Studies on the erythrocyte sedimentation rate in the treatment and prognosis of pulmonary tuberculosis

Abstract

More than fifty years have elapsed since Robert Koch's discovery of the tubercle bacillus, which gave such an impetus to research in tuberculosis.

In spite of the manifold investigations carried out since then, there still remain many problems to be solved in this disease.

In the case of pulmonary tuberculosis, the two great needs to -day are, first, a satisfactory method for the early diagnosis of the condition, and, second, a specific form of treatment.

Apart from these fundamental problems, there are several minor problems to be solved. Among these, one of everyday importance is the estimation of the progress of a patient suffering from pulmonary tuberculosis, and the evaluation or the results of any special therapy which may be employed.

We have, of course, at our disposal several clinical guides to the progress of a case, viz. the temperature, the pulse rate, the weight, and the physical signs, aided by radiological appearances. taut frequently the temperature and pulse rate are within normal limits, and changes in the physical signs are difficult to evaluate. Also, the exudative type of lesion is frequently to a great extent "silent" on auscultation. It is in these cases that the difficulty arises.

Fortunately, a. laboratory test has been discovered, which has been shown to be .of definite value in esti- :mating the progress of the condition. it is known that, if blood be citrated to prevent clotting, and be set up in a vertically placed tube, the red cells sink, leaving the clear plasma as a supernatant fluid. This "Sedimentation Hate" has been shown to be constant in normal individuals, but in persons suffering from, among other conditions, pulmonary tuberculosis, it is increased in proportion to the severity of the disease. This test has now been used in the study of pulmonary tuberculosis for a period of fifteen years, and numerous papers have been published on the subject. While its value has been definitely established, several impotent problems in connection with it remain to be solved.

in these studies two main problems have been investigated. The first - a serological one - deals with the influence of red cell concentration on the sedimentation rate. It has been shown that the smaller the red cell concentration, the more rapid is the sedimentation rote. The majority of methods of estimating the sedimentation rate do not take this factor into account. in the method used by the author, a correction is applied to the reading in order to allow for any change in the red cell concentration from normal. The object of this study is to determine whether such a corrected reading gives a more accurate estimation of the patient's progress.

The second study is a pharmacological one, and deals with the action or gold therapy on the erythrocyte sedimentation rate. This is a. problem or sore interest, in view or the present widespread use of the method, and the conflicting opinions which have been expressed regarding its value in the treatment of pulmonary tuberculosis.

We begin with a historical survey of the erythrocyte sedimentation rate, followed by a consideration of the technique and theory of the subject. Thereafter, the practical application of the subject to the study of pulmonary tuberculosis is entered into in detail.