rate and the serum C-reactive protein in our series.Methods and Material I.The erythrocyte sedimentation rate (E.S.R.) was read at one hour in 200-mm.tubes of 2 5 mm.internal diameter (Westergren, 1921) using citrate solution as already described.Any reading of more than 10 mm. in one hour was regarded as abnormal.II.The serum tetrammonium turbidity reaction (TET) was estimated by the method of Jacox (1951).The turbidity was read in 1 cm.cells in a twin-cell Spekker absorptiometer, using an Ilford spectrum violet filter No. 601.Cetyl-dimethyl-benzyl-ammonium chloride was used in place of octyl-dimethyl-benzyl-ammonium choride, since it has an identical effect on serum protein (Jacox, 1953).The barium sulphate standard suspension (Jacox, 1951) gave an extinction value of 0 585.The upper limit for normal serum was taken as 0-295.III.The serum diphenylamine reaction (DIP) was estimated by the method of Coburn and others (1953), using the sensitive diphenylamine reagent of Ayala, Moore, and Hess (1951).Correction for the serum blank was not made in view of the findings of Coburn, Bates, Hahn, and Murphy (1956).The reaction was read at 530 mu in 1 cm.cells in a Unicam S.P. 600 spectrophotometer.The instrument readings were brought into line with those of Coburn and his co-work- ers.This was done with the help of Dr. E. L. Hess, Ph.D., who kindly supplied a suitable calibration graph; from this reference sucrose standards were prepared.The normal range of coefficient of extinction for our instrument was 0-246-0 379, with an average of 0 330 (this value corresponds to the colour given by a 0 106 g. per cent.solution of pure sucrose).IV.A capillary qualitative test for the presence of serum C-reactive protein was made (Anderson and McCarty, 1950), using C-reactive protein antiserum- Schieffelin.