Question 1

What is the role of ANA as an entry criterion?

Accepted Answer

ANA positivity ensures that virtually all patients classified as SLE are ANA-positive. However, approximately 2–5% of SLE patients may be ANA-negative by standard immunofluorescence but have other lupus-specific antibodies.

Question 2

Do the criteria require items to be present simultaneously?

Accepted Answer

No — items can be accumulated over time. The entry criterion (ANA) can be documented at any time, including retrospectively.

Question 3

Can the criteria be used to diagnose SLE in clinical practice?

Accepted Answer

The criteria are designed for classification (research), not diagnosis. However, many clinicians use them to support diagnostic reasoning.

Question 4

How do the 2019 EULAR/ACR criteria handle renal involvement?

Accepted Answer

Renal involvement carries the highest weight (8–10 points). Biopsy-proven lupus nephritis scores 10 points, which alone nearly meets the classification threshold when combined with ANA.