Pulmonary hypertension on systemic sclerosis-lupus erythematosus overlap syndrome

There are authentic observations of combination of systemic lupus erythematosus (SLE) with systemic sclerosis (SS) and with polymyositis defined as overlap syndromes. The prevalence of pulmonary hypertension is unknown in SS-SLE overlap syndrome because of its rarity. The aim of our study was to precise clinical, paraclinical and evolutive features of pulmonary hypertension in patients with systemic sclerosis-systemic lupus erythematosus (SS-SLE) overlap syndrome.

Sixteen cases of SS-SLE overlap syndrome were retrospectively studied in a period of 16 years (2000-2015). SS-SLE overlap syndrome was diagnosed in the presence of at least 4 criteria of the American College of Rheumatology (ACR) for the diagnosis of SLE and a major criterion or 2 minor criteria of ACR of SS classification. Pulmonary arterial pressure (PAP) was estimated with doppler echocardiography. Pulmonary hypertension (PAH) was defined by a PAP superior than 30mmHg. We distributed groups according to the existence (Group 1) or not (Group 2) of a PAH. Epidemiological, clinical and evolutive features were compared between the two groups with bilateral fisher test (P significant if inferior at 0.05) RESULTS: Sixteen cases of female patients with SS-SLE overlap syndrome with a middle-age of 39 years, extreme (29-58 years) were studied. PAH complicated the evolution of SS-SLE overlap syndrome in six cases with a middle-age of 41 years. Ten patients of the group 2 had an average age of 40 years. The average age of the beginning of the disease was 28 years in the group 1 and 31 years in the group 2. SS preceded SLE in 6 among 16 cases (Group 1: 2/6, Group 2: 4/10). SS was revealed most frequently by Raynauw's Syndrome in both groups (Group 1: 4/6, Group 2: 7/10). Cutaneous and articular involvements were the most frequent observed manifestations of SLE (Group 1: 5/6, Group 2: 6/10). In the group 1, the PAH was discovered approximatively11 years after the beginning of the SS-SLE overlap syndrome. The average PAP was 52mmHg, extreme (32-80mmHg). A right cardiac insufficiency complicated the evolution of the PAH in 3 cases. The PAH was primitive in 3 cases. There was no significant difference concerning the SS-SLE overlap syndrome onset disease symptoms, the frequency of lung involvement and esophageal, neurological, articular and trophic manifestations. PAH was not associated with lupic proliferative renal disease, neither with cutaneous proximal sclerosis nor with anti-Scl70 positivity. Patients were treated with vasodilator treatment in eleven cases: prostacyclin derivates in five cases and endothelin receptor antagonist in six cases. Two patients received corticosteroids and boli of cyclophosphamide for renal involvement and neurologic involvement in each case. Stabilization of PAP was observed in these two cases. Mean follow-up disease was 67 months, extreme (4-124 months) Cutaneous sclerosis evolution was not significantly different between both groups. Global cardiac insufficiency secondary to PAH caused death in one case.

According to the results of our study, SS-SLE overlap syndrome complicated with PAH seems to be associated more frequently with limited and distal cutaneous manifestations. Patients that have developed lupus nephropathy and/or had positive anti-Scl70 seem to be protected from appearance of PAH during the SS-SLE overlap syndrome.