APOH and pulmonary arterial hypertension: Meta-regression did not find any other factors significantly associated with aPL prevalence: continent, disease subtype, disease duration, age, proportion of patients with ILD, DU, SRC, PAH, ACA, and anti-topo I. Meta-regression revealed a significant association between prevalence of LA and disease duration (p < 0.0001), between prevalence of aCL and proportion of patients with ACA (p = 0.0055), and between prevalence of anti-β2GpI and continent (p = 0.0040), age (p = 0.0333), sex ratio (p = 0.0469), respectively.