Higher Incidence of Pulmonary Hypertension in Antiphospholipid Antibody Positive Lupus

Antiphospholipid antibodies (APAs) are detected in 30-40% of SLE patients, but only few develop APLA syndrome. Incidence of pulmonary hypertension (PH) is reportedly high in APA positive patients; however, Indian data is missing.

This cross-sectional, observational study was conducted from Jan 2009 - Dec 2011, on 50 SLE patients, fulfilling ACR criteria. SLE patients were selected serially from OPD and IPD. Pregnant females and children were excluded.Tests for presence of anticardiolipin antibody, lupus anticoagulant and anti-β2 glycoprotein antibody were performed in all patients. Pulmonary artery pressure, was measured on transthoracic 2DECHO, by TR jet and graded as, mild (25-40mm), moderate (40-60) and severe (> 60mm). CT - pulmonary angiography and lower limb venous Doppler were performed in patients of moderate and severe PH.

Out of 50 patients, 46 were females, 4 males, aged 17-50 yrs. Twenty-three were positive for at least one APA, 14/23 ACLA positive, 3/23 positive for LA, 16/23 positive for anti β2 glycoprotein antibodies, 11 were positive for 2 or more antibodies. Pulmonary hypertension was present in 11 out of 23 APA and 2 out of 27 APA negative patients, with moderate to severe PH in 7 out of 11 APA positive patients. Four out of 7 patients with moderate to severe PH tested positive for more than one APA and in higher titers. CT pulmonary angiography and lower limb venous Doppler were performed in 4 out of 7 patients with moderate and severe PH and were normal. Three patients with moderate PH expired.

Lupus patients with APAs are more prone to develop PH, with a possibility of formation of microthrombi in the pathogenesis of PH. As regards treatment of PH, in addition of PH lowering drugs, place for anticoagulants or antiplatelet agents needs to be studied in PH with APA positive patients.