A retrospective study shows that 83.9 percent of patients suffering from systemic lupus erythematosus (SLE) and pulmonary arterial hypertension survive at least five years after diagnosis. Also, those with anti-U1-RNP antibodies tend to have better survival rates, the study shows.
The research, “Pulmonary Arterial Hypertension Associated With Systemic Lupus Erythematosus: Results From the French Pulmonary Hypertension Registry,” was published in the journal Chest.
Pulmonary arterial hypertension (PAH) is characterized by too much pressure inside the arteries that pump blood from the heart to the lungs. The disease may lead to heart failure and is life-threatening.
Previous studies have demonstrated that cases of pulmonary arterial hypertension (PAH) in systemic lupus erythematosus are extremely rare, especially when PAH diagnosis is based on right heart catheterization (RHC). That is why systemic screening for PAH in SLE patients is not recommended by the European Society of Cardiology and the European Respiratory Society.
While rare, some patients develop both diseases. So, researchers in France set out to study the characteristics and survival rates of patients with SLE-PAH, compared to patients with SLE but no PAH.
The study involved SLE-PAH patients from the French Pulmonary Hypertension Registry who met the European Society of Cardiology/European Registry Society definition criteria regarding mean pulmonary artery pressure and mean pulmonary artery wedge pressure. The SLE-PAH group was compared to a group of patients with just SLE, who were identified from participating connective tissue disease centers.
Data from a total of 51 patients with SLE-PAH and 101 patients with SLE (but no PAH) were used in the current study. The mean time from SLE to PAH diagnosis was 4.9 years and ranged between 2.8 and 12.9 years.
No significant differences were observed between the two groups in regards to age, sex, duration of SLE, or cutaneous, neurological, cardiac, and renal involvement.
However, patients in the SLE-PAH group had higher frequencies of anti-Smith (Sm), anti-Sjögren’s syndrome types A and B (SSA/B), and native anti-DNA antibodies. While the findings suggest that the presence of these antibodies is a risk factor for PAH in SLE patients, more studies are needed to address this matter.
At three and five years after diagnosis, 89.4 percent and 83.9 percent of patients were still alive. Interestingly, no patients (of 14) with anti-U1-RNP antibodies died during the follow-up, whereas there were six deaths among the 24 patients without anti-U1-RNP.
The study also found that patients who received hydroxychloroquine at the time of PAH diagnosis or during the following months had a trend for better survival. The researchers, however, do not deem this as conclusive due to the small number of untreated patients, and suggests that more studies are required to investigate this further.
The researchers concluded that “PAH is a rare complication of SLE, occurring within the first five years of SLE onset in roughly half of all cases. The overall five-year survival rate of patients with SLE-PAH was relatively good (83.9%). Anti-SSA/SSB antibodies may be a risk factor for PAH in patients with SLE. The presence of anti-U1-RNP antibodies appears to be a protective factor regarding survival.”