TOPLINE:
Patients with both systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are more likely to be female, Black, and diagnosed with limited cutaneous SSc.
METHODOLOGY:
- Researchers used the 2019 SLE classification criteria from the European Alliance of Associations for Rheumatology and American College of Rheumatology to identify patients with SSc who also met criteria for SLE at a single academic center.
- The study population included 402 adults with SSc.
- The researchers compared demographics, laboratory data, clinical features, and mortality between patients with SSc-SLE and patients with SSc only.
TAKEAWAY:
- Among the 402 patients with SSc who were analyzed, 40 (10%) met the 2019 EULAR/ACR Classification Criteria for SLE.
- Patients with both SSc and SLE were significantly more likely to be female and Black, which is consistent with previous studies; patients with both conditions also were more likely than those with SSc alone to have limited cutaneous SSc (75% vs. 52.2%; P = .006).
- The prevalence of anti-U1-RNP antibody positivity, a classic marker for mixed connective tissue disease, was 30% in SSc-SLE patients and 6.6% in those with SSc only (P < .001).
- Mortality was similar between the two groups, and similar rates were also seen between the two for severe SSc-related end-organ damage, including pulmonary fibrosis, pulmonary hypertension, and scleroderma renal crisis.
IN PRACTICE:
The results highlight the need for clinicians to recognize the SSc-SLE overlap syndrome and to watch for scleroderma organ involvement in patients with features of SLE, Raynaud syndrome, anti-U1-RNP antibody positivity, or an isolated nucleolar pattern of antinuclear antibodies.
SOURCE:
First author Ronald D. Bass, MD, MBA, of Georgetown University, Washington, and colleagues published their report online in Arthritis Care & Research.
LIMITATIONS:
The primary cohort was designed to compare Black to non-Black patients with SSc, and the process of matching these patients may have introduced unmeasured selection bias. Also, since the study was based on classification criteria and not diagnostic criteria, the overlapping patients may not reflect patients with true overlapping of both conditions.
DISCLOSURES:
No outside funding source was listed by the authors. The researchers report no relevant financial relationships.
A version of this article first appeared on Medscape.com.