Alarming laboratory tests results in SLE

Kimberly Legault, MD, MSc, is an associate professor of medicine in the Division of Rheumatology at McMaster University.

What abnormalities in laboratory test results of a patient with newly diagnosed systemic lupus erythematosus should be most alarming?

I think that the lab abnormalities that concern me most in a patient with new systemic lupus erythematosus would be ones that indicate significant organ dysfunction. The elevated creatinine indicating nephritis would certainly be concerning, although even abnormal urinary sediment can be a harbinger to significant nephritis that could be impending even in somebody who has a relatively normal or only mildly elevated creatinine, where we could see that get much worse.

I think that making sure that your urinary sediment is paid attention to, especially significant changes in it: new proteinuria, new hematuria would definitely be causes for concern. Significant cytopenia, certainly anemia—especially if that anemia is caused by hemolytic anemia, because we could see significant falls in a precipitous period of time—and, of course, significant thrombocytopenia that was dropping. So, really anything that indicates end organ dysfunction would be the most concerning.

Of course, a flare can be evidenced by falling complement levels, elevated double-stranded DNA levels. Although the most concerning would be those [abnormalities] that were showing significant organ dysfunction.