The presence of specific autoantibodies may help to identify the small percentage of patients with systemic lupus erythematosus (SLE) who are at higher risk of developing pulmonary arterial hypertension after SLE diagnosis and may also detect those at lower risk of death, according to findings from a retrospective study of French patients.
Eric Hachulla, MD, of the University of Lille (France) and his coinvestigators reported that 51 SLE patients in the French Pulmonary Hypertension Registry who had a diagnosis of pulmonary arterial hypertension (PAH) confirmed by right heart catheterization were more likely to have the condition if they had anti-SSA and anti-SSB antibodies, compared with a control group of 101 SLE patients without known PAH who were selected from SLE expert centers participating in the registry. Overall, anti-SSA antibodies were present in 62% of PAH patients vs. 40% of non-PAH patients, and anti-SSB antibodies were detected in 27% with PAH, compared with 8% of those without.
Following SLE diagnosis, the 51 SLE patients had a median delay in diagnosis of PAH by about 5 years. Their survival was 89% at 3 years and 84% at 5 years. “Survival appeared to be substantially better than that still observed today in [PAH associated with systemic sclerosis], where estimated 3-year survival is about 50%. Our survival rates are comparable to those reported by Sobanski et al. in the recently published study for the U.K. SLE-PAH cohort (85% at 5 years),” the authors wrote.
In the current study, mortality during 10 years of follow-up was significantly lower among patients who had anti–U1-RNP antibodies than among those who did not (0% vs. 25%; P = .04). This finding of improved survival in patients with anti–U1-RNP antibodies mirrored the results reported in the British SLE-PAH cohort study and a 2016 Chinese study, indicating that “the presence of anti–U1-RNP antibodies appears to be a protective factor in terms of survival.”
Treatment with hydroxychloroquine followed a trend toward increased survival, but was not statistically significant (hazard ratio, 0.31; 95% confidence interval, 0.09-1.11; P = .07).
“These findings must be interpreted with caution due to the small number of untreated patients and require further investigations in other cohorts,” the investigators wrote. But “based on our results on the potential effect of hydroxychloroquine, this treatment might be used in association with the immunosuppressive strategy for SLE-PAH patients.”
Read more of the findings in CHEST (2017 Aug 26. doi: 10.1016/j.chest.2017.08.014).