Laboratory tests as predictors of disease exacerbations in systemic lupus erythematosus. Why some tests fail

✍ Scribed by John M. Esdaile; Michal Abrahamowicz; Lawrence Joseph; Todd MacKenzie; Yin Li; Deborah Danoff

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 875 KB
• Volume: 39
• Category: Article
• ISSN: 0004-3591
• DOI: 10.1002/art.1780390304

✦ Synopsis

Objective. To evaluate whether changes in laboratory test values are either simultaneous with or precede disease exacerbations in patients with systemic lupus erythematosus (SLE).

Methods. At 9,6, and 3 months preceding a flare in disease activity (defined as a rise of 2 6 points in the modified SLE Disease Activity Index), laboratory tests were performed to measure patients' hematocrit levels, white blood cell, lymphocyte, and platelet counts, erythrocyte sedimentation rate, Clq binding, DNA binding, and levels of C3 and C4. Flares were classified as either present or absent, and were divided into renal, vasculitic, central nervous system, skin, serosal, and musculoskeletal subgroups. The predictive patterns were 1) the simultaneous change in the test value from the mean of 9,6, and 3 months preceding a flare to the time of the flare; 2) the gradual change, following a linear time trend, in test results for the same time points; and 3) the change from the mean of 9 and 6 months to 3 months preceding a flare, as a measure of predictive ability. These analyses used repeated-measures analysis of variance models. Multiple linear regression was used to study the cross-sectional association of average-overtime differences in test results with patients' flare subgroup.