Pulmonary arterial hypertension (PAH) associated with connective tissue diseases is the most common cause of pulmonary hypertension. Systemic lupus Erythematosus (SLE) is characterized by the second highest prevalence of pulmonary arterial hypertension (PAH), after systemic sclerosis, among the connective tissue diseases. The prevalence of PAH in SLE is less than 4% when the PAH diagnosis is based on the gold standard, namely right heart catheterization. The aim of this study was to describe the clinical and biological presentation of PAH in SLE.

The study population consisted of 238 Tunisian patients with SLE who fulfilled the revised criteria of the American Rheumatism Association and were admitted to the internal medicine and rheumatology department in Fattouma Bourguiba University Hospital between 2010 and 2020. All patients underwent Doppler echocardiography study. PAH was hemodynamically defined by increased systolic pulmonary artery pressure (SPAP) at rest≥25mmHg.

Of the 238 patients, 12 women presented PAH (5%). Mean age were 38, 2 years. SPAP ranged from 25 to 36 mmHg. Two patients had associated systemic scleroses. Comparison of patients with and without PAH found out that patients with PAH had significantly higher frequency of Reynaud's phenomenon (41,7% VS 13,4%; P=0.023) and serositis (50% VS 21%; P=0.046). Immunological variables associated with PAH include anti-SSA (P=0.003), anti-SSB (P=0.023) and anticardiolipine antibodies IgM/IgG (P=0.029). No significant differences between the two groups regarding cardiac involvement, thrombosis, anti-DNA and anti-SM antibodies were found. On follow up, the PAH was associated with an increased risk of mortality (OR=7, 23; 95% CI=1.294–40.447).

PAH is a rare complication of SLE. Other studies are needed to confirm whether the presence of PAH is a risk factor for mortality in SLE patients.