SLE Latex Test Kit

Abstract

To the Editor.— In answer to the comment on our data concerning the Lederle Diagnostics Systemic Lupus Erythematosus (SLE) Latex Test Kit for detection of SLE by the latex agglutination slide method (225:637, 1973), Wolfe noted that only 38.8% of our 121 patients with SLE had positive LE cell tests compared with 70% in most series (226:357, 1973). All of these patients had documented SLE and met the American Rheumatism Association diagnostic criteria 1 ; we studied both treated and untreated patients which explains the lower incidence of positive LE cell tests. It helps to use patients with varying degrees of SLE activity in such an investigation, because the presence of classic LE cells is as diagnostically important as a strongly positive preparation. Furthermore, the 70% finding of LE cells in SLE is cumulative and refers to the total incidence of LE cells in a patient over the span of many