A Comparative Evaluation of the Sensitivity of the L.E. Cell Test Performed Simultaneously by Different Methods

Abstract

Abstract 1) A group of at least three types of L.E. cell tests should be performed in order to adequately screen strongly suspected cases of SLE. This battery consists of the sieved two hour clot, the Snapper-Nathan ring method and the Zinkham-Conley rotary glass bead technic. Utilizing these three methods in studying a group of 47 proven cases of SLE both treated and untreated, 63 batteries were performed. In 42 of these batteries there was at least one positive test. In 5 batteries only the rotary method was positive, in 4 the clotted method and in 2 the ring method. The largest numbers of L.E. cells and hematoxylin bodies were found by the rotary method. If only one test is to be performed this latter technic is the method of choice. 2) The use of excessive amounts of heparin over 0.75 mg./10 cc. of blood resulted in a depression of the L.E. phenomenon. The technic of adding "small amounts" of heparin to blood or "heparinizing a syringe" to draw specimens for L.E. studies is to be avoided. 3) The explanation for the augmentation of the L.E. phenomenon by clotting or rotation with glass beads seemed to be the production of leukocyte trauma by either method. This explained the poor results obtained when the clotted blood specimen is broken up with wooden applicator sticks rather than macerated through a fine sieve. The clotting mechanism itself probably has little to do with the increased numbers of L.E. cells. 4) With adequate treatment the L.E. cells disappeared in many patients. Forty patients with positive L.E. cell tests treated two months or more had a simultaneous battery performed on them as described above. All the tests were negative in eighteen patients, seven patients had fewer than 5 L.E. cells per 500 leukocytes and fifteen patients had more than that number.